I need to push a 180g 30cal over 4000fps what are my options

[winmag]

Tell him to buy a 223wssm. he can break 4600fps with a 40gr bullet, and break 4100fps with a 50gr bullet, That satisifies some ''speed freaks'' but a 30 cal at 4k with a 180 is insane. Cool idea, but definately insane.
Keep us informed if he comes up with an idea of how to make it work. Like others have said, Im guessing Kirby is the only guy I can think of who may be able to give any insight to it even being in the rhelm of possiblity. Ive got my doubts, but it sure would be neat to see it achieved somehow.

 

[BobbyL]

I have a 30-338 LM IMP and its running the 180's at close to 3800 fps. I think with a little more barrel and some other improvements i might be able to get close. But thats a hard goal to hit.

I have messed with some CT varients that will be able to do what your asking though... If a 338 Snipe tac will run a 225 grain accubond at 3800 the 180 would be well over 4k. Shrink the cheytac case a little bit and neck down you shouldn't have any problem being able to do it. But i believe you may be running into the end of that bullets jacket strength if your pushing them that fast. May have to try a solid projectile or a slowed twist to correct that.

bobby

 

[ICANHITHIMMAN]

THis is great info guys thanks so much you have all helped.

 

[Pdvdh]

If a 338 Snipe tac will run a 225 grain accubond at 3800 the 180 would be well over 4k.

bobby

Dropping the bullet from 225gr to 180gr, would help the cause. But decreasing the caliber from .338 to .308 will hurt the cause (increase the difficulty). I calculate a 20% reduction in bullet weight (good), but 17% less surface area at the base of the bullet for the cartridge pressure to push against (bad).

Does anyone have knowledge of such an accomplishment? 4000 fps MV in .308 caliber with a 180 grain bullet? Even if not, it wouldn't necessarily mean it couldn't be done. Might only mean that no one believes the end product would have enough merit, advantage, or practicality, to invest in the cause.

Banded bullet technology should provide a big advantage by reducing bullet to bore friction/drag.

 

[davewilson]

as stated the rpm's are going to be the killer with a jacketed bullet. i'll bet a 130 barnes out of a RUM would be in the ball park. a 180 though, humm, that'll take some big medicine. i never had a gun that the barrel was worn out before i got it broke in!
where's that young fellow that had the 300 varminter with folk lore legend status on here a while back? now he was the "4000 man"

 

[ICANHITHIMMAN]

as stated the rpm's are going to be the killer with a jacketed bullet. i'll bet a 130 barnes out of a RUM would be in the ball park. a 180 though, humm, that'll take some big medicine. i never had a gun that the barrel was worn out before i got it broke in!
where's that young fellow that had the 300 varminter with folk lore legend status on here a while back? now he was the "4000 man"

Its funny you said BARNS the Father in law sent a whole buch of pic's and write ups to them following his experences with the 130g XLC coated. He is pussing them at 4000+ ( dont quote me have to check with him again) out of a 300 RUM sendero. But they dont make the bullet anymore so he has a limited supply.

He wants to up the BC so the bullet has to be bigger we where thinking 180g.

I will see if he has any digital pics of what that bullet does to a whitetail at 700 yards.

 

[BobbyL]

You may be best off running gs custom bullets trying to get something like this done. As far as barrel life goes i could build up one that would last close to if not more then 2000 rounds.

 

[Tyler Kemp]

Quickload has two huge 30 calibers, the 300 Pegasus and 300 RUMBO.

I have heard of the Pegasus but not the other. The Pegasus is pretty much a rimless 30-378 Weatherby. If you improved that to the max, and put a 40" (yeah that's long ) barrel on it...you may get sorta close.

I'll do some Quickload figuring when I'm on the other computer!

 

[Camshaft]

Pegasus is a beltless. 30/.378 weatherby. Rumbo is a .300 rum improved and shortnecked way be ackley specks

 

[Pdvdh]

QuickLoad have any programming intended for application of the new breed of banded bullets? I think not from what I've read. The load and pressure data for the banded bullets is a fair amount different than for conventional full caliber bullets, based on what I've read and understand.

 

[Tyler Kemp]

300 Pegasus Improved (theoretical, 145 grain case capacity)

40" barrel

173 grain GS Custom bullet seated .2" into the case neck.

70k psi max pressure

136.1 grains ADI AR 2218-4064 fps

129.6 grains Vihtavouri N570-4020 fps



So according to Quickload it can be done. Would be the edge of pressure assuming calculations are all correct. Also, 40" is a dang long barrel. If you're gonna do that, might as well bump it up to 46".

Velocities are well over 4100 fps...or you could reduce loads to just be at 4000 fps.

Either way it's not very feasible, but would be a neat project for some short term fame.

 

[Tyler Kemp]

Of course if 4000 fps isn't enough, you should be able to push the 86 grain Hornady pistol bullet over 5000 fps!

Nothing like 5000 ft lbs with something weighing less than an 87 grain Vmax.

 

[ICANHITHIMMAN]

I like where this whole thing is going. Thanks for racking your brain's guys this is great

 

[LouBoyd]

You could have Pac-Nor make a 36" 50 BMG 0.510" groove barrel with a 10" twist (a standard option) which could shoot 30 caliber bullets in sabots with up to 300 grains bullet plus sabot weight at 4000+ fps at 90% of SAAMI pressure with decent barrel life. Loads of around 260 grains of VV N560 (depending on sabot design and seating depth) would do the job. I expect most jacketed lead 30 cal bullets would just blow up at 288000 rpm but copper alloy solids should survive.

I haven't tried a fast twist 50 BMG but it sounds like a fun project. I've shot 55 grain 224 bullets at over 4250 FPS in sabots from a 10" twist 300 Win Mag. With the larger bore barrel life is much improved. Look at how the US Army gets 5500 FPS from the 120mm cannon on the Abrams tank. The projectile is only 27mm, but are fin stabilized.