Whelen Case Head separation

[Singlebarrel]

I am loading for a 35 Whelen Thompson Pro-Hunter.  I am having problems with head separation on cases after the 2nd. reload.  The brass is from Hornady Superformance loads.  My reloads are mild, runing an average of 2649 fps  with a 200 grain Hornady Jacket SP bullet using H-4895. 
Is this normal for a Whelen?  Or does that superformance load (2915 fps chronographed out of my barrel) really put a strain on the cases? 

[JustaShooter]

Probably not caused by your load per se.  Are you full-length resizing or just bumping the shoulder back?  Break action rifles like the Encore are notorious for flex (leading to overworking cases) and longer than normal head spacing so figuring out what the optimal head spacing is for your rifle is important, and then just bump the shoulder back to match head space.

[Singlebarrel]

Thanks for the comeback.  I am full length resizing.  Funny thing, though, I had two batches, most from the Superformance load and a smaller batch from Remington Cor-Loks.  Only the Hornady brass had the problem.
I am starting over with new brass to see what happens. You seem to think there is a head spacing problem?  That was my initial thought. 

[Larry L]

The Contender and the Encore both suffer from what I call head space issues. It's not like they are dangerous it's just that you can optimize brass life due to the tolerances in the lock up of this type of action. I would suggest fire forming the brass and then start resizing the brass by backing off the sizing die at least one full turn. Size a piece of brass and if it doesn't chamber, turn the die in an 1/8th of a turn and resize. Do this until the action closes reliably and tight. That stops the brass from being stretched and compressed during ignition and resizing. I would suggest this method of resizing brass even for the rimmed cartridges available in these actions. It make s a world of difference in brass life.


As you probably know the Superperformance powders are tailored to ignite and build pressure quickly  hold that pressure, and then drop the pressure quickly. It's a non-linear burn. The brass is surely going to take a beating. I won't even consider brass from any Superperformance ammo, but that's just me busy being me.

[jleem66]

I threw away 20 .308 Superformance brass a friend gave me. The headstamp was nearly gone. Don't know if it was the rifle or ammo, but I was not gonna try to reload them. They were shot out of an Encore.

[max1138]

larry has the answer,back your dies out till it wont chamber, them work in at 1/8 turn intervals till it does. you will basically be neck sizing with a full legenth die but thats what you need in this case.
chambers are cut to the generous end of the spec and ammo is sized to the smaller end to make sure it works in tight chambers so you wind up overworking the brass in just a few sizing/firings. also the break actions tend to have more flex than a rotary bolt or falling block which lets the brass stretch more on firing promoting separation of the already too undersized case. the case body is pressed tight to the walls of the chamber  by the internal pressure so it cant move so the only give is in the case head area, and it fails pretty quickly. took me a bit to get it right in my whelen handi rifle. 

[Singlebarrel]

Great adivse, guys.  I had already backed the die out a little.  I will take it another step back it out and run it back 1/8 at a time until it fits. 
I had suspected that the superformance ammo was too good to be true.  It is relatively inexpensive and I thought it was an extremely good deal considering the price of brass.  And it does shoot well.  Just something had to give with that kind of velocity when compared to everything else on the market.  Too, I have trouble handling the recoil of that round.  That is why I was working with the milder loads.  I have old injuries that make recoil painful and I develop a flinch real quick if I do not watch what I shoot.
 
 
T
 
 

[geezerbiker]

I wouldn't put that super performance ammo in any gun that I really cared about.  I saw a friend shoot 10 rounds and 6 of them blew the primers out.  If it were me, I'd have stopped after one.  He sent the ammo back to the factory and they told him there was nothing wrong with it.

If I had any super performance ammo, I'd pull it down for brass and bullets but dump the powder...

Tony

[oneoldsap]

              I've seen very little positive feedback on SuperFormance ammo ! Lot's of over pressure storys though !