Case sticking in the chamber

[sailhertoo]

Got a friend with two guns, 306 and 6br, and on both of them the cases are very hard to extract and leaving scratch marks on the base of the cases where they stuck.

What is going on here? Bad brass? I thought brass expanded upon fireing and then contracted to allow the case to slide out easy. This is with mild loads.

Thanks for any help you can give

 

[bheadboy]

my first response is is this factory ammo?
if handloads they are too hot!!! back of 10% and work up again,

stuck cases are almost always from too much pressure, thus overload!!!

Bob

 

[fdshuster]

Gotta know the history of the brass. Fired in a chamber other than your friends? How many times? If it fires and extracts new, once fired brass without any problems, then it's a brass problem. You're right, brass does expand to the limits of the chamber walls, then springsback for a normal extraction. Throw in some old, many times reloaded, workhardened brass and all bets are off.

 

[sailhertoo]

This is new Lapua brass with mild loads. He will get 3 reloads out of it and on the 4th one it sticks at the base. He has not had this problem before and neither have I. I never have to full length resize and he has'nt either until now.

He has to after 3 fireings now.

 

[LHSmith]

.306? Sounds like they might be match chambers (on the tight side of SAAMI specs) in which case off -the -shelf dies won't do.

 

[Preacher]

Sooner or later almost all cases will need to be full length resized so they will go into the chamber without a problem like your having...
A mild load in one may not be mild in another.......
Did you mean 30-06 ??

 

[Jeffvn]

Plus one on what Preacher said. Check the length of the brass. I knew a guy that had the identical problem on the second time he fired the brass. I have a 7WSM with tight-neck and custom chamber and custom dies that the brass would stick and I needed to push it out with at cleaning rod from the muzzel if I didn't keept it trimmed every 2 or 3 firings.

JeffVN

 

[ordnancemarine]

You need to full length re-size and trim your case necks. It wouldn't hurt to anneal them as well. My two cents worth...

 

[fdshuster]

Good information you provided about the new Lapua brass/ throws my theory right out the window. I also use Lapua only when it's available for whatever cartridge I'm using. Many of my 6ppc & 6BR Lapua have been loaded 35+ times and extraction, (and everything else ) is completely normal, but I do full length size using the Redding neck bushing dies, just bumping the shoulder back .001" to .002" maximum. Case lengths are always checked for length, but seldom need trimming and when it does, only a couple of thousandths. I'm also wondering what caused the scratches around the case heads? Scratch markings on the case (anywhere) are not normal. Interesting problem, keep us advised of what you find.

 

[LHSmith]

This is new Lapua brass with mild loads. He will get 3 reloads out of it and on the 4th one it sticks at the base. He has not had this problem before and neither have I. I never have to full length resize and he has'nt either until now.

He has to after 3 fireings now.

Sailher2- Pls. expand on your not having to FLS. What cartridges have you been using? # of times your cases have been reloaded? Custom chambers? custom dies?

 

[sailhertoo]

Thanks for all the help.

He is having this problem with his 308 and 6br.

I mostly shoot a 308 and I never full length resize. Every so often I do bump the shoulder with a body die only.

The small scuff marks around the brass at the base are from where it gets stuck in the chamber.

 

[artbosco]

I mostly shoot a 308 and I never full length resize. Every so often I bump the shoulder with a body die only. The small scuff marks around the brass at the base are from where it gets stuck in the chamber.

Throw that old brass away and start over.

Full Length Size each and every time you reload and you'll see a world of difference.

 

[Laurie]

sailhertoo,

do the rifles have minimum SAAMI chambers by any chance? I know through personal experience that Lapua 6BR brass is marginally large in the lower body area for minimum SAAMI chamber dimensions, or at least those provided by my gunsmith's reamer.

The simple test is to try a selection of brand new cases straight out of the box in the chamber. If you have what I think, a percentage will be only slightly tight on chambering, but need a whole bunch of effort to pull the bolt handle back. Lifting the handle isn't the problem, it's the rearward pull as the primary extraction cam won't break the case-chamber seal. You then see the 'witness marks' on maybe a third of the case body above the extractor groove.

If this marginal chamber-case interference fit is the problem, a Redding or similar small-base body die is the answer. You run every new case through it - but be careful not to set the shoulder back which it will (a lot!) giving you excess headspace if you simply set it up to be in hard contact with the shellholder at full press operation. Such body resizing lasts around five loading / firing cycles before the brass gets tight again and needs another pass through the small-base die.

The short-term but completely unsatisfactory answer is to take a soft-face mallet with you to the range and gently tap the bolt-handle root after lifting it every time you have a 'tight one'. This does cause nervousness amongst fellow shooters and RCOs as the assumption is you're running seriously over-pressure loads!

 

[alf]

The way I see it, trying to fit the too large brass to the too small chamber is the wrong approach.

I'd pull the barrels and have the back end of the chambers honed out/enlarged back at the web where it's scratching the brass.

 

[RonAKA]

I would check fired brass dimension and compare to SAAMI spec. See link below.

http://www.saami.org/PubResources/CC_Drawings/Rifle/308%20Winchester.pdf

 

[sailhertoo]

Well, messing with a chamber with sand paper after I was so careful with chambering, sounds, well, not the best thing.

Well, maybe now thats its done, but the problem should not have accured anyway.

 

[1shot]

I have a 6.5x284 with a match chamber that would stick every time from the 1st firing on. Additionally, I full length resized after every firing. Finally narrowed the problem down to a burr in my top end Redding size die that wouldn’t allow the brass to be re-formed properly. Having said that, Redding made it right with me after I sent them the die and several fired cases.
I hope this helps,
Lloyd

 

[tunered]

Due to the scratchs on the brass, i believe the chamber is the problem not the brass. ed