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jvencius
03-07-11, 23:02
Since my DMR upper from Centurion should be in my grubby hands this week sometime, can anyone recommend a procedure for testing different loads? I'm curious what advantage, if any, I'd gain from shooting 8 5-shot groups vs. 4 10-shot groups or if there's another regimen that would be more efficient for verifying which load my rifle likes?

So far I have two boxes each of Hornady 75 gr. BTHP Match, 75 gr. TAP, and Federal 77 gr. SMK GMM--on Friday (payday) I'm going to order myself a box or two of ASYM 77 gr. SMK Match since Monty recommended that load specifically as being a good fit for that barrel. Does anyone have a good source for Black Hills other than Ammunitiontogo.com (had a so-so experience with them a while back) and Midway (would spend waaaaay more than a box or two of ammo if I go there)? Monty said Federal, Black Hills, and ASYM are all pretty much the cat's ass of factory-loaded match 5.56 ammo so in the name of getting a good representative sample, I'd like to try both the Mk.262 and their standard 77 gr. SMK loadings to see if my rifle likes one over the other.

FWIW, here's the "build" specs:

CMMG stripped lower (got it @ the height of the post-inauguration scare)

Colt A2 stock

Geissele SSA-E trigger (on order but should be here by the end of the week)

small hard parts (detents/springs) out of a DPMS kit (bought it at the same time as the lower)

Centurion DMR upper with a Smith Vortex

KAC 200-600 rear/Troy front BUIS

I'm still undecided on an optic and will wait until after the tax refund comes in to buy one (depending on how much we get back, that might open up some possibilities I couldn't afford right now w/o having to use the CC).

Birddog1911
03-08-11, 22:41
Let me just be the voice of reason, and say that you need to fire a baseline with factory ammo first. I've made the mistake with my new Mk12 rifle by not doing that, and now I have to go back. My first loading results were not impressive, and I'm going to be switching powders. But first, I'm gonna get some BH 77grn SMK from my local dealer to shoot the baseline group.

High Caliber Sales sells the BH ammo, and from what I can tell with little research, it seems to be a good deal.

Belmont31R
03-09-11, 02:11
I would get 4-5 different types of ammo, 2-3 boxes each, and shoot 3-5 10 shot groups. Average them out, and then see which one does best. Then buy a crap ton of it, and stick to that ammo.



After shooting many thousands of rounds of different ammo types and looking back Ive felt Ive wasted a lot of money and time. It doesn't help build skill when you are spending half your range time and money figuring out where each ammo type is shooting. If all you shoot to is 300 yards it doesnt make a big difference but it does when you shoot 500-700+.


I would get the new BH 5.56 77GR, SSA 5.56 77GR, and the Hornady .223 SuperPerformance 75GR. Try a couple others, too.


One last piece of advice is if you shoot LR velocity does make a big difference. 5.56 loads spend less time in the air (less wind deflection), and have a flatter trajectory.