DPMS Uppers I saw at the Wanenmacher's show in Tulsa

[Wyon8ve]

They appeared to be post ban barrels with the bore reamed out, the resulting enlargement threaded and a funky flash suppressor/brake then screwed in (with washers inserted to maintain vertical suppessor/brake orientation). I ask because the last 1/2" of the barrels, where you would normally place threads for a flash suppressor, were still a slightly smaller in diameter than the body of the barrel like the ends of post ban barrels.

If I order a preban upper directly from DPMS, is that what its going to look like when it arrives?

[fm23-10]

Your post made me dig out the DPMS upper I got about a month ago (from DPMS)

At first I didn't notice it, but I think you're right--except the "washer" is actually an adapter, made to fit the barrel's (new) internal threads while still using a mil-spec FH.

Pics:

http://www.gunsnet.net/album/data//500/19547barrel_measurement-med.JPG

http://www.gunsnet.net/album/data//500/19547Muzzle_detail-med.JPG

I/we could be wrong....perhaps DPMS would care to clarify?

[fm23-10]

By dropping a cleaning rod down the barrel (with the BCG fully closed) I get a measurement of 17 3/4"....the FH and "washer" is 1 7/8", so the barrel length (if a "post-ban" and thus with internal threadings) would have been 15 7/8"...just a bit under legal (unless the FH is permanently attached; I didn't see any welding)

I don't know...I would think, with 1/2" (external "normal") threads, the barrel would be 16 3/8" (or thereabouts). I'm thinking now maybe it just *looks* odd. (I don't have the ability/desire to take off the FH to verify)

[Wyon8ve]

Thanks for the reply fm23-10. I'm going to Email DPMS directly with the same question, but they have a crappy record for responding to Emails... that's why I posted it here.

I figure they have a boat load of post ban barrels and are "modifying" them to sell with flash suppressors. It would be nice to know for sure why the different look, however.

[fm23-10]

but they have a crappy record for responding to Emails...

Just mention that your decision to purchase (or not!) will be dependent on their prompt answer...there are other companies out there selling uppers who are eager to answer.

[mnblaster]

I talked to DPMS at a show in St. Paul about what they were going to do with the "post ban" stock they had. They told me it isn't cost effective to convert the barrels to accept "pre-ban" accessories and they wouldn't do it, they also said they were not going to fire-sale the post-ban ARs because there is still demand from states that have their own restrictions. In my case DPMS service and responses have been excellent.

[308]

They appeared to be post ban barrels with the bore reamed out, the resulting enlargement threaded and a funky flash suppressor/brake then screwed in (with washers inserted to maintain vertical suppessor/brake orientation). I ask because the last 1/2" of the barrels, where you would normally place threads for a flash suppressor, were still a slightly smaller in diameter than the body of the barrel like the ends of post ban barrels.

If I order a preban upper directly from DPMS, is that what its going to look like when it arrives?
Pre-ban uppers\barrels from DPMS are threaded like normal, with a screw-on FH and 1/2x28 threads....that "washer" in the photo will be on the DPMS threaded barrels...it is a "crush washer" which takes the place of the original "peel washers". The crush washer does not look as slick as the peel type, but it is much easer to time the brake\flash hider with the crush washer.

That's really weird about the internal threading...never heard of or seen that one...:dunno:

[Wyon8ve]

A crush washer would explain the funky look (call me a purist, but I like the look of the shiny peel washers). But it doesn't explain the turned down area before the flash suppressor that I don't see on any of my prebans. Even if they were using a crush washer, wouldn't that be the area they would thread to accept the suppressor?

Guess I'll have to buy one and take the flash suppressor off to be sure (expensive way to find out though).

BTW 308: the reamed bore thing was my idea of why it looked that way. No one else has subscribed to that thought, other than me.

Thanks for your inputs guys, enquiring minds want to know! :bye:

[308]

But it doesn't explain the turned down area before the flash suppressor that I don't see on any of my prebans. Even if they were using a crush washer, wouldn't that be the area they would thread to accept the suppressor?
My DPMS preban M4s look like this at the end.

http://www.gunsnet.net/album/data//500/12680m4-fh.jpg

[Wyon8ve]

O.K. So all I have to do is get a DPMS upper and change the crush washer to a peel washer (I'm still a purist).

Thanks 308.

[Epinephrine]

Well, you wont be a purist for much longer as the military is switching over to crush washers. :D

[Wyon8ve]

I better stock up on peel washers then. :D

308,

How long ago did you order that PreBan?

[308]

I better stock up on peel washers then. :D

308,

How long ago did you order that PreBan?
A friend had a couple new ones he needed to move along.

[Wyon8ve]

Well thanks for the info guys.

Looks like I'll just have to take the plunge. :)

[Epinephrine]

Believe me, when you go from peel washers to crush washers, you will never go back!