Need Some Help Sizing .257 STW

I purchased a custom .257 STW die set from Lee which consist of the Collet Neck Sizing Die and a bullet seater. Lee made the die using fired cartridges from my gun and the bullet that I intend to shoot.

The problem is that the collet neck sizing die (.259) will not resize the 7mm STW case neck (.287). I tried several and the result was the same each time, crushing the neck.

I know that I will have to step the case neck down. I am not sure about the best way to do this. Some sage advice would be greatly appreciated. Please let me know your thoughts.

Thanks

Buy a .264 bushing, or a 6.5-300 Weatherby neck-size die.

https://www.midwayusa.com/product/187334/rcbs-neck-sizer-die

Not sure the press you are using it in but if it is a cam over type like a rock chucker. You need to bring the ram up screw down until contact. Then lower the ram and add two more turns. It shouldnt crush anymore. You may have to take the collet out now and spring it back out however.

I use a non bushing sizer to neck down. my bushing dies just wad the necks up

My experience using the collet dies is that they won't resize cases from one caliber to another. I think you will need a sizer die of the caliber you shoot to get it from .287 to .259 then the collet die will work.

morning, I have a 257STW. I bought the 7mmSTW brass. I purchased
a Hornandy 6.5 and 25cal. neck sizing dies. no problem, trim to
length. b carful not to crush the neck. use case lub for neck sizing.
TUM

I am using a forster press. I just bought a full length .257 die sizer die. Hope this gets it done.

Thanks for the replies.

just country said:

morning, I have a 257STW. I bought the 7mmSTW brass. I purchased
a Hornandy 6.5 and 25cal. neck sizing dies. no problem, trim to
length. b carful not to crush the neck. use case lub for neck sizing.
TUM

Click to expand...

Which Hornady 6.5 die are you using?

aldeerhunter said:

Which Hornady 6.5 die are you using?

Click to expand...

the neck sizing only die

Adeerhunter:

If you bought a two die set with the FL sizer die, you can use the seater die first then go to the FL die.

Bought collet neck size die and seater. Do d not think I needed the full lengjth size die. I just bought a RXBS .257 STW full lenghth die set and also ordered a 6.5 Hornady die. I will see what works best.

I received the .257 RCBS die set which contained a full size die and a bullet seater. I also received the 6.5 Hornady die.

I tried the Hornady die trying to size the 8mm Remington brass down and again it seems as though the neck is collapsing rather than sizing.

I decided to try the RCBS full size die using a piece of the Norma 7mm STW brass I purchased. The neck sized down but left a bulge in the neck at the shoulder where the excess brass has been pushed down.

I tried to upload a photo but have not been able to. As I type this message it dawned on me that I may now be able to finish the sizing with the colllet die or 6.5 die and remove the ring. If not,I guess I will have to trim the necks.




Am I on the right track?

looks like in the pic that you didnt make it down to the shoulder yet

TwoMore said:

looks like in the pic that you didnt make it down to the shoulder yet

Click to expand...

Thanks. I was afraid the case would collapse. I went ahead and resized a little at a time pushing the excess to the shoulder:


The round will actually chamber. Just wondering if I will have to trim the excess.