User Panel
User Panel
User Panel
|
Posted: 9/19/2009 1:26:56 PM EDT
I just picked up a RRA mid-length upper at a gun show on the assumption it is 5.56. But the paperwork says 6.8 SPC.
 WTF???
I have no experience with 6.8 SPC, but I slipped a spent round of 5.56 in the chamber and it fit snug enough I had to push it out with a cleaning rod. There's no way 5.56 brass should chamber snugly in a 6.8 chamber ... right? Like I said - no snickering allowed. There are no markings on the barrel or upper except the Cerro keyhole, and nothing under the handguards except a funky little punch mark that looks like "MK". Wouldn't a 6.8 upper be marked as such? Reassure me, lads. . . |
|
|
|
Posted: 9/19/2009 1:31:56 PM EDT
[#1]
Go buy a box of 6.8 and see if it fits
|
|
|
|
Posted: 9/19/2009 1:34:10 PM EDT
[#2]
There should be engraving on the barrel telling you exactly what type of round it was made for...
|
|
|
|
Posted: 9/19/2009 1:34:58 PM EDT
[#3]
Pull the bolt carrier group. Place a cartridge against the bolt. If the 5.56/223 is smaller than the recess in the bolt face... it probably is a 6.8.
|
|
|
|
Posted: 9/19/2009 1:52:49 PM EDT
[#4]
Sounds like someone used the 6.8 lower to build a 5.56 (if that's what it turns out to be).
The lower is logged on the 4473 according to the upper it wears when it is sold. If it was later rebuilt as a 5.56, there would be no record of it. |
|
|
|
Posted: 9/19/2009 1:58:19 PM EDT
[#5]
check your 5.56 ammo against the boltface. If the boltface is larger than the ammo your in trouble
|
|
|
|
Posted: 9/19/2009 2:02:12 PM EDT
[#6]
Quoted:
There should be engraving on the barrel telling you exactly what type of round it was made for... Not. Like I said, I even pulled the handguards and it's not marked. But neither was the other RRA I had, and it was a factory rifle. . . |
|
|
|
Posted: 9/19/2009 2:03:09 PM EDT
[#7]
Quoted:
Pull the bolt carrier group. Place a cartridge against the bolt. If the 5.56/223 is smaller than the recess in the bolt face... it probably is a 6.8. Yeah, I did that and it's 5.56 sized. Liek I said, I don't what a 6.8 cartridge even looks like, but I'm sure the dimensions of the case are different. . . |
|
|
|
Posted: 9/19/2009 2:12:09 PM EDT
[#8]
They gave you the wrong paperwork. RRA marks thier 6.8 as 6.8 on the side of the upper. I have thier middy, and it's heavy under the HG's also. A 5.56 would be noticably loose in a 6.8 chamber.
|
|
|
|
Posted: 9/19/2009 2:20:58 PM EDT
[#9]
Quoted:
Sounds like someone used the 6.8 lower to build a 5.56 (if that's what it turns out to be). The lower is logged on the 4473 according to the upper it wears when it is sold. If it was later rebuilt as a 5.56, there would be no record of it. Nah - no hanky-panky going on. These folks are a big dealer and they stock all sorts of lowers and uppers, as well as parts and complete guns. This was just an upper. I've been able to talk to the dealer at the show and the guy said he just wrote it up wrong. Said if it were 6.8 it would say so prominently on the upper. Base diameter of the 5.56 is .377", while the 6.8 is .421. I figure a 5.56 case would rattle around in the chamber of a 6.8 - at least enough to allow it to drop out without having to push it out with a cleaning rod. I guess I'm satisfied. . . |
|
|
|
Posted: 9/19/2009 2:30:31 PM EDT
[#10]
Quoted:
They gave you the wrong paperwork. RRA marks thier 6.8 as 6.8 on the side of the upper. I have thier middy, and it's heavy under the HG's also. A 5.56 would be noticably loose in a 6.8 chamber. Yep, this is apparently what happened. The guy at the show apologized and said he was just too busy and not paying enough attention. Thanks for the confirmation of the upper markings. ETA - After trying spent brass in the chamber, I just dropped an unfired round into the chamber and once again had to use the cleaning rod to dislodge it ... and it wasn't even chambered by the bolt - just dropped in. Too tight for a 6.8! . . |
|
|
|
Posted: 9/19/2009 2:44:59 PM EDT
[#11]
Quoted:
Quoted:
Sounds like someone used the 6.8 lower to build a 5.56 (if that's what it turns out to be). The lower is logged on the 4473 according to the upper it wears when it is sold. If it was later rebuilt as a 5.56, there would be no record of it. Nah - no hanky-panky going on. These folks are a big dealer and they stock all sorts of lowers and uppers, as well as parts and complete guns. This was just an upper. I've been able to talk to the dealer at the show and the guy said he just wrote it up wrong. Said if it were 6.8 it would say so prominently on the upper. Base diameter of the 5.56 is .377", while the 6.8 is .421. I figure a 5.56 case would rattle around in the chamber of a 6.8 - at least enough to allow it to drop out without having to push it out with a cleaning rod. I guess I'm satisfied. . . My bad. When you said "gun show" I assumed it was a used AR, a complete rifle. I totally missed the part about it being just an upper. I guess it's true what they say about when you ASSume... If it's just the upper then the paperwork snafu is no biggie. |
|
|
|
Posted: 9/19/2009 3:00:18 PM EDT
[#12]
RRA 6.8 uppers have 6.8 SPC engraved above the ejection port in big bold letters. If it doesn't have this then something is wrong.
|
|
|
|
Posted: 9/19/2009 3:37:28 PM EDT
[#13]
I would think you should be able to tell just from looking at the bore diameter.
|
|
|
|
Posted: 9/19/2009 4:34:40 PM EDT
[#14]
Quoted:
RRA 6.8 uppers have 6.8 SPC engraved above the ejection port in big bold letters. If it doesn't have this then something is wrong. LOL. No, something is RIGHT if it's not there, since a 5.56 is what I wanted! But I appreciate your confirming the markings. . . |
|
|
|
Posted: 9/19/2009 4:40:00 PM EDT
[#15]
Quoted:
I would think you should be able to tell just from looking at the bore diameter. Well, that's actually the first thing I looked at after checking for markings. It LOOKS like .223/5.56 to me, but then, I've never seen a 6.8 before! I'm not sure I could eyeball the difference between .223 and .276 bore diameters, anyway, especially looking down through an A2 flash hider. . . |
|
|
|
Posted: 9/19/2009 4:59:22 PM EDT
[#16]
Quoted:
Quoted:
RRA 6.8 uppers have 6.8 SPC engraved above the ejection port in big bold letters. If it doesn't have this then something is wrong. LOL. No, something is RIGHT if it's not there, since a 5.56 is what I wanted! But I appreciate your confirming the markings. . . Ah, no LOL 6.8 is what you want.  
|
|
|
|
Posted: 9/19/2009 4:59:47 PM EDT
[#17]
Quoted:
Quoted:
I would think you should be able to tell just from looking at the bore diameter. Well, that's actually the first thing I looked at after checking for markings. It LOOKS like .223/5.56 to me, but then, I've never seen a 6.8 before! I'm not sure I could eyeball the difference between .223 and .276 bore diameters, anyway, especially looking down through an A2 flash hider. . . or try running a 5.56 bore brush thru it and see if it's tight or not. |
|
|
|
Posted: 9/19/2009 5:54:00 PM EDT
[#18]
Quoted:
Quoted:
Pull the bolt carrier group. Place a cartridge against the bolt. If the 5.56/223 is smaller than the recess in the bolt face... it probably is a 6.8. Yeah, I did that and it's 5.56 sized. Liek I said, I don't what a 6.8 cartridge even looks like, but I'm sure the dimensions of the case are different. . . left 6.8SPC, right .223 
|
|
|
|
Posted: 9/20/2009 11:34:15 AM EDT
[#19]
Quoted:
Quoted:
Quoted:
Pull the bolt carrier group. Place a cartridge against the bolt. If the 5.56/223 is smaller than the recess in the bolt face... it probably is a 6.8. Yeah, I did that and it's 5.56 sized. Liek I said, I don't what a 6.8 cartridge even looks like, but I'm sure the dimensions of the case are different. . . left 6.8SPC, right .223 http://www.chiefaj.com/223_6.8_W_TEXT.jpg Based on that picture , a 5.56 wouldn't even chamber in a 6.8 rifle, since the case neck is farther forward than a 6.8's. That being the case, I'm safe, since a 5.56 round seats flush in the chamber. . . |
|
|
|
Posted: 9/20/2009 11:37:37 AM EDT
[#20]
Does this dealer fly a blue banner at the show
 |
|
|
|
Posted: 9/20/2009 1:08:20 PM EDT
[#21]
Quoted:
Does this dealer fly a blue banner at the show Nothing secret about it - it's Texas Star - they also have a company called Lone Star Wholesale. They're usually the very first set of tables at the 11:00 corner of Will Rogers if you consider you enter the hall at 12:00. Stacks of Rock Rivers and cases full of lowers, uppers, parts and accessories. Located in The Colony. Good people. You'll also find them at Mesquite and Dallas shows and I think they also make the shows in Houston and other places. . . |
|
|
Win a FREE Membership!
Sign up for the ARFCOM weekly newsletter and be entered to win a free ARFCOM membership. One new winner* is announced every week!
You will receive an email every Friday morning featuring the latest chatter from the hottest topics, breaking news surrounding legislation, as well as exclusive deals only available to ARFCOM email subscribers.
AR15.COM is the world's largest firearm community and is a gathering place for firearm enthusiasts of all types.
From hunters and military members, to competition shooters and general firearm enthusiasts, we welcome anyone who values and respects the way of the firearm.
Subscribe to our monthly Newsletter to receive firearm news, product discounts from your favorite Industry Partners, and more.
Copyright © 1996-2024 AR15.COM LLC. All Rights Reserved.
Any use of this content without express written consent is prohibited.
AR15.Com reserves the right to overwrite or replace any affiliate, commercial, or monetizable links, posted by users, with our own.
