Just found this thread. Data going into a permanent archive of mine. Golden. Thanks OP.

Five years later you're still helping people....

This is a gold mine.  Wish I would have found it days ago - would have saved me a lot of wall head banging.  

Definitely going to help me pick a rifle.  

Didn't read it all in depth, but scanned it all.  

I'm not seeing a effective range chart for the xm193.  Am I missing it somewhere?

Thanks again!

The generally accepted threshold for reliable frag from M193 is 2700fps

To you and everyone else, you're welcome. I'm glad this thread is still being helpful to people here.

I didn't get around to M193 charts immediately and then life got in the way, but the data is still useful if the companies haven't changed the loadings. 2700fps is the threshold for reliable frag with M193. I still wouldn't want to be hit with it at 1000fps though so there is that

Looking at the data from the tests, there's quite a spread in muzzle velocity between all the varieties of "M193". In other words, there is no "standard" that companies use to make a product and call it M193 from a practical standpoint. There is definitely a .Mil standard, but industry wise it's all over the map.

If I had to rebuild my entire collection today I probably wouldn't buy any barrels under 12.5" if that means anything to you.

That is interesting.  
In large part due to this thread, I settled on 77gr IMI being my "SHTF" ammo (back during salad days when Midway had it cheap) and 12.5" being the shortest I go in 5.56 (16" and 12.5").  I turned my 10.5" 5.56 barrel into a semi-full time .22LR weapon and switched over to .300blk for short barrel stuff.

I hunt whitetails with an 8" .300BLK pistol. I've taken two 4x4's (8pt) that dressed over 170LB with 110gr TAC-TX. It's suppressor ready and lives in my truck (locked to the back seat) outside of hunting season, with quite a few mags for parties.

I don't have a 10.5" barrel on an AR in 5.56 currently, only 11.5" and up. I wish a couple of the 11.5's I built were 12.5's because of my ammo testing, but I don't want to do barrel swaps on all of them just for an inch.

I settled on Black Hills 77gr TMK and 62gr Fusion MSR and have cases of it stocked from the salad days. I also have some cases of Mk318 MOD 1 I got a deal on for "visual 2nds" straight from the factory. Those cost me...wait for it...$225/K. That was a stellar hook up while I had it.

Your choice of 77gr IMI is a good one. Almost wished I would have stocked some but that was during the time I was swinging deals on the TMK and MSR. I do have a couple K of pulled 77gr SMK bullets from either American Reloading or RMR. I'll get loads worked up at some point. The 77 SMK bullet is great in a general purpose round or precision round in the right gun.

Nice info. 12.5” is pretty efficient.

I know this is an old thread, but being as Type A as I am I love this s**t.  Thank you.

This data is awesome, but I suspect that the velocity data from the 12.5 is a little misleading based on other tests I have seen.  That 12.5 is obviously a *fast* barrel for it's length.  Chrome vs nitride, rifling differences etc etc.  Stuff like chamber differences and port sizes can cause the same barrel from the same manufacturer to have repeatable velocity differences.  All that said, I do think 12.5 is the sweet spot velocity efficiency.


Just an example of a more apples to apples comparison would be triarc data on their track 2 barrels which shows pretty consistent 40-60 fps increases between 11.5 and 12.5. nice, but the 100+ fps this test implies with some rounds.

Necroposting, but I'd love to see some of these brands tested again. I can confidently say I've been using PMC's M193 clone for a couple years now and never noticed velocity issues like you're seeing in these tests. It shot 2890 from a 13.9" Criterion and 3140 from an 18" Faxon. Maybe they got their shit together after 2017?

Does adding a suppressor equate to adding barrel length.
IOW Would a 8.5" barrel with a 6" suppressor equate to the same velocities as a (8.5+6=) 14.5" barreled rifle?

You will see probably 20-30 fps at most, but never the equivalent of the same overall length barrel.

I always come back to this thread every couple months. Would love to see this done with .300 blackout.

I consolidated to a 16 and 20 inch. This thread is making me build a 12.5 and buy a K can so I can John Wick shit.

DD MK18 - 10.3" - B&T Rotex IIA => 2208 FPS
Adcor Bear (GI) - 10.5" - B&T Rotex V => 2336 FPS
KAC SR15 - 11.5" - B&T Rotex IIA => 2339 FPS
DD V4s - 11.5" - Surefire RC2 => 2299 FPS

Measures taken with Magnetospeed v3.
GGG .223 HPBT 77gr

Yep. You may get an additional 1-1.5% velocity gain with a suppressor.

Glad I could help you spend your money

Several years on I still consider 12.5 to be the best .5. Heck, in most situations it beats a 16.

I'm late to the party (again). Just discovered this terriffic thread, thanks to @bfoosh06. Thanks for the link.

Thanks a million to @Eagle_19er for expending the time, effort and expense to compile this information. It's just what I was looking for.
It's now 2024. I can't believe I missed it all these years.