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.308 Win Handloads Test 1

PostPosted: Sat, 31 Aug 2013 23:53:45
by NovaHunter
I finally set up my single stage for .308 recently, and loaded up a bunch of different ammo. I had a variety of brass (Rem, Federal, and Lapua) and wanted to test and see if there was a difference in performance between batches loaded in different brass, and also if seating depth affected accuracy.

Firearm that all loads were shot through is a Remington 700 PSS 1in10in twist barrel with H-S Precision Police stock. The gun had some light after market work done to it including custom trigger work, re-setting the headspace, and re-crowning the barrel about 10 years ago. All shots were fired at 100 yards using a front rest and homemade rear bags (old socks filled with black beans works great and is inexpensive).

First batch of Loads that I tested yesterday are:

Load 1:
Brass: Remington
Primer: CCI 200
Powder: 42.5gr IMR 4064
Bullet: 168gr Sierra Match Kind (SMK)
COAL: 2.78in

Load 2:
Brass: Remington
Primer: CCI 200
Powder: 42.5gr IMR 4064
Bullet: 168gr Sierra Match Kind (SMK)
COAL: 2.80in

Load 3:
Brass: Remington
Primer: CCI 200
Powder: 42.5gr IMR 4064
Bullet: 168gr Sierra Match Kind (SMK)
COAL: 2.825in

Purpose of firing these loads was to find the best group with Remington Brass, and to see if seating depth of the bullet affected accuracy in the rifle. Results of shooting one 5 shot group at 100 yards for each of the above 3 loads are:

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Results: Load 1 is the group above the bullseye with a group size of 1.240 in, Load 2 is below the bullseye with a group size of .610, and Load 3 is top right with a group of .924 (sorry for the crappy cell phone pics). To be completely scientific, I should have fired a control group of 168gr FGMM which is what I normally shoot through the gun. In prior shooting sessions,168gr factory FGMM produced groups in the .6 to .75 range. FGMM is loaded to a COAL of 2.800 and the powder load was picked to be close to the muzzle velocity of 168gr FGMM. With only firing one group per Load, it's hard to say definitely but Load 2 did perform the best of these 3. The 4 shot group for Load 1 was about .600 and then the one flyer on the last shot opened the group up. Very possible that I contributed to that flyer.

Second batch of loads I tested were two loads in Lapua brass:

Load 4:
Brass: Lapua
Primer: CCI 200
Powder: 42.5gr IMR 4064
Bullet: 168gr Sierra Match Kind (SMK)
COAL: 2.80in

Load 5:
Brass: Lapua
Primer: CCI 200
Powder: 42.5gr IMR 4064
Bullet: 168gr Sierra Match Kind (SMK)
COAL: 2.825in

Purpose of firing these loads was to find the best group with Lapua Brass, and to see if seating depth of the bullet affected accuracy in the rifle. Results of shooting one 5 shot group at 100 yards for each of the above 2 loads are:

Image

Results, Load 4 proved to be a very nice group .478 center to center and was the best group of the day. Load 5 produced a grouping of .665. All the loads were shooting high and left relative to my point of aim, and the 5 shots on the right of the target were me adjust the cross hairs to get the gun sighted in dead nuts at a hundred yards. The last 3 shot on the right side of the target needed no adjustment and measured .417.

Both the Lapua load and the Remington Loads seated to 2.800 did the best within their respective groupings so I have a some preliminary data that my rifle does indeed like this specific COAL. Another item I wanted to measure was length of the different types of brass after firing. The Remington brass was once fired and trimmed to 2.005 before loading. The Lapua brass was new, and was 2.005 out of the box. Measuring the brass when I got home, all the Laupa brass measured between 2.005 and 2.008in in length except for one piece that measured 2.010. The Remington brass measured from 2.10 to beyond 2.20 in length so some of these will need to be trimmed again before reloading a 2nd time. Since the Remington brass was fired once before, this wasn't an exact comparison but I do think the brass length is worth noting.

All in all, I think I will be loading some more Lapua brass with the Load 4 recipe and then repeat the test with the same loads 1, 2, and 3 but with Federal brass to see if the results are similar as above.