Want to duplicate 5.56 Nato w/ civilian parts

[Rscout6945]

I am trying to duplicate the 5.56mm Nato/M855 round for my AR-15 using civilian parts.  The specs call for a 62 grain FMJ bullet at 3100 fps out of a 1 in 7 twist 20" barrel.  

The best bullet I can find is the speer 62 grain FMJ and casings are not a problem but the powder is.

I would like something as close as possible but if there is a powder that burns a little cleaner I will try it.  Any suggestions, Thanks.

[Wlscott]

M855 is the military's designation for a cartrige with a SS109 projectile.  The SS109 projectile is a 62 grain bullet with steel penetrator (Not Armor Peircing!).

These projectiles can be bought individually from outfits like Cheaper than Dirt every once in a while.  

Brass is either Lake City Arsenal, WCC, etc.

Primers....I don't know.

Powder is a spherical type.  I have heard BLC2 is very close to, if not the same powder used in development of the 5.56mm round.  H335 should also be very close.  

Hope this helps.

[Larry Gibson]

Rscout6945

"I am trying to duplicate the 5.56mm Nato/M855 round for my AR-15 using civilian parts.  The specs call for a 62 grain FMJ bullet at 3100 fps out of a 1 in 7 twist 20" barrel.  

The best bullet I can find is the speer 62 grain FMJ and casings are not a problem but the powder is.

I would like something as close as possible but if there is a powder that burns a little cleaner I will try it.  Any suggestions, Thanks.[/quote]"

I have chronographed (Oehler 35P) several different lots of M855 through my Colt HB Comp with 1-9 twist, a Colt HB with 1-7 twist and several M16A2s.  The actual velocity at 15' is closer to 3150 to 3180 fps.  The only powder I found to duplicate this safely is AA 2460.  I use 26.5 gr in LC88 cases and WSR primers with both 69 gr MKs and pulled M855 green tip bullets.  Velocity runs 3150 to 3185 fps.  Accuracy is excellent as is functioning.  Many manuals do not list that much but Lymans does.  I have been using that load for over 10 years without any problems.  As always start lower and work up with your componants.

Larry Gibson

[PA-Joe]

IMI & Wideners all carry the ss109 62 grain steel core fmj point. Wideners also has some lead core Russian stuff that works.