6mm 87-gr Vmax top speed ?

[hemiford]

Will this bullet withstand 4000 ft/s MV ?
I'm going to build a 6mm SAUM, with a long barrel, so I expect very high MV,
will this bullet survive the launch ?
I was also looking at the Berger 6mm 87-gr VLD Hunter, same question for that one.
I'm considering a 10 twist barrel, not 9 or 8 for this build.

 

[DUCKMAN11]

Buy 50 and try them. You are kinda in the death zone of rpms even with a 10tw and 4kfps

 

[Benchrest Braxton]

you are under 300krpm, typically this is not associated with blow ups. i'd consider going with a 237 bore over a 236 as well

 

[lancetkenyon]

With a 1:7" they will vaporize at about 3450fps.

 

[VinceMule]

V max and burgers may not give desired results as their base may cave in due to rotational torque during obturation. If you see issues, immediately try the 90 and 95g Nosler Ballistic tips, as their thick "solid base" resists the deformation due to rotational torque.

Hemiford, use a ballistic program and see what twist works with a 1.5 stabilization factor, and choose twist accordingly. Also, you may want a 1* leade angle vs 1.5* leade angle. Since you are talking V max, Make the throat dia .2440-.2445 as some lot numbers are running a .2435 dia on the shank, you do not want jacket material being scraped off in the throat which would spike pressure.

I know a guy here that is shooting the 55g,70g, Nosler ballistic tips on deer out of a 6 Gibbs at incredible speeds that I will not repeat, very slow twisted, 30" barrel.

 

[DSheetz]

VenceMule; So many people don't think about lead angles, and the effect they have on the bullet jacket, or that the spin affects the shape of the bullet base and the bearing surface, as do the explosive effects of the powder charge starting to launch the projectile. Good information and food for thought for those people that haven't been taught about it yet, most people just let their smith do that kind of thinking for them, and hope that they have learned it in school or by experience, or from their journeyman smith.

 

[hemiford]

OK thanks very much gents, more to think about. There is also the Absolute Hammer 87-gr,
that one needs an 8 twist though, but it would definitely stay together.

 

[VarmintBob]

It's not about velocity. The 87gr Vmax won't hold together over about 310,000 rpm. I've had them strike the ground at least 4 ft from the target at 100 yds when spun to around 315,000 rpm. It has the weakest jacket of any Vmax I have used.

 

[CA48]

87gr v max at 4K I feel like a 10-11 twist would be ideal.

This guy has sone experience with them.

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[Dhughes]

I have some friends running 87's out of 6 prc's, but they're only running around 3400, I think. I'm running the 95 grain tipped match kings out of my 6 saum at 3660. 20" barrel. It will hammer a coyote!

 

[wldcat]

I can't speak to high velocity but I do know the 87 grain vmax is stable in my 6br with a 1:12 tube. Haven't shot it past 650 but they stay within a Copenhagen can at 650, I think they shot in the .3's at 100

 

[Hugnot]

I am on my 2nd 6mm AI. A 10 twist should be optimum for the 87 VMax. I get just under 3500 fps from my 26 inch barrel. I blew up 87 VMax bullets at about the same velocity out of an 8 twist 6mm-06.

 

[Hugnot]

Running numbers for 12 twist:

 

[VinceMule]

Hugnot hit the nail on the head. An 11 twist should be dead nuts in the 6 Rem AI, but the 10 twist should also be adequate for the 95g Noslers and perhaps the 95g SST. 95g Noslers at 3500 is real world in the 6 Rem AI. In the 6 Rem AI, 4100 fps with the 70g Ballistic tips with 14 twist I have had and a 10 twist was 4000 on formed rem cases with Win 760, 26" barrels on all.