6x6.8 barrel

I think either of those would be great. H322 and 8208 seems to be the go to powders for 55s. I shoot the 70's with ARComp. The powders available to you may help dictate which bullet to shoot. Otherwise I would choose the bullet that is most accurate.
 
carpdoctor said:
Does anyone make any 6x6.8 cases drilled for checking bullet seating. I have the hornady system. Might as well figure all that out before I install the barrel. I have a 6.8 that I shoot hornady SST bullets out of. They have red tips just like the vmax bullets. To help avoid a mix up I want to try the Nosler ballistic tip varmint bullets because they are purple. It looks like some people shoot the 55 and others the 70.
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Before building the upper, I just make a dummy round seated long with the bullet(s) of choice. Smoke the bullet with a Bic light, slide it in the barrel, push on the ass end to make sure it's all the way in, pluck it out, & look for marks. Rinse & repeat til you get to where you want to be, whether in the lands a hair, just off the lands, or max mag length, etc.
 
carpdoctor said:
Does anyone make any 6x6.8 cases drilled for checking bullet seating. I have the hornady system. Might as well figure all that out before I install the barrel. I have a 6.8 that I shoot hornady SST bullets out of. They have red tips just like the vmax bullets. To help avoid a mix up I want to try the Nosler ballistic tip varmint bullets because they are purple. It looks like some people shoot the 55 and others the 70.
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I made one . It eased my mind . I’ve never owned an AR that magazine length would get any where near the lands .
 
Before installing the barrel just drop each bullet in the barrel and measure from the rear of the barrel extension to the rear of the bullet. Add the bullet length to that number then drop in a sized case and subtract the distance from the rear of the barrel extension to the rear of the case. That number will be the coal where the bullet is touching the lands.
I can tell you the nosler bts will hit at around .095" longer coal than the VMAX of comparable weights and the Sierra 60 hp. 70 blitzing is way out there too if I recall.
 
A modified case is just the easy button. I figured someone on here was making them, that is why I asked. Without a collet it's a pain to drill the brass when making one.
 
carpdoctor said:
A modified case is just the easy button. I figured someone on here was making them, that is why I asked. Without a collet it's a pain to drill the brass when making one.
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When I was using the Hornady set up to drill mine I just insert the case until tight in my sizer die and put the die upside down in the press and drill and tap my hole. I then just reverse the die and slide my standard shell holder into the ram over the rim and pull the case.

I got tired of drilling cases so bought the Sinclair Distance to Lands Tool from Brownells with the appropriate action adapters. It was cheaper than buying custom cases, more repeatable and faster IMHO. You use a case fired in your rifle that you have lightly sized the body to allow free drop in and out of the chamber and not alter the shoulder placement so you are not having head space variation like on a Hornady factory gauge. That case goes in my box so I can always check each rifle specifically. AS I have five 6X6.8's it saves me a lot of time. Brownells has a video on it.
 
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My barrel came in and it looks good. I haven't been able to find any 8208 or 322 locally. Any other suggestions? I think I saw benchmark mentioned somewhere?
 
I used H322 in the end but since there's none to be had. Here's what I did to get started on my 6x6.8 SPC loads.

I did some case comparisons (water weight in grains) and decided to start a grain below (just to be safe) the top 6 PPC load data and slowly worked my way up until I got to 3400-3500 (18" BHW barrel w/ 10 T) and/or seen some type of pressure signs (primer flatting/cratering, swipes, burrs, etc.).

I highly recommend GLSHOOTERS method to find the distance to the lands for COL.

FYI-Benchmark and H335 falls between H322 and 8208 on the burn rate chart.
 
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