Dented brass

[Oldschool280]

so i went to the range today with the.257 weatherby and some speer 120's. I used speer's data and had some denting occuring in much of
The brass. Feom what i have read this is from under pressure or hardened necks. The brass was annealed and trimmed just prior to use. Speer lists the starting charge for rl25 at 63 grains and max at 67. Other bullet manufacturers list a starting load for a 120 grain bullet at 67 and max at 71. I did not get any blowby in the face, perhaps the belt helped with that?.it didnt do it every time, it put two through the same hole at 64 grains but only dented one of the two cases. No signs of pressure at the listed max of 67 by speer. I think i might keep going up to find the next node. Any suggestions?

 

[Dmagna]

What was the speed?

 

[Oldschool280]

What was the speed?

No chronos allowed at this place, i need a magnetospeed

 

[Orange Dust]

so i went to the range today with the.257 weatherby and some speer 120's. I used speer's data and had some denting occuring in much of
The brass. Feom what i have read this is from under pressure or hardened necks. The brass was annealed and trimmed just prior to use. Speer lists the starting charge for rl25 at 63 grains and max at 67. Other bullet manufacturers list a starting load for a 120 grain bullet at 67 and max at 71. I did not get any blowby in the face, perhaps the belt helped with that?.it didnt do it every time, it put two through the same hole at 64 grains but only dented one of the two cases. No signs of pressure at the listed max of 67 by speer. I think i might keep going up to find the next node. Any suggestions?

A guess and that is all it is. I have seen that with too lite a charge of very slow burning powder. If it happened with the upper charges, try a little faster powder like 7828 or re22. Only happened to me once and it was with a weatherby. Seems like it was a 257 too but may have been a 270.i read an explaination years ago but i forget.

 

[jimbires]

that's caused by light loads . the pressure was low enough to not expand the brass case to properly seal the chamber .

 

[MagnumManiac]

Have seen this myself several times. The soot below the shoulder is a dead giveaway that pressure was low.
Interestingly, it too, was when using RE25 in several large capacity cartridges. The worst was my 25 Pronghorn, aka 25-300WSM.
Soot would be evident all the way to the bolt face, even at 2gr under predicted max.
Next worst was 7mmRUM I was working up loads for buddy, nearly every powder tried did it with start to middle loads.

Anyway, increase the powder charge, with care, and the problem will stop.

Cheers.

 

[KNOTFERSAIL]

My 257 Roy love's 70 gr. Of imr7828 w/110 AB's at mag length.

 

[DRock]

I've had this same issue with this same cartridge before and my brass looked identical to the picture posted above. I was newer to reloading and it was on a colder day and it was the first loading with a new custom 257 Wby so I started on the low end. I thought I had gun troubles. I talked to quite a few other handloaders before someone verified what has been mentioned above. Load charge was not sufficient to expand the brass and seal the chamber. I increased my powder charge and never looked back. I was using RL22.
I mentioned the colder day as it was suggested to me that this could affect minimum charges the way maximum charges could be affected on a hot day. I am not 100% sure about this but I have since changed to using powders that are more temperature stable just for reassurance that I wont have any issues due to swings in temperature.

 

[fmuguira]

More powder. I shoot 67 grs R22 with 115-120 class bullets. R25 is significantly slower.... probably 68-71 grains. Work up.

And as someone stated a chronograph velocity would tell you much regarding pressure.

 

[Oldschool280]

Thanx gang you are all very helpful!

 

[Coyote Dan]

Had it happen with a 7 Ultra-Mag. Guy at the gun shop told me to he used standard primers. A top gun builder told me do not do that on these magnums, the long case is creating a delayed ignition in the cold winter weather, very dangerous conditions, went to mag. primer and never had a problem again. Was using max. load of Re-25 at the time.

 

[30BR]

so i went to the range today with the.257 weatherby and some speer 120's. I used speer's data and had some denting occuring in much of
The brass. Any suggestions?

Looks to me like excess lube on a few cases...

 

[del2les]

If the brass has been fired in your chamber prior and you are beginning development
of a new load/powder or wishing to run non-top end pressures for varied reasons, I partial neck size only. This leaves the back 1/4-1/3 of the neck closer to chamber size to help seal the chamber and helps prevent back flow. YMMV

 

[LazzInc]

oldschool ,,, your chamber throat must be really long in that rifle ,,, very simple problem, the back of the bullet is exiting the case BEFORE the front of the bullet has fully engaged the barrel ,,, expanding gas is wrapping around the case BEFORE the pressure has built enough to fully expand the case into the chamber walls ,,,