Ammunition performance question

[panzer0170]

Ah. I think I have read this backwards;

'Distance till the round DROPS to 2700fps'.

Now it makes much more sense.

[karl]

Thanks, guys.

Erick, I read that other post to see if you had looked at the rounds I was asking about.

Also there is the MC X-Tac in both 55gr, and 62 gr penetrator. The 62 grain from reviews I've seen is considered to be fairly significantly mofre accurate than M855, and considerably less money. Also the Wolf 62 gr that you were so happy with, IIRC that also has the penetrator.

[Erick]

May 31, 2016 11:23:37 GMT -5 karl said:

Thanks, guys.

Erick, I read that other post to see if you had looked at the rounds I was asking about.

Also there is the MC X-Tac in both 55gr, and 62 gr penetrator. The 62 grain from reviews I've seen is considered to be fairly significantly more accurate than M855, and considerably less money. Also the Wolf 62 gr that you were so happy with, IIRC that also has the penetrator.

PMC XTac 62 gr is still a green tip M855 style round... It is however more accurate than most other Green tip style rounds yes.
But still not an economy round for stashing deep IMO or good effects on body.

The 62 gr Wolf MC does not have the penetrator.
You can get it in both FMJ and HP both of which are 1.5 MOA rounds in my experience which for the price is incredibly good I think.

[panzer0170]

Question;

Why, if M855 is so tonk, and it's relatively expensive, does the military pay for it rather than some other contract from a better manufacturer?

[Erick]

Jun 1, 2016 6:14:12 GMT -5 panzer0170 said:

Question;

Why, if M855 is so tonk, and it's relatively expensive, does the military pay for it rather than some other contract from a better manufacturer?

Because they go by requirements.

In the 1980s when the SS109 (which became the M855) was developed by FN herstal for the Minimi (later to become the M249 SAW) the requirement was to penetrate a Warsaw pact Flak jacket (or helmet the history is  a bit fuzzy to me) at 1000m (or some such distance) from the Minimi's barrel.

This requirement did not exist for the M193 (aka 55gr 5.56mm)

This became codified in STANAG and the NATO M855 5.56mm rounds current must still meet that requirement as beraucracies are very slow to adapt to chnaging environment and old requirements are very difficult to get dropped ( after all who wants to be the bureaucrat that "lowered" the standard for an estalbished performance parameter ?? Thats not how successful Gov't  careers are made)

How useful is the requirement that has shaped the M855 for our purposes? Not very since none of us have that requirements set so I buy ammo that for our purpose performs better at a lower price point.

A historical example to illustrate this point is the 30-06. The requirement for it was to be able to kill a cavalry horse at 1000 m.
Is that something that any of us need to be able to do with our standard carry rifle ?
No.

Hence the dearth of 30-06 military rifles in the military and among civilian 1st Defenders.

Now understand this discussion is for the basic issue/carry rifle for your fire team that forms the basis of your fire power in a generalized environment .......and it doesnt make the M855 round useless... for example if you have Intel that you are up against a team of raiders wearing Body Armor rated IIIA or below then I would break out the M855 as a mission specific load.

(Also there is nothing wrong having a guy around who when mission requires who carries a distinct and heavier, perhaps even much heavier caliber than the rest of the team.
This can be in order to present the enemy with additional tactical challenges which give you extra tactical options and/or which may deny him some tactical options.
But that is  a separate conversation about specialist rifles, non standard environment for engagement distances, DMR ammo, Sniper ammo, or as heavy caliber to punch thru some types of cover or Armor w/ 30-06 AP, 50 BMG etc etc etc etc)

PS: Disclosure: I worked half a decade in US Joint Force material acquisitions.

[panzer0170]

I figured the short answer would be 'bureaucracy', I wondered mostly at what level it was tied up; Given the US's history of totally fucking off STANAG requirements and process, doing their own thing and then waiting for everyone else to change what their doing to suit, and the near two decades of relatively fast paced warfighting, with heavy SF involvement, I would have expected somewhat of a faster 'Well fuck this' approach. It's one of the things that I quite LIKE about the way the US Mil seems to work, compared to our own. (IE there seems to be more troop driven requirements at least in SOME areas, than there are 'big idea' driven requirements...)

Didn't know the .30-06 fact, but that's a fun/interesting bit of history, and I totally agree about having a guy/guys with a different specialist loadout. Being too generic is just as bad as being too specialist.

[karl]

IIRC the requirements for the M855 were to penetrate a Soviet steel helmet at 800m. Which not only required the SS109 bullet, but the very long M856 800m tracer. Most 5.56 ammunition shoots best from a 1:8 barrel (which is why you'll find your match guns in this), but the long tracer shoots best from a 1:6, so the military split the difference and went with 1:7.


I believe another criteria was the European standards, the M193 "Meat Axe" was too damaging and violated The Hague Agreement (which the US didn't sign onto that part of it, though for some reason we still handcuff our forces). I still don't understand this idea that when you are killing a nation's people and burning their country down, that there are "rules" for the humane killing and burning......

But no matter, this isn't the military. Seems we need to equip for our mission and what we need to accomplish. It'd be nice if the 5.56 had something that could shoot through brick and cement block, but it doesn't look like you get that at less than .30 Cal at this point (perhaps the mid-6mm rounds as well)). So, penetrate steel doors, car doors and windshield glass, and tear someone up on the other side.

[Erick]

Jun 5, 2016 9:33:32 GMT -5 karl said:

IIRC the requirements for the M855 were to penetrate a Soviet steel helmet at 800m. Which not only required the SS109 bullet, but the very long M856 800m tracer. Most 5.56 ammunition shoots best from a 1:8 barrel (which is why you'll find your match guns in this), but the long tracer shoots best from a 1:6, so the military split the difference and went with 1:7.


I believe another criteria was the European standards, the M193 "Meat Axe" was too damaging and violated The Hague Agreement (which the US didn't sign onto that part of it, though for some reason we still handcuff our forces). I still don't understand this idea that when you are killing a nation's people and burning their country down, that there are "rules" for the humane killing and burning......

But no matter, this isn't the military. Seems we need to equip for our mission and what we need to accomplish. It'd be nice if the 5.56 had something that could shoot through brick and cement block, but it doesn't look like you get that at less than .30 Cal at this point (perhaps the mid-6mm rounds as well)). So, penetrate steel doors, car doors and windshield glass, and tear someone up on the other side.

This is very close..
But the original compromise twist was 1 in 9 which all the data show works equally well for M855 62 gr and M193.

It is true the tracer drove the 1 in 7 adaption because the tracer did not work well with 1 in 9.

The common 1 in 8 you find is because people perceive it as  a compromise fit between 62 gr and 55 gr ammo.
However 1 in 9 was already the compromise twist, with not just 55 gr but even 62 gr M855 working better in 1 in 9 than in 1 in 7.(!)

The only reason 1 in 7 has flooded the market is due to peoples misguided obsession with MILSPEC which in this case causes them to go with a twist that wears faster and is also less effective for the vast majority of ammo on the market in other words a lose-lose.

However due to market issue most of my barrels are 1 in 7 because thats what quality CHF barrels are most often made in these days.
Ruger (in its SR556 series offerings) and a few others being  a notable and laudable exception.


Be that all as it may this discussion is fairly academic and most ammo will shoot reasonably well out of most common twists for our minute of man purposes.. the big exception at the greater (by Infantry standards) distances being (X)M855 which shoots poorly out all of all common twists but least poorly out of 1 in 7 than the others.

However this is all theory as individual barrel variations are greatly responsibly for the actual accuracies observed .
This is why a quality 1 in 7 barrel might shoot a M193 better at time than a low quality 1 in 9

[karl]

Mine actually shoots M193 well. Typically 2.5 MOA @ 200 yds (longest range I have to shoot at). It's probably better than that, and me that's not quite up to snuff.

BCM has some nice 16" uppers with 1:8 twists I was thinking of getting. They seem to shoot everything well, and should I want the heavier bulle4ts, can handle them where the 1:9 typically can't. Plus, it was cool to have the longer barrel (and I think it's sexier), when I was younger, but reducing weight sounds nice as I get older and fartier, and 16" seem the sweet spot where you don't lose too much over the 20" in performance, and you take a bigger drop going to 14.5".

I have a shitload of M193, so I'll probably stick with the old Meat Axe for now, and spend the $$ on the new upper.