The SAAMI pressure for .450 Bushmaster is 38,500 psi for operating in an AR. With that big a case in an AR platform it is simply a matter of bolt thrust. However, this should not be an issue in a bolt rifle, which should easily be able to operate at 50,000 psi, vastly improving the performance. Has anyone developed any loads for the 450 Bushmaster in the a bolt rifle?

Good hunting!

I actually built 7 450 Bushs last year on Mausers 91 and 98 for hog hunting.
Everyone just uses standard loads though; it kills with big holes.
If I wanted to work up loads, I recommend doing it like anything else; watch the primers, bolt lift, and marks on the case head, and primary extraction.

My own AR15 load is 34 gr of H110 and a 300gr. XTP for around 1900 fps in 20" barrel. It's a mildly compressed load.

I'm not sure what more I could want.

Technically speaking though, H110 might be slow for a pistol powder but it's still plenty fast compared to rifle powder. I'm not sure I'd want to load a faster powder in a rifle...and I don't know if there's enough case capacity to handle a slower rifle powder.

At some point, the limitations are limitations.

In any number of cases, what critter really isn't manageable with 300 grains at 1900? Grizzly maybe? Bison? Heck, if it's 300 grains of hardcast gas checked...it will work there too, just as the the .45-70 has done 100+ years earlier.

I kinda stopped trying when my handload cut a 1" group at 100 yards. Eh, job done. Mov'n on.

Buy a 458 WM load it up or down as you wish.

I use Lil'gun and a 300 grn Hawk spitzer.
2150 fps from a 16" ruger american.

Thank you each for the responses.

My curiosity was in exploring the potential range of capabilities of the .450 Bushmaster (easy to load down to heavy .45 Colt or .454 levels but the other end?) (I've taken many deer with a heavy .45 Colt load in a Marlin lever rifle as well as revolver). For example, many published reloading manuals offer three sections of data for the venerable 45-70; one for older trapdoor-tyoe rifles, one for strong modern lever rifles, and another separate set of data for bolt guns and falling blocks such as the Ruger No. 1.

Regarding the .458, oddball regulations in a number of states require short, straight cartridges, hence the .450 Bushmaster and .350 Legend.

Good hunting!

Steve

https://youtu.be/LW0_cu73ZoY

Watch this video. Jeff was right. I have a 250gr bullet going 2500fps with absolutely no sign of pressure.

Steve
I have very similar results as The back 40.
2100-2200 fps with a 300 grain bullet is in the mid 45/70 ,444 Marlin and 405 Winchester territory and that's saying something.
My rifle is that same Ruger 16" and I stopped before I hit pressure signs.
It's one of the few currently new cartridges that I have been impressed with. I shoot the Speer Deep Curl 300 grain hp and its bonded so it holds together very well.

Yes, I have one. It’s a Ruger American ranch rifle with a stupid muzzle brake. I bought it from my friend BPESteve, who is a member here as well. He couldn’t resist it, because it’s so ridiculous. Found it kicked a little more than he liked, and I bought it, also because it’s incredibly stupid, and I like recoil more than he does. We are a pair of dimwits. Put the rifle is fun in an insipid way. It’s also surprisingly accurate with factory, Hornady ammunition.

I haven’t developed any loads for it yet, but will be trying some soon. I’m sure my AR enabler, Steve, will be along and chime in about a few things he tried.

quote:

We are a pair of dimwits.

Hey, I resemble that remark!

Ok, neither of you are dimwits. I know some dimwits.
However you do not need to "work up" loads for a 450 Bush. You just load, and hunt with them. Another 100 fps or another .5 MOA doesn't matter with those. Of course, if you are shooting an AR, then do not try to change it; you will shear the lugs off.

Tom makes a good point: the Bushmaster kills with big holes.
But Steve, I know what you are getting at. For example, the 6.5 Grendel was designed for the AR platform and most of the published data I have seen max out at AR pressure limits. A bolt gun could safely take quite a bit more.
Hornady acknowledged the difference when it published data for the 6MM ARC, one set specifically for gas guns and another set specifically for bolt guns at a meaningful increase in pressure.

https://www.hornady.com/assets...as-58-105gr-data.pdf
https://www.hornady.com/assets...ata/6mm-arc-bolt.pdf

Kinda the same old story----don't try to make it into something that isn't!

Hip

quote:

Originally posted by dpcd:
Ok, neither of you are dimwits. I know some dimwits.
However you do not need to "work up" loads for a 450 Bush. You just load, and hunt with them. Another 100 fps or another .5 MOA doesn't matter with those. Of course, if you are shooting an AR, then do not try to change it; you will shear the lugs off.

Or better yet, throw it in a lake and get a real Rifle.

It is a good round for up to 200 yards; big hole in the barrel, which I like. For deer and hogs; not a Cape buffalo rifle. Not an all round rifle for sure. But it will keel, as they say on the knife making show.
Trust me, it is a real rifle, or I would not touch them, and I build a lot of them; bolt actions of course.