After looking through my books I found the 58 VMAX loadings with the H322 and a few other things in this barrel. This is an 18" 6X6.8 upper that Ritch built for me back in 2013 that has languished on the shelf for a long time. It's only made it to the desert twice. Once in 2013 and this last trip.
The H322 load was shot at the request of Ritch who got it from Nick. Generic length of 2.255 that seems to work well across the board in all the chamberings we have in this using the VMAX. Obviously not all barrels.loads shoot the same so another data point is always handy. I did use the 450's on this load though I usually do the Rem 7 1/2's. All brass shot was once fired Federal on this run using a 267 bushing. ).002 neck tension. All targets I post are at 100 yards unless indicated otherwise.
I found that speeds were excellent with the H322 in that short tube. In fact they were quite nice and higher pressure indicators were absent. Rifle ran 100% as I expect out if these. Starting at 30.5 I got 3367. I loaded in 0.2 increments up to 31.5 that garnered me a very nice 3460.
I put 30 rounds down range on this inspection. Not as many as I normally shoot but adequate for a quick inspection to either throw it out or whet my appetite. This one seems somewhere in between. Groupings were kind of a tease as the faster it went the better it shot until the last one of 30.5 and it blew up. Admittedly this was a small test and the last group was the last one shot at the end of a solid seven hours on the range at 104 degrees. Who knows? Maybe my body finally yelled calf rope. I do know that historically on the BHW barrels the hotter the loads the better they shoot.
I never cracked an MOA on these combinations which is neither bad nor good. I am not the fellow tat says the rifle has to shoot THIS bullet or THAT powder. It's all a trade off just like a god relationship everyone has to work together. I'll revisit this now that it is cooler and I have grundle of the 598's to play with now.
This was my best efforts that day on this. By reports Ritch and Nick are getting down to about 50% size wise on these but not for me that day.
Certainly a usable load but not one that I would be happy with across the board. I will cheat and shoot this same batch in two other 6X6.8's I have and see what I get in contrast for speeds and results. One is a 22 and the other is a 24 so the stir step will be interesting.
As I mentioned this was only its second outing so I went to the Way Back machine to 2013 and bullet out my initial 58 VMAX test using the tried and true 8208 and Remington primers. It was a cooler day then at only 92..LOL
The powder charges chosen this day have some historical significance as Ritch and I were just developing this cartridge for commercial loading with accuracy and an eye to genuine pressure testing of the loads. This span of 31.0 to 31.5 of 8208 has been found to shoot in the vast majority in this chambering. I only shot 25 for record on this test as it was for verification of the efficacy on the load in a different tube.
The first ten shots at 31.0 were enough to make me happy as it has shot well across the board in other rifles too.. Bumped to 31.5 skipping the 31.2 I normally shoot got me bigger results but still under an MOA. They were looking a bit vertical and I would pursue a bit more on this one on a re-vist if I try one plus I want to shoot a REM. vs. CCI primer test on it.
So that's the crunch guys. Not a lot of data as I tend to shoot longer tubes but who knows with the potential suppressor bill in the offing a threading might happen.
Greg
