6.8 case variants

TXCOONDOG

Well-known member
Looking to build a dedicated predator rig and trying to stay away from the AR 10 platform.

I don’t save hides so pelt damage is not a concern. At times we get temp swings from 90-30 degrees so I like powders that are not affected as much by huge temp swings.

I also hunt suppressed so barrel lengths 20” and under work best for me.

I believe the 6.8 case variants will offer the best options for me using the 58 grain V-Max bullets in the 6x68.

I believe the 1:10 twist would work best but not sure about barrel length and powder to push a 58 grainer to 3000-3100.

Any help or suggestions are appreciated.


 
I think you're on the right track. Love the 6x6.8. Will definitely hammer coyotes. Running 8208xbr will avoid temp sensitivity and easily push the 58vmax faster than 3100 in a 20" or 18".
 
I have over 8lbs of varget..... Would I be able to get enough in the case to reach my velocity goal with accuracy ?

 
Unlikely, the slower burn rate and case capacity are going against you.
Since you already have Varget, try working up a load, carefully.
If someone has QL data for 6x6.8 wildcat, they could run an estimate on Varget & 58 Vmax.
I use 8208 under 58 Vmax and am pleased with its muzzle vel.
 
Varget will not give you much in teh top end. Just a tad to slow in comparison with the volume of the powder. CFE 223 is one you might look at. Slow burn rate but very dense and it will get you where you want to go.

Greg
 
What Greg said, he is our 6x6.8 resident guru.
If you have Ramshot TAC, it would be ideal in burn rate vs Varget and worth a try.
 
for 55's and 58's I found that h322 and TAC were the best, Tac was less peaky and more forgiving. I noticed no temp sensitivity. it pours like butter so BAM its tac!

also I would go with the 6mm hagar, I hate how these various 6.8 offerings keep chiseling away on the 6.8 case till they neuter it down to a 223 case capacity. The hagar case is the non trimmed case the others are based on.

Also as much as I prefer something 6mm in just about everything. if you wanna shoot light 6mm at warp speeds you only have 3 choices. 55's in nosler, ( I can't get nosler to shoot when loaded full house in ANY ar 15 I have tried them in) 55's in sierra's, less optimal bullet because its flat base and brick like BC. Or 58grain vmax's The extra weight gives up some speed and the vmaxs are built to explode which may or may not be what you want

with that said I would consider a 22 nosler still. you get a full range of 22 cal bullets in all flavors and hardnesses. you get a full length hagar case. The other really interesting wildcat I would love to see is a 20 nosler. That seems like one wicked AR 15's round.

lastly I lust after something that holds 40 grains of powder and has plug and play parts. a modified AR 15 upper, that runs rebated 6mm BR cases.
 
You can get that speed and better out of a 6x45 with either A2230/Exterminator or IMR 4198 with a 20" barrel, so you should be able to get way above that with the 6x6.8.
 
Originally Posted By: GLShooterYeah the 58 will do 3450 in the 20" without breaking a sweat. The cartridge was actually designed around that bullet.

Greg

And it will do it with a lot less than 40 grains of powder
 
Originally Posted By: MerditOriginally Posted By: GLShooterYeah the 58 will do 3450 in the 20" without breaking a sweat. The cartridge was actually designed around that bullet.

Greg

And it will do it with a lot less than 40 grains of powder

True dat.

Greg
 
Thanks for the feedback all.

I need to think about things for a bit as I do love my suppressed bolt actions.

Greg,

Does Rich or anyone make a 6x68 barrel for a Savage ?w
 
Originally Posted By: TXCOONDOGThanks for the feedback all.

I need to think about things for a bit as I do love my suppressed bolt actions.

Greg,

Does Rich or anyone make a 6x68 barrel for a Savage ?w

Absolutely. No problem. Give him a call.

Greg
 
Originally Posted By: steve garrettAlso as much as I prefer something 6mm in just about everything. if you wanna shoot light 6mm at warp speeds you only have 3 choices. 55's in nosler, ( I can't get nosler to shoot when loaded full house in ANY ar 15 I have tried them in) 55's in sierra's, less optimal bullet because its flat base and brick like BC. Or 58grain vmax's The extra weight gives up some speed and the vmaxs are built to explode which may or may not be what you want
Have you tried the 55gr Nosler Ballistic Tip Lead Free? Fantastic bullet. 5 shots:

41507918552_385617eb21_c.jpg
 
Originally Posted By: TXCOONDOGLooking to build a dedicated predator rig and trying to stay away from the AR 10 platform.

I don’t save hides so pelt damage is not a concern. At times we get temp swings from 90-30 degrees so I like powders that are not affected as much by huge temp swings.

I also hunt suppressed so barrel lengths 20” and under work best for me.

I believe the 6.8 case variants will offer the best options for me using the 58 grain V-Max bullets in the 6x68.

I believe the 1:10 twist would work best but not sure about barrel length and powder to push a 58 grainer to 3000-3100.

Any help or suggestions are appreciated.



I have a 20" barrel that I'm using to launch 87 grain vmax's at 2900 fps using varget. I think you could get 3100 fps using 55 grain bullets and varget, but has been stated by others, using xbr8208 I've seen speeds over 3500 fps with 55-58 grain bullets.
 
Originally Posted By: TXCOONDOGI’m sure this will vary by manufacture since there isn’t a SAAMII spec. What is the freebore in the 6x6.8 ?

The 6X6.8 as designed by Ritch was built around the 58 VMAX and bullets up to the 87/90 range at mag length. The freebore is set at ZERO. The current ones from Tactical Ordnance that Ritch sells are to this spec. Those from BHW are all over the map and are nothing like what they started with.

Greg
 
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