450 Corvette

Talk about the AR15 style rifles chambered in 450 Bushmaster.

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Re: 450 Corvette

Postby 68maro » Fri Feb 12, 2016 1:58 pm

I'm ok with that idea. Let me mull it over a bit. I really appreciate it. I have a lot of fast stuff from guns to cars lol. One of my favorites is a 6.5 leopard. 6.5x300wsm throwing pills fast lol.
The car doesn't run bad either.
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Re: 450 Corvette

Postby MarkCO » Wed Aug 03, 2016 6:55 pm

Stealthshooter wrote:Im surprised this thread is so far back. You guys been shooting any 300's out of the conversions? If so how is the velocity and accuracy doing?


I have run from 300 to 400 so far. Remember, my .450C is an 18" 1:12 twist, so a slightly different beast. This winter I plan to do more in the 400-500 grain range. I am getting decent accuracy using AA2200 with 350s and a stab crimp. I am going slow and working slow while I am adjusting gas and mass. I have blown up a few sub 300 grain .45 caliber pistol bullets I think. At 100 yards, they did not make round holes, but they did at 50. So far, it seems like the Beartooth bullets I am going to have to stick with, or the 300 grain Barnes ML bullets. I have not gotten good enough groups yet, but in talking to a Barnes tech, that might be crimp. I know I can swage .458 bullets, but I really want to avoid giving the Socom fanboys any fodder. I am at an easy 400 fps improvement over the 16" .450BM with the same bullets, but I am not quite done yet.

I plan on shooting some pigs before I take on elk and other large game to make sure the terminal performance is there. As long as I use solids, I am fine, but if I use a jacketed, that will be a whole other level of testing.
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Re: 450 Corvette

Postby MarkCO » Sat Nov 04, 2017 7:08 pm

I have my .450 Corvette running pretty good now. I used a Heavy (.308 carbine) buffer with a JP .308 flatwire spring and it is running really well in terms of brass life, recoil and accuracy. I shot some pigs, and a Coyote with it so far and the performance has been very good.
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Re: 450 Corvette

Postby Al in Mi » Sun Nov 05, 2017 9:36 am

Might have to pick your brain after seasons over, like I need another project with 4 on the burners now!!
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Re: 450 Corvette

Postby Bmt85 » Sun Nov 05, 2017 2:26 pm

I thought the 450 Corvette was a 450B with a rifle length gas system. So I'm curious, why use 308 buffer and spring?

Anyways, does anyone have more test results for the 450 Corvette?
I'm actually doing my own version of this. I custom ordered a BHW 20" barrel; Semi bull profile, Target crown, 1:18 twist, Caudle 3-land polygonal rifling, with a rifle length gas system. Kind of hoping it works out.
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Re: 450 Corvette

Postby MarkCO » Tue Nov 07, 2017 8:10 am

A .308 carbine buffer is about the same weight as a rifle buffer. Flat wire springs are smoother operation. Just testing, with the loads I am running, this turned out to be the best tune.
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Re: 450 Corvette

Postby Bmt85 » Wed Nov 08, 2017 8:19 pm

Ok
I have a question about loading for a rifle length gas system. I know you have a bit different set up than the converted 20" uppers, but I would like to know if your running slower powders than what is used in normal 450B loadings.
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Re: 450 Corvette

Postby plant_one » Wed Nov 08, 2017 9:10 pm

MarkCO wrote:A .308 carbine buffer is about the same weight as a rifle buffer. Flat wire springs are smoother operation. Just testing, with the loads I am running, this turned out to be the best tune.


i would recommend being REAL careful about which 308 carbine buffer you use - they are not all created equal.

the DPMS carbine buffer for the LR308 rifles is significantly shorter than a standard AR-15 buffer, due to the extended length of the BCG itself. the two are NOT interchangeable.

additionally its only 3oz, so its not the same weight as a standard rifle buffer.



this is one of the things that annoys the hell out of me about the AR-308 platform - there not even a close version of "mil spec" for the bigger ar's
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Re: 450 Corvette

Postby MarkCO » Sat Nov 25, 2017 9:16 pm

Bmt85 wrote:Ok
I have a question about loading for a rifle length gas system. I know you have a bit different set up than the converted 20" uppers, but I would like to know if your running slower powders than what is used in normal 450B loadings.


Yes, I am using slower powders. Basically on the faster side of the .223 powders seems to be the sweet spot for my set-up.
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Re: 450 Corvette

Postby Earnhardt » Sun Dec 31, 2017 10:12 pm

Are these 450 Corvette conversions still being made?
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