I finally broke in my 24" Grendel upper this evening.   I follow the break-in method suggested by Kreiger Barrels.

I had to fire 12 single shots before I was happy enough with the copper fouling per shot to proceed to firing multiple shots.   After the first 5 or so shots, I noticed that most of the fouling was showing up on one side of the patch, I'm guessing that it's from the gas port which was drilled after the barrel was lapped.

I was using 30.8gr of AA2520 under some cheap 120gr Remington Core Lokt bullets.   I only had time to fire one 5 shot group at 100 yards before I ran out of light (ok, I was already out of light, but I fired the group in the dark anyway  :D ).

Wonderful!!! Was that the surplus 2520, or the canister grade?

D*m Fine group there.
Yeah I'd say you were off to a good start....

Quoted: Wonderful!!! Was that the surplus 2520, or the canister grade?

Canister.   I can't wait to how this upper does as it settles down and I try some match grade bullets.  

Keep us updated....

Quoted: I finally broke in my 24" Grendel upper this evening.   I follow the break-in method suggested by Kreiger Barrels. I had to fire 12 single shots before I was happy enough with the copper fouling per shot to proceed to firing multiple shots.   After the first 5 or so shots, I noticed that most of the fouling was showing up on one side of the patch, I'm guessing that it's from the gas port which was drilled after the barrel was lapped. I was using 30.8gr of AA2520 under some cheap 120gr Remington Core Lokt bullets.   I only had time to fire one 5 shot group at 100 yards before I ran out of light (ok, I was already out of light, but I fired the group in the dark anyway  :D ). www.skinwagon.com/grendel_first_group.jpg

Damn you!  Now I 'm going to have to have one of these too  But at least I get d-pricing

Nice group!

Bigant

Quoted: Quoted: I finally broke in my 24" Grendel upper this evening.   I follow the break-in method suggested by Kreiger Barrels. I had to fire 12 single shots before I was happy enough with the copper fouling per shot to proceed to firing multiple shots.   After the first 5 or so shots, I noticed that most of the fouling was showing up on one side of the patch, I'm guessing that it's from the gas port which was drilled after the barrel was lapped. I was using 30.8gr of AA2520 under some cheap 120gr Remington Core Lokt bullets.   I only had time to fire one 5 shot group at 100 yards before I ran out of light (ok, I was already out of light, but I fired the group in the dark anyway  :D ). www.skinwagon.com/grendel_first_group.jpg Damn you!  Now I 'm going to have to have one of these too  But at least I get d-pricing Nice group! Bigant

Couldn't have said it better.

I took it out again yesterday, but my groups were not that impressive.   I burned up the rest of the box of Rem Core-Lokt bullets I had loaded, but out of 6 groups fired, only 2 were sub-MOA, the rest were 1 to 1.5 MOA.   That first group ever fired out of my gun sure was a great begining though

I mainly loaded those Core-Lokt bullets to use as cheap break-in fodder.   I'm going to try again in the next few weeks with some better bullets.   I have a good variety on the way: 123gr and 108gr Lapua Scenars, 120gr Match Kings, 120gr Nosler Ballistic Tips, and 90gr Speer TNT.  I also have an assortment of powders to try.

I'm hoping to find a solid .5 MOA load before I make the trek to my dad's hay farm in SC for some 450 yard testing.....   If I get busy with the chainsaw and tractor I might even be able to get a 700 or maybe even 1000+ yard shot   There are another 2 hay fields behind the hedgerow that is 455 yards away in this pic: www.skinwagon.com/rangejune10a.jpg

Well, hell! I was gonna buy another AR, but now it looks like I'm gonna end up buying 2! h.gif

Actually, I was thinking of the .21 Genghis from AA, but a fella came out to our club last weekend with one and the accuracy wasn't any better than 2 MOA @ 100 yds, using standard Russian ammo.

I spent the day on the range with my reloading press and a selection of bullets.   This was at 100 yards with a 24" Alexander Arms upper.  It was 75 degrees F, 244' above sea level.

I got great results (.5 MOA and better) with 120gr Match Kings (30.5gr AA2520)  and 90gr Speer TNTs (30.5gr Benchmark).   Those TNT's were screaming along at 2950 fps.  (I ran out of light for the chrono before I got to the Match Kings.)   One of the 5 shot Match King groups looks like I only shot 3 shots .   I did have one batch of Match King loads that I accidently seated a little deep (2.20" OAL) which opened the groups up to about 1.2 MOA, I adjusted to 2.26" OAL and was back to .5 MOA or better.

I wasn't happy at all with the Lapua Scenars in 108gr (using H335) or 123gr(using AA2520).  They were consistantly giving 1 MOA groups but I couldn't get much better out of them.  I varied OAL and powder charge, but couldn't get them to do much better or worse.

I couldn't get 129gr Hornady SSTs (using AA2520) to consistantly group well either, they were grouping between 1 MOA and 2 MOA.

Next time out, I'm going to try some 120gr Nosler Ballistic Tips, and I'm going to try some BLC(2) with the Match Kings and the Ballistic Tips.    I'm going to try some Varget with the rest of the 129gr SSTs.

I spent the day at the range again yesterday with my press clamped to a bench.   The wind was gusting up to 30 MPH, so I didn't get to use my chronograph, it was hard enough to keep *me* from blowing away, much less try to secure a chrony on a tripod.

It was impossible to use a powder scale in that wind, but I knew what settings on my powder measure were safe for each powder/bullet combo, so I started there and worked my way up blind. I repeated the settings for the good loads and weighed test charges after I got home.

Here's the loads that worked for me in my 24" Overwatch:

All loads were 2.265" OAL

120gr Sierra Match King
31.3gr BL-C(2)

120gr Sierra Match King
31.1gr AA2520

100gr Nosler Ballistic Tip
34.1gr BL-C(2)

I had several groups where I put 4 shots into .1 or .2 inches, then flubbed the 5th shot.   If I could stop choking under pressure my Grendel would really shine :)    There are also several groups in these pics that were fired with the wind changing drastically from one shot to the next.  First shot would be a 30 MPH tailwind, next shot the wind was 15 MPH from the right, next shot dead calm, etc etc etc.... it was a crappy day to be shooting... I think the wind was affecting my ability to hold the gun steady more than it was affecting the bullets in flight.