RPM’s

[phil]

Anybody ever had a Ballistic Tip Hunting or AccuBond fly apart because of extreme RPM?
I haven’t.
may be using a faster twist than I intended soon and appears I could hit 320,000

Any concerns?

 

[JD338]

What caliber, twist and velocity are you talking?

JD338

 

[phil]

25 Sherman Max 1-8” 3400-3500fps. This velocity will be easy to attain with a 28”

Ive got a 7.25 tw barrel also, it’s the one I’m most concerned about. “only” 26in

 

[phil]

Surely someone has found the limit here…?

might have to check with all the experts on another forum.
I know they are quite plentiful on LRHF.!

 

[JD338]

I don't think you will have any issues with the AB, the maximum velocity is unlimited. The BT has a maximum velocity impact rating of 3200 fps. Nosler doesn't specify a rating for RPM.

JD338

 

[Ridge_Runner]

whats the formula to figure rpm's?

edit: looked it up , have ran 160 accubonds to 289k rpms

 

[Joec7651]

I’ve broke 300,000 rpm’s with .224 bullets without blow-ups. It’s surprising how well bullets stay together even at high rpm’s. A lapped, smooth bore helps immensely with bullet integrity. Any tear or imperfection imparted to the bullet jacket by lands and grooves causes bullet imbalance. Centrifugal force makes quick work of ANY imperfection in the jacket. Use a quality barrel and mid flight blow ups shouldn’t be an issue. You could also load a mono bullet to ease your mind a bit.

 

[TexasLife]

Construction has some to do with jackets departing. Average might be around 326,000-340,000?
formula for rpm's,
muzzle velocity x 12 / twist x 60 = rpm
3,500 x 12 / 7.25 x 60 = 347,568rpm
3,400 = 337,655rpm

Hope this helps?

 

[RL338]

I’ve broke 300,000 rpm’s with .224 bullets without blow-ups. It’s surprising how well bullets stay together even at high rpm’s. A lapped, smooth bore helps immensely with bullet integrity. Any tear or imperfection imparted to the bullet jacket by lands and grooves causes bullet imbalance. Centrifugal force makes quick work of ANY imperfection in the jacket. Use a quality barrel and mid flight blow ups shouldn’t be an issue. You could also load a mono bullet to ease your mind a bit.

Very well spoken.

 

[phil]

I’m going to attempt AB/BT first, though I have looked at Hammer and Badlands monos. May have to slow them a tad, hopefully not though.
Bartlein and Benchmark barrels.
Stay tuned

 

[Joec7651]

Well you’re running two of the best barrels made, so there’s that. I’ll be very surprised if you have any issues.

 

[frankm]

Something to ponder is shooting a heavier, higher BC bullet at a somewhat lower velocity. Drops won t change much and it could provide some “bullet blowup protection” if needed…. Just another angle…

 

[TexasLife]

With a 7.5 twist you max out around 3,500fps.

 

[phil]

Something to ponder is shooting a heavier, higher BC bullet at a somewhat lower velocity. Drops won t change much and it could provide some “bullet blowup protection” if needed…. Just another angle…

I wish they were made by nosler, while I’m wishing. 125 gr AB/BT
Got the twist and power, need the bullet!

 

[SJB358]

Surely someone has found the limit here…?

might have to check with all the experts on another forum.
I know they are quite plentiful on LRHF.!

I don't think you'll have any issue. I have blasted 120's out of the 1-8 Mashburn, 55's out of a 6 Creed with 1-7.5 and never had a problem with Ballistic Tips myself. Not sure if they reach the 320K but I bet with the 55's in the 6 Creed I was close.