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Mk262 mod1

 

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Mk262 Different Barrel lengths

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The old hotness Hornady 5.56 75gr TAP T2

 

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.223 75gr TAP 

 

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The new hotness Black Hills 5.56 77gr Tipped Matchking

 

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On 6/6/2018 at 3:16 AM, Vicious_CB said:

M855A1 in ballistics gel with velocity and pressure

 

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The problem here is that "M855A1" isn't really one unified round. It's very likely, given those results, that the rounds tested were early spirals loaded with 28grs WC846 - a hot load indeed! More recent spirals run a much more sedate load of 26.1 grains SMP-842, an entirely different propellant with a slower burn curve.

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Its says the Avg powder load is 25.8gr using an unknown powder for the A1(look under "Parameters - Physical on test sheet) so I don't think this is one of the earlier hot rod loads. I didnt know they changed the burn rate since the burn rate is supposed to be optimized for 14.5" barrels, I thought the switch to SMP was because it was a much more temp stable powder. 

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35 minutes ago, Vicious_CB said:

Its says the Avg powder load is 25.8gr using an unknown powder for the A1(look under "Parameters - Physical on test sheet) so I don't think this is one of the earlier hot rod loads. I didnt know they changed the burn rate since the burn rate is supposed to be optimized for 14.5" barrels, I thought the switch to SMP was because it was a much more temp stable powder. 

 

At this point, I'm not sure I can say for sure. Given what I knew a year ago, I would have said SMP was more temperature stable - but since then I've been told it's not as temperature stable. I have no idea. There are enough variations that I don't think I can say anything for sure, right now. I do know the current state of M855A1 is not good, because they are running the machines so fast the ammo isn't anywhere near as consistent as it should be.

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2 hours ago, Sturgeon said:

 

The problem here is that "M855A1" isn't really one unified round. It's very likely, given those results, that the rounds tested were early spirals loaded with 28grs WC846 - a hot load indeed! More recent spirals run a much more sedate load of 26.1 grains SMP-842, an entirely different propellant with a slower burn curve.

 

I reread your post, isnt WC 846 a 7.62 NATO powder? I guess that would explain alot! Or did you mean WC 844 which is the current green tip propellant? But like you said it probably doesnt matter since its all probably different by now. If they really wanted to push it they would use WCR 845 a double base powder they use to hot rod M995.

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5 minutes ago, Vicious_CB said:

 

I reread your post, isnt WC 846 a 7.62 NATO powder? I guess that would explain alot! Or did you mean WC 844 which is the current green tip propellant? But like you said it probably doesnt matter since its all probably different by now. If they really wanted to push it they would use WCR 845 a double base powder they use to hot rod M995.

 

IIRC it's WC 844, my typos notwithstanding.

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Im pretty impressed with the new round. Current production issues aside or things like feedramp wear which are overblown by the 6.X mafia, there's no need for a caliber change. I just wish the round isn't so damn expensive. They should have made a cheaper ballistically equivalent training round or something. 

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On 6/12/2018 at 8:43 PM, Vicious_CB said:

Im pretty impressed with the new round. Current production issues aside or things like feedramp wear which are overblown by the 6.X mafia, there's no need for a caliber change. I just wish the round isn't so damn expensive. They should have made a cheaper ballistically equivalent training round or something. 

 

Yes, but if you do make a cheaper training round, they'll just adopt that one over the more expensive round for general issue

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