Why aren’t there more OTMs in 5.56

[Wake27]

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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[One More Time]

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.

[sinister]

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.

[Eurodriver]

I have tons of 5.56mm pressured OTM.

I made it.

[turnburglar]

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.

[sinister]

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.

[mike_f]

...crimped GI primers (typically a CCI 450 or a #34 military).

Minor point, but isn't #41 the small rifle primer?

[sinister]

Minor point, but isn't #41 the small rifle primer?

Dang. Thought I'd fixed that before posting.

[turnburglar]

@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.

[Pappabear]

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