Comparison between Pat’s 32/8mm Checks & Hornady commercial checks
Finally got around to getting some 8 X 57 loaded up for the comparison tests..
I loaded 20 rounds – 205 grain nominal dropped from Lee 329-205-1R dual cavity mold. Sized to .323 with .014 Amerimax aluminum gas checks made with Patmarlin’s Checkmaker. Brass is Remington once fired, Winchester WLR primers and 12.5 grains of IMR Trail Boss.
My wife loaded 20 rounds – same bullet, also sized to .323 but with Hornady .32 caliber commercial copper gas checks. Same brass, primers and powder. All powder charges were individually weighed using an RCBS 5-0-5 scale. and the seating die was set to produce an OAL of 2.855 which puts the crimp right in the center of the first driving band.
The rifle that will be used for the comparison is a 1940 Berliner Lubecker Maschinenfabrik 98K that was captured by the Russians. The only thing they messed with was the stock, some bolt parts and they punched out the swastikas. The barrel & receiver have the original serial numbers and are matching. It slugs .3219 in the grooves.
I used an ATI no-gunsmithing mount and have a Chinese clone of a Sightron 8.5-24 X 40 sniper scope on it.
The test will be run on an indoor 100 yard range and the targets will be set at 100 yards.
All 40 bullets were weighed and sorted. Out of 100 I was able to get 40 that were within .2 grains of 205. They ranged from 205.0 to 205.2 grains and I think that will be close enough for a good comparison. The ones that I didn’t select ranged from 204.3 on the light side to 207.7 on the high side. They were cast from wheel weight lead with a bit of solder added to the mix and were water quenched. After setting a couple weeks, the average hardness is BHN 24 measured using a SAECO tester.
I have a lane reserved at the range tomorrow morning for the test and I’ll post the results when I get them, including pictures of the targets.
Results are in:
The .014 Amerimax aluminum Checkmaker chex performed marginally better than the Hornady commercial copper gas checks all other factors being roughly equal – same weight bullet, brass, primers powder (12.5 gr. Trail Boss), same rifle, same distance (100 yards indoors) and from a front rest.
Just for grins, I also included 5 shots loaded the same but with checks made out of .005 brass shim stock. These looked like little brass bottle caps but crimped on the boolits okay so I loaded and fired them as part of the test.
The bottle cap ones didn’t group as tight as either the Hornady commercial checks or the ones I made out of the Amerimax aluminum, but they were certainly consistent and accurate enough to be useful in pretty much any hunting or defense situation.
Here’s the 5 shot group I ran at 50 yards with the 8mm 205 grain Lee 329-205-1R sized to .323 using .014 Amerimax GC’s made with the 32 caliber Checkmaker.
I got back to the range last evening. The lane I got had target carrier problems and I could only shoot at 50 yards instead of 100, hence the high group. It probably wouldn’t be this tight at 100 yards.
The powder used was pulled from 1950’s vintage Yugo surplus ammo and is reported to be Hotchkiss glass plate flake powder. A friend who goes by Black Wolf over on the Surplus Rifle forum had done some pretty extensive research and testing of this powder and he has worked up a chronograph verified velocity chart for this powder and the 205 grain GC boolit I use. 17gr of the stuff clocks at 1238FPS and 28 grains clocks at 1854FPS with the velocity increase between those two points graphing very linear. He ran chrono averages in one grain increments between 17 and 28 grains.
I loaded these up with 28 grains of HGF and got the resulting group last night. I had shot this stuff before using Hornady checks with basically the same results. It actually will cloverleaf them at 17 grains and gradually opens up to what you see in the target as you progress up through the 28 grain load. No leading was observed even at the higher speed.
The 1950’s Yugo powder burns very clean with almost no residue and doesn’t appear to be corrosive in the least. (I accidentally forgot to clean the rifle for almost a week after one particularly intense range session where I had shot 50 rounds of the surplus ammo I pulled this powder from and the bore showed no signs of rust or any other evidence of corrosion, so the primers in this older ammo (vintage 1955) don’t appear to be corrosive either.