Bullet Disintegration

[jfjohn77]

I'm curious if there is any published information available as to the Max RPM a given bullet has to kept under before disintegration will start to occur? Do the bullet manufacturers have this info? Or is this something found through trial and error?

 

[STOMP442]

Not all bullets are created or constructed equal. Totally depends on what you are doing with them and what you are shooting them out of. My only experiences with bullets coming apart has been with Hornady 6.5 147 ELD-M and the 7mm 180 ELD-M. I know for a fact that both of these bullets do not like to be pushed hard or even moderately hard.

 

[D-4297]

^^^^^^ What he said . I shot next to a guy at the SWN a couple years ago , and watched several of his last shots in the final relay disintegrate about half-way to the target during the Mid-Range .
It was a .308 , and he said a Hornady ELD-M .

 

[243winxb]

Post # 4. "there are numerous contributing factors for jacket failure including barrel length, twist rate, bore dimensions, land configuration/geometry, bullet velocity, bullet bearing surface length, and probably a few more ."

This is how i see it. Plus condition of the barrel causing damage to the jacket.
https://forum.accurateshooter.com/threads/berger-bullet-failure-test.2481280/


https://forum.accurateshooter.com/threads/bullet-rpm-range-worth-knowing.4103845/ See post 4.

 

[M14AMU]

Sixty years ago in Manitou Springs Colorado I watched a riflesmith named Ormsby blow up .22 caliber bullets in flight using a .308 Win case necked down to .224 diameter. He couldn't get on paper and he was wondering what was going on? I told him I was watching them blow up about 60 yards after leaving the barrel looking through my spotting scope.

 

[PhilKeil]

The wrong bullet in my son's 22 243 AI and they turn to dust at about 50 yards.

 

[jackieschmidt]

Several years ago, Gary Walters had a new 1-14 twist (supposedly), barrel chambered in 22PPC Short, shooting 52 grn Match Bullets At 3600 fps.

He could not get it on paper. None of the bullets made it to the target. We finally checked the twist with a cleaning rod, and it appeared to be a 7 1/2.

Krieger miss marked the barrel. I believe they gave him a new blank and reimbursed him for the chambering.

You could do the math on how fast that bullet was spinning.

 

[Stumpy1]

345,600 RPM -now, what do I win?

 

[swd]

There’s just too many variables that affect bullet blow up. From rifling type, depth and number of grooves. Bore condition. Lapped barrel or not. How hot the barrel is and on and on.
The little grey puffs are kinda fun to see, lol…

 

[jelenko]

Hornady tech said to keep 223 75HPBT's under 280K
Sierra tech said to keep 223 69HPBT's under 260K.

But, as mentioned, condition of the barrel [especially the throat] has a significant effect.

 

[clowdis]

I had Hornady 88ELDM's blowing up so I called Hornady and asked their tech about what was the maximun RPM that bullet would take. His reply was 290,000 RPM max. I was running them in a 6 1/2 twist barrel that was spinning them at about 325,000 so his information seemed correct.

 

[jk80]

Years ago I was loading hornady 50 gr sx in a 222. They were great and thought they'd be outstanding in my 220 swift. Not so much! They wouldn't make it to the target at 100 yards. Talked to hornady about it and was told to keep them under 3500 fps. Later boxed of them had a small note stating that enclosed.

 

[jackieschmidt]

345,600 RPM -now, what do I win?

Poof!
just a gray haze at 50 yards.

 

[Idaho-Lefty]

130 and 140 grain, ELD-M's Work GREAT,.. in,. a 6.5,.. CREEDMOOR !
LOL !

 

[mikecr]

A long time ago I defined Krpm limit for reported VLD(original jacket) blowups and this led to 310Krpm for 22cal down to 290Krpm by 30cal.
The trick is that my limit is based on the CORRECT SL standard twist for the bullet.
At that twist, and applying the energy to reach the Krpm limit, original VLDs would begin failing.
Other bullets, like SMKs, could go another ~10Krpm, and I imagine this is inline with revised 'target' VLDs.

Krpm =(720*MV/twist)/1000
Cal adjusted Krpm limit at correct twist for bullet =(0.308-BulletDia)*238.095+290
Velocity limit at correct twist =1.38889*KrpmLimit*Twist

When Berger tested VLD failures they came to the conclusion that it was the customer's fault -every time.
We were applying conditions to cause too much heat to bullet jackets.
I didn't like that answer, but Berger was right, and there was nothing wrong with the original VLD (now hunting VLD). A rational person following a good plan will never blowup bullets (any).

 

[searcher]

If you look at the bullet manufacturer websites, they typically list the maximum recommended velocity for each bullet. The faster the twist, the sooner they will come apart at/before reaching those velocities, as a rule.

 

[JSH]

 

[JSH]

Don’t recall where I got that

 

[ebb]

Time to change to a Barnes.

 

[C.E.Smith043]

12 twist Savage
22-250 with 40gr Vmax come apart at about 4120 fps. Right at about the 80 yard line