.303 sizing question

[glmf]

shooting cb loads out of my SML and just neck sizing with great results. After about five firings, the bolt is starting to close hard on some of the rounds. I really don't want to full length size as it really shortens case life. I have a lee collet neck sizer and full lenght sizing die as well. Is there any way to just bump the shoulder back a little. I must be missing something as to move the shoulder back, I can only seem to do it by using the FL die. Any ideas???

[BruceB]

For my .303s, which run mostly on relatively-moderate loads, I just use an RCBS .308 Winchester case-sizer die.

This die will set the shoulder back very nicely, and VERY accurately....I size just enough to allow the rifle's bolt to close with a bit of "feel". The die will not touch any part of the case except the neck, when doing this. Therefore, the as-fired dimensions of the .303 case are preserved, except for the neck diameter and shoulder location.

I use water-dropped wheelweight alloy, and haven't noticed any reduction in bullet diameter from the slightly-smaller case neck diameter.

It occurs to me that one might try using the .308 SEATING die to set the shoulder back with less reduction of the neck, but I haven't tried that as yet.

[Piedmont]

You can use the full length die. It is what I use all the time. DON'T BOTTOM IT OUT. Only screw it in enough to allow your cases that won't chamber, chamber with whatever force you are comfortable with, from no resistance to slight. That is the way you should set up your dies for all bolt actions anyway.


BTW my case life is long. My dies happen to be Redding but I have a hundred cases with 15 firings with no cases lost and no annealing yet.

[HARRYMPOPE]

I also do what BruceB does with a 308 sizer.it works very well.

HMP

[Multigunner]

I've been using the fired cases from my Ni.4 as snapper caps. I use each case once for dry firing and the impact of the striker is just enough to micro size the case so it chambers easily after neck sizing and reloading.

I obtained a set of full length dies awhile back and figure to start setting the shoulder back slightly when I start loading for my SMLE to avoid wear on the older rifle.

PS
An old time brenchrest trick that works for me is to size only 2/3 of the neck. The unsized portion at the rear of the neck helps center the bullet to the origin of rifling for a clean start.
This compensates a bit for loose milspec chambers.
Also the less neck tension the less the effect of variations in neck tension for more consistent pull strength. So long as theres enough tension that is.

lso one cause of the case becoming progressively harder to chamber is work hardening of a stretched case, if an annular ring appears inside the case then after a few firing the case will crack there. My No.4 has very tight headspace due to a new bolt body and No.3 bolt head. My SMLE has better than average headspace at .068 and an uncommonly well cut chamber so neither has that problem.

[glmf]

Thanks for the replies. I don't quite understand the .308 die procedure. Won't a .308 die size the neck even tighter? And the shoulder is quite different between the two rounds? Not saying it doesn't work, I am just not sure how it works. Could you please give me a little more detail,, thanks very much

[tomme boy]

Bottom out your die on the shell holder. Now unscrew the die one full turn. Take the piece of brass that is giving you trouble an lube it. Run it threw the FL die. Try to chamber it to see if it made any differance. If it did not change, then turn the die in 1/8 to 1/4 turn and FL size it again. Chamber the round again and see if it chambers better. If it does, stop right there. If it has not changed, then screw the die in a 1/8 turn more. Keep doing this until it chambers easily.

Now, once you get the brass with a problem to chamber more like you want, I do one more step. I back the die off until it gets hard to chamber again. Now I will fine tune the die as I know how far to turn it either way. You want it to JUST bump the shoulder, NO more. Lock the ring on the die and call it good.

[PAT303]

I just screw the FL sizer down so it just touches and bump the shoulder,thats all it needs. Pat

[Larry Gibson]

+ another who also use's BruceB's method.

Larry Gibson

[glmf]

Reread BruceB's post again and it makes sense now. Will try that. Thanks very much for all the help.

[303Guy]

I've never needed to set a 303 Brit shoulder back. I find that a case that closes tight will come out free. Not so much with lighter loads. I do lube my loaded cases and I believe this helps. (Not dripping with oil - just what is enough for case sizing). I've also never needed to trim my cases other than to square the mouths in the first place.

[madsenshooter]

glmf, you can put a 303 expander ball in a 308 die, so the neck diameter will remain the same.

[1Shirt]

Have not tried BruceB's 308 method, but will give it a try next batch of 303 that I load. Has anybody tried a lee collet neck sizer?
1Shirt!:coffeecom

[nanuk]

is the 308 seater die body reamed to 308 dimensions with a slightly oversized neck?

[onondaga]

"After about five firings, the bolt is starting to close hard on some of the rounds."

If that was happening to you, I believe your initial die setup was incorrect.

Set your die up to a fire formed case according to Lee instructions and try again. If you can't get it correct, call Lee. They will help you trouble shoot your die setup. The increase in bolt closure resistance is related to something else if your die has been set correctly to a fire formed case.

Gary