308 Winchester AR Only

[jLorenzo]

FWIW, my test results out of 16" AR10 "self-build"....

Load Date = 23 Aug 2015			Powder = AR Comp
Bullet = Hornady 155 OTM BTHP		Primer =	WLR
Ballistic COE = .405				COAL =	2.280"
	Grains						Avg FPS	Std Dev	ES
Start	42	2659​	2596​	2619​	2659​		2633	27	63
	42.2	2514​		2554​	2648​	2657​	2593	61	143
	42.4	2643​	2647​	2630​	2625​	2620​	2633	10	27
	42.6	2606​	2603​	2588​	2593​	2592​	2596	7	18
	42.8	2618​	2595​	2600​	2609​	2628​	2610	12	33
	43	2599​	2599​	2585​	2669​		2613	33	84
	43.2	2622​	2630​	2630​	2608​	2612​	2620	9	22
	43.4	2658​	2630​	2646​	2659​	2662​	2651	12	32
	43.6	2656​	2652​	2688​	2663​	2640​	2660	16	48
MAX	43.8	2640​	2661​	2683​	2669​		2663	16	43

Weird that the velocity barely changed over that range of charges.

 

[Ape_Factory]

Latest load that really works out of my POF 16" Revolution gas gun.
Sierra 169SMK's
LC Brass, I sort by year now and these were '07's
CCI34 primers
IMR 4046 powder
43 grains on the nose
2.820 COAL (I'll have to look up the ogive measurement and will update when I do)
.004 under fired case length (1.625 on the Hornady comparator)

10-shot group data after bulk loading on a Dillon with manual powder throw
2528.9 FPS average
SD8.0
ES 24.3

This was sub-MOA for a 10 shot group. I probably could have made it tighter but my scope was dialed for POI and I took out the "dot" to aim at.

I've since experimented with the Berger 175 OTM's with Vhitavouri 550. First load was slooooow but five shots touching. Came in at 2289 FPS but super accurate. I had one result with a higher charge that was almost as good but need to do a 10-shot proof group first. I have 185 Juggernauts arriving today and will test those on Saturday. I have a feeling both would be better with 4046 but the VV can be used in a powder thrower and it burns so clean.