The vast majority of heavy OTMs seem to be .223. Why don’t more companies make 5.56 variants? My basic understanding of ballistics would make me think that if a shooter was trying to push distance and possibly fight wind, a higher pressure loading would increase muzzle velocity and achieve those effects better. Magtechs 262 clone is one of the few that seems like it’s moving quickly. Why not more?
ETA - meant IMI’s 262 clone, not Magtech.
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I don’t think the magtech 77gr is available anymore.
I have a couple hundred of S&B 5.56 77gr OTM to try out.
Looks like their own projectile and not a SMK like the IMI.
A bit faster than the IMI on paper anyway.
If a factory doesn’t make their own precision bullets they have to buy from an outside source (i.e., Hornady, Sierra, Berger, Barnes, Lapua, etc.), cutting into profit margin and depending on an outside source.
The market sells cargo ship loads of cheap blaster ball (including steel case). People who want match-grade typically load their own.
I have tons of 5.56mm pressured OTM.
I made it. 
I mean… What are we using to differentiate 223 vs 556? Pressure? Velocity?
I think it really boils down to: good 556 is harder to make than it looks like. Go on youtube and watch the “Cloning mk262” reloading series where a guy tries dozens of very popular powders and you realize how hard it really is to get close to factory 262 much less beat it. Lastly when making truly hot loads its hard for a large manufacturer to know what guns/chambers these are going into. As reloaders we get to work up loads for the exact barrel they going in. A manufacture just doesn’t have that. Recently while shooting my buddy had Berger factory 73 gr that normally perform very well for him start popping primers bad once it got over 100*. It’s not as easy as it seems. To avoid all these issues a commercial reloader will just find a lower and safer node.
IIRC I got 77gr reloads from freedom munitions and they made like 2450 FPS from my 14.5. I had a load that makes 2700 FPS FROM A 14.5 in my load development book but I know NO commercial maker would send that out to anyone.
Step one for true 5.56mm is crimped GI primers (typically a CCI 450 or a #34 military).
Western powders publishes their 5.56mm load data:
I prefer Varget for 77s, and that data comes from trading between competitive highpower rifle shooters.
Minor point, but isn’t #41 the small rifle primer?
Dang. Thought I’d fixed that before posting. :eek:
@Sinister: I agree that a primer crimp would help a lot. I regularly use 450 or #41 primers so that component isn’t the issue, but I dont know how to crimp my own primers.
Would you mind sharing your load with Varget? I just got a jug and worked up to 24.5 gr under a 77SMK and had low/no pressure signs. Haven’t checked for a Node yet, and wondering what is popular. If you dont want to post the load publicly a PM will do.
I just checked 3 different factory loads I have at home, never noting that one was 556 vs 223. All were 223 loads. Norma, Outback, Lapua all 223. I guess only Black Hills can sack up and make great 556 ammo. I guess that’s why BH dominates contracts, as they should.
Federal still makes XM556SBCT3 62 grain bonded and T556TNB1 62 grain OTM which was made and sold for a hot minute. I have a few boxes left for BS testing back in the day.
PB
I shoot 24 – I use an H3 buffer for mid-lengths and an XH for 20-inch rifles (with collapsing stocks).
I used to use 24.5 but it crunches powder when you seat a 77.
In no particular order,
Shooters use 5.56 ammo in .223 bolt guns or suspect chambers locking them up, dropping primers, calling to complain. I think this is less than cited but still a factor.
Shooter knowledge or ability isn’t enough to produce the gain. Normal .223 pressures and velocities are fine for those.
Shooters stretching loads out and seeing the gains are probably reloading.
Faster isn’t always better. Bullets may prefer a certain velocity window. (Even when present, may be small enough to escape knowledge/ability.)
When we talk about a “5.56” variant, are we talking about just speed, or other stuff too?
This. We load our OTMs slower than we could because the accuracy is a little better for us.
I generally stay away from 5.56 MAX loads, but I do exceed .223 Rem pressure loads. I’m looking for a balance of velocity, accuracy, and long brass life.
I load my 77 grain OTM’s with 24.2 grains of TAC (LC brass, CCI 450 primers, 2.250" COAL). Book 5.56 MAX is 24.8 of TAC. Book .223 Rem MAX is 23.4 of TAC.
In other news, I recently got 500 new Starline 5.56 cases, so I will be working up some new loads with those. Surprisingly I found the new Starline cases only 1 grain on average heavier than my average LC brass cases.
I haven’t done any water capacity tests with these new cases until I have some fired Starline brass. Too hot out right now for this old man. I think I’ll wait until fall.
That’s what I do too. Lately though, I’ve been running current production CC 41s. And it seems like no matter how much I reduce the load, the brass is still roasted… swipes, popped primers, etc. I literally pick up my brass and toss it all into the recycle bucket. ZERO chance of getting more use out of it.
Is that with H322 exclusively or with any powders your currently using? What are your velocities looking like with this new lot of CCI 41’s??
I haven’t really insulted H322 with those annoying ass primers. I’ve shot TAC and IMR 3031. Backed the 3031 off a half grain (from my Wolf SRM load) and still get swipes and a popped primer with 69 gr bullets only going 2850 out of a 20" bolt gun. 2850 is a decent velocity, but shouldn’t be popping primers.
The factory Norma 69s were over 2900 fps for reference.
Mark, you think CCI 41’s have gotten significantly hotter in the past few years? That might explain my increasing velocity woes and wrecked primer pockets.
I never tried them before so I have no history/frame of reference. There’s a guy here, tommeboy, who claimed there’s reports of 41s are popping on other forums.
For what it’s worth, chasing an extra 50-75 fps isn’t worth the potential problems. Do the wind on the difference and you will see 95% of folks most likely can’t work the wind difference let alone the accuracy of the “system”
It just worked out this way for accuracy, my bolt gun is 23.6 8208 with the 77 TMK and the LMT 20" is 23.2. The semi is at mag length and bolt is longer, no pressure and at 3 loads, annealed each time. Both FGMM 205’s
I always laugh at folks to dumb to find 5.56 online and will come in the shop asking for it and if we don’t have it say “I only shoot 5.56 in my gun” -well guess your not shooting then are you? Keep in mind these folks are shooting at 25 yards.