Fireforming,and barrel-breakin) with lighter, less-expensive bullets

[jeffreybehr]

I Searched and couldn't find anything quickly, so...

Are there any good reasons NOT to use less-expensive, lighter bullets and faster-burning powder to fireform cases? I have a Shehane 6.5-284 on the way,this month, I hope) and of course need to break-in the barrel and fireform a bunch of cases. ,I bought 500 of the latter.)

Bill suggests using the 142SMKs and 50 grains of H4831SC and shooting a match with that load, but I have perhaps-lots of load development to do before I compete with the rifle. I already have a 8-pound bottle of H4831SC and thought I'd also try RE-19, one of only 2 powders,AA-4350 being the other) that Sierra uses to get the 142SMK to 2900FPS.

So...maybe 45g. of RE-19 and the 100g. HP?

 

[billmo]

You should be able to fire form with a lighter bullet. Just try to jam the bullet at least touching the lands. You want to blow that brass out as much as possible the first time you fire it. That is what Bill told me when he built my 6 X 47 Shehane.

 

[cbonner]

That's exactly what I did with my 7WSM. I necked down Norma 300WSM brass, which required fireforming to blow the shoulder forward. My real bullet is the Nosler Accubond, which is rather expensive for fireforming fodder. Considering I really could't begin my load workup, or accuracy testing until after the cases were fireformed, I didn't like the idea of just blasting the expensive Accubond bullets into the backstop. I fireformed with the Hornady 120 grain VMAX, at 1/4 of the Accubond cost. I seated the bullets about .02 into the lands and loaded with the bottom range of the powder charge recommendation. The bolt took a bit of force to close the last 1/4 of its vertical travel, indicating the bullet was engaging the lands. Anyhow, it worked like a charm... I saved a bunch of $$ in bullets, and the recoil was noticeably milder - Craig

 

[jeffreybehr]

TYVM, Craig. I bought some Sierra 120s and a couple pounds of H4350 and will start breaking-in the barrel and FF cases this week, as Bill will be shipping the rifle tomorrow, Monday the 24th.