IMR 8208 XBR in a 6x6.8 variant

CZ527

New member
Hello,

I'm a big fan of the 6x6.8 stuff (the BHW version, the WOA, the Dtech.)

My personal is a 6 WOA. It shoots extremely well with 65s and 80s. It's also quite a paper puncher with barts boattail ultras.

But lately I've been trying to find a good load for the 70 gr blitzking. I have found several that shot better than .4 consistently (3 trips in a row.). But... None of them break 3200.

So now I'm looking at 8208. Certain BR guys are claiming 3500 with 66s from their PPCs.
I figure with a little extra capacity, I should be able to get close to that with 70s.

My 65 gr load is pretty much the standard with benchmark. It clovks at 3375, with a lot of capacity left, probably 1.5 grains.

I tried benchmark with the 70, and accuracy just wasn't there, 3/4" groups with everything.

Anyway, anyone using it? How's it do?
 
I can't believe no one has answered. I don't have one, but when I read about the 6x6.8 on here it seems 8208 is the go-to powder, at least with the lighter bullets.
 
I know right... I have used everything in it's neighborhood both faster and slower, say from benchmark to RL-15.
I have sure gotten some goods groups with that 70, several sub-.25 and like I said above many loads that have shot .4 or better in various conditions. I've been really impressed with N135, but the only place I can get it the guy wants $51 a pound. Insane.....

So I saw I still had a can of first production run 8208.
I just loaded a ladder testing set, from 28.5-(pretty hot) grains, in .1 increments. I'll be shooting 3 of each at 200 yards tomorrow under a spotting scope. Those loads are probably a bit stiff, but I'll quit if it seems I should. If not, I'll run back home and load above them a little more. The range is just 3 miles away.
 
I know nothing about WOA load levels. The BHW 6X6.8 yes. I'll dig up some numbers in the AM but the numbers are not 1:1. It does shoot well.

Greg
 
I am not the biggest fan of 8208 in my 6x6.8. Others have reported much better results with it than I have gotten but it does work.

In one 20in barrel 31gr runs 70smk to something like 3250fps IIRC and accuracy is pretty good but AR comp will run them 3300fps from the same barrel just not quite as accurate. In a 22in barrel 31gr ar comp runs the 70smk at 3350fps and 30.5gr comp runs75gr hornady vmax at 3300fps +/-.

I have another 20in barrel I am just starting to work with so I will hopefully have some more data to post up before too long.


I am not sure how the WOA chamber and barrel will stack up as far as pressures go so due diligence on your part will be needed.

How many gr is "pretty hot"?
 
Well I guess what I thought was pretty hot really isn't after all. I wouldn't have dared to try 31 grains, probably ever, but seems like a lot of folks use it to that level. I've gotten a few PMs containing similar numbers. That seems like a bunch, to me. I stopped at 30.5, but if they're safe I'll load above that to test.
 
30.5gr 8208 probably wont be a slouch load and may very well be top end. Like anything, watch your brass and listen to the rifle. It will tell you when its had enough.

h335 is another powder that has done well for me with 58-65gr pills. I have not tried them with anything heavier but I might try a batch with 70s and see what happens.

CFE223 has shown some accuracy potential for the 70-75gr range as well but velocity was not there for me.

I have half a mind to try some imr4320 sometime too. I can get dang near 34gr in my FC brass filled to the top of neck but I have not seen any data for any of the 6.8 variants.
 
My only 8208 load was at 30 grains at 3123 in a 20" tube in an AR. Pressure was very slight just loafing along. My notes so going up would not be an issue. Accuracy was very good. I moved up to CFE at 33.5 for 3272 not bad on pressure and it shot well also. I shoot very few 70's in it going more of the 55-58's and 87's.

In a bolt gun I'd pushed both these but the AR is not the platform for saving primer pockets way up there.

Greg
 
In my 6x6.8 testing I ran 30g x8208, 70g nbt in my 20" ar15 and it spit out at 3104 fps. No way are you going to get close to 3500 fps in any 6.8 type case w/a 70g bullet.
I would look at H335 or aa2015 also.
aa2015, 27g in my ar15 20" is 3039 with room to spare for more powder, this was my starting load.
29g h335 is at 3104fps and room for more powder.

I built a 6x6.8 on Savage action, 22" bbl.
70g nbt, 29g x8208 3182fps

I do not really have a use for the 70g bullet overall as I run the 55-65g bullets for coyote and they do the job perfectly.
I do jump right up to 80-95g though for antelope.
 
Ladder testing revealed a couple of small nodes, around .6 gr. some of those groups had less than 3/8" vertical over a spread of .6 gr

I realized right away that the target was going to get very busy, so I shot one round from each of three identical bullets at 3 separate targets. The results lined up quite well.

The higher node broke well above the 3200 barrier. Nearing 3300. I am going to load a few of those, but I think they'll be hard on brass. There will certainly be a good shooting load in there, as it shot very well when I paralled the targets.

It was a lot of work with a spotting scope, marking each consecutive shot with a sharpie on an identical target back at the bench.

My rifle is 20.5". I see no reason you couldn't approach 3400 from a 24-26" 6 WOA. A 6 DTI should be able to make short work of it. In my supplied data from john, he broke 3400 from the WOA with some old "T" stuff. I'm sure that was from a long tube.

All in all, I don't know that the 8208 will outshoot my N135 loads. I'll try and see, but I doubt it.

Anyway, it was fun.
 
I think I should add that in my original testing I got much lower velocities from flat based bullet. Obviously this was related to bearing surface, so I ditched them and went with the sierra BK. When nosler quits making them purple then I'll try a few.... Sheesh, haha
 
I also think you're right about 335, I've had a lot of folks tell me they liked it.
I just don't care for spherical stuff, but without good reason.
I wish I could get AA and western powders, but I've never seen a just of any kind of either one in my whole life.
I would like to have some 2015 and would love to have a few pounds if TAC, just never seen it.
 
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Quickload shows the highest velocity with the 6mm DTi and the 70gr bullet was with IMR 3031.
I tried the load since I had a can sitting around and with 30.2 gr my average was 3333fps and it shot great. I was using the Nosler BT though.

Might want to have a drop tube handy to get that much in there.
cool.gif
 
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Hey! I was wondering where you were venatic.

I am using hornady brass for the most part, and some pre-nosler SSA. I realized back in the Relaoder 15 days of my load development a drop tube was a must. Some of my N135 loads I have to pour in very slowly with a Forster blue ribbon drop tube and some tapping.

I may try some 3031. I think I have about half a pound.

Thanks for the tip.
 
Originally Posted By: CZ527I also think you're right about 335, I've had a lot of folks tell me they liked it.


I have been using 31.o grs of 8208 with 58 vmax's and getting ok groups, about 1" @ 100. Tried some H335 today and wow, what a difference. So much better IMO.

I was getting desperate. I even cut my 6x6.8 barrel down to 18" hoping to stiffen it up. I still have plenty of gas to operate my rifle length gas tube with an adjustable gas block. Looking forward to shooting this BHW barrel some more, hoping to repeat the groups I got today. I also want to shoot it out to 300 or so.
 
I have the first ever built 6dti and checked my group again this fall and shot three in .205 with 30.0gr of 8208xbr. That runs 3150fps in my 22in barrel.
 
I use 30.5 grains 8208 in my 6x6.8. Using the 68 grain bergers I get one hole at 100 yards and run about 3300 by by best guess per my drop data!
 
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