Powder coated bullets: What max velocity can be run and what BHN required to do it?

[Targa]

Thats a good question, I only use gas checks because the molds I am using are designed to be used with gas checks. I wouldn’t hesitate to run 2300 fps without gas checks as long as the fit of the bullet was accurate. As for BHN, I am going to run at least 15 BHN for rifle velocities.

 

[JimGnitecki]

Thats a good question, I only use gas checks because the molds I am using are designed to be used with gas checks. I wouldn’t hesitate to run 2300 fps without gas checks as long as the fit of the bullet was accurate. As for BHN, I am going to run at least 15 BHN for rifle velocities.

OK, that makes sense. On the BHN: Uing the alloy calculator, I carefully alloyed a mix of Pure Lead, Tin, and Rotomold's "Superhard (30% Antimony and 70% Lead) to make what was supposed to produced BHN 21.5. BUT, after a few days of aging, it was still only about BHN 16, and after over 2 weeks it's not gotten any harder. Can an alloy take longer than 2weeks to get to final BHN??

By the way, I selected BHN 21.5 based on the 28,000 psi peak pressure I am running, and Richard Lee's hardness recommendation table.

Jim G

 

[kcofohio]

A number of you guys have mentioned using gas checks even with powder coated bullets. So the powder coating alone is not sufficient? Or, is it sufficient only if you have a high BNH?

Jim G

That's a good question. I still have plenty of Missouri bullets 140 gr. Zingers that are coated. Maybe they can be pushed closer to 2000 fps.

 

[archeryrob]

This was very interesting. The fliers (for the GOOD loads) were due to barrel heating up? You are sure of that? I know it was always the ;ast shot, but any chance that could ave been shooter fatigue? How thick is the barrel? Hot warm did it FEEL?

Jim G

Oh, the barrel was starting to get hard to hold. That was my first ladder shoot and I entirely rushed the entire thing. I learned that patience is a quality needed for that and have since built a barrel cooler. I may even try the cold water some guys do and dry/clean the barrel between steps.

I clearly remember this being July and every time I tried to move things along instead of waiting things went south. I have since shot the gun back in with 2400 fps and the load for it and the bullets and load do great at 200 yards, with a cool barrel.

 

[JimGnitecki]

Hmm. My Pedersoli's thick (1" octagonal) and heavy barrel never gets beyond " a bit warm", never hot.

Jim G