SOLD/EXPIRED Brass brakeing

[deltaco]

I shoot a Thompson Center Encore, in a 300 win mag, 26" barrel. I reload my ammo to the Berger Bullets manual specifications, never hot loads. Can anyone tell me why after about 4 to 6 reloads the cases brakes off about a 1/4" above the belt. But in a Savage, in the same caliber after 5 to 7 reloads only the neck splits. Driving me crazy.
Thanks
Deltaco

 

[FearNoWind]

The 300 Win Mag slams brass pretty hard. Are you annealing? Not that annealing is going to be possible 1/4 inch above the belt but it might help the split necks.

 

[hubb]

Go to stevespages.com/diagnosing problems , there is a good article that will help you figure this out. It basically says any of these may cause it, over bumping the shoulder, over working the brass, excessive trimming and reloaded several times.
He has some good pictures there of cutaway cases, it shows how the brass has stretched and moved forward causing a ring above the base where the brass has thinned for moving forward, after thinning so far it breaks.

 

[Deerhunter85]

Sounds like your over sizing the brass with a full length die

 

[37L1]

Pushing the shoulder back too far is causing the brass to stretch too much with each firing this is giving you your case head separation.

 

[deltaco]

Which is better using a neck resizing die or a full length resizing die for reloading?

 

[hubb]

A short answer to your question would be use a full length resize die and set the shoulder bump for the .001" to .0015". Get you a set of calipers and a bump gauge for your caliber rifle and measure the shoulder on a fired case with the bump gauge. Then carefully measure the shoulder bump as you adjust the die up or down until to have the proper bump then lock your die. You want to measure your brass for length with your calipers to see if it needs trimmed or not every now and then as well.
Reloading can get pretty involved but for a hunting rifle the regular full length die will do you fine.

 

[Charters]

Reloading for the "break action" guns like the encore is a bit different than a bolt. This is the place u go to find answers for the questions you have.. www.bellmts.com

 

[remingtonman]

I shoot a Thompson Center Encore, in a 300 win mag, 26" barrel. I reload my ammo to the Berger Bullets manual specifications, never hot loads. Can anyone tell me why after about 4 to 6 reloads the cases brakes off about a 1/4" above the belt. But in a Savage, in the same caliber after 5 to 7 reloads only the neck splits. Driving me crazy.
Thanks
Deltaco

How does your encore group with that particular load? Could be a possible headspace issue with your encore. Get ahold of mike bellm hes a great guy to deal with and REALLY knows his stuff.
Bellm TCs - Headspace, How to Get it Right

 

[Lone Hunter]

What remingtonman and others have said. I've found on my TC's that they have excessive headspace. Go to bellm's site and there is a lot of help there. You might be able to call him also.

 

[ATH]

Not a ton of experience with the Encore, but I wonder if with the break action you are getting excessive stretch and needing to push the shoulder back excessively. Do fired cases easily chamber?

FWIW, in a bolt action, I have 300WM brass with 8 firings which have never seen a FL sizing die. Out of 200 cases through 8 firings, I've lost a single one to imminent case head separation.

So I'd say it's case stretch, either from something with your headspace (which you should get an idea on firing a new case and measuring) or issues related to the gun design and this particular chambering. I know some cases have too much thrust for the Encore.

 

[BountyHunter]

Your going to need to FL resize the brass just enough to get the action to close smoothly. Pretty sure you have been bumping the shoulders way too much and causing the stretch and split cases.

Mike Bellm sells a headspace tool for Encores that is useful.