![]() ![]() The one left of the 10 ring is shot 1(fouler) to the right are shots 3,4,& 5. On the second shot of the string I get this in the lower right. Was shooting my Swift, 55 grain BK, H-380 trucking along at 3700. Having shots that can be as much as 100 - 150 Fps different just because you used the wrong primer, or had a case capacity larger than what you used before, than it is pretty much worthless in todays market as you have no reason to believe that you will be able to get those exact components again. Nosler actually has this load as 1 grain under while Hodgdon it is 1/2 grain under.Ĩ208 unfortunately needed smaller case capacity, hotter primer, and a max load to attain its book stated velocity. And according to Hodgdon this was not a max load, but max book velocity was exceeded. Norma is known for being a little more generous in case capacity, so even with a 1/2 grain increase in powder charge the change in velocity as minimal. My reaction to the data is that Benchmark is a much better match powder than 8208 for the simple fact that it exhibited more stability in velocity over a variety of changes.īenchmark retained basically the same velocity even though brass, primer, an powder charge was altered. I was completely surprised by the amount of gain that a primer and match brass change would give in the 8208. Temp at the time of the strings was 66 deg. ![]() Got everything set up and fired a test string from each rifle using rounds left over from the previous test. Next time out I am going to use match brass formed to the rifles in question and use 20 rounds in each rifle of 8208, 20 rounds each Benchmark, and throw in 20 rounds each of H-335 (another known velocity load)and see how that compares.įinally got all of my data sorted out so here goes. I don't think that 8208 XBR is going to make the cut, same powder charge, more recoil, less velocity, and no better accuracy. So no advantage there between the 2.Īccuracy was tilted slightly to benchmark as it turned in 4 5 shot clusters (.5 in) or better compared to only 2 with the 8208 Velocity variations between high and low per string were pretty much even. The recoil difference was obvious while firing. So conclusion on my limited test sample of 8208 XBR (max load pressure 53,400 psi) is that it creates more pressure/recoil, and less velocity for the powder charge than Benchmark (max load pressure 49,800 cup). 3167 from the 14 Twist and 221 FPS slower than a known Benchmark load of 3398. The difference between 2 strings of 8208 was 18 FPS/ avg. 204 FPS slower than the known Benchmark load of 3389. The difference between 2 strings of 8208 was 35 FPS/ avg. ![]() String 6 Benchmark out of a 14 twist Avg. String 5 Benchmark out of a 12 twist Avg. Barrels were still dirty from last outing. The rifles were allowed to sit for 30 min and no cleaning between strings. All strings were 10 shots fired 1 shot per minute. Temp was 39 degrees with a 10 - 4 o'clock variable wind at 10 to 15 mph with gusts to 23 but this was shot for velocity not group as the rounds were not optimum for either rifle to shoot for group. 4 off of max for that bullet, 25 grains of Benchmark is 1 grain off max according to hodgdon. 21 MV 24" barrel, exact copies except 1 is a 14 Twist and 1 is 12 Twist.Ģ5 grains of 8208 is. (didn't want variance due to brass being mated to 1 rifle chamber) ![]() 002, trimmed to 1.750 as I was going to use 2 rifles. (this is a known load for velocity from both rifles)īrass prep was FL sized w/ shoulder bump. Load 2 - 25 grains Benchmark, 52 SMK, RP once fired brass from same lot as above, Federal GM primer. Test subject load - 25.0 grains 8208XBR, 52 SMK, once fired RP brass, Federal Gold Medal Primer. The BR guys around here panned it but being the curious type I had to try it. Awhile back I picked up some 8208 XBR on a whim when it was brought up as a powder for the 223. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |