Revolver powder cycle success?

Talk about the AR15 style rifles chambered in 450 Bushmaster.

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Re: Revolver powder cycle success?

Postby Reiska » Wed Aug 26, 2020 2:44 am

It appears this LilGun gives velocities 2400 FPS, or so?
Too much for pistol bullets?
Maybe the LilGun does not differ too much from N110?
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Re: Revolver powder cycle success?

Postby Hoot » Wed Aug 26, 2020 3:46 am

Reiska wrote:It appears this LilGun gives velocities 2400 FPS, or so?
Too much for pistol bullets?
Maybe the LilGun does not differ too much from N110?


I have used both Lil Gun and N110 powders and you are correct, they perform very similarly.

Forget the "Pistol Bullet" concern. I've shot just about every .451-.452 bullet available for this caliber. They hold up just fine. My only caveat is to avoid plated jacket bullets. Their copper plating is foil thin and can tear at 450b velocities, throwing shards downrange. I have a couple of them embedded in my chrony. Look at this burn rate chart:

Relative Burn Rates

Stick to numbers 54-73 for jacketed and monolithic copper bullets, with the lower numbers for lighter bullets and the upper numbers for heavier bullets and you'll be best served. You may see some members using faster powders for cast boolits and sub-sonic recipes. They are a different animal. If you are using jacketed or monolithic copper bullets, Those are not for you!

As already noted, consider reading the front of the Hornady reloading manual. It goes into detail about what is happening inside a cartridge during combustion.

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Re: Revolver powder cycle success?

Postby Reiska » Sun Aug 30, 2020 1:25 am

There are things I disagree.
Revolver powder 3N37 appears to give hit points close to N120. Obviously high velocity.
Pistol Powder N310 gives much lower velocities, subsonic or ultrasonic.
To use such powders, you have to know what you are doing.
And they do not reload an AR.

Regarding "pistol bullets".
Manufactureres give some velocity ranges, at least if asked.
But is velocity essential, or possibly acceleration?
If the latter is dominating, you can get much higher velocities from a 16 inch barrel, in comparison to a 6 inch barrel, and the bullets will still hold.

I have experience with some plated bullets working fine with normal velocities in 45-70, but not in 9,3*62.
If thin-skinned bullets work with 45-70, some of them may work in 450B (?).
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Re: Revolver powder cycle success?

Postby Bmt85 » Sun Aug 30, 2020 9:00 am

Most pistol bullets have thicker jackets, and are usually a harder alloy, so they can tolerate higher velocities and higher spin rates. They do have limits, though. I seem to remember a member on here that could blow up pistol FMJ's because he was running higher charge weights and he had a faster twist rate. I think 1:16. I would think if you're blowing up pistol FMJ's or seeing excessive copper fouling, you're running them too fast. If not, then you should be fine, as long as you are not seeing any pressure signs.

Plated bullets have a much thinner, and softer "coating". Doesn't take much to scrap it off. They are usually listed at a much lower velocity than jacketed bullets. With 45-70 there seems to be 3 different power levels; old school low pressure type loads, modern medium pressure loads, and stout loads that should only be shot in certain firearms. The plated bullets I have seen are rated around for low pressure (lower speeds and spin rate). Now, the plated .458 bullets should work for the 450B, because they are heavier then what is typically ran in the 450B, so they will run at lower velocities. Plus, the 450B usually has a slower twist rate. Should be able to size them down and run at middle to high end of loads for 450B, and they should still hold together, while still being able to cycle the action. As long as you are using the right powder.

I wouldn't think acceleration (initial acceleration of the projectile when fired) would be an issue for us, unless maybe you're trying to run a plated pistol bullet at 60,000 psi. It would be an experiment all it's own, because you have other factors at play.
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Re: Revolver powder cycle success?

Postby plant_one » Sun Aug 30, 2020 9:40 am

the big risk of using the wrong pistol bullet in the 450 bushmaster is the base of the bullet over expanding due to the pressure and basically sealing itself into the walls of the barrel and potentially causing some very dangerous pressure spikes.


for example, the hornady 250 gr XTP #45200, its not designed to be used past 45 colt pressures. as such its highly at risk for the above mentioned issue - base deformation of the bullet on firing causing a potentially unsafe pressure spike. hornady tech support specifically cautions that being a legit concern with this peticular bullet in any rifle application above those pressures.



modern bullets are often VERY specifically engineered for optimum performance in a specific range of usage, as such one can get in a real pickle when used outside of those design limitations. there can be a little wiggle room, but we have to understand those differences or face the consequences.


the colt runs at 14,000-15,900 PSI, 45-70 is only a 28,000 PSI rated cartridge in its standard format (yes i know theres 40k CUP high pressure stuff for the ruger #1, etc but i'm discussing standard SAAMI stuff). our bushmaster is running upwards of 38,500 PSI.
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Re: Revolver powder cycle success?

Postby s4s4u » Sun Aug 30, 2020 1:42 pm

the colt runs at 14,000-15,900 PSI


While this is true for "cowboy" loads, there is a "Ruger Only" level that runs @ 30k PSI and many of us run the 250 XTP at that max, about 1.4k FPS from a handgun, without issue. I personally know a guy who is running them in his 460 S&W Encore pistol @ 2k+ FPS and getting fantastic results on deer. They do tend to "over-expand" as he calls it, but they drop DRT upon impact most of the time. I plan to give them a try in my 450BM when I get her done. Will work up slowly of course.
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Re: Revolver powder cycle success?

Postby kermit hunter » Tue Sep 08, 2020 8:50 pm

My2 cents
I'm a relative newb in the reloading world (8yrs)
I have done some experimental loads for different calibers with some success and alot of failures. It always leads me back to the basics and firm published data! I hope that you have taken heed to posts from other seasoned members no one likes to see accidents happen. Reload responsibly please
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Re: Revolver powder cycle success?

Postby kermit hunter » Tue Sep 08, 2020 9:13 pm

Please reload responsibly and stick to published data
No one likes to see accidents
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Re: Revolver powder cycle success?

Postby OVERKILL » Mon May 17, 2021 9:36 pm

The 454 Casull runs at quite a bit higher pressures than the 450 Bushmaster. You cannot extrapolate data between the 2.
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Re: Revolver powder cycle success?

Postby Texas Sheepdawg » Thu May 20, 2021 3:50 am

OVERKILL wrote:The 454 Casull runs at quite a bit higher pressures than the 450 Bushmaster. You cannot extrapolate data between the 2.


SAAMI Specs indicates the 454 Casull at 65,000 psi (450 MPa) to be precise. That’s almost twice the PSI of the 450 Bushmaster. (38,500PSI).
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