Powder/load for 77gr SMK

[GregJ]

I'm trying to work up a load for my AR. It's a RRA with a Predator Pursuit upper. I recently had it rebarreled with a Krieger 1:7.7 20" SS bull barrel. It really like Federal Gold Match 77gr and can shoot around 1/2 MOA @ 100yds if I do my part.

I've tried TAC, Varget, and RE15 with the 77gr, but according to Sierra's load data, TAC and AA 2520 are the only powders that get close to the velocity of the FGM (2720 fps). My results with 23.7gr of TAC and OAL of 2.250 (measured at ogive with comparator) have been ok, but not stellar. Brass and bullets were weighed and sorted, all LC headstamp, CCI 400 primers. I did notice from my last outing cratered primers. Need to investigate into this some more, may try some CCI 450.

Anyway, looking for advice on accurate load for 100yd target work with this setup.

[DWFAN]

I think Sierra's data is pretty conservative. I think I was close to 2720fps or over with RE-15, but would have to check my spreadsheet at home.

[pjb45]

23.4 grains of VV133 produces 2877 fps for 69 SMK out of my JP barrels. I have never tried 77 SMK since I can get the job done with 69gr SMK.

VV is a very clean powder. VV140 has a good following also.

[Kasteel]

I loaded 25.0 grains of TAC under 75 gr. BTHP bulk bullets from Wideners, which I heard were of Prvi Partizan manufacture. I got 2707 fps (measured over an Ohler chronograph) out of an 18" barrel. Accuracy was just under 1" at 100 yards from a Black Hole Weaponry barrel.

24.3 grains of TAC under a 77 gr. SMK gave me .75" groups out of my 16" LaRue. Average velocity was 2541. Standard deviation was 18 fps. Used Lake City primed cases from a contractor pull down. That load is .5 grains under the max Ramshot listed on their site for 5.56 NATO loads.

[Alaskapopo]

My load of 22.3 grains of N135 outruns federal match in all the guns I have tried it in and its more accurate and has less variance and standard deviation.

Lake City Brass

Federal Match or Remington Match primers

77 grian Sierra SMK.

Pat

[ClutchUSMC]

I load over sierra's max with RE-15, I'm not saying you should but it works well for me.

[sierra77mk]

For me a 77gr bullet is for use at 350 yds plus. I can find a 55gr bullet at .75-1 MOA for 100yd work much cheaper. Even with a 1:7 I'd use HDY 68's

But the secret to tightening my groups with 68's & 77's was the Remington 7 1/2 Match primer. I wish I had found them when I was shooting highpower. I might have made Master sooner instead of parking at expert for so long.

All the powders you listed are what the heavy bullets like RE-15 Varget TAC

This is a good reference you should bookmark.

http://www.njhighpower.com/cart_tech.htm

[GregJ]

Thanks guys, good info.

sierra77mk, great link, that one will be printed and go into the binder.

Thanks again

[GregJ]

I have some 69 gr SMK and 75gr Hornadys, I need to do some more testing with these. Thanks!!

[Dan Sierpina]

If you can get some AR Comp, try that too. It's supposed to be a temperature insensitive powder with a burn rate very similar to RL15.