Loading Nosler 100 grain BTSP in .257 Roberts

[Reloader2025]

It is a shirt action.

 

[Reloader2025]

short action.

 

[Reloader2025]

This rifle actually belongs to my son and it has the short action. I gave him a couple boxes of the old Nosler 100 grain BTSP and he immediately ran in to the issue at hand and called me for advice on loading these bullets as they kept falling back into the case after crimping with his RCBS 3rd stage crimp die. I suggested moving the bullet beyond the stated maximum OAL but a modest 0.002 increase in OAL and the cartridge would not chamber. Therefore, I thought about asking you fine gentlemen for your suggestions and I can see that was the correct solution! I agree that a flat base bullet would be the solution for this particular rifle. I ordered a Lee Factory Crimp Die for his future hunting loads but I do not think crimping too far up the olgive is a good idea. Thank you all for your advise on this problem.

 

[JD338]

Thanks for confirming that the rifle is a short action. As Guy mentioned, run the 100 gr PT and you should be able to crimp.
As a side note, I only crimp 44 Rem Mag and 45/70. All other cartridges, including 338 RUM, 375 HH Mag and even the 416 Wby Mag, do not get crimped and I have never had any issues.
We are glad you are here and the members here were able to offer their knowledge to assist you.

JD338

 

[PJGunner]

Hey Paul, is it possible to remove the block in the magazine well then use a longer follower so it will accommodate the longer cartridge length?

You might be able to as I think it's just tack welded in place. I know you have to replace the ejector and maybe something else but I forget what. I called the parts places and they always seem to be out of stock on those particular parts. Must be a lot of people doing that conversion. The easiest way is just replace the magazine pox and ejector from what I understand.
Paul B.

 

[Guy Miner]

I gave him a couple boxes of the old Nosler 100 grain BTSP and he immediately ran in to the issue at hand and called me for advice on loading these bullets as they kept falling back into the case after crimping with his RCBS 3rd stage crimp die. I suggested moving the bullet beyond the stated maximum OAL but a modest 0.002 increase in OAL and the cartridge would not chamber. .... I ordered a Lee Factory Crimp Die for his future hunting loads but I do not think crimping too far up the olgive is a good idea. Thank you all for your advise on this problem.

I just saw that - the part in bold attracted my attention.

Neck tension alone should grasp the bullet firmly, even without a crimp.

I think something is wrong with the neck sizing. It's not tight enough. Could be a die issue or it could be a brass issue...

Try adjusting the die, and perhaps try a different brand of brass. Are these factory 257 Roberts cases or are they made from something else?

Worth a thought.

Regards, Guy

 

[RL338]

I found that in so doing, the slightest bump and the bullet falls back into the case due to insufficient crimp.

What brand of dies are you using?
Just a guess would you be using a Lee Collet die and work harden brass that is leaving you with next to no neck tension.