Are you F/L sizing or Neck sizing?  Both should provide sufficient neck tension, typical neck ID's should be 0.002 inches smaller than the bullet diameter.  I assume your loading a .311 diameter bullet?

One more thing, presses have a significant mechanical advantage, so what might "feel" like a low seating force, could well be 30 lbs or more.  Try pushing the tip of the bullet against your bench with about 20 to 30 lbs and see if the bullet moves.  If it doesn't then no need to worry.  If it does move, measure the diameter of the expander button on the decapping rod; it might be oversize. 

The RCBS XL14 Full Length resizing die using a .3075" expander will give the 303 case enough tension to hold a typical .310", .3105" and .311" projectile. After the cases have been fireformed you would want to switch to a Neck Sizing Die like the RCBS Neck sizer P/N15430 or the Lee Collet Die Set.

My advice is to not crimp at all; if there is insufficient neck tension to hold the bullet in place with normal handling, you have a problem with the dies, they are expanding the necks too much.  

Be careful not to buckle the shoulders of the cases...

Just out of shear curiosity edteach. Why are you exceeding the advertised maximum charge weight of 46.0grns and using 47.0grns of H414?

Every publicized form of reloading data I have gives a maximum charge weight of 46.0grns of H414 when using a 180grn RN .311" projectile.  Seems a tad excessive considering all the published data out there suggesting otherwise so, I am very curious as to where you have recieved your reloading data from...

I don't. its yet another variable & so I avoid it.

A correctly made & used die should not need a crimp.

That's actually a dodgy situation because bullet set back can increase chamber pressures considerably & with as hot a load as you're using that could be dangerous!

Might the die be out of spec or someone changed the expander ball?

What internal diameter does it measure at inside the neck, before, & after resizing?

I posted 47 but I meant to post 45g. I pulled a couple of bullets to check and it was 45g.

Did you fix the original "too large a case neck issue", or just hide it?

You won't ever load good ammo by simply burying mistakes with another add on if you don't fix the actual problem, the case neck I.D. after resizing.

Something is not right. If you have to use the crimping die to secure the bullet after seating it to keep it from falling or being pushed back into the case, something is not right with your reloading procedure. 

Are you resizing the the neck of the cases. Neck sizing?

Are you resizing the cases and the neck. Full-length resizing?

I just pulled a brand new PPU case out of its bag and then seated a .311" Hornady 174grn FMJ-BT on top of it without doing anything else and it was tight enough that I needed 25 foot pounds of force to remove the bullet from the case.

Are you using .311" projectiles or are you using 

.308" projectiles?

Sierra, and most all other manuals, recommend crimping should be avoided entirely in rifle cartridges by setting sufficient neck tension, which is achieved by sizing cases such that the neck ID is .002 to .003 inches smaller than the bullet diameter.  If your using Lee dies, you can get undersized mandrels for their collet neck sizer or decapping rod with the integral expander for F/L sizer direct from Lee Precision. 

Have you measured neck ID of your sized cases? 

 Even with the Lee Loader Whack-A-Mole that doesn't have an expander ball you still get a decently resized neck so your comment that the bullet easily pushes back into the case is a little concerning due to you stating that you are using Lee Dies...

Crimping rifle cartridges seems to have been in favor 20+ years ago, but I don’t know anyone reloading for current and historic/vintage service rifles who crimp the cases, not even for the M1 and AR rifles.  My own tests showed no improvement in accuracy, and on occasion, detrimental to accuracy if cases are not all trimmed to the exact same length and crimps were moderate to heavy.  Crimping a bullet loose in the case, no telling what the results will be.  

We have given our best advice, but sometimes we have to learn these things on our own. 

I noticed he says "with a set of Lee dies", that doesn't sound like a Whack-a-mole to me but a press & dies. That would mean an resizing die of some kind with an expander ball.

I'd like to see the diameter of the mic'd somewhere. Preferably with a "before" & "after" case neck I.D. too.

That seem to be the real problem.

If you disregard the loading procedure with a Lee-Loader "Whack-A-Mole" and go straight to the seating step, you get the same results. Recheck to make certain that the resizing die is correctly adjusted to the make of your reloading press, especially if you are using the Lee Collet dies...

Easy way to tell is "smoke smudge" the case then run it into the die as you would when loading normally. the soot should be removed as the die resizes then expands the neck inside & out.

That will tell you the amount & position of the resizing die's contact, simple inside & outside diameters measured with a caliper will tell you the diameters.

Similar issue here.

I have the lee pace setter 3-die set for when I have to full length size.  I sized some once fired hxp brass (fired from someone else's rifle).  After sizing, when using 150 or 174 grain hornady soft points with a cannelure, when seating the bullet and the edge of the brass gets to the cannelure, the bullet gets loose.  The bullet will move up and down the distance of the cannelure.  So I had to crimp.

I had another expander in the die box, which is .310 and put it in the die for the next time I use it.  I had to get a smaller expander for my 7.62x39 dies too, .308 I believe.  The crimped x39 didn't shoot noticeably different than the tighter non-crimped ones.  I hope that holds true for the ~40  303 I loaded.

I have the Hornady 174grn FMJ-BT projectiles and everyone is .311".

My RCBS die has the .310" expander ball and that leaves me with .001" of tension with no crimping needed.

Double check everything.  Your answer to your dilemma is in there somewhere.

If anything, use the .308" expander in your 303 die. 

I found my notes from couple years ago when I messed with them before. The bullets measure .312 as did the expander that came in the die. Apparently the reason that I had the smaller expander is because i went through this before. I called Lee and they said I need the.310 one. Apparently I just forgot to put it in the die. I will try it out this weekend. 

I’m also trying to figure out whether I want to unload these rounds I did and re-do them or just shoot them. 

Relatedly, the mandrel in my Lee neck sizing die is supposed to be .3085. I’ve never used it. 

I also have a whack a mole loader. It has been so long since I used it that I can’t recall if you can size the necks without setting off the primers 

Alternatively, back your FL die out a turn and use it as a neck sizer. 

Using a small plastic mallet, you can resize the neck of the primed cartridges in that Whack-A-Mole...

"It has been so long since I used it that I can’t recall if you can size the necks without setting off the primers "

its possible, but I wouldn't go bashing them with a mallet. Slower squeeze in a press is safer. The decapping stem inst used when resizing in the Lee & there's a hole below the prime seater to help prevent shock discharges.

You do have to be extra careful with the Whack-a-mole though as the seating die has an open top.

And as previously mentioned, I put the smaller expander in my full length die for when I prep some more of the once fired hxp brass I have. 

You can also get undersize or oversize mandrels from Lee. The more times you resize cases without annealing, the more springback the brass has and you gradually loose neck tension. The best way to deal with this is to anneal on every reload, but that is a bit of a pain (although, that’s what I now do).  So it’s handy to have a -.001 mandrel available if you find neck tension is fading (that’s much better than crimping in my opinion). 

I have been looking at annealing options. I decided I’m going to put together a “bean machine.”  And have started accumulating pieces for it. 1st video is a short of one someone built. Second is by the gentleman who designed and produces the 3d printed parts for it. 

https://m.youtube.com/shorts/C1ZNBk_zinM" rel="nofollow - https://m.youtube.com/shorts/C1ZNBk_zinM

https://m.youtube.com/watch?v=qNNylrha6NY&t=84s&pp=ygUVYmVhbiBtYWNoaW5lIGFubmVhbGVy" rel="nofollow - https://m.youtube.com/watch?v=qNNylrha6NY&t=84s&pp=ygUVYmVhbiBtYWNoaW5lIGFubmVhbGVy

But I full sized some more of my once fired brass (first fired in someone else’s gun) using the smaller.310 expander I mentioned a couple posts above. The neck was tighter than before but with two of the rounds, there was still some slight movement at the cannelure. The projectiles were .311 ppu fmj-bt with cannelure. I ended up running them through the neck die too. 

So I’m thinking I’ll chuck the expander in my drill and hone it a little with some maybe 1000 grit sandpaper. 

Or, will a Lee .308 expander from a Lee 30-06 or .308 win die work in the 303 die? 

Edit:

Lee se2169 is the expander Im thinking of.

Per lee's website it is the same length as the se2358, which is currently in my 303 Brit. full length die.  Both the se2169 and se2358 are alternates for 7.62x54r. The se2169 lists it as an expander for 7.5x54mas, 308 win, 300 savage, 30.40 krag, 7.62x54R and 300wsm.  So, I'm going to give one of those a try.

I have new and once fired Winchester brass, once fired  Hornady/Frontier brass, and a mix of PPU and IVI brass. No issues with any of those when seating bullets. 

The only time I have ever heard of loss of neck tension after resizing brass is when someone had polished the inside of the case neck or, not putting enough downward pressure, "25 Foot Pounds" or more on the press arm to get the Collet Die to engage the case neck properly...

I had a similar issue with my 7.62x39 Lee dies on .310 bullets. The smaller of the two included expanders, which I believe is .308, gave adequate neck tension, however. 

My Lee collet neck sizing die is fine. It’s the full length sizing die that is the issue, same for the op.

I do utilize the 180 deg turn when I use the collet neck die. 

I currently use a Forester FL die, the expander measures .3100 and the case necks have good grip on the bullet. It may be your cases have had a a number or reloads without annealing the necks, this causes about .002 springback after pulling the neck thru the expander and loss of neck tension.  Until I started annealing the necks, I used a -.001 expander from Lee. 

They seemed tight until the bullet is almost to the top of the cannelure groove. With this smaller expander only 1 or 2 got loose whereas with the other expander all of them were loose. It’s not much trouble additionally running them through the neck die. But hopefully the 308 expander will fix the problem.  I’ll be building an Annealer soon. 

I ran a small test and removed everything from inside both my full length and neck sizing dies made by RCBS so that they resemble my Lee Loader "Whack-A-Mole." I ran 20 fired cases through each die. 20 cases per die. I then ran 20 cases through the Whack-A-Mole. I put all 60 cases in a pillowcase and gave it a good shake to jumble everything around and then I reached in and one-by-one, seated those cases with a .310" Lapua 200grn FMJ-BT right to the cannelure. That is only 0.1405" of  case to projectile surface contact. Every projectile stayed in place and did not need to be crimped.

 

Something is not correct with your reloading setup and even though using a 30 caliber expander ball should rectify your current issue, it still doesn't fix the root of the problem. In essence, you are putting a small band-aid on a wound that needs stitches. Double check and make certain the die you are using is not misaligned somehow or, you might consider purchasing a new 2 Die set from RCBS and set it up according to the instructions...

I’ve not come across any Boxer primed Mk VII cordite loads. Not that they don’t exist, I’ve just not seen them. 

Goosic, 

I think that you are exactly right - that there is something wrong with the Lee full length sizing die. I was actually looking at other brands on line last night. 

I would pull out the expander/decapping rod and size a case. Measure the neck ID. It should be about .303 - .305. If it’s larger than .308- .309 it’s not going to give sufficient grip on the bullet and the expander is not doing anything. 

Pin gages are the best way to measure this, but you can get fairly close with calipers. 

 

My recollection is that I canfeel it. Because of the way it gets loose on cannelured bullets, it as if only the top of the neck is small enough. I will try what you suggest the next time I full length size some cases. I have a good stock built up that I am only neck sizing now. 

I just reloaded the last 20 that I had full length sized. These are the ones I used the neck sizing die on after full length sizing and they secure the bullet as they should. 

I purposely messed up the neck and mouth on one of my once fired Hornady cases. I have a .310" neck expander and I adjusted it to unnecessarily flare out the mouth of the case. I then full length resized it using my RCBS XL14 resizing die that has a .310" expander ball. I took a .311" 174grn FMJ-BT and seated it just to the bottom of the cannelure. The neck tension is as it should be. The main focus here is the inside diameter of the case neck @ .310". The .311" diameter projectile when seated, has enough neck tension placed on it to firmly hold the projectile in place, even after the case was 

purposely mistreated.

It is of my personal opinion that your Lee full length resizing die was machined out of specification...

Here a number of people break down surplus ammunition, replace the cordite with powder and reload with the projectile of their choosing.  As such, my comment was more about the lack of neck annealing during the manufacturing stage if the case was originally loaded with cordite.  Apologies for any confusion.

I edited a little to make the images clearer.

I hope no-one minds I didn't change anything significant.

My experience has been that cordite has a long shelf life and remains reliable, but some of the old Berdan primers don’t, especially if exposed to hot weather.  Ammo that is pre-WWII have primers that just fizzle, creating a hang fire. Cordite loaded .303 is getting on in years…

Perhaps some are worried about the throat erosion effects  of cordite, so they are replacing it with NC powder. Unless you’re shooting a few hundreds of rounds of Cordite loaded ammo, I wouldn’t worry about it. Cordite loads probably cut barrel life in half, perhaps a bit more.  Somewhere there is a British MOD report of .303 barrel life when using cordite and NC powder exclusively, and what happens when mixing these. It also compares flat base to boattail bullets. Shamu may know what I’m referring to. Would like to find this document again…

 To those who may not be aware, there are no, "internal" parts to the neck forming area of the tool, just an open hole.

After priming the cases and charging each case with my chosen smokeless propellant, I seated each bullet accordingly. Every bullet has sufficient "projectile-to-case" tension without the use of a crimp.

Based off of my tests using different reloading dies from other manufacturers and one antiquated hand held reloading tool as well as testimonials from two individuals, I can only surmise that there is something inherently wrong with the Lee Full Length Resizing Die...

Are you thinking of the "long range" Mk8Z ammo?

"Only for Machine Guns"!

There's was a prohibition of using it in rifles because it was causing "more wear"?

It was rumored to be "Overly Hot NC loads" to get the longer range, but that wasn't the problem. The odd rebated base boat tail MkVIII bullets was.

The other story I’m remembering was in the Mil Surp forum I think, that was about reloads for barrels that had a lot of cordite shot thru it. The experience was the throat erosion was so severe that these barrels quickly deteriorate such that they could not stabilize a boat tail bullet even though they continued to shoot flat based bullets well…

Sorry if this is confusing….

A .310 neck ID and a .310 bullet OD? Are you super gluing the bullets in the neck? 

No problem.

I think the second one was limited to 2-groove bores that were worn?

A .310 neck ID and a .310 bullet OD? Are you super gluing the bullets in the neck? 

Nope. It just works Geoff...

I don’t use less than .001 interference, usually go for .0015 to .0020 interference to get sufficient neck tension for magazine feeding.  .001 interference is OK if single shot feeding. 

Not truly interested in going above and beyond by using a pin gauge. I trust my digital calipers and my .310" neck expander.

The point I was making here is in reference and regards to the issue with two gentlemen not being able to get their bullets to hold to the case neck without using a crimp and something internally out of specification with their Lee made full length resizing die. 

Lee is a good company to deal with, if you have a problem with their dies, they will make it right.