Loaded up some rounds and hit the sand pits today, here are the results:

Bullet: Sierra 52 Gr BTHP Match
Brass: LC 91, fully prep
Primer: WSR
Powder: 26.0 W-748
       25.5 IMR 4895
OAL: 2.915"

Used a Bulls bag off Bronco hood, I got some good groups, all I have now is a Tasco 6x24 Tgt scope which seemed to do well, at least for now.

W-748
1st= .840"
2nd= .740
3rd= .475" (best)
Avg= .685

IMR 4895
1st= .740"
2nd= .985 (worst)
3rd= .700
4th= .695
Avg= .780

I think that if I can sit down at a bench and really get comfortable, the groups will be more consistant, .475 to .985 seems a little large does it not?

None the less, I am very pleased with the start of my load development for my Bushmaster Varminter, anyone else have one and want to share loads/results?

Very nice, but you forgot to post pics

Right now, mines is half way thru the first 120 rounds break in process. So far, I am getting groups from under 1/2" to 3/4" with the first sixty rounds. I would have shot more but I was getting tried from cleaning the damn thing.

AR 18,
What kind of scope set up are you using and what loads?

Bowhntr6pt, shoot a higher number of rounds per group and you will likely watch your group sizes approach your final average.


Won't have such a wide spread from say 1/2 inch for smallest group to 3/4 inch for largest group, approaching 10 shot groups will often display what's really going on.   I usually shoot 3-4 10 shot groups when testing a load then compare the average of all 4 groups against the groups.   The standard deviation for group size is what I'm looking for, at 5 shots it can seem like something is the matter because the average for the groups may not seem to mesh with when comparing it to the larger or smaller groups.



As for my own personal favorites, I like to use mild-medium charges of H322 or AA2015 with 40-55grn bullets.    I've found that it seems to burn a bit cooler than the IMR powders, next time you're at the range do a casual fast fire group of 10 shots(say all shots fired within 1 minute) and see how hot your barrel is.     Then compare it to something like a AA2015 load that was fired in a similar manner, my experience is that the barrel seems to be a bit cooler after the rounds have been fired for a similar amount of time.

4895 and 3031 were two real hot powders for me, and it's a pain to use the stuff in a powder throw.    AA2015, H322, and H335 run very nicely through a powder throw and I've had some wonderful groups with the stuff(40-55grain bullets being best from my 1:9 twist barrel).

Old pics: Leupold 3.5-10x40 LR M3, A.R.M.S. #19A, #21 STANAG.



I also use Q3131A in all three of my Varminters