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| Peace through superior firepower  |
I'm a big fan of M193 ammunition for defensive use in the AR. Most of my ARs are the ubiquitous 16" length. I have a coupe of 14.5" M4 barrelled ARs with pinned/welded flash hiders. Recently, someone in the forum mentioned M193 being loaded to lower velocities. M193 is rated at 3240 fps out of 20" barrels twisted 1:7. For years, I have seen M193 tested on youtube, and in 16" barrels, the velocity hovers at around 3000 fps, sometimes approaching 3100 fps, depending upon ambient air temperature, height above sea level, and the inevitable variations among rifles and ammunition lots. I took a look around and I'm not sure I found the answer, but I think I have. First, here's are videos from Mrgunsgear and Paul Harrell, both of which compare M193 and M855 velocities (and terminal ballistic effect) in ARs with various length barrels. Their findings are what I would expect. And now, here's a video from a gent I don't know. It seems that ammo manufacturers are stating 55 grains at 3240 fps, but the velocity testing is done in 24" barrel bolt action rifles. On top of that, from what I can tell, the ammo he is testing- Remington and Fiocchi is not even designated as 5.56mm ammo it's marked as .223. Now, have I found the reason people are saying they are finding that M193 is downloaded these days, or have I missed something? It's difficult to imagine Federal or IMI putting out ammunition marked as M193, but which is loaded to lower velocity than stated. I have some IMI, but for the most part, I use the Federal M193 in my ARs. | ||
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| Green grass and high tides  |
Remember the chatter (even here) about the banning of M855 a few short years ago. That put me in favor of it. Having something, is better than having nothing. I have always enjoyed variety myself. It's all good!  "Practice like you want to play in the game" | |||
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| Member |
XM193 works better at putting a serious pause in a hog @ 100 meters and in than the green tip. I hunt with a 14.5” Colt SOCOM barrel. I don’t have measurements type of equipment but I can attest to what XM193 does to hogs and coyotes at around 100 yards so there must still be enough velocity out of an M4 barrel to allow the 193 to do what it does inside a critter. I see no need for a 20” barrel on the AR platform. If I want to put down a hog in it’s shadow at 200 yards and beyond then I’m using a different caliber anyway. If it’s a shtf zombie scenario then I’m not giving up my position until the horde is close enough to give it a go with the head shots so again I don’t need a 20” anchor to lug around.. | |||
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Wait, what? |
Also, factor in that you lose as much as 400fps at 100 yards with M193 from a 20” barrel. That is a substantial difference on target. It makes you wonder if non-military manufacturers are throttling down to keep the M193 from achieving the devastating yaw and fragment effect the round is known to have at higher velocity. “Remember to get vaccinated or a vaccinated person might get sick from a virus they got vaccinated against because you’re not vaccinated.” - author unknown | |||
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| Freethinker |
As you point out there are many variables that affect the ammunition we can shoot in our AR-15s, and one of them is that. Some of my own velocity test results with averages: August 2020, JP Enterprises JP-15, 18 inch barrel: 19 rounds Federal AE223, 55 grain 223 Remington: 3019 fps.* 10 rounds Lake City M193, 55 grain 5.56 NATO: 3247 fps. 10 rounds Lake City M855, 62 grain 5.56 NATO: 3082 fps. August 2014, Colt LE6920, 16" barrel: 10 rounds Lake City M193, 55 grain 5.56 NATO: 3039 fps. March 2014, Tikka T3, 20" barrel: 10 rounds Lake City M855, 62 grain 5.56 NATO: 3065. I usually rotate through my ammunition by date and shoot the older first, so I can’t say when the different ammunition types and lots were manufactured. * Although I can shoot 5.56 ammunition with my T3 that’s marked for 223 Remington with no signs of excessive pressure, I usually use Federal AE223 for training with that gun. Federal AE223 might be confused with M193, though, because of similar packaging and bullet weight. The one obvious difference in appearance other than the head stamps is that the 223 cases have the annealing discoloration polished off as usually does other commercial ammunition. ► 6.4/93.6 | |||
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"Member" |
I bought 1k rounds of Fiocchi once for a large match, I only cared about price as I was only going to use it on the closer range stages. Testing it I could tell it was a weaker loading right away. You didn't need a chronograph, you could feel and hear the difference between it and other ammo. _____________________________________________________ Sliced bread, the greatest thing since the 1911. | |||
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| Freethinker |
Now that this thread has gotten me thinking about the question, is M193 used by the US military at all any more? If not, and despite the fact that manufacturers still make what they label and what appears to be that load, how concerned would they really be about maintaining some specification that isn’t subject to a major contract requirement? Long ago Evan Marshall stated in a post on another forum (IIRC) that ammunition manufacturers load for pressure standards, not velocity. This is something that’s been discussed here about precision rifle ammunition. At least a couple of us shooters have found that even a quality product like Hornady match ammo can have large velocity variations among lots. I may have to do some more experimenting and testing with ammunition that I believe was made more recently than my old stocks. But testing for one variable while controlling for all the others can be difficult in itself. The Colt 6920 that I used for the velocity measurements posted above doesn’t have the same barrel as was used then. Although some environmental conditions like air temperature and station altitude don’t have much effect on short distance velocities, the temperature of the ammunition itself does affect things. That’s why I try to keep it from being unusually hot or cold when I test it myself. Interesting question. ► 6.4/93.6 | |||
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Member |
I wouldn't have guessed that it would take 35-40 rounds (esp. green tip) to chew through Mr. Harrell's concrete block setup. ____________________ | |||
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| Member |
Same reduced result with PMC bronze.  | |||
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Glorious SPAM! |
Here is some velocity info taken back in 2013 with Federal XM193: Colt 14.5” 1/12 twist: XM193 1) 2875.0 -28.8 2) 2894.0 -9.8 3) 2884.0 -19.8 4) 2911.0 7.2 5) 2955.0 51.2 High: 2955.0 Low: 2875.0 E.S.: 80.0 Ave.: 2903.8 S.D.: 31.6 Colt 20” 1/7 twist: XM193 1) 3153.0 28.0 2) 3123.0 -2.0 3) 3114.0 -11.0 4) 3119.0 -6.0 5) 3116.0 -9.0 High: 3153.0 Low: 3114.0 E.S.: 39.0 Ave.: 3125.0 S.D.: 16.0 24” Stainless 1/9 twist: (forgot the manufacturer) XM193 1) 3329.0 -15.4 2) 3332.0 -12.4 3) 3355.0 10.6 4) 3349.0 4.6 5) 3357.0 12.6 High: 3357.0 Low: 3329.0 E.S.: 28.0 Ave.: 3344.4 S.D.: 13.1 | |||
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| Member |
the thing i love about M193 is: using the same load for HD and training / practice cost is not prohibitive of doing both -- load it -- shoot it -- rinse and repeat if i was a LE sharpshooter, distance shooter, or needed a higher tech bullet for hunting that would be a different matter but for GP uses : M193 is a great loading to have a big stock of -------------------------------------------- Proverbs 27:17 - As iron sharpens iron, so one man sharpens another. | |||
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fugitive from reality |
The only 'real' M193 is\was manufactured at the Lake City ammunition plant by whomever holds the contract to operate the plant. XM193 is M193 that failed to pass some part of military QA\QC. Real M193 was never loaded in NATO cross marked brass. Everyone else's M193 is a 55gr bullet running at at an advertised velocity of 3,250 FPS out of a 20" barrel. Most of it is probably running a little bit slower because there is no standard to be held to. Unless they have been recalled there are still DOD M16A1's out there being used by LEO agancies on a kind of lend lease basis. I have no idea where they get their ammo, but AFAIK the federal military hasn't used 55gr 5.56 in over a decade. _____________________________ 'I'm pretty fly for a white guy'. | |||
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| Freethinker |
Thanks for that discussion, SgtGold. ► 6.4/93.6 | |||
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semi-reformed sailor |
A071(M193-55grain fmj) was still in use when I retired in 2011 and there was enough of it to be used for training for 25-30 years forward. It can be used in the M16A2-forward for training in short ranges like the USCG uses (1000inch/27.7 yards) targets because they can’t use or get access to Known Distance Ranges& at that distance the ballistics is good enough. There was a lot of A071/M193 in storage or prepositioned when A059/M855 was given the go ahead for use in everything but the origina M16 & A1. I’m sure regular Army and Marine units ran thru their stuff on site within a year and replaced it in the 90’s when they went to the A2,A3 &M4 but huge numbers of USANG units and CG units still field A2s. As to police units issued M16s, my dept got ten of them and a pallet of M855 with it…dunno why but that’s the ammo they gave us. (The guns came from FtBragg and maybe that’s all the ammo they had on hand) this was back in 2007-8. I retired in ‘17 and I’m sure the rifles were turned into the Army as we never used them-the chief didn’t want full auto rifles given to us lowly street cops. (The swat guys got new semi/full auto m4s on a grant later) "Violence, naked force, has settled more issues in history than has any other factor.” Robert A. Heinlein “You may beat me, but you will never win.” sigmonkey-2020 “A single round of buckshot to the torso almost always results in an immediate change of behavior.” Chris Baker | |||
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Member |
Winchester is advertising their current Lake City M193 with a muzzle velocity of 3180 fps vs. 3240 fps. Is anyone aware if this ammunition is manufactured at a lower pressure or if the published specs more accurately reflect performance in < 20" barrels? Thanks.   | |||
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Member |
Can confirm. I recently shot some Federal XM193 in a Beretta AR70/90 and it was flawless. Ran a few mags of American Eagle M193 and it short-stroked at least once a mag. I've had the same issue with AE 147gr vs. Lawman 147gr when running in my B&T's. | |||
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| Sigless in Indiana  |
Can confirm that commercial 223 is tested in 24 or longer barrels. Many people with enough knowledge to be dangerous will punch those velocity numbers into a ballistics calculator and try to shoot at longer ranges (400 +) based on those velocity numbers. Usually with dismal results. A 16" rifle that is bleeding off pressure to cycle the action is a much different animal than a 24" bolt gun. 2900 FPS is usually a pretty safe starting point for commercial 55gr 223 from a 16" AR. | |||
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Member |
When I was in the Corps, we transitioned to the M855 from the 193. I can't remember what year that was but it was prior to 1990. We had to adjust the BZO on the rifle for the M855. We were told it was a couple hundred feet faster than the 193. I remember that it did change the rear sight setting from previous. It didn't take long and everything we shot was green tip so at least everything coming out of the ASP on Pendleton was pretty quick to burn through the old ammo and issue the green tip. | |||
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Member |
"Among a people generally corrupt, liberty cannot long exist." Edmund Burke | |||
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