I would need and appreciate your experts' advise on what follows:

Yesterday I went at the farm i'm shooting at and sent a handful of bullets with my 1943 Longbranch Mk1* at 100 m where i usually use to get grouping around 5-6 cm with the loading I stick with for the last months (37 gn of Varget and Hornady 150 gn .312). This time I repeatedly started to literally spray the bullets all over the target, getting somewhere like 10-12 inches (!!) groups....not just once but three times in a row.  OK, there was a bit of wind but, apart from that, all conditions were pretty much the same.  What makes me worry and believe it would be unlikely the shooter is that I kept getting good groups with the Mosin...!!

So my question to you guys is, apart from making sure the barrel is clean and taken care of, which I always do, what could be the issue?  I was thinking about woodwork that might have come loose or something similar but, at first glance, nothing seems to have moved.  still have vertical pressure of the barrel at the front sight level, the front sight still not touching the wood...

Shall i dismantle it completely? check something in particular??

Thanks for your help ;)

Philtno

If no loose screws and barrel is cleaned of all fouling (copper and powder), and you know the load has proven good in the rifle before, I would remove the hand guards and check the barrel pressure on the forend at the muzzle.  Slip a piece of paper between forend and barrel at the barrel bearing point and lift the barrel up with a spring scale until the paper will slip. 

If you decide to remove the forend, don’t pull the forend down from the muzzle, use a wood block and gently tap down along the upper edge of the forend at the rear supporting the barrel at the muzzle. 

The issue might be the muzzle end of the rifling is no longer in contact with the bullets allowing them to roll out and tumble through the air causing your displaced group. Two groove barrels are notorious for losing their rifling at the muzzle and sometimes in the center of the barrel. Check for any bulges in the barrel, check the rifling,and check that the bullets are seated to the specific depth and not set back. You might also consider trying a box of PPU 174grn FMJ's against your handloads and see if they do the same thing as the 150's.

Yes, I'll check that.

Thanks for the advice.

Philtno

Yes, those bullets are flat based.

I guess if that was a loss of rifling it would have appeared progressively, not that sudden, isn't it??

Regarding bullets seating, the COL was 2.995 - 3.000, basically what Hornady is recommending.  But I have to say that some of them were a bit "hard" to push into the chamber, just like if they would be too long, which is strange because I checked the chamber by trying to push an empty case with a bullet set loosely into the chamber to estimate the length available before it touches the rifling and came up with 3.050...I did the same exercise with different bullets i have (174 gn, 150 gn, Speer, Hornady, S&B) and all of them came up much longer than what i'm using (2.995-3.000) while still having the feeling that I have to "push them" into the chamber.

I have checked all my cases and made sure they are below or at 2.221 max

Now, i'm using the Lee Loader to reload my rounds and the Lee Loader is only neck sizing...could that be part of the issue?? the case being too "deformed'...I have been reloading the same cases about 15 times now.

I just ordered some greek milsurp to renew my cases....I'll shoot them to see if they behave the same way.

Thanks for your input Goosic.  Please let those advices keep coming my way....I want to learn about it.

Cheers

Philtno

Yes, I did that and couldn't spot anything wrong...Didn't use a magnifying glass though but I'm kind of very careful with them rifles as I know these are pieces of history i don't want to damage.

I'll have a second look tonight.

Thanks for the input.

Cheers

Philtno

Thanks for that Britrifles...

Now, as I mentioned in my earlier post, I don't use any press for reloading, only the Classic Lee Loader...the one where all you need is a rubber mallet and a very tolerant wife (hahaha).  

I also have trimmed my cases so they are below max length (2.221) so my understanding is that, when you say "full length size the cases" you mean pushing the shoulders back a bit so they don't hit the bottom of the receiver keeping from closing the bolt easily. is that what you mean?? if it is how can I achieve that without a reloading press and the appropriate die?? I guess I can't?? is that correct?

Also, side question, could that be the reason for spraying bullets like I did??

Cheers

Philtno

Goosic,

you seem to insist on the "commercial" rounds I should fire to test if it behaves the same way.  Wouldn't you do the same with non-corrosive milsurps, like the greek milsurps I mentioned in my earlier post?  From what I receives as information from the gun store I get them from (guncity.com) those are certified non corrosive.

Now, you said something that worries me a bit. you said thay "overfiring" it would have the same effects, which I definitely can understand, but what would you consider "overfiring" a No4Mk1*?? I purchased that one in April and have probably shot 7-800 rounds since then, 900 max.  Would you consider that as "overfiring it"??

Cheers

Philtno

 You mention that the Greek milsurp ammunition was "certified" non-corrosive. Did the seller personally  breakdown each individual round and remove the primers and then reload each individual round with "certified" non corrosive powder and primers?

 Commercial ammunition from Herters, Winchester,Remington,and Privi Partizen are all built to tighter tolerances then the milsurp ammunition and will give you a better grouping if,all is well with your rifle. You asked a question in your original post and I have given my answer based off of past experiences with the same exact issue. 

 

Good advise, but the Greek surplus is known to be non-corrosive and has been known as such for a very long time.  It is good stuff as well.

I still do not see why a rifle shooting well, should suddenly "go to pot" at the very next outing, so think there is another problem rather than barrel wear.  No ideas What exactly, but it might need going through with a fine tooth-comb, so to speak!

The complete erosion of barrel rifling forward of the chamber is typical of cordite loaded service ammunition (Mk 7 as opposed to Mk 7z).  Cordite burns hotter than NC powder, and will burn the throat away.  Accuracy life with cordite is on the order of a few thousand rounds. 

 

 

 

I agree with Richard here, the description indicated that last time the rifle shot, it grouped well with the same ammunition.  Certainly no harm in trying commercial ammunition to rule out a problem with the load that might have occurred.  Give the barrel a good cleaning, preferably with a solvent that will remove copper such as Boretec Eliminator or Sweets 7.62. 

 

I'm not sure about the Classic Lee loader, if the die only neck sizes, then you likely have the problem I described.  The cases have stretched such that the shoulder on the case is now bottoming out in the chamber and you can't completely lock the bolt (this is what I mean by the case "headspacing on the shoulder", it should headspace on the rim).

 

You need a Full Length sizing die, which requires a reloading press (I don't know if there is a version of the Lee Loader die that full length sizes the case).  The full length die will re-form the fired cases back to the dimensions of the unfired brass and will allow easy chambering. 

 

Most .303 chambers are fairly long regarding position of the shoulder.  The shoulder on the case typically blows forward on initial firing.  If you set up the full length sizing die by screwing it all the way down to touch the she!! holder, it will drive the shoulder of the case back to it's original dimension significantly work hardening the brass.  You won't get many reloads this way.  If you back the die out of the press a bit (half a turn perhaps), just so that the shoulder on the case is bumped back (shortened) a bit, you will minimize the cold working and extend brass life.  The object is to set up the die so that the shoulder is pushed back only a few thousands of an inch.

 

 

The Lee Whack a Mole is neck sizing ONLY. There just isn't the leverage available to full length resize. I have both full length & neck sizing dies for my press, but I do notice with neck sizing only the last fraction of an inch is harder, probably because of the shoulder problem mentioned.

Its a known fact that neck sized cases will need to be full length resized eventually.

That's why I went with "Partial Full Length Resizing", with a full length die baked off just enough to give minimum clearance at the shoulder.

I'd try one box of PPU factory, or new XHP, what we're looking for here is if an unfired, non resized case behaves the same. Try either, just to see what happens. Hey its reloadable too, whichever you use, so you get 20 more pieces of brass!

How many cases do you have in total that may need full length resizing?

I should have mentioned that, since I bought that rifle, I have been really cautious cleaning it thoroughly including with copper remover  right after shooting and the bore is like a mirror with clear rifling.  Of course, I'm far from being an expert but, for what i can see, it doesn't look much different from what it was when I first got it.  

Shamu,

in total, I have 100 cases made of 20 PPU and 80 XHP (greek milsurp).  I got the PPU first and reloaded them a couple of times before buying the HXP.  In total I might have reloaded them between 10-15 times.  I trimmed them manually a some point when i saw that the case length were far beyond the recommended case length.

Cheers

Philtno

at 10~15 reloads they are getting near the end of their life. Things like work hardening & metal flow have probably begun to take their toll.

Have you done a paperclip test (bend the tip of a paperclip & run it up & down inside the case). If they "grab" anywhere your brass is getting ready to separate. Like the top ones in these sectioned cases) I'm thinking old, tired brass may be a factor here.

You've done really well to get them lasting that long, many get 3~4 loads at best.

Thanks for the illustration, Shamu.

I'll try that...although I am pretty sure that those old cases are actually past the average life.  Over the batch that I bought (talking about the HXP), I only had 4 that I had to remove from the pack, two with neck splitting, one with some kind of longitudinal crack along the case and one that went brittle underneath a patch of corrosion. 

You must always check for case length after sizing (even after neck sizing), the brass will gradually grow and cause the same problem to locking the bolt as the case mouth will contact the end of the chamber.  I don't know what this might do to chamber pressure, but I would avoid it.  2.222 inches is max length.  I set my calipers to 2.222 and run every case thru them.  Ones that don't go thru get trimmed back to 2.215. 

 

If you don't shoot much, then throwing out brass after 10 or 15 reloads is fine, but I want to get all the life out of the brass I can.  Yes, I've gone too far and had a few case heads separate (the LE action safely vents the gas from the port on the left side of the receiver), but I have learned to recognize the impending separation and toss the case at that point.  Inspect them before every reload. 

 

 

Now I need to find someone who has a press and the 303 resizing die in the area.....bring him/her a pack of Stella Artois and make friends :D

 

If I spelled it right, and if they're still in business!

This may be a bit radical but... Have you thought of buying one? Believe it or not, my favorite press is the Lee hand press. I have 5 presses and I haven't used any of the others for years. You don't need a special room it can be used anywhere including on the range.

 

Back to the OP, I'm experiencing a similar issue with a sudden loss of accuracy on my Dad's No. 4(T).  It was shooting great last month, 10 shot groups at 100 yards in the 1.5 to 2.0 inch range.  Even had a five shot group under an inch.  Now, it's throwing out fliers 5 inches off the group!!   I had previously found the solder joint had broken on the front scope mount pad, but I fixed that with new screws and red Loctite, it hasn't moved.  After the repair, it shot great for the next 150 rounds, then suddenly went bad.  I removed the scope, shot it with the Mk 1 service sight, still bad.   

 

I removed the forend, the only problem I found was the end was cracked vertically along the grain in the trigger slot area. I wouldn't think that would be the problem.  Very frustrating.

Well, that was not my original intention as I want to stay simple/cheap/easy with as less moving part as possible (i'm a musician and my fingers are important, you know....although I have to admit that having to bang the Lee Loader with a hammer does really help with my ears....but 35 years of playing R'n'R have had serious impact on them already ) but I guess I will have to make that step...one day....sooner or later, I guess.

There are some second hand press available on the market...

Pukka,

I already have something to trim my cases...as I understand, what I need is bumping the shoulders back a tad...well a few tens of thousands.

Cheers

Philtno

You're a bit far or I'd offer to do it for you, but the shipping is probably more than the cost of the brass!

That's very nice from you, Shamu.  I really appreciate 

In the meantime I have had a chat with the local gun shop owner and he gave me the details of the previous owner of the same gun shop who is now retired but who, apparently, could help me with that...

Thanks again for the offer..

Regards

Philtno

 

Hi Stanforth,

Actually I'm wondering if that wouldn't be an easy solution.... my concern is that I might have to push hard to resize the brasses to an acceptable level.  Is it really doable with .303....and eventually 7.62x54R.  The problem is that I don't want to invest too much without being sure that it would help me somehow, and I currently don't really have the space at the moment to set up a press.  We're looking at moving to another house but that is just a "wish" at this stage.

Lee Hand press is relatively cheap and I can find decent dices for a good price as well, I think...

Please advise

Cheers

Philtno

.295X23 Morris.. 7X57 Mauser.. .43 Egyptian Remington... .303 British... 7.62 Nato... 50/70 Govt.... 6.5mm Swedish... 

Apart from the usual loading progress it also handles medium case forming.

On the barrel knox,(the flat spot). Is there a stamp that looks like an asterisk ? Also,is there an R stamped on the flat spot of the barrel ?

I guess I will have to remove the front guard to check that???

P.

Hi Goosic,

I haven't got the time to do that yet but I will have a look.

What is that asterisk and that R supposed to mean?? 

Cheers

Philtno

The barrel is very shiny with no pitting (it's cleaned thoroughly and checked after each shooting) so I doubt i will find those marks, but I will check. 

I haven't been able to shoot it for approximately a month as i broke the extractor's spring some weeks ago...and it took some weeks to find some new ones....Canuk was actually very nice sending me some which were received on the exact same day i received those I ordered from the UK.

I just replaced the spring and haven't had the chance to fire it.  I put the old cases on the side for now (will probably try to full length resize them, just to see if I can reuse them) and will shoot some HXP I recently bought... we'll see how it goes and I'll let you guys know 

Cheers

Philtno

Hi Goosic,

No there is no such marks...

Cheers

Philtno

No I don't have any bore gauge and no other Enfield, unfortunately.

I hear what you say but would that happen that suddenly?? All my shots of the previous shooting session were all within normal Enfield accuracy boundaries.... I would even say that I had pretty good results, to the point that I really believed I had found my perfect combination powder/projectile/loading.

The only thing that changed from that session to the next one was that my cases had one more load and that they started to be difficult to chamber and to eject.....which led to my questions about the resizing issue.

It did not happen suddenly.  You are not the first person to handle or fire that weapon either. The 42 stamped on your barrel is a date and 77-78 years has elapsed between the time that date was struck to today. The possibility that thousands of rounds of ammunition, corrosive and non-corrosive,reloads and factory have been fired through that barrel in the span of three quarters of a century is very likely then not. When I made a suggestion to you to test factory made ammunition against  your reloads to examine if the grouping changed or not,I was by no means condemning your chosen handloads. The factory rounds simply give you a baseline to compare against. If the factory ammunition produces the same results your handloads produced you will have eliminated one issue you think might be the cause.  Someone here knows this and can answer correctly.  I remember reading that the Enfield rifle barrel started losing its accuracy after 7700-9500 rounds passed through it. 

I have HXP to shoot and I guess it will give its verdict...at least eliminating one of the possible causes.

Yep, really looking forward to it...

Thanks for that

Philtno

Worn barrel or no, no-one here as yet has a Good reason for the rifle shooting well on one outing and Not on the very next outing.  Barrel wear does not show up like this in shooting results. 

A worn barrel will start to taper off, not suddenly decide to shoot badly Between outings.

 

Phil, can you tell us about how many rounds you have put thru it with good results?  I'm at a loss as to what may have suddenly happened.  Could the bedding have gotten damaged (in the draws particularly), have you had the forend off prior to the accuracy problem surfacing?

 

Barrel life is tricky to estimate.  Even gaging won't necessarily tell you if it will shoot good.  It still may be worth trying some factory rounds if you have them, although it's not likely to be a problem with your reloads. 

 

 

 

I wonder if its the MK VIII bullet that will suddenly loose accuracy as a barrel wears. I'm having trouble understanding the physics of why a barrel accuracy suddenly "breaks down".  Perhaps that bullet shape may suddenly loose stability in the bore whereas a flat based bullet with a longer bearing surface may remain stable in a worn bore.   

 

I estimate I've shot about 5,000 rounds thru my No. 4, about 95% of that with 174 gr HPBT bullet.  If the accuracy suddenly goes to crap, this will be my first thought. 

 

 

This is the acceptance standard, so the ammunition is not supposed to be worse than this.  For the Canadian MK 7z ball ammo I have shot, extreme spread of 10 rounds was in the 2 to 3 MOA range out of my No. 4 Mk 1/3 Fulton prepped match rifle which had a new 5 groove BSA barrel at the time.   Post WW II Mk 7z produced for matches shot under 2 MOA.   

Hi Britrifles,

I can say, without any exaggeration, that the grouping I achieved over the last 3-4 shooting sessions were very good.  Before that, I was mostly experimenting with projectiles, powder, loadings and bullet seating which means results were varying a bit more....some were not working well and some other leading me to the direction I finally took with that specific loading I was using for the last shooting....and that was working very well.  I would say that, since I kind of found my ideal loading, I might have put something like 250 rounds with that loading.  The woodwork has not been played with since the initial check up when I got the rifle.  The only thing that changed was that I attached a sling and the fact that most of the rounds were very hard to chamber.... I might well be a combination of factors...

I had planned to go shooting tomorrow but it has been cancelled so it will be next week.  I have some HXP to shoot.  For my own information, I took twenty of them rounds from the pack I bought and measured the weight of the bullets and the powder loading (I have no clue of what kind of powder it is. All I can say is that it's very fine spherical powder)...some slight variations but globally pretty consistent so the shooting should be pretty consistent as well, I supposed

Yesterday I took those cases that I previously put aside, those that were causing some chamber issue and tried to chamber them again.....over the 120 I had, 20 only were chambering normally, all the others I had to push hard to chamber them.....some I didn't even tried to push them completely, being concerned that they would get stuck in the chamber.

I truly hope that the issue was due to the rounds and not the barrel...if no changes, I'll bring the rifle to the gunsmith for a thorough inspection.  I'm not qualified nor knowledgeable enough to do that myself

 

 

 

Have you measured the length of your cases?  Each firing causes them to stretch slightly which will eventually result in the case mouth contacting the end of the chamber and get jammed between the chamber walls and the bullet.  This shows up as resistance to closing the bolt.  The Sierra Reloading manual says this will give rise to dangerous pressure levels.  This in turn will cause wild shooting.  The max length is 2.222 inches.  

I also suggest giving the chamber a good cleaning with a bronze chamber brush.  I clean the chamber completely after each shooting.  Wrap a powder solvent soaked patch around the brush and turn in the chamber.  A chamber cleaning rod like Deweys brass rod is very useful for this.  Before firing, remove all traces of solvent and oil by wrapping a patch around the brush and apply brake cleaner to the patch.  Get it squeaky clean. This not only ensures reliable feeding/chamber in for fire formed cases, it reduces thrust load on the bolt.  

I don’t know what the effect is on accuracy with cases that have grown headspace and get difficult to close the bolt. This would put some slight preloading of the action.  I’ve not noticed a problem when the bolt shows some light resistance.  At that point, I’ve always FL sized the cases.  If you can get the cases FL sized and test fire again, and see if you still have the problem.  But you will have to check case length after FL sizing, they will likely lengthen by .010 to .015 inches. 

Its possible, but unlikely. Its far more likely to be the shoulder being too far forward though.

There's a gauge for that also, the

GO = 0.064"

I think Phil said he has loaded the cases 15 times or more.  If he did not have resistance in closing the bolt when the cases were new, it’s not a short headspace problem.  

Gossic may be right, but I’m hoping not as it means a barrel replacement.  Still, I’m suspicious given the sudden loss of accuracy shooting flat based bullets.  

I can't give you more details for now but will surely do so once I will have had that opportunity to shoot those HXP.  And I just ordered a hand press with the .303 (and 7.62x54R) dies to F/L size the cases. I also have what it needs to trim them back to recommended case length. 

Cheers

Philtno

After all that rumble I created with my post, you bet I will

Cheers

Philtno

54R dies will push the 303 shoulder .21" farther down and change the shoulder angle, there is @ 2deg diff between the two, this should make it fit better in the chamber.

+1

resize 303 with 303 dies for proper sizing specs.

I also noted the load is a bit light in the pants.  This can be a factor with bores that are on the large side.  The .303 starting load published by Hodgdon for Varget with a 150 gr bullet is 39 grains.  Along with factory loads, I would try 40 gr Varget with a 174 gr bullet.  I’ve not had good success with Varget and light loads.  H4895 is a better choice if you want to shoot light loads.

Gaging or slugging the barrel would be good information to have.  But keep in mind that large bores have been know to still shoot good with the right bullet and load.  

Phil. What where you shooting through the rifle prior to this incident? What bullet weight and powder charge? Not that it matters as well. britrifles, you of all people here knows that a 125 150 174 and 180 grn bullet performs differently in bullet drop at a given distance.  The same can be said for the general grouping,to a degree.  A handload if properly sized,trimmed and loaded to the same standards as a factory round should perform just like the factory counterparts, agreed? The belief here is that there is no way that the accuracy JUST went to crap,its because of a reloading issue. This issue did not JUST happen. It took 77 plus years,countless amounts of ammunition going through it,with an unknown amount of previous owners that fired those countless amounts.Not to mention if the rifle saw actual combat or not. What would or should be the first thing to check for when you are shooting a vintage rifle and the accuracy goes to $!#t on you. Mine would be to check the rifling by a competent gunsmith.  

I struggled for a few years with a M1 that had a brand new barrel when I bought it from the CMP.  After a few hundred rounds, accuracy went to crap.  Sometimes it would cluster groups nicely, then start double grouping, or throwing one or two rounds wide out of the group.  Think of a 8 MOA group, very ugly.  

After a few thousand rounds, I gaged the barrel, .3000 gage ran thru, .3005 would not pass.  Rifling looked perfect in a bore scope.  I removed the barrel and returned it to criterion.  They gaged and inspected it and confirmed my previous findings (.3002 bore, very little wear), they said it looked excellent and well maintained.  Then they sawed it in half lengthwise and found that the throat had been reamed off center, the depth of the grooves were asymmetric in the throat. Likely a bad headspace reamer and subsequent firing just made it worse.  The new barrel fixed the problem.  

Since Enfield barrels in new condition are hard to come by, it may be worth one last shot (pun intended) to check factory rounds and perhaps another bullet.  But I do agree, poor shooting is rarely a problem with correctly and carefully assembled handloads.  

Hodgdon Varget (ADI version of 4064) seems to have a particular issue with light loads, many shooters have experienced it including myself.  Inconsistent velocity and even ignition problems in loads with moderate airspace, especially in colder weather.  Hodgdon recommends not reducing the loads below their published minimums.  I use their load tables, other published data shows reduced max load.  I have chrono’ed my 40.0 grain load with the 174 SMK and it’s right on with Hodgdon data.  For info, Hodgdon is the distributor in the US, the powder is made by ADI and Hodgdon publishes their reloading data.  

I'd just like to clarify.

Are you suggesting using the 7.26X54R dies to push .303 shoulders, or is it you have both calibers & so have ordered a press & both die sets to use on the respective cases?

There is a bit of mis-communication here I think!!

I never said I wanted to use 54R dies on my .303 or inversely.....At this stage I just ordered .303 dies, 54R dies and a hand press.....I haven't got the stuff yet!!

 

Goosic, I really appreciate your comments and your questions "why", and I will certainly keep that into consideration but at this stage, I haven't fired my 303 again yet since that very day I noticed the spreading!! I broken the spring the day before the very next shooting session.....and I just replaced it last week. And I haven't said I intended to disregard the potential barrel issue....I just haven't done anything yet!!

 

And, I basically agree on everything you guys would say, but please give time to be in a position to implement your advice and to see if that brings anything new.  Also, please consider that you guys have different opinions and advice to give me.  I'm certainly not about to favour or disregard any of them.....just give me the opportunity to soak my mind with them and make my decision on which way I'm keen to try first.

 

I feel a bit harassed by so many questions on why I have done this or haven't done that....Keep in mind that I don't have your experience for sure, I'm new to that (the only experience in shooting and maintaining a gun was 35 years ago when I was doing my military service)...but I'm learning from everything you guys say....just give me time to go at my own pace, make my own experiments, eventually, and share that with you when it's done...

 

Again, I really appreciate all your advices. Thank you very much for that, it's really great help.... but too much information at once, too many questions or too many different options at once is a bit pressuring me and makes me believe I'm in deep $h!1{....

 

I'll let you know when I have new elements to this very issue....maybe the whole issue will be solved?? Who knows?? I want to be and stay positive

 

Cheers

Philtno

 

No worries.... I really appreciate your good advices and experience . 

I guess I'm just much slower in my reasoning and my action taking to solve my issue :)

The good side of it is that I'm learning....which is good!!

Cheers

Philtno 

Please don't feel harassed, thats not the intent I assure you.

The problem with troubleshooting on-line is that the knowledge is remote & the hands are on site, so there has to be a lot of too & fro & asking of questions because we don't have the item in hand.

Take your time & let us know how it turns out.

My earlier encouragement was not intended to pressure you Phil, this is all supposed to be fun. 

First off, Merry Christmas and Happy New Year to every one

Then, I finally had the chance to shoot the No4 again with some non-reloaded ammo i.e. HXP milsurps.

Remember that, during the last shooting session, I was suddenly "spraying" pills all over the place while previously having relatively good results with reloaded ammo, basically consistently reaching very acceptable results at 105m (meaning 2"-3" groupings with sometimes even better than that). 

The question arose that it might have been the barrel, the woodwork, the bedding, the ammo, the loads...my main concern being that my reloaded ammo were just fitting the chamber with some steady push to close the bolt.

Well, yesterday I went shooting some 1968-1976 HXP (pretty mixed years of production) and managed to shoot 1.5" at 50m and 3.5" at 105m....despite one split case and one pierced primer (the rest was in pretty good condition for 45-50 years old ammo).

I also tried again some old reloaded ammo (some left over hard to chamber rounds from that previous terrible shooting session) and guess what.....all over the place!!

I also shot some rounds loaded with 37 gn of H4895 and 150 Hornady (.312) projectiles using the few cases I was left with and which were still chambering relatively smoothly and managed to get a 3-5cm groupings at 50m, meaning 1.2-2" grouping which is similar to those I was used to get before.

In the meantime, I received the hand press I ordered and have started to full length resize those old cases and trim them to standard which was far from being luxury as some of them were up to 2.235".....whereas the recommended max is 2.221.

However, the previous discussion and the various considerations addressed here made me conscious that, at one stage, I will have to have the No4 checked and eventually "serviced" by a gunsmith anyway...

But for now, smile is back on my face  and I'm currently reading The 2012 Complete Book on Lee Enfield Accurizing by Roger Wadham

Cheers

Philtno

It is normal that the cases will lengthen by .010 inches or more after FL sizing.  I typically trim FL sized cases to about 2.22 inches as they will actually shorten on the first firing.  

The case shorten on the first fire?? I thought it is the opposite....that firing the round was actually "blowing" the brass to the size of the chamber and, given that the LE chamber is rather generous, it was expanding it rather than shortening it??

Can you explain??

Philtno

Your reloading manual gives you a maximum case length of 2.222" but, it should also give you a "trim to length" of 2.212" to allow for the brass to flow and be reworked after every subsequent firing.

Neck sizing helps to minimize this case length stretching/shortening cycle and prolongs case life. But when you encounter the problem you did with difficulty closing the bolt, you must FL resize.  

It is well worth the time and effort to experiment with different bullets.  The 2 groove barrel performed well with the .303 Mk 7 service bullet, it was flat based and had a long bearing surface for its mass.  Like any other barrel, bore and groove diameters will influence the bullet stability and accuracy.

It would be an interesting exercise to get our members to slug their bores and measure the land and groove diameters to see if there is a correlation with accuracy.  Pin gages can also be used to get the bore diameter, they are inexpensive typically available in .0005 inch increments.  The two No. 4 .303 rifles I have are both 5 groove:

Long Branch Mk 1/3 with BSA barrel:  bore .3035, groove .314

Savage Mk 1/3 with FAZ barrel:          bore .3025, groove .314

Both these rifles shoot the Sierra (.311) and Hornady (.312) 174 gr boat tail match bullets under 2 MOA.

It’s taken at least 5000 rounds for my BSA barreled LB to wear the lands from .3030+ to .3035.  When I got the rifle, it was a new barrel, the .30300 Parker Hale gage would pass with a slight drag, the .30325 would not enter the throat.  Now the .30350 gage will pass with a slight drag (.3040- pin gage will not enter the muzzle or throat). So that’s at least .00025 inch wear over 5000 rounds.  Not much.

From your latest results I think there's something "bad" in the load that all over the place. When I say "bad" me an not tuned to that exact rifle.

If it were a gun related problem I'd expect to see it consistently now it started but this seems to come & go depending on the load.

It can happen you just get a load where not all the components work together well. One possibility is barrel harmonics. When you fire your barrel vibrates like a plucked guitar string several waves all at the same time. A good load (sometimes for that exact rifle) will release the bullet from the muzzle when the bore is fully deflected in a particular direction. I know it sounds odd but the bore is actually stationary at the point, briefly, so the bullet always leaves in the exact same direction. If you now have a load the vibrates differently it might easily release when the barrel is whipping past neutral, so its moving at (comparatively) high angular speed.