WC872 in 6.5x55 report

[Jimro]

I used AA8700 data to do a load workup with a 140 gr Nosler Custom Comp. 140gr HPBT bullet. Virgin Winchester brass, Tula LRM primer. Rifle is a 1941 Husqvarna M38 Swede Mauser.

I started at 47 grains and worked up to 50 grains which was the published maximum for AA8700. What is interesting to me is that I didn't get powder residue on the outside of the necks as I normally get from reloads, and the primer was pushed back out even with 50 grains of powder (generally a pushed out primer is a sign of low pressure).

I don't know if I have a particularly slow lot, but I have read of others who have used 51 grains of WC872 in the 6.5x55. I don't have a chronograph so I can't talk about velocity, and I don't have a ballistics lab that measures pressure. I think I will do another load workup to 51 grains to see if that is safe in my rifle, but in the end I'll see where best accuracy lies.

Jimro

 

[davery25]

sweet, i love threads about the 6.5.

a pushed out primer might also be a sign of excessive headspace though. other than that i havent tried the powder or that brass so i cant comment.

you probably know this but remington and winchester brass have an incorrect case head sizes (4.73mm instead of 4.8mm), should have an effect on primers though, just extraction

 

[Jimro]

Sorry for thread necromancy, but follow on report.

I upped the charge to 51 grains (above published data for AA8700 but no pressure signs). This gives me a full case fill.

I used this load in a Vintage Sniper Match using an M41 clone. I took a "well and lovingly used" M96 Swede with a good bore and had a Short Side Rail installed, and I used a made in USA Weaver 4x Marksman scope (the rules state that the Weaver K4 is an authorized substitution but you can't tell the difference without reading the model inscription on the scope body. If the judges ever disqualify me so be it).

The match was held at 300 and 500 (with distance corrected 500 yard targets). I shot a 97-4x at 300, and a 92-1x at 500. My drop from 300 to 500 was over 10 MOA if I counted correctly, and this corresponds to a muzzle velocity in the range of 2100 fps with this load.

I'm more than happy with the accuracy and mild recoil, although I think I need to get a slightly faster powder to not get so beat up by the wind at the 500 yard line.

Jimro