[sharpshooter33]

I've noticed a move to the 1:11 twist vs the 1:10. Is there a reason for this? I also noticed that it looks like from the test report that stainless tends to stay alittle lower on the pressure?

Anybody have any insight on this?

thanks
SS33

 

[paulosantos]

Yes, the stainless steel barrels tend to produce less pressure, most likely due to the chrome.
The 1:11" also reduce some pressure, but a good 1:10"/SS/SPCII OR DMR chambered barrel is fine unless you are trying to get every last FPS out of the SPC.

 

[ron169]

I've noticed a move to the 1:11 twist vs the 1:10. Is there a reason for this? I also noticed that it looks like from the test report that stainless tends to stay alittle lower on the pressure?

Anybody have any insight on this?

thanks
SS33

The reason most have moved from a 10 twist to an 11 is because the 11 twist yields lower pressure, which means you can throw more powder behind them and get more velocity

 

[sharpshooter33]

I'm looking to build a carbine length(16") that I can shoot accurately out to 600 yards and still get away with some CQC also. Looking for the do it all rifle build. My local range goes to 600yards. I'm 46 been in LE for 20yrs with a little reserve time. I've been a shooter for quite awhile, but my eye sight and hold is starting to fade so realistically I'm only good to about 600yards. 8)

Most of my hunting is probably going to be under 200 yards, however I would like to score out to 600 if I go on any hunting trips west. I've had several AR's over the years, but I'm looking to find one now that I can focus on. I'm trying to build the best I can because I figure this is my last one. I want the barrel to be able to handle newer bullets as they produce them with better BC's.

If I understand the SPCII it's just a longer bullet seating area before it hits the grooves?
The DMR I'm not sure about. When it gets to reloading do you have to have DMR dies or do the SAAMI dies work for both the DMR and SPCII?

I've seen a couple of drawings of the SPCII and SAAMI, but haven't really had a chance to digest them. I've really just been into the 6.8 build and research since around December so I've got a lot more research to do.

Yes, the stainless steel barrels tend to produce less pressure, most likely due to the chrome.
The 1:11" also reduce some pressure, but a good 1:10"/SS/SPCII OR DMR chambered barrel is fine unless you are trying to get every last FPS out of the SPC.

 

[constructor]

I'm looking to build a carbine length(16") that I can shoot accurately out to 600 yards and still get away with some CQC also. Looking for the do it all rifle build. My local range goes to 600yards. I'm 46 been in LE for 20yrs with a little reserve time. I've been a shooter for quite awhile, but my eye sight and hold is starting to fade so realistically I'm only good to about 600yards. 8)

Most of my hunting is probably going to be under 200 yards, however I would like to score out to 600 if I go on any hunting trips west. I've had several AR's over the years, but I'm looking to find one now that I can focus on. I'm trying to build the best I can because I figure this is my last one. I want the barrel to be able to handle newer bullets as they produce them with better BC's.

If I understand the SPCII it's just a longer bullet seating area before it hits the grooves?
The DMR I'm not sure about. When it gets to reloading do you have to have DMR dies or do the SAAMI dies work for both the DMR and SPCII?

I've seen a couple of drawings of the SPCII and SAAMI, but haven't really had a chance to digest them. I've really just been into the 6.8 build and research since around December so I've got a lot more research to do.

Yes, the stainless steel barrels tend to produce less pressure, most likely due to the chrome.
The 1:11" also reduce some pressure, but a good 1:10"/SS/SPCII OR DMR chambered barrel is fine unless you are trying to get every last FPS out of the SPC.

The same dies work for all 3 chambers, you may want to use RCBS small base dies to ensure reliability in all chambers, DPMS chambers are known to be tight and some Redding dies are a little large which causes issues.
The DMR corrected the cone angle from the case mouth to the leade(freebore) it is also .277 at the leade instead of .278 like the SPCII and SAAMI so it should be more accurate in most cases. There are some other small changes to keep from overworking the brass and making the most of the OAL restriction due to the mags at 2.30"
DMR= "designated Marksman rifle" it is a reliable match chamber

 

[paulosantos]

The SAAMI chamber is like the .223 chamber.
The SPCII chamber is like 5.56 chamber.
The DMR chamber is like the .223 Wylde chamber.

If I was in your shoes, I'd get one of the MK 16" uppers from AR15Performance.

The 6.8 SPC is best if used from 0-300 yards for hunting. If you want to go past that, I would get an AR10.

 

[ArtFWTx]

If you research further you'll see the original 6.8 designers preferred slower twists and knew these twists would perform better. 1:10 twist barrel blanks were used initially due to being popularly available... as .270 Winchester.

Make sure to read the stickied 6.8 barrel testing reports above, and search the thread histories for topics such as DMR, SPC II, etc. There is tons of info on this forum if you have the time to read it.

Long story short... at a minimum you want the SPC II chamber, or DMR chamber, and twist rates of 1:10 at the fastest, and preferably 1:11, or 1:12. The industry has largely moved away from the ridiculous SAAMI chamber (thanks Remington), and many companies are moving to different twist rates or rifling types to further reduce pressure and increase performance.

For the hunting and shooting you mentioned, you have several good selections to choose from. The Xtreme 6.8 uppers, LWRC, Noveske, Stag, RRA, WOA, Denny's GTS, POF, Addax Tactical, CMMG.

 

[sharpshooter33]

I've got an AR10. It's just too heavy to be hunking around it definitely is not much on CQC.
I know I can shoot 600+ with my AR10, but I really wouldn't want to take it on a hunting trip locally where my shots would probably be around 50-150yards. My AR10 along with my AR15NM sit in my gun safe. I want something I can take with for camping, hunting and also shooting at the range out to 600. I want a rifle I can keep by my bed and throw it in the car and do most everthing I want it to. The one thing I've not liked with my prior AR15 is the 223/556 not being a good hunting round for medium game. I think it's possible to get a 6.8 to shoot MOA out to 600 and still be a fun little close range rifle. So that is my goal.

I did not realize the DMR and SPCII would use the same dies. I thought the old Wylde chamber 223 needed different dies?

I do like the .277 instead of .278 of the DMR. It should lead to better accuracy in general. I thought the SPCII also corrected the leade angle also?

Constructor, are your barrels SS or CM? Who make the barrels Lothar?
I'm kinda partial to Douglass SS

The SAAMI chamber is like the .223 chamber.
The SPCII chamber is like 5.56 chamber.
The DMR chamber is like the .223 Wylde chamber.

If I was in your shoes, I'd get one of the MK 16" uppers from AR15Performance.

The 6.8 SPC is best if used from 0-300 yards for hunting. If you want to go past that, I would get an AR10.

 

[sharpshooter33]

Thanks ArtFWTx for your input. I know there is a lot of info on these pages and I hope to digest as much as possible with the time I have. Unfortunately I don't have the kinda time I used to for shooting and firearms research. I've got children in college, cars to keep running and a home to maintenance. So I try to streamline my research and your answers from all of you help with that.

Thanks all
SS33

If you research further you'll see the original 6.8 designers preferred slower twists and knew these twists would perform better. 1:10 twist barrel blanks were used initially due to being popularly available... as .270 Winchester.

Make sure to read the stickied 6.8 barrel testing reports above, and search the thread histories for topics such as DMR, SPC II, etc. There is tons of info on this forum if you have the time to read it.

Long story short... at a minimum you want the SPC II chamber, or DMR chamber, and twist rates of 1:10 at the fastest, and preferably 1:11, or 1:12. The industry has largely moved away from the ridiculous SAAMI chamber (thanks Remington), and many companies are moving to different twist rates or rifling types to further reduce pressure and increase performance.

For the hunting and shooting you mentioned, you have several good selections to choose from. The Xtreme 6.8 uppers, LWRC, Noveske, Stag, RRA, WOA, Denny's GTS, POF, Addax Tactical, CMMG.

 

[mtruette]

I have the Douglas SS, with 1:11 twist, and I am completly satisfied. However, I haven't tried it further than 150 yards as of yet. You have peaked my interest, and I now will take it to the range and run through a few rounds at 600 and 800 yds. just to see what happens.

 

[ArtFWTx]

Thanks ArtFWTx for your input. I know there is a lot of info on these pages and I hope to digest as much as possible with the time I have. Unfortunately I don't have the kinda time I used to for shooting and firearms research. I've got children in college, cars to keep running and a home to maintenance. So I try to streamline my research and your answers from all of you help with that.

Thanks all
SS33

Many have busy schedules and other things to do. If you do have a few minutes, this link is probably the most important to read before investing in 6.8 products.

viewtopic.php?f=1&t=3473

 

[sharpshooter33]

Who made your barrel for you? Which chamber does it have? I talked to CLE, but they only do the SAAMI. I've also been looking at PAC-NOR. A friend of mine had one of their barrels in 5.56 and it was nice and a good shooter.

I have the Douglas SS, with 1:11 twist, and I am completly satisfied. However, I haven't tried it further than 150 yards as of yet. You have peaked my interest, and I now will take it to the range and run through a few rounds at 600 and 800 yds. just to see what happens.

 

[constructor]

I've got an AR10. It's just too heavy to be hunking around it definitely is not much on CQC.
I know I can shoot 600+ with my AR10, but I really wouldn't want to take it on a hunting trip locally where my shots would probably be around 50-150yards. My AR10 along with my AR15NM sit in my gun safe. I want something I can take with for camping, hunting and also shooting at the range out to 600. I want a rifle I can keep by my bed and throw it in the car and do most everthing I want it to. The one thing I've not liked with my prior AR15 is the 223/556 not being a good hunting round for medium game. I think it's possible to get a 6.8 to shoot MOA out to 600 and still be a fun little close range rifle. So that is my goal.

I did not realize the DMR and SPCII would use the same dies. I thought the old Wylde chamber 223 needed different dies?No, same dies

I do like the .277 instead of .278 of the SPCII. It should lead to better accuracy in general. I thought the SPCII also corrected the leade angle also?added length to the freebore but did not correct the 80 degree angle at the cone

Constructor, are your barrels SS or CM? Who make the barrels Lothar?The first Mk68 Recons will be CM,chrome lined Lothar polygonal 11.25 twist, the lapped bores of these are smoother than the Douglass. Most of the guys want chromelined barrels because they last longer.
I'm kinda partial to Douglass SS

The SAAMI chamber is like the .223 chamber.
The SPCII chamber is like 5.56 chamber.
The DMR chamber is like the .223 Wylde chamber.

If I was in your shoes, I'd get one of the MK 16" uppers from AR15Performance.

The 6.8 SPC is best if used from 0-300 yards for hunting. If you want to go past that, I would get an AR10.

 

[rothamber]

I've got an AR10. It's just too heavy to be hunking around it definitely is not much on CQC.
I know I can shoot 600+ with my AR10, but I really wouldn't want to take it on a hunting trip locally where my shots would probably be around 50-150yards. My AR10 along with my AR15NM sit in my gun safe. I want something I can take with for camping, hunting and also shooting at the range out to 600. I want a rifle I can keep by my bed and throw it in the car and do most everthing I want it to. The one thing I've not liked with my prior AR15 is the 223/556 not being a good hunting round for medium game. I think it's possible to get a 6.8 to shoot MOA out to 600 and still be a fun little close range rifle. So that is my goal.

I did not realize the DMR and SPCII would use the same dies. I thought the old Wylde chamber 223 needed different dies?No, same dies

I do like the .277 instead of .278 of the SPCII. It should lead to better accuracy in general. I thought the SPCII also corrected the leade angle also?added length to the freebore but did not correct the 80 degree angle at the cone

Constructor, are your barrels SS or CM? Who make the barrels Lothar?The first Mk68 Recons will be CM,chrome lined Lothar polygonal 11.25 twist, the lapped bores of these are smoother than the Douglass. Most of the guys want chromelined barrels because they last longer.
I'm kinda partial to Douglass SS

The SAAMI chamber is like the .223 chamber.
The SPCII chamber is like 5.56 chamber.
The DMR chamber is like the .223 Wylde chamber.

If I was in your shoes, I'd get one of the MK 16" uppers from AR15Performance.

The 6.8 SPC is best if used from 0-300 yards for hunting. If you want to go past that, I would get an AR10.

Are the Douglas barrels lapped? They don't seem to mention it on their website.

 

[constructor]

I've got an AR10. It's just too heavy to be hunking around it definitely is not much on CQC.
I know I can shoot 600+ with my AR10, but I really wouldn't want to take it on a hunting trip locally where my shots would probably be around 50-150yards. My AR10 along with my AR15NM sit in my gun safe. I want something I can take with for camping, hunting and also shooting at the range out to 600. I want a rifle I can keep by my bed and throw it in the car and do most everthing I want it to. The one thing I've not liked with my prior AR15 is the 223/556 not being a good hunting round for medium game. I think it's possible to get a 6.8 to shoot MOA out to 600 and still be a fun little close range rifle. So that is my goal.

I did not realize the DMR and SPCII would use the same dies. I thought the old Wylde chamber 223 needed different dies?No, same dies

I do like the .277 instead of .278 of the SPCII. It should lead to better accuracy in general. I thought the SPCII also corrected the leade angle also?added length to the freebore but did not correct the 80 degree angle at the cone

Constructor, are your barrels SS or CM? Who make the barrels Lothar?The first Mk68 Recons will be CM,chrome lined Lothar polygonal 11.25 twist, the lapped bores of these are smoother than the Douglass. Most of the guys want chromelined barrels because they last longer.
I'm kinda partial to Douglass SS

The SAAMI chamber is like the .223 chamber.
The SPCII chamber is like 5.56 chamber.
The DMR chamber is like the .223 Wylde chamber.

If I was in your shoes, I'd get one of the MK 16" uppers from AR15Performance.

The 6.8 SPC is best if used from 0-300 yards for hunting. If you want to go past that, I would get an AR10.

Are the Douglas barrels lapped? They don't seem to mention it on their website.

Douglas match barrels are lapped, every company laps to a different level though. Some look like polished stainless and some look like the rumble strips have been smoothed out a bit. IMO Douglas makes a good inexpensive match barrel.

 

[Test_User]

C,

I just did some checking and Douglas does not hand lap their barrels. I think that may be one of the main reasons they are cheaper to buy compared to the other match barrels. But their steel is harder then PacNor and much more so the Shilen which have the softest barrels with the shortest life this is all from reports. All will shoot better in a bolt gun then just about anyone can shoot so.....From what I have seen posted some of Douglas's xxx match barrels are found to be almost slick as glass and others have visible tooling and no feathering. From their site the only dif between the reg and super match is the super match are air gauged to insure min runout. They also mark one end if it is tighter so you can make sure its the muzzle on straight blanks. That is nice.

 

[sharpshooter33]

C,

I just did some checking and Douglas does not hand lap their barrels. I think that may be one of the main reasons they are cheaper to buy compared to the other match barrels. But their steel is harder then PacNor and much more so the Shilen which have the softest barrels with the shortest life this is all from reports. All will shoot better in a bolt gun then just about anyone can shoot so.....From what I have seen posted some of Douglas's xxx match barrels are found to be almost slick as glass and others have visible tooling and no feathering. From their site the only dif between the reg and super match is the super match are air gauged to insure min runout. They also mark one end if it is tighter so you can make sure its the muzzle on straight blanks. That is nice.

Yea, but here's the big question...If I wanted to get a true match grade SS barrel 1:11 twist in 6.8SPC DMR or SPCII where would I go to get it done?.... Noveke/PACNOR is backlogged on their barrels, AR15 Performance is backlogged. CLE has the barrels, but only does SAAMI. I really don't want to order a custom barrel then have to try to change the chamber to SPCII. Getting a Match Grade stainless barrel chambered in DMR or SPCII seems like it will be awhile. :roll:

 

[constructor]

C,

I just did some checking and Douglas does not hand lap their barrels. I think that may be one of the main reasons they are cheaper to buy compared to the other match barrels. But their steel is harder then PacNor and much more so the Shilen which have the softest barrels with the shortest life this is all from reports. All will shoot better in a bolt gun then just about anyone can shoot so.....From what I have seen posted some of Douglas's xxx match barrels are found to be almost slick as glass and others have visible tooling and no feathering. From their site the only dif between the reg and super match is the super match are air gauged to insure min runout. They also mark one end if it is tighter so you can make sure its the muzzle on straight blanks. That is nice.

Yea, but here's the big question...If I wanted to get a true match grade SS barrel 1:11 twist in 6.8SPC DMR or SPCII where would I go to get it done?.... Noveke/PACNOR is backlogged on their barrels, AR15 Performance is backlogged. CLE has the barrels, but only does SAAMI. I really don't want to order a custom barrel then have to try to change the chamber to SPCII. Getting a Match Grade stainless barrel chambered in DMR or SPCII seems like it will be awhile. :roll:

Try MSTN or PRI

 

[Test_User]

I second that they would be my first choices along with GAP.

 

[sharpshooter33]

MSTN didn't show anything except the Noveske which I'm checking on chamber and twist for the barrels they have. Couldn't find the website for PRI. Who's GAP?

I second that they would be my first choices along with GAP.