405 grain .450 Bushmaster powders

[KyleM]

I recently built myself a .450 Bushmaster AR, 18" Bear Creek upper. I've been reloading and casting for about 11 years now and recently got into powder coating cast bullets. I found a post on another forum that I of course can't find now of someone using 27.0 grains of Lil"Gun behind a 405gr bullet I believe velocity was around 1550fps from a 16" barrel. So I gave this load a try, Lee 405gr Hollow Base that I use for my .45-70 Sharps, air cooled and sized to .452" with a lee push through sizing die, then powder coated in Eastwood Ford Light Blue 20 minutes at 400 degrees. Then sized again in the same die. Loaded with a fairly heavy crimp just past the last lube groove.

I shot ten rounds as a test today with no signs of over pressure, the gun cycled flawlessly, accuracy was a good as I can do offhand at 25 yards, recoil did not seem as heavy as Hornady Black factory ammo. I was too lazy to drag out my chronograph.

Now here is my question. For Powders I have a fair amount of Lil'Gun, H110, and a ton of IMR4198 because I shoot a lot of cast .45-70 and IMR4198 is my go to powder for .45-70. My question is does anyone here have any suitable 405gr loads with H110 or IMR4198 that will reliably cycle an AR? Thanks in advance for any advice.

[Texas Sheepdawg]

Watching with extreme interest.

[Hoot]

Looking at QuickLoad, try starting with 32.5 IMR4198 and work up in half grain increments. No, I don't shoot cast boolits or any bullets more than 325gr but QuickLoad says you're safe going that route. It may take a few half grain increments before it cycles reliably but its summer and better safe than sorry, hence the 32.5gr starting point.

Let us know if you go that route and how it works out for you, and for goodness sake, take the chrony with you. No point driving while blind.

BTW, Welcome Aboard!

Hoot

[KyleM]

Thanks for the reply, I will give that a try and take the chronograph along. I will update with my results.

[KyleM]

Still no update on this. I recently started experimenting with a 230gr piece coated bullet and haven’t gotten back to the 405. I built this rifle as a plunked/range toy and i think the 230 will be more fun to shoot. I’ll save the 405’s for my .45-70’s for now.