BruceB
04-08-2006, 10:51 PM
Yeah, that IS quite a contrast in calibers, isn't it?
I'm putting this in the Off Topic forum because the .223 used jacketed bullets. This is the Interarms Mini Mauser that I bought in new condition at last month's Big Reno Show, and today it finally moved into the sub-inch-size groups from 100 yards. Up 'til today, I hadn't fussed with the bedding at all, as I was mostly looking for the speed/pressure range in which it preferred to operate.
So, I used two different loads today, one with factory-loaded WW 45-grain bullets, and the other with Sierra 52 HPBT Match bullets and H335. They were tested for group (a) as the rifle left the factory, (b) with a barrel shim at the front of the forearm, and (c) with a shim under the chamber area (meaning, a floated barrel). The (c) method was best, and gave me a couple of very decent 5-round groups in the 3/4-inch area. The rifle is VERY touchy, and demands great care on the benchrest because of its light weight and round-bottomed stock. Still, if the shooter can manage it, the rifle will deliver. The 52-grain HPBTs departed at 3297 fps average, which is certainly "full power" in a 20" .223!
The .404 was more fun. The load was an air-cooled Lee .44-310 peestol boolit, actually weighing 322 in my straight-WW alloy and sized to .424", Felix lube, and they were driven by 37 grains of XMP 5744 with dacron fill. Speed was 1680 average, and the extreme velocity spread was only 22 fps over a 20-round sample. NO visible leading. The scope is a Weaver K1.5 with post reticle, and it was last zeroed for full-power 400-grain X-bullets at 2130 fps. It was therefore shooting about eight inches high at 100 yards with the cast load, but once I got it zeroed, it fired a beautiful five-round group of only 1.6" at that same distance....with a 1.5X scope, yet! Yippee! Quite comfortable to shoot, too, but not exactly like the .223.....
I then proceeded to burn up the remaining 30 rounds of .404, plinking at targets of opportunity. Great fun, and this rifle is going to see a lot more use than it has lately. On getting home, I die-formed forty rounds of new .375 Ultra Mag brass, and loaded them for fireforming in the .404 tomorrow (20 grains of 2400, caseful of cornmeal on top of the powder, and capped with a tuft of dacron to hold it all in place). These will travel to the range muzzle-up in a loading block. They're pretty fragile.
I'm putting this in the Off Topic forum because the .223 used jacketed bullets. This is the Interarms Mini Mauser that I bought in new condition at last month's Big Reno Show, and today it finally moved into the sub-inch-size groups from 100 yards. Up 'til today, I hadn't fussed with the bedding at all, as I was mostly looking for the speed/pressure range in which it preferred to operate.
So, I used two different loads today, one with factory-loaded WW 45-grain bullets, and the other with Sierra 52 HPBT Match bullets and H335. They were tested for group (a) as the rifle left the factory, (b) with a barrel shim at the front of the forearm, and (c) with a shim under the chamber area (meaning, a floated barrel). The (c) method was best, and gave me a couple of very decent 5-round groups in the 3/4-inch area. The rifle is VERY touchy, and demands great care on the benchrest because of its light weight and round-bottomed stock. Still, if the shooter can manage it, the rifle will deliver. The 52-grain HPBTs departed at 3297 fps average, which is certainly "full power" in a 20" .223!
The .404 was more fun. The load was an air-cooled Lee .44-310 peestol boolit, actually weighing 322 in my straight-WW alloy and sized to .424", Felix lube, and they were driven by 37 grains of XMP 5744 with dacron fill. Speed was 1680 average, and the extreme velocity spread was only 22 fps over a 20-round sample. NO visible leading. The scope is a Weaver K1.5 with post reticle, and it was last zeroed for full-power 400-grain X-bullets at 2130 fps. It was therefore shooting about eight inches high at 100 yards with the cast load, but once I got it zeroed, it fired a beautiful five-round group of only 1.6" at that same distance....with a 1.5X scope, yet! Yippee! Quite comfortable to shoot, too, but not exactly like the .223.....
I then proceeded to burn up the remaining 30 rounds of .404, plinking at targets of opportunity. Great fun, and this rifle is going to see a lot more use than it has lately. On getting home, I die-formed forty rounds of new .375 Ultra Mag brass, and loaded them for fireforming in the .404 tomorrow (20 grains of 2400, caseful of cornmeal on top of the powder, and capped with a tuft of dacron to hold it all in place). These will travel to the range muzzle-up in a loading block. They're pretty fragile.