Making the 6X6.8

I just crunched the numbers on the Starline 6.8 brass that was from their NEW PRODUCTION that is much harder and showed less deformation on firing. It ran side by side with my SSA and showed no difference in appearance of the primers or the head. I am very pleased. I shot 50 pieces necked to 6X6.8 and found that they were as good in the 6X6.8 as they were in the 6.8 in comparison with the Old SSA.

WT UNFIRED FIRED
STARLINE 121.4 34.88 36.08 first run
STARLINE 119.52 34.98 36.2 second run

Greg
 
I got my fired case tapped to check distance to lands. I loaded 30 rds with 58vmax and 8208. Ended up seating them .011" off the lands. Will load some tomorrow with H322. We've got Alberto dumping rain on us now. Hopefully I can get to the range with the crony this weekend and see how she does. I was pleased the 58's .011 from lands are well within standard mag length
 
Finally got to the range. Loaded 58Vmax with XBR & H322 started both at 30gr ended up seating them for .015 jump. The XBR loads were lit with 41 primers & the H322 with 450's. 30.5gr of X gave a good group Avg.3202 fps ES 59* 31.3gr of X looked good also Avg. 3318 fps ES 77* 31.5gr Avg 3339 fps ES 43 but grp started to open. No X grp much bigger than moa two were 1/2 moa or less. No pressure signs. H322 was another story 30gr A. 3358 ES 58 4 shots moa 1 flyer could have been me, but showing some swipes and ejector marks. 30.5gr A 3414 ES 69 grp moa more swipes & pressure signs. 31gr A 3490 ES 34 only fired 3 rds. because pressure signs getting worse grp 1 1/2 moa or bigger. All grps but last were 5 rds. Target at 100yds Crono at 10 feet very little wind. Don't really know why I used different primers. Broke my own rule of not changing but one thing at a time. Wondering if the primers caused pressure issues. BTW gase block was fully open on all tests. I have pics but don't know how to post them. I think Ritch's barrel is going to be a shooter. It has just but 45 rds thru it and is showing a lot promise. It is a TO 20" 1-10 twist. Thanks Ritch!
 
Sounds like a good outing. 450 and 41's are essentially the same primer with the 41 being a bit thicker. No real difference from pressure is normally noted. More likely the change in powder. I'll have to look at my notes on the 322. The XBR loads are doing what most of us expect in speeds and accuracy.

Greg
 
From my testing with 322 I'd say that 3500 from a 20in tube is cooking pretty good. I've never ran any of my tests with the gas wide open but I would expect to see swipes and case head marks that way. Without pics I can't say with any certainty what your seeing but I'd back off to 30.5-30.8gr, turn the gas down to just cycle reliably and check case head. If that looks good then I'd play with seating depth to tighten up the group's some.

Or do the same with 8208. We run adjustable blocks for a reason so take advantage of the benefits they provide.
 
Adjustable gas blocks are new to me. I put my first on an Ar10 .260 because it is wrecking brass, but have not actually did any adjusting on it. I put one on this new 6X6.8 build because I eventually want to suppress it. I forgot the wrench to adjust it at the range so I was stuck with wide open. I think I will focus on XBR since it is grouping so good, but I like the speed of H322. Are you all see more speed from H322 than XBR? I probably need to push the XBR a little harder to see if I can get the speed up some. I want to get the 58's dialed in before I work on the 87's. It's been a while since I've had a gun shoot this good right from the start. The last one was a 6BR it will shoot anything. I'm going to like this barrel!
 
I'm going to try to get out this weekend to test more. I'll adjust the gas where it won't cycle and see what the brass looks like. If the swiping goes away I'll play with 322 and seating depth. I think I'll push the XBR a little harder since I had no pressure signs with the gas wide open. I would really like to find something around 3500 but it has to shoot good. what are you guys jumping the 58gr Vmax?
 
I load 58 vmax .005" off the lands. 22" BHW runs 3325 with 31 gr of xbr. 30.5 of 322 runs 3575 in my barrel. Using Hornady brass, capacity is down from SSA but it is holding up well. No swiping or torn up rims, running adjustable block so it barely locks back when empty. Both loads shoot very well.
 
So I formed some brass tonight and without checking the inside diameter of the neck I went to seat a bullet and I pushed the neck of the brass back into the brass case. I then measured the inside diameter and the are to small. What could I have done wrong in order to get then neck size wrong and what is it supposed to be? How do I change it and get the brass I’ve sized back to the correct inside diameter?
 
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