Neck size only won't chamber after fireing x1

[MrAndrew47]

Dear Board,

First post. I just got into reloading again after my father had taught me back when i was ~15yo (I'm 26 now) using his lyman 300 tool and dies.

For my 22-250 (Ruger M77 Mark II Target), after firing my S&B factory rounds, i decided to neck re-size only those cases with my Lee Collet dies for longer case life, better theoretical accuracy, and to avoid having to lubricate.

The problem is, while the case length is well within the range, about 20% of the rounds will not chamber (i can't close the bolt) and there are some circular marks on the primer after i attempt to do so. The COL is exactly where it should be, and there are no signs of the bullet touching the rifling (i moved the COL down a little to make sure that wasn't the case and the bolt still wouldn't close).

Also, with the rounds that do chamber, i went from 1/2MOA with the S&B factory ammo to about 3MOA with my reloads. I am using Armscor 55gr FMJBT with 32gr Varget and CCI Benchrest Primers (that's all they had). I understand 32gr Varget is a bit low for 55gr bullets.

Do i need to full-length re-size this brass after the first time i fire it? Is that something that happens commonly?

Andrew

 

[R.W.Dale]

S&B rifle cases are notorious fir having primer pockets that are too shallow. Which sounds almost exactly like what you're describing.

 

[MrAndrew47]

Brilliant. I never thought of that. I did notice that my primers were sticking out a tiny bit more than usual despite being seated well. Any ideas as to what the solution is? Trim the case a bit more?

 

[Walkalong]

Trimming the case won't help. Bumping the shoulder more would, but could result in excessive headspace. You need to get the primers flush or slightly below flush.

They make tools to square up and cut the proper depth on primer pockets. If they won't seat any further, that would be the best option I believe.

Primer pocket uniformers

 

[MrAndrew47]

Many thanks, I'll order a primer uniformer ASAP. I was a bit upset since i ordered 200 factory rounds for $13 a box and was hoping to just reload them.

 

[ArchAngelCD]

Looks like there's nothing left to do here except to welcome you to the forum...

 

[243winxb]

Do i need to full-length re-size this brass after the first time i fire it? Is that something that happens commonly?

Not common at all. An oval chamber is possible but rare. Try indexing the factory fired brass, does it chamber before neck sizing? Check measurements of the fired brass, it should not be larger than .003" of the measurements given here. http://www.stevespages.com/page8d.htm FLRS should fix it, if its not the primers.

 

[R.W.Dale]

i went from 1/2MOA with the S&B factory ammo to about 3MOA with my reloads. I am using Armscor 55gr FMJBT with 32gr Varget and CCI Benchrest Primers

Don't expect great things from FMJBT bullets. 3MOA is probably the best you can realistically expect from these. IMO the 55grn and 147g FMJ BT are the two must universally inaccurate bullets ever made.

 

[Walkalong]

When checking for accuracy potential, give your barrel a chance and use good bullets, as krochus pointed out.

 

[gandog56]

Well, the first problem I see is the use of S&B brass. I haven't trusted them in a long time. Their primer pockets have always been too tight. And my Lee Enfield has had two case head separations. Both times, you guessed it, S&B brass. No other brand of brass has done it in that rifle, so I am not blaming the rifle!

 

[Slamfire]

I don't neck size because I want my ammo to chamber each and every time.

It is possible that if you bought a cartridge headspace gage, such as the Wilson gages pictured below, you would find that your cartridge headspace is over the No Go mark.

You will reach the point where crush fitting your cases to the chamber, using the camming power of your lugs, won't work any more.

 

[MrAndrew47]

Thanks everyone. I got a primer pocket uniformer and now the primers sit flush or a little below flush and chamber easily. I didn't realize using the cheap Armscor 55gr FMJBT bullets would destroy my accuracy. I'm going to pick up some match grade bullets and try again.