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Thread: M855A1 article

  1. #51
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    Quote Originally Posted by Arctic1 View Post
    Seriously dude, I think every second post you make is a DI vs Piston comment. You don't like piston guns, we get it. Have you even shot a piston AR platform?

    And why is the mechanism cycling the action relevant in regards to the effectiveness of the new round?

    Can we please keep this thread about the M855A1?
    Yes I have shot Piston AR's and a SCAR-L, but I think you misunderstood my comment.

    In no way is it a DI vs Piston etc, Doc brought up earlier that this is a good LMG round(which are generally pistons) but not a good carbine round(which in america are DI).

    a few issues are excessive pressures, reduced barrel life, and excessive fouling.

    that is why I asked what rifle the good reports were for. I was in no way trying to discuss the merits of DI or Pistons systems but more how this ammo may have an effect on the performance of the rifle which is what this is all about anyways. Jason mentioned no reports of gas port wearing down, and no reports of early bolt breakage. Bolt breakage could be different between piston and DI guns so I was just trying to get an idea of what rifles are reporting good results and what rifles are not experiencing the "Supposed" negatives of this round.

    ETA: NVM Jason, I obviously am blind and missed the big M4 in your post.
    Last edited by sinlessorrow; 04-08-12 at 22:18.

  2. #52
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    So, with no sarcasm, the M855A1 is (at best) performing on-par with Mk318/SOST at several times the price?

    Thank you, Jason, for the update. However, I'm still not seeing an upside to the new round over the pre-existing Mk318/SOST round that the Corps uses.

    With the additional chamber pressures, the toll taken on weapons may not be seen for some time.

  3. #53
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    I talk to the ammo guys for the Marine Corps they provided the following on current year ammo costs.

    US military pays $.40 a round for AO59 Ctg, 5.56mm Ball M855 10/Clip; $.56 a round for AA53 Ctg, 5.56mm Ball Special Match LR MK 262 Mod 0; $.57 a round for AB49 Ctg, 5.56mm Ball MK318 MOD 0; $.68 a round for AB57 Ctg, 5.56mm M855A1 EPR

  4. #54
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    Quote Originally Posted by R0N View Post
    I talk to the ammo guys for the Marine Corps they provided the following on current year ammo costs.

    US military pays $.40 a round for AO59 Ctg, 5.56mm Ball M855 10/Clip; $.56 a round for AA53 Ctg, 5.56mm Ball Special Match LR MK 262 Mod 0; $.57 a round for AB49 Ctg, 5.56mm Ball MK318 MOD 0; $.68 a round for AB57 Ctg, 5.56mm M855A1 EPR
    While the $0.11 difference between MK 318 and M855A1 doesn't seem that much to us, it adds up in the quantities of ammunition that the Army buys each year. Add onto that the hundred million plus dollars spent developing and promoting this round, and it's substantial.

    More like mind blowing...

  5. #55
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    Posted the following in a concurrent M855A1 thread in response to an assertion that M855A1 is not an improvement over M855:

    -------------------------------------------------------------------------

    While M855A1 was absolutely, definitely not the best choice, and does have numerous issues and deficiencies, one cannot be intellectually and objectively serious and claim that it is not a more effective round than regular M855. I may be wrong but I don't think I've seen Doc make that claim; although he has pointed out deficiencies which do in fact exist.

    The marked improvement in accuracy alone qualifies M855A1 as "better." It's so far been a consistent ~2 MOA round from what I've personally experienced with it, while some batches of M8555 were as high as 5 MOA right around the time we made the switch. This seems to be due to the fact that the steel portion of the old M855 was hard to center in the projectile, introducing wobble and other problems. The construction of A1 mitigates this.

    As far as the effects of higher pressure on the weapon system's lifecycle, I cannot comment. I only used the A1 for a period of around 6 Months, so clearly not enough time to observe any kind of a trend. For what it's worth, during that 6 month period, I observed 10-15 M4's (100% suppressed operation) shoot around 2.5K rounds each with no issues. But, again, this is not enough to prove or disprove anything. Logic should tell you that the higher pressures are certainly not a good thing.

    When looking at this thing, we need to keep our heads screwed on straight and not go too extreme one way or another. M855A1 is better than what we had, but absolutely not as good as what we could have had for less money. In my view, that's the best way to characterize it.
    -------------------------------------------------------------------------

  6. #56
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    Quote Originally Posted by Beat Trash View Post
    While the $0.11 difference between MK 318 and M855A1 doesn't seem that much to us, it adds up in the quantities of ammunition that the Army buys each year. Add onto that the hundred million plus dollars spent developing and promoting this round, and it's substantial.

    More like mind blowing...
    Yes, with an unknown quantity of that initial R&D cost being spent to pay off a private patent owner who HAD ALREADY DEVELOPED the design that the Army 'invented' as the M855A1. This was after years of testing and millions and millions spent.

    My point is the Corps is paying less per round for something that already existed in US commercial supply chains and is delivering similar performance without ANY negative side effects. There is no need to pay even a fraction of a cent more per round for M855A1. Any improvement that M855A1 has over M855 was already realized with Mk318 SOST.

  7. #57
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    According to what I've read, comparing M855A1 to Mk318:

    M855A1:
    - Better BC and trajectory (better shape factor and higher MV) than Mk318. This of course means a little different POI compared to M855, specially noticed at longer ranges and with optics.
    - Higher retained energy.
    - Higher chamber (and gas port) pressure.
    - Better steel plate penetration than Mk318. Perceivable difference, since you have the steel penetrator and higher retained energy.
    - Little better cinder block penetration than Mk318, not as marked as steel.

    Mk318:
    - The POI is also a little different from M855.
    - Better performance after windshield penetration, due to weight retention and little deflection of the original path.
    - Pressure basically the same as M855 green tip.
    - Better common intermediate barrier penetration than M855, due to higher weight retention and relatively hard rear all copper shaft.

    I have no idea of their comparative gel effects, it would be nice to see them compared at different impact velocities, and after passing some intermediate barries too.

  8. #58
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    Quote Originally Posted by TiroFijo View Post
    According to what I've read, comparing M855A1 to Mk318:

    M855A1:
    - Better BC and trajectory (better shape factor and higher MV) than Mk318. This of course means a little different POI compared to M855, specially noticed at longer ranges and with optics.
    - Higher retained energy.
    - Higher chamber (and gas port) pressure.
    - Better steel plate penetration than Mk318. Perceivable difference, since you have the steel penetrator and higher retained energy.
    - Little better cinder block penetration than Mk318, not as marked as steel.

    Mk318:
    - The POI is also a little different from M855.
    - Better performance after windshield penetration, due to weight retention and little deflection of the original path.
    - Pressure basically the same as M855 green tip.
    - Better common intermediate barrier penetration than M855, due to higher weight retention and relatively hard rear all copper shaft.

    I have no idea of their comparative gel effects, it would be nice to see them compared at different impact velocities, and after passing some intermediate barries too.
    That's about what I've heard as well.

    I'll also add that Doc has already said the 'Optimized Brown Tip' round eclipses the M855A1 and Mk318 in most aspects aside from cost. Surely an economy of scale could have been used to mitigate that issue. That is a round that was already in the chain. I'm no expert, though.
    Last edited by BufordTJustice; 04-09-12 at 13:53.

  9. #59
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    Some facts from ends-users employing the 70gr 'brown-tip'.

    1) Broken bolt lugs while using this round.

    2) Broken hydraulic buffer while using this round.

  10. #60
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    Quote Originally Posted by Jason Falla View Post
    Some facts from ends-users employing the 70gr 'brown-tip'.

    1) Broken bolt lugs while using this round.

    2) Broken hydraulic buffer while using this round.
    Interesting, I wonder what pressures brown tip is running at? As for number 2, from what Ive heard, tend to break under normal use just fine on their own.
    Last edited by vicious_cb; 04-09-12 at 20:39.

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