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Neck vs FL Resizing

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Category: Reloading
Forum Name: Reloading .303 British
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Printed Date: January 27 2021 at 9:07pm
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Topic: Neck vs FL Resizing
Posted By: britrifles
Subject: Neck vs FL Resizing
Date Posted: July 14 2020 at 5:38am
There’s been some interesting debate on several other forums of late regarding resizing cases for reloading.  And, the debate has been intense.  

It has been a widely accepted practice to only FL size cases for autoloading rifles, and that’s what I do for my M1 and AR.  The reason is to ensure reliable bolt locking and extraction.  Failure to fully lock the bolt can cause a slam fire in the M1.  I adjust the die to give a cartridge case headspace that falls within min and max using a case headspace gage.  All very simple, has never given me a problem in thousands of rounds each in of these rifles.  And brass life has been very good, I eventually get neck cracks in the .30-06, but never had a case head crack.  I’m sure I’ve loaded my RP .30-06 cases 50 or more times, Win brass cracks at the neck after about 30 reloads.

Bolt rifles, I will neck size.  I use a Lee Collet die for .303, .30-06 and .308.  Two reasons:  significant time saver (no need to lube case and then clean lube off) and seems to lengthen life of the case.  This seems particularly true for the .303. But does it really?  What about reliable bolt locking and extraction?  I continue neck sizing until I feel light resistance to fully locking the bolt. “Light” is a relative word, so say a few pounds pressure with the thumb on top of the bolt handle.  Once I feel this resistance on say 10 out of 40 cases, the next resizing cycle will be using a FL die.  Because the .303 has a very long chamber from breech to shoulder compared to commercial sizing dies, I use a case length comparator to measure the distance to the shoulder on a few of the cases that I feel resistance to bolt fully locking.  I then adjust the FL die to push the shoulder back .003 to .005 inches and check the case in the rifle to be sure the bolt locks with no resistance.

Before I had the case length comparator, I used the rifle chamber as a go/no go gage on the resized case.  But, before I had the comparator, I‘m sure I pushed the shoulder back much farther than necessary, and certainly enough that the sized case would no longer headspace on the .303 chamber shoulder

How case head cracking figures into this I believe is fairly complicated and I don’t really know.  My experience tells me the .303 case head cracks show up after FL sizing the second or third time.  At this point, I have 30 or more neck sizing cycles on the brass, perhaps more than 50.   From others experience, I should not complain and just carry on what I’m doing. 

With a new batch of PPU, I’m monitoring my reload cycles.  I’ve neck sized the brass 8 times now for my 0L Mk 1/2, a new rifle to me, and I’m just beginning to feel slight resistance of bolt lock up in the last few degrees of bolt rotation. I will likely FL size after 10 neck size cycles, setting up the die as explained above, and continue back with neck sizing after that.  I’m thinking of running a new lot of PPU and only FL size with the same method to bump back the shoulder each reload cycle to see what affect this has on case life. 

Benchrest and F-Class shooters will say that FL sizing is more accurate, it offers better alignment of the bullet to the throat.  I doubt a LE rifle is accurate enough to see this difference, so I’m mostly interested in prolonging case life and ensuring reliable lockup and extraction.  I’ve not noted better accuracy with FL sized cases vs neck sized in my rifles. 

I’ve rarely encountered any moderate to heavy resistance to bolt lift by neck sizing, however, I do feel some resistance if I neck size for too many cycles after I first feel resistance to bolt lock up.  Even some resistance in locking and unlocking the bolt is not helpful during rapid fire stages of match shooting, so I’m usually careful not to go into a match with brass that is approaching my threshold for FL sizing. 

I know several forum members who use a FL die to bump back the shoulder, Shamu does, maybe a few others.  Zed and Goosic, not sure what you do.  I would like to hear from our members who shoot a lot and what resizing dies (type and manufacturer) you are using and how many reloads cycles do you get? Do you anneal?  Issues with neck cracking and case head cracking?  

Posted By: britrifles
Date Posted: July 14 2020 at 6:13am
 Here is what James Sweet said about headspace, rim thickness.  This was not about reloading, as competitions at that time used issue Mk 7 Ammunition.  But, the statement about erratic shots when “extra force is needed to close the bolt” is interesting.  

James Sweet was a competitive Service Rifle Shooter, Queens Prize winner, wrote a book titled “Competitive Rifle Shooting”.  You will recognize the name if you use Sweets 7.62 bore cleaner.  

He also stated that a very high degree of accuracy can be obtained by sorting cases by rim thickness (Using a rim thickness gage) and selecting a bolt head that gives headspace just over rim thickness.  Jerry Ward was said to have shot a 3/8 inch group at 50 yards with headspace adjusted to regular rims.  That’s remarkable if it’s with Mk 7 service ammunition.  I’ve not tried this yet, but I do like to have headspace set at or just above minimum.  

Posted By: Shamu
Date Posted: July 14 2020 at 12:30pm
As I posted on the other thread. I found the "perfect" for me method was the "Partial Full Length Resize". I find it gives me the best of both worlds & apart from initial set up of the dies is the same workload as full length resizing.

Don't shoot till you see the whites of their thighs. (Unofficial motto of the Royal Air Force)

Posted By: britrifles
Date Posted: July 14 2020 at 1:11pm
Sham, right, but I do find neck sizing with a collet die so much quicker.  Here lately, I’ve been shooting upwards of 200 rounds a week, so neck sizing is a major time saver.  

Perhaps I should consider a fixed interval of “partial FL sizing”, more frequent than I do currently, perhaps every fifth neck size.  Have to track all that to...

I do believe that fully resizing the .303 case back to SAAMI specs (i.e screwing the die all the way down to the she!! holder) excessively works the brass and will shorten case life, perhaps to only 5 reload cycles before case heads crack. That’s too expensive for me.  

Posted By: 303 Hunter
Date Posted: July 14 2020 at 3:10pm
I don’t shoot as much as others on here do, but I have been full length resizing my brass with Lee dies and I have only just lost some cases to head cracking.
Those cases are part of an odd assortment of brass from factory loads that I’m trying to use up.
The cases I lost were Winchester and were reloaded about four or five times.
I have a Lee neck resizing die but can’t get it to squeeze the case necks enough for sufficient hold on the bullet.

The Lee Enfield is to the Canadian north what the Winchester repeater was to the American west.   Cal Bablitz

Posted By: britrifles
Date Posted: July 14 2020 at 3:15pm
303 Hunter, you might benefit from the “partial resizing” method to extend brass life.  You can also buy the Lee .303 collet neck sized separately.  

Posted By: 303 Hunter
Date Posted: July 14 2020 at 3:33pm
The Lee collet neck sizing die is the one I have.
After reading the posts here I was thinking about the “partial resizing” method

The Lee Enfield is to the Canadian north what the Winchester repeater was to the American west.   Cal Bablitz

Posted By: Long branch
Date Posted: July 14 2020 at 4:22pm
Essentially, the more brass you move, the shorter the case life. There is a lot of space in an enfield chamber, especially at the shoulder. Sizing back to SAMMI spec moves a lot of material and makes for a short case life. 

Neck sizing will give you the longest case life, but chambering starts to become difficult after a while.

For those who don't know, partial full length sizing is done by setting the sizing die so that it sizes the neck and case walls but not the shoulder (at least no more than necessary for easy chambering). This is what I do with brass meant to be used in magazine-fed rifles.

If you're not getting feeding problems with neck sized brass, I would continue with that until chambering starts to become difficult. Then, I would do a partial full-length size.

You can gain accuracy with factory ammo by selecting rounds by rim thickness. With ammunition loaded with either of the two methods above, you'll be headspacing on the shoulder, and the rim thickness won't be relevant anymore (that involves a long explanation about what headspace is and what it does that I'm sure nobody wants me to go into).

If you're getting neck cracks, the occasional annealing cycle will mitigate that largely. It just depends on how much work you want to put into it before you buy new brass. You may also find that your loads are more accurate if you anneal the necks every 3 or 4 loadings.

Posted By: britrifles
Date Posted: July 14 2020 at 6:45pm
Long Branch, what you have described is exactly what I have been doing for many years, except that I am now a bit more precise in how far I move the shoulder back, no more than necessary to be able to easily lock the bolt.  

I have annealed case necks before but I’ve not noted any improvement in accuracy.  I’ve also very rarely, if ever, experienced a neck crack in my .303 brass, always head cracks.  

Posted By: Goosic
Date Posted: July 14 2020 at 8:55pm
(Jerry Ward was said to have shot a 3/8 inch group at 50 yards)
How many bullets in the group britrifles?
I put ten shots inside a penny @ 100 yards, .750" with that Long Branch. 

Posted By: britrifles
Date Posted: July 15 2020 at 4:21am
Goosic, Sweet didn’t say, but I’d expect it was 10 rounds, that’s usually what is considered “a group”.  He also didn’t say if it was handloads with match bullets or Mk 7 service ammunition; scoped rifle or aperture sights; bench or prone.  These things make a difference.  

I’ve never been able to shoot a group that small prone, unsupported, with aperture sights.  About 1.5 inches is the best I’ve done.  More like 2 to 3 inches on average.

Posted By: Goosic
Date Posted: July 15 2020 at 9:56am
I guess I have some testing to do now. 
The M700P using The Mexican Match loads and the No4MkI* LB with be using the GRAF BTHP. 
Should be interesting. 😎😎😎

Posted By: britrifles
Date Posted: July 15 2020 at 10:56am
The fun never stops!  😊😊😊

Goosic, what is your case resizing routine?  Neck size, F/L size, partial F/L, all three?

Posted By: Goosic
Date Posted: July 15 2020 at 11:13am
Full length resizing.  I run each case through the resizing die two times slowly and then trim to length.  For the 303B 2.215" and for the 308W 2.005". Once my initial trim to length is done after the first resize, I typically do not have to retrim the caaes until the forth or fifth reloading session.

Posted By: Zed
Date Posted: July 15 2020 at 12:16pm
I gave up neck sizing when I got to the range and found the bolt wouldn't close on the ammo. Having reloaded the cases from one rifle for a different one. So now I've adjusted my Dillon rig to just resize the case enough to fit any of the .303's. That way I'm sure I won't turn up to the range with dodgy ammo.
I started off having different tin's for used brass; but when cleaning and trying to reload seperately for 3 different rifles I found I just don't have the time. The partial resize makes life easier for me for case peparation.
Then I can just load for each rifle; although this is still a work in progress. Difficult finding enough time to get to the 200 metre range and our 50m range is currently closed to large calibre rifles.
Regarding accuracy; most of the errors are my fault, so until I get some improvement in regularity of my shooting. (That really means more range time) I consider my current load for the No1MkIII* to be quite good; so I'm not changing it at the moment. Last time out with this load with newly fitted PH5A rear sight; first 5 shots from prone with sling; got approximately a 4" by 3.5" group, with about 5.5" diagonal of furthest spread at 200 metres. I was happy with the group size; but it adjusting the sight to centre got a few unforced errors on my part. So need to go back now it's zeroed and concentrate! Still need to finalise loads for the no4's with the new powder (Vita Vouri 140).

A friend of mine does a lot of Service rifle competitions and plenty of practice. He shot a 195/200 in practice with his 1903 Springfield. He called the two 8's left of centre, but had a group of 7 in the 10 within 1.5 inches. This is at 200 metres, prone with sling. (The 10 is 8cm ,about 3"). I enjoy shooting with him; as it shows me what is possible with practice. He's free with advice too!

It's nice to be important, but it's more important to be nice!

Posted By: britrifles
Date Posted: July 15 2020 at 1:37pm
Zed,  thanks for this information.  I’m nearing this same conclusion with now having to manage 4 separate lots of brass for my three No. 4 rifles and my Dad’s T. 

How many reload cycles do you get with your brass using this method?  

Your 200m target 10 ring at 3 inches is a challenge.  That is the diameter of our X ring at 200 yards.  Have you or anyone else managed a score of 200/200 (or 100/100 for that matter) on that target prone with any vintage service rifle?  I just haven’t been able to crack that nut, 9/10 consecutive shots is the best I’ve done.  I think 20/20 would be next to impossible (for me anyway).  

I see you are also trying N140, I just loaded up 40 rounds to try.  I’ll report results when I get to the range.  I’m starting at 38.5 grains with 174 SMK.

Goosic, this might explain something you said on another thread, I suspect FL sizing results in shorter case life than neck sizing, perhaps substantially.   I’m going to run that comparison with new brass, I won’t fully resize (won’t screw die down all the way to she!! holder) but set up the die to size to just below chamber length + bolt head clearance.  This should still get the case to headspace on the shoulder, but ensure the bolt locks easily.  This might be the ticket. 

Posted By: Shamu
Date Posted: July 15 2020 at 6:18pm
You might try what I do for "casual" (plinking)l rounds.
Take 5 or more fired cases from each rifle.
Get one of those case measuring dinguses. you know the sliding rod with the comparator inserts for the case.
Now record the longest & shortest measured to the shoulder.
Partial F/L size to THAT dimension for everything except "match rounds".
Its not as precise as measuring each one individually & segregating them, but it IS minimal "universal" case resizing. Wink

Don't shoot till you see the whites of their thighs. (Unofficial motto of the Royal Air Force)

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