Exceeding Plated Bullet Recommended Velocity

[WrongHanded]

I'm not intentionally trying to do this. But a 45-70 load I've been working on with a Berry's 350gr plated bullet may (have to double check chrono data) have exceeded the 1700fps max they list on their website.

Does anyone know what happens when a plated bullet is pushed too fast?

 

[Olon]

I've wondered this myself.

Check out @mcb 's reply here:
https://www.thehighroad.org/index.php?threads/44-magnum-question.868118/#post-11493200

 

[edwardware]

The safe failure would be stripping (skidding across) the rifling. This could lead to craptastic accuracy.

The not-so-safe failure would be blowing the core through the jacket, leaving the jacket as a bore obstruction. This could lead to that magical experience known as a Rapid Exothermic Spontaneous Disassembly, sometimes followed by a ceremonial Soiling of Undergarments.

 

[WrongHanded]

Thanks guys!

 

[jmorris]

They start coming apart, spewing lead if you have a target close enough to the muzzle to see.

Accuracy gets worse as well.

 

[MikeInOr]

They start coming apart, spewing lead if you have a target close enough to the muzzle to see.

Accuracy gets worse as well.

That is very cool to see what happens! I would have never guessed.



With a plated bullet there isn't really a jacket so it is hard to envision the thin copper plating being stripped and being left in the bore as a shell of the bullet??? I can see how this would build up a heavy layer of copper and lead causing the barrel to foul very quickly.

 

[Slamfire]

That is very cool to see what happens! I would have never guessed.



With a plated bullet there isn't really a jacket so it is hard to envision the thin copper plating being stripped and being left in the bore as a shell of the bullet??? I can see how this would build up a heavy layer of copper and lead causing the barrel to foul very quickly.

I would not be surprised to see a blue streak down range. I have seen that with jacketed bullets. I don't remember the distance but it seems to have been around 25 yards from the muzzle. And, in those instances, nothing hit the 200 yard target.

 

[mokin]

I loaded some ammunition for an M-1 Carbine with Berry's. When I think about it I thought they were 110 grain bullets at the time. We weren't hitting paper at 50 yards. I don't recall exactly how things transpired but I ended up shooting some over my chrony and found they were much higher velocity than what they should have been. I admit that I probably didn't start working up the load at the bottom of the published data because it seems like I tried that and the load didn't function the action. Anyway, I ended up working a load down to get reasonable accuracy and operate the firearm.

 

[WrongHanded]

Turns out only 1 of the 5 I put over the chrono was higher than 1700fps. That loads is not consistent anyway. Gonna have to seek some data for another powder that's more consistent. I've got 15 rounds of that load left, but I suspect they'll be okay.

 

[Eddietruett]

Simple Solution. Switch from Berrys to Missouri HyTek Coated. I've run them really hot, and heard of several people running them at 2000fps with no problems.

 

[jmorris]

With a plated bullet there isn't really a jacket so it is hard to envision the thin copper plating being stripped and being left in the bore as a shell of the bullet???

I have never seen that, just the plating breaking free of the lead, like the shell from a hard boiled egg.

I have also seen FMJ's come apart, like thin varmint bullets designed for slow twist 1-12 or 1-14 barrels pushed out of1-7 barrels, "poof", centrifugal force in action.

To keep the math simple lets look at the RPM of a bullet going 3000 feet per second out of a 1:14 twist barrel, 3000x720/14= 154,285 RPM. When we change that to 3000x720/7,for the 1:7 barrel its spinning at 308,571 RPM, well at least until it turns into dust upon exiting the barrel.

 

[forrest r]

Try putting a coat of Johnsen's paste wax on them.

 

[Toprudder]

IMHO, velocity is not the only factor. The bore of the gun can have a lot to do with it. A bore with rough machine marks and sharp edges to the lands can cause plating failure at lower velocity, where a smooth bore with polygonal rifling can probably get away with much higher than rated velocity.

Don't remember where I saw it, but there were some photos of targets where it was obvious that the plating had failed along the rifling groves, strips of the plating hanging off the bullets were leaving marks on the paper target.

 

[jmorris]

IMHO, velocity is not the only factor

It's not. I have seen evidence of plating fail at subsonic velocities. Crimp would be #1 on my list for messing them up and even if everything is perfect they just don't like gain twist barrels.

 

[mcb]

From another recent thread on Berry's I posted similar below, it's linked near the top of this thread too.

When you push Berry's too fast:

The blue arrows indicate places where the plating has peeled off the bullet and it sticking out.

Some riflings are harder on Berry's than others. The above bullet where fired in an XD-40 at ~960 fps. That same exact ammo going roughly the same velocity but fire in my S&W 610 revolver almost never had a peeling problem. The corners of the XD's rifling where sharp enough to make the problem worst. Over crimping Berry's can also cause or exacerbate this problem too. That is also from 10+ years ago and I believe Berry's bullet have also improved their plating process since I was shooting a lot of them back then in USPSA when metal prices pushed Montana Gold out of my price tolerance. I suspect I would not have the same issues with the newer Berry's bullets until I got them going a bit faster than 960 fps.

 

[rfwobbly]

With a plated bullet there isn't really a jacket so it is hard to envision the thin copper plating being stripped and being left in the bore as a shell of the bullet???

This is true. Due to the electroplating process itself, molecules of copper are individually bonded onto the lead core at the molecular level. It's not 2 separate parts, like the cup and core of a jacketed bullet.