fire forming

[skeeter]

How much accuracy is lost when shooting brass that has not fire formed to shooting brass that has been fire formed, in 257 stw. Brass that has not been fire formed is 7mm STW. skeeter

 

[Varmint Hunter]

I am not sure of the answer to your question but; in my 6mmAI I was able to get .5moa groups while forming my 7x57 brass.

Actually, I was able to find several loads that would shoot to about .5moa. Other shooters have had a similar experience while fireforming brass.

Sounds to me that you will be doing very little "forming" while firing the first round in your 257STW.

 

[Mysticplayer]

Depends on how straight the necks are after sizing down. The more out of whack, the lousier the accuracy.

If you can run the brass through a FL sizer in your last step, it could shoot just fine.

Jerry

 

[JustC]

I have had numerous fireforming loads go under .5moa (even with cheap spire points)