"Mexican match" 5.56

[M90A1]

Anyone here ever made some "Mexican match" ammo, using 62gr. OTM bullets to replace the greentips in M855? This was a popular way of making good 7.62 match ammo, using Sierra 168gr. MatchKings in M118, long before M852 was available.

If you've ever tried this, how did it work out?

[MegademiC]

Not exactly what your asking, but iirc markm reduced the charge and placed 77otm over m193 or m855 with great success. Hopefully he'll weigh in here. I should be quite accurate, as I think mil surplus ammo is well made, it just the crap bullets that are so inconsistent.

[T2C]

At what distance are you going to shoot the "Mexican Match"?

[M90A1]

At what distance are you going to shoot the "Mexican Match"?

Don't understand the relevance of the question, but 300-800 yards. I realize that any significant difference wouldn't show at really close range. With the old 7.62 ammo, enough difference from 200-1,000 yards was realized to make the effort worthwhile.

[markm]

I do this all the time for Defensive ammo. For precision ammo, I like to use Tula/Wolf primers (for much lower SDs). But for Hot 77gr OTM defensive loads, I like the crimped primer and don't care about single digit SDs. None the less, subbing an SMK for SS109 is going to yield monumental accuracy improvements.

[T2C]

Don't understand the relevance of the question, but 300-800 yards. I realize that any significant difference wouldn't show at really close range. With the old 7.62 ammo, enough difference from 200-1,000 yards was realized to make the effort worthwhile.

We use to shoot the old .30 caliber "Mexican Match" out to 600 yards. Expecting match accuracy beyond the 600 yard line without doing some work to the brass and ensuring powder charge consistency is optimistic.

Smaller caliber ammunition is less forgiving of variations in projectile quality and weight, consistent powder charges and bullet jump when shooting outside the medium distance range. I've shot out to 300 yards with half baked match 5.56mm ammunition. Once you start stretching out to 400 yards and beyond with a .223 projectile, more attention to detail is needed. It would be a good idea to drop the powder, trim the cases to the same length and reweigh each powder charge. I you want to shoot beyond 500 yards, I believe an 80g projectile is a solid investment.

I haven't had as much luck cutting corners with smaller caliber ammunition as much as with larger calibers and heavier projectiles. If you develop a recipe for a price point 5.56mm match cartridge that performs well out to 800 yards, please share it with us.

[Quick Stick]

What type of adjustment with powder are you making after the swap? What would be a safe starting load to work up from after the subbing in the m193 and/or in the m855?

[markm]

What type of adjustment with powder are you making after the swap? What would be a safe starting load to work up from after the subbing in the m193 and/or in the m855?

When I do this, I replace the powder and bullet. I'll sub in some XBR. I save the ball power for blaster 55 gr fmj bullets or something.

[Quick Stick]

Sounds good, I think I might give this a try. Thank you

[markm]

I use a press mounted bullet pulling die, then give the brass a light kiss with a VLD debur tool, replace the powder charge, seat the OTM, and put a light Factory Crimp on the round to ensure decent neck tension.

If it's XM193, I'll save the bullet and drop the powder charge at least one full grain... Then I'll put those components in used brass for blasting.