Monday, November 22, 2010

Going the distance

Yesterday was a watershed moment for me in that I maxed out my little AR15 at distance. We were shooting out at 710 yards, and my 69 grain Varget handloads were punching outstanding groups as they were de-stabilizing. My AR only has a 16" barrel like many on the market today, so my average velocity is 2,582 fps which JBM Ballistics tells me my loads will run out of gas at 700 yards. I was not zeroed for any of the loads that I shot, as I was just testing groups. The group above the bull marked "223":

I'm tickled pink with that for several reasons: for one, I know exactly what the limits are for my gun; and two, despite the 69 grain bullets starting to keyhole as they hit the target, I'm still getting 4" or less vertical dispersion, which is awesome; and three, I now know that there's no point in going for another .223 chambering for the MK11 Mod 0 build that I was planning as I would only pick up another hundred yards capability. Looks like I'll be checking out 6.5 Grendel again!

This little AR with its 2-7 Burris FFII Tactical scope and lite barrel shoots circles around my custom built, Krieger barreled 308 with 3-12X50mm scope. Weird.

The little group was fired at the black dot, and I hadn't adjusted my dope from my first group. The large group was also fired with the same dope, but into a 8mph wind while chasing the yellow balloon around. It was getting dark, and everyone was packing up, so I figured what the hell. Almost all of the shot holes are slightly elongated from the rounds not hitting square. It's really cool though because they were not hitting completely sideways yet, so they were in the process of going transonic. Some of them hit straight on too, which have to be the ones that left the barrel with a little more speed.

I brought my reloading press and all associated gear to find a Varget load for my 308, and it ended badly. I again, for reasons I can't recall, I decided to shoot off of the Harris bi-pods for an OCW test, and again found out the hard lesson that bi-pods bounce like shit on any surface, at least for me. I do think that it's shooter induced error, but I've tried every trick in the book and it still happens: putting a towel under the bi-pod feet; digging a little trench in the dirt for the feet to push into; loading the bi-pod with various tention; watched the Sniper's Hide video on how to shoot off bi-pods without bounce; none of this helped. I then did myself the greatest favor by removing those pieces of shit and slinging them down as far into the woods as I possibly could. I will never ruin another load development effort because of bi-pods again.

For fun, I brought along a box of 175 grain Federal Gold Medal Match to see how it shoots from my gun at distance. The wind was slightly breezy, between 2-5 mph, and I didn't use a wind call:

The vertical dispersion is about 2 1/2", which makes me happy. The horizontal spread I blame on the wind. Mirage was also really bad when we first started shooting. My plans at this point are to stop wasting valuable long range time by testing loads, so I'm going to have to get sorted out close to home and decide on a load. My Reloder-17 OCW test a few days ago went alright, but I didn't find a load that I wanted to use; and without any data for the powder, I'm scared to go any higher. I also didn't get the velocity I was hoping for with 175 grain bullets until I was at almost 49 grains of the stuff, which is a lot of powder.

Either way, I'm glad to have success with the AR knowing that it's minute-of-groundhog at over 700 yards. You can't ask for more of a 16" factory barrel.

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