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 6mm WOA
firemannw  [Member]
9/16/2010 4:01:10 PM EST
Does anyone have any experience with the 6mm WOA? I seen on another forum where guys were getting 2700fps out of the 6mm SMK 107gr bullet. Do you have to fire form brass? Who makes barrels and die? What is the best barrel length? Any information is welcome.
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sititunga  [Member]
9/17/2010 6:16:44 AM EST
Originally Posted By firemannw:
Does anyone have any experience with the 6mm WOA? I seen on another forum where guys were getting 2700fps out of the 6mm SMK 107gr bullet. Do you have to fire form brass? Who makes barrels and die? What is the best barrel length? Any information is welcome.


I think ar15performance and Dtech make uppers for the WOA. They also make uppers for the 6mm BRX which supposedly delivers +3000 fps with 107/108 gr bullets. BTW the 6mm Turbo 40 Improved (necked down 6.5 Grendel) delivers 2900 fps with the same class of bullets. Just some other options you may want to consider that deliver a little more performance than the WOA.



Cartridge line-up left to right:

223, 6.5 Grendel, 6mm AR, 6mm WOA, 6mm BR, 6mm BRX, 6.5x47, 260 Rem


borderpatrol  [Member]
9/19/2010 12:34:26 PM EST
Consider this a match cartridge, that's what it's designed for. 2750 fps has been run with Sierra 107 Match Kings with around 27.5 grains of Varget. Some have gone faster, some slower.

You have to buy the custom dies, they aren't cheap. I use SSA brass for conversion. It's suppose to have greater internal capacity than Remington and last longer. You simply run the brass through the die and shoot a 6mm bullet through it. Case "forming" is done with the first load fired, accurate enough to shoot 200/300 tournaments and not notice a difference from the second (already formed) firing.

I also selected SSA brass beacause of the small rifle primer pocket. I see no need for a large rifle primer in this caliber.

Hornady's 87 grain BTHP # 2442 is a great 200/300 bullet. You can use the same powder charge as the 107's or bump it up a little. Whatever works best in your rifle.

I'm running 26" barrels in my 2 uppers. They are Bartlien 1/8 twist barrels custom profiled by White Oak Precision (John Holliger) to my specs. I didn't want a bull barrel, they aren't necessary. It's .850" under the handguard, .812" from the gas block to the muzzle. The gas port has been moved forward 2" and a custom gas tube installed.

This is very close ballistically to the 6mmAR of Robert Whitely's and 6mm Hagar that has won the Nationals (also built by John Holliger) and placed 2nd this year. It's a custom chambered rifle and all the problems/joys that accompany a wildcat cartridge come with it. I like mine, it's a good thing, resale on something like this is almost impossible to accomplish. People buy these things new, never used.
firemannw  [Member]
9/19/2010 1:49:47 PM EST
Are you getting the 2750 out of the SMK 107 using mag length loads? Is there a big velocity drop from a 26" to a 20"? With non fire formed loads can you still push them to 2750? How much do barrels run and how makes them? How makes dies and how much do they run. Sorry for all the questions, just unable to find a lot of info on the 6mm WOA. I also interested the 6x41 SPC that AR performance is working on.
borderpatrol  [Member]
9/23/2010 4:12:13 PM EST
No magazine length load exists above the 87 grain Hornady BTHP. Even Sierra's 95 grain Match King must be long loaded one at a time.

I purchased a quantity of Berger's 90 grain Match BT but haven't tried them yet. I'm hoping they will be magazine compatable but I doubt it.

The other magazine length bullet I'm using is Sierra's 80 grain SBT Blitz. It looks just like a fat 69 grain .224 and has an identical B.C. I haven't chronographed them yet, but believe 2900 fps will be easy with those.

You resize new 6.8SPC cases in a custom 6mmWOA die then load and shoot. After the first firing you do it all over again. The first firing is very accurate and can be done while shooting a reduced course match or 200/300 yard stage of the full course. I would use at least once fired as a 6mmWOA for the full course 600 yard stage. I need all the accuracy I can get at distance.

2750 fps is about it for speed with 107's. You don'yt have to run them that fast to get good groups. The 107 6mm match bullets are some of the very best bullets made. They lack nothing in the accuracy department.

RE-15 is another powder option. Illinois High Power shooting page has some discussion of this cartridge. John Holliger competes with them and has sold a rifle or two to the members there.

Good Luck
sititunga  [Member]
9/23/2010 5:57:22 PM EST
Originally Posted By borderpatrol:
2750 fps is about it for speed with 107's. You don'yt have to run them that fast to get good groups. The 107 6mm match bullets are some of the very best bullets made. They lack nothing in the accuracy department.

Good Luck


The Grendel gets that speed with a 108 grain bullet, furthermore the 6mm Turbo 40 Improved gets 2850 - 2900 with that weight bullet.

firemannw  [Member]
9/23/2010 6:32:36 PM EST
The reason I was looking at the 6mm WOA was because of the availability of 6.8 SPC brass and price. Even with hornady making brass its still around $65 to $70 per 100, where as 6.8 SPC is $45 to $55 per 100. The 6mm Turbo 40 is also based off 6.5 Grendel brass some not big help. I really like my Grendel but the price of brass is starting to get old. Even with fire forming cheap 7.62x39 brass by the time you buy bullets, powder, primers, and brass your not saving anything. I know you get a lot of shooting practice by fire forming but it would be nice to stock pile some brass without spending a fortune.
mjcarter  [Member]
9/24/2010 10:02:16 PM EST
Originally Posted By sititunga:
Originally Posted By borderpatrol:
2750 fps is about it for speed with 107's. You don'yt have to run them that fast to get good groups. The 107 6mm match bullets are some of the very best bullets made. They lack nothing in the accuracy department.

Good Luck


The Grendel get's that speed with a 108 grain bullet, furthermore the 6mm Turbo 40 Improved gets 2850 - 2900 with that weight bullet.



The BC of the 6mm 107 is higher than the Grendel's 6.5mm 108. Does the 6mm Turbo have a .308 size case head or is it the same size as the Grendel?

sititunga  [Member]
9/25/2010 4:19:49 AM EST
Originally Posted By mjcarter:
Originally Posted By sititunga:
Originally Posted By borderpatrol:
2750 fps is about it for speed with 107's. You don'yt have to run them that fast to get good groups. The 107 6mm match bullets are some of the very best bullets made. They lack nothing in the accuracy department.

Good Luck


The Grendel get's that speed with a 108 grain bullet, furthermore the 6mm Turbo 40 Improved gets 2850 - 2900 with that weight bullet.



The BC of the 6mm 107 is higher than the Grendel's 6.5mm 108. Does the 6mm Turbo have a .308 size case head or is it the same size as the Grendel?



It's a Grendel case with the shoulder blown forward. Robert Whitley, the inventor of the turbo 40, builds mind blowlingly accurate ARs. The other option if you want even more speed from your AR15 is the 6mm BRX which has velocity claims of +3000fps with bullets in the 105 to 108 range, also pictured below.

http://6mmar.com/6mmAR_Turbo_40_Improved.html


]

Cartridge line-up left to right:

223, 6.5 Grendel, 6mm AR (NOT the Turbo 40 Imp), 6mm WOA, 6mm BR, 6mm BRX, 6.5x47, 260 Rem
borderpatrol  [Member]
9/26/2010 9:45:18 AM EST
Originally Posted By sititunga:
Originally Posted By borderpatrol:
2750 fps is about it for speed with 107's. You don'yt have to run them that fast to get good groups. The 107 6mm match bullets are some of the very best bullets made. They lack nothing in the accuracy department.

Good Luck


The Grendel gets that speed with a 108 grain bullet, furthermore the 6mm Turbo 40 Improved gets 2850 - 2900 with that weight bullet.



My Grendel is over 100 fps slower, closer to 150 fps slower and the bolt has less case support at the head. My Grendel's barrel is 2" shorter which has a effect on speed also. The 107 6mm SMK has a B.C. of over .500, the 107 6.5mm SMK is only around .400 B.C.

The OP was intereste in what 6mmWOA does, not in a caliber vs. caliber debate.

The advantage, in my opinion, lies with Whitely's wildcats just because the quality of the brass is better. Lapua is the premier maker of brass, although they do a better job with their PPC and BR brass than some others, Grendel included. The shotcoming has already been mentioned, weaker bolts because of less metal.

Grendel shooters have their "proud member of the broken bolt club" which I'll try very hard not to join.

edited to add - Grendel uses a nominal 7.62X39mm case head bolt .441" to .444" +/- a little. AR Performance and others are producing .308 case head bolts and extensions which will allow 6mm Norma BR based cartridges to run through an AR chassis. Magazines may be the only glitch to be worked out.

also added - I would like to see AR Performance give us a .441" to .444" face bolt based on their new .308 bolt. This will give the Whitely Grendel based wildcats a better home to live in.
sititunga  [Member]
9/26/2010 11:21:47 AM EST
Originally Posted By borderpatrol:
Originally Posted By sititunga:
Originally Posted By borderpatrol:
2750 fps is about it for speed with 107's. You don'yt have to run them that fast to get good groups. The 107 6mm match bullets are some of the very best bullets made. They lack nothing in the accuracy department.

Good Luck


The Grendel gets that speed with a 108 grain bullet, furthermore the 6mm Turbo 40 Improved gets 2850 - 2900 with that weight bullet.



My Grendel is over 100 fps slower, closer to 150 fps slower and the bolt has less case support at the head. My Grendel's barrel is 2" shorter which has a effect on speed also. The 107 6mm SMK has a B.C. of over .500, the 107 6.5mm SMK is only around .400 B.C.

The OP was intereste in what 6mmWOA does, not in a caliber vs. caliber debate.

The advantage, in my opinion, lies with Whitely's wildcats just because the quality of the brass is better. Lapua is the premier maker of brass, although they do a better job with their PPC and BR brass than some others, Grendel included. The shotcoming has already been mentioned, weaker bolts because of less metal.

Grendel shooters have their "proud member of the broken bolt club" which I'll try very hard not to join.

edited to add - Grendel uses a nominal 7.62X39mm case head bolt .441" to .444" +/- a little. AR Performance and others are producing .308 case head bolts and extensions which will allow 6mm Norma BR based cartridges to run through an AR chassis. Magazines may be the only glitch to be worked out.

also added - I would like to see AR Performance give us a .441" to .444" face bolt based on their new .308 bolt. This will give the Whitely Grendel based wildcats a better home to live in.


The 6.5 108 Lapua has a BC of 478 which is pretty close to the BC offered by the 6mm 107gr SMK. I chronographed some 6.5 108 grain Lapuas out of my Grendel the other day and was achieving 2740 fps from a 22 inch barrel. AR15 Performance's bolt would certainly handle the Grendel or Whitely's wildcats with more pressure comfort room. Harrison at AR15 Performance has already indicated he could offer bolts for the Grendel. However I do think the 6mm BRX is the cartridge to watch in the AR15 platform.
borderpatrol  [Member]
9/27/2010 11:58:01 AM EST
What load are you using to drive your bullets that fast?
sititunga  [Member]
9/27/2010 6:20:59 PM EST
Originally Posted By borderpatrol:
What load are you using to drive your bullets that fast?


Ramshot X-Terminator 29.5 grains - 0.3 grains over max listed.

http://www.ramshot.com/powders/

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