WTB --- New 6.8 Complete Upper or Barrel ...

[Extreme Velocity]

Looking for a NEW complete upper assembly (with or without carrier/bolt assembly) and/or components/pieces to build a new upper as follows:

16" or 18" barrel --- chrome moly steel (chrome plated bore and chamber or not) or stainless steel, medium/medium heavy contour, 1-11" twist, SPCII chamber, mid-length gas port and threaded muzzle end.

Flat top upper receiver --- may consider an upper with "high-rise" rail and/or a left-hand upper.

Free float aluminum handguard tube (mid-length). [I'll buy the "right" upper assembly regardless of what handguard assembly it has on it!]

Please let me know if you've got something for sale that might match these needs! :)

[fireguy]

Xtreme, hands down. There are other options (i.e. see the Barrett vs. POF thread), some of which have performance approaching the Xtreme, but at a much higher price.

The bad news is the wait on the Xtreme; but then again, that will give you time to hunt for ammo while you wait.

[Extreme Velocity]

OK.....

Only looking for a 6.8 Rem SPC Bolt now. That's the last thing I need to complete this build.

[Extreme Velocity]

Xtreme, hands down. There are other options (i.e. see the Barrett vs. POF thread), some of which have performance approaching the Xtreme, but at a much higher price.

The bad news is the wait on the Xtreme; but then again, that will give you time to hunt for ammo while you wait.

I'm curious --- what makes the Xtreme so great? I read the only thread I could find that was "Barrett vs. POF" and that didn't help. As a guy that has been a licensed Type 01 dealer/gunsmith, Type 07 Manufacturer/Class II S.O.T. and has been knee-deep in several R&D projects for DOD and DOE contractors, I'm looking for "hard data" to support claims.

Not trying to give you a hard time (really!!), but you made a pretty strong statement and I just want to know what info you've got to back it up.

[marinesg1012]

The Xtreme was designed and is being produced by the guys who helped do all the research for the new specs that all the manufactures are switching too, Harrison (constructor) designed the DMR-C (chrome) chamber to be used in these chrome lined barrels, the bore diamtier was also designed with chrome lining in mind. Several members that have the uppers already are reporting 1-1.5 MOA groups with factory SSA ammo....

For a 16 inch chrome lined carbine upper this is at the top of the list...

[ron169]

I will expound upon what MarinesG said. The Xtreme upper is a collaborative effort from 2 guys who pioneered many of the aspects concrning the 6.8 mm cartridge. The Xtreme upper utilyzes the proper barrel twist, 1:11.25, with a 5R button. The chamber is a DMR-C chamber, which is an improved chamber which maximizes accuracy while keeping pressure down. The combination of Barrel twist and chamber enable the Xtreme to handle the hottest of loads, while keeping the pressure safe, all whilst shotting accurately.

Combine all that with all components being at or above mil spec rating, having properly staked carrier keys, and M4 ramps, and you have what is arguably the best possible upper for the money. At under 700 for the whole uppr, it directly competes with major manufacturers such as Stag, DPMS, RRA etc, but has many of the things that they are missing.

[Jamesb74]

I will expound upon what MarinesG said. The Xtreme upper is a collaborative effort from 2 guys who pioneered many of the aspects concrning the 6.8 mm cartridge. The Xtreme upper utilyzes the proper barrel twist, 1:11.25, with a 5R button. The chamber is a DMR-C chamber, which is an improved chamber which maximizes accuracy while keeping pressure down. The combination of Barrel twist and chamber enable the Xtreme to handle the hottest of loads, while keeping the pressure safe, all whilst shotting accurately.

Combine all that with all components being at or above mil spec rating, having properly staked carrier keys, and M4 ramps, and you have what is arguably the best possible upper for the money. At under 700 for the whole uppr, it directly competes with major manufacturers such as Stag, DPMS, RRA etc, but has many of the things that they are missing.

+1

[6.8henry]

Once I get my extreme upper in July or so, I will have Stag model 7 upper for sale. It has a rifle length 20.77" SS barrel with 1:11 twist, and it has hogue overmolded forearm and flat top receiver. I am working on getting the M4 feed ramps done and refinished to protect it. If you cannot find smething by then PM me.

[Extreme Velocity]

I appreciate the info. And it sounds/reads a whole lot better than "this is what everybody else on the 'net is buying --- so I bought one --- so it must be the best". You know what I mean! :)

Like I wrote a couple of days ago, the only thing I'm looking for to complete THIS particular upper is a 6.8 bolt (or complete 6.8 bolt/carrier assembly). The upper I'm assembling right now (when the parts show up) will have a YHM flattop upper receiver, Bison Armory 20" stainless steel barrel, Hogue rifle length overmolded free float tube, YHM low profile gas block and ArmaLite .308 A2 flash hider.

But(!!), I may decide I want do something different down the road! Ahhh, the beauty of the AR-15 design --- if you don't like something it can easily be changed/replaced. :D

Yeah... I know that I originally posted that I was looking for a shorter barrel, but with the political climate being what it is and the long wait times on "black rifle" stuff I'll try the 20" version and see how I like it.

[Extreme Velocity]

The bad news is the wait on the Xtreme; but then again, that will give you time to hunt for ammo while you wait.

Hunt for ammo? Handloaders don't understand that concept!! :lol:

I've got everything I need to make ammo for the 6.8 --- just need the gun!

[Extreme Velocity]

The Xtreme was designed and is being produced by the guys who helped do all the research for the new specs that all the manufactures are switching too, Harrison (constructor) designed the DMR-C (chrome) chamber to be used in these chrome lined barrels, the bore diamtier was also designed with chrome lining in mind. Several members that have the uppers already are reporting 1-1.5 MOA groups with factory SSA ammo....

For a 16 inch chrome lined carbine upper this is at the top of the list...

Good info. Yes.... I was aware that there were problems with high pressures associated with certain barrels --- 1) Due to the chamber/lead (free bore) dimensions, and/or 2) Problems with chrome plating that were too thick/not uniform throughout. Those are the primary reasons that I chose to go with a "plain" 416 stainless steel barrel (1:11 twist - SPC II chamber) from an experienced barrel maker for MY testing.

[marinesg1012]

I have a chrome moly barrel for precision low round count shooting, I ordered the chrome lined for matches and other work....

[Extreme Velocity]

I have a chrome moly barrel for precision low round count shooting, I ordered the chrome lined for matches and other work....

Cool --- and understood. Got data?? :lol:

[Extreme Velocity]

........Combine all that with all components being at or above mil spec rating, having properly staked carrier keys, and M4 ramps, and you have what is arguably the best possible upper for the money. At under 700 for the whole uppr, it directly competes with major manufacturers such as Stag, DPMS, RRA etc, but has many of the things that they are missing.

Good points. But the prices on "ready to go" uppers (and/or complete AR-type rifles) are totally crazy these days. The man/woman that KNOWS how build these guns (and can select the proper receiver with M4 cuts, look for proper materials and heat treating, DO properly staked carrier keys, pick the "right" components for the assembly, etc...) isn't that concerned with getting it all on a "ready to go" upper assembly.

If you DON'T know how to do all the work (correctly) and/or DON'T have all the necessary tools to do it RIGHT, then I ABSOLUTELY AGREE that the Xtreme upper sounds like a bargain!! :D

[marinesg1012]

I have a chrome moly barrel for precision low round count shooting, I ordered the chrome lined for matches and other work....

Cool --- and understood. Got data?? :lol:

I dont, I had the 1-11 18 inch upper and am on the back order for the 16 inch MK68, I am getting my 18 inch changed out to a 20 inch 1-12.... I hope to have all my reloading stuff and such when I get home next, but there is a ton of data on this site.

[Extreme Velocity]

I have a chrome moly barrel for precision low round count shooting, I ordered the chrome lined for matches and other work....

Cool --- and understood. Got data?? :lol:

I dont, I had the 1-11 18 inch upper and am on the back order for the 16 inch MK68, I am getting my 18 inch changed out to a 20 inch 1-12.... I hope to have all my reloading stuff and such when I get home next, but there is a ton of data on this site.

No problem. You're right --- there is a lot of useful info/data on this site. And hopefully YOU and I can add some more useful info/data in the very near future! :)

[marinesg1012]

I hope so, I want to see Harrisons tests on which powders are better for longer barrels compared to the faster powder for shorter barrels ect ect....

[ron169]

........Combine all that with all components being at or above mil spec rating, having properly staked carrier keys, and M4 ramps, and you have what is arguably the best possible upper for the money. At under 700 for the whole uppr, it directly competes with major manufacturers such as Stag, DPMS, RRA etc, but has many of the things that they are missing.

Good points. But the prices on "ready to go" uppers (and/or complete AR-type rifles) are totally crazy these days. The man/woman that KNOWS how build these guns (and can select the proper receiver with M4 cuts, look for proper materials and heat treating, DO properly staked carrier keys, pick the "right" components for the assembly, etc...) isn't that concerned with getting it all on a "ready to go" upper assembly.

If you DON'T know how to do all the work (correctly) and/or DON'T have all the necessary tools to do it RIGHT, then I ABSOLUTELY AGREE that the Xtreme upper sounds like a bargain!! :D


Yeah I would agree with that assessment. My first two black rifles are going to be made by others. For my third, I plan om doing it all myself, now to collect the tools and learn as much as I can. Through this site and arfcom, I finally put a lower together, was a lot easier than I orignally thought.