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RAMCHARGER
07-25-2007, 11:31 AM
I'm trying to get a "tight" fit between my upper and lower.

Looks like I get a wiggle on my dane lower but a tight fit ona FAB10. When you look at the lower recivers from the top I see that the FAB10 has no cut out on the right-inside side wall where the takedown pin hole is. Where the rear holddown block of the upper would go into.

I see that on the Dane and other lowers have a slight cut out on the inside on this part. Thus allowing some side to side movement.

I want to find a OLL that is not cut out so I can have the tight fit of the Fab10. Unfortunately I only see pictures of the sides and mag wells of lowers and not a lot of "top view" pics.

So who makes a lower (OLL) that does not have this cut out. I think I saw a Stag "LEO" marked lower that doen't have this cut out but it was too hard to tell since the pic wasn't that good.

PIRATE14
07-25-2007, 11:57 AM
We usually the RRA lowers are the tightest...........

But they are supposed to have some movement......:chris:

BossHogg
07-25-2007, 12:11 PM
So who makes a lower (OLL) that does not have this cut out. I think I saw a Stag "LEO" marked lower that doen't have this cut out but it was too hard to tell since the pic wasn't that good.

Not sure about what cut out your talking about. I have a RRA upper rec and it fits my stag oll like a glove. Here is a pic of my Stag LEO. Hope it helps.
http://i102.photobucket.com/albums/m95/jjdday/IMG_0240.jpg
http://i102.photobucket.com/albums/m95/jjdday/IMG_0244.jpg
http://i102.photobucket.com/albums/m95/jjdday/IMG_0247.jpg

PanzerAce
07-25-2007, 12:51 PM
I get basically no movement b/w my CMMG upper and stag lower

RAMCHARGER
07-25-2007, 12:57 PM
THANKS! Looks like I get a stag lower. :)

BTW what kind of hammer you got there?

Jicko
07-25-2007, 1:30 PM
Looks like RRA 2-stage trigger.

http://www.rockriverarms.com/images/nmtrgg.gif

BossHogg
07-25-2007, 1:58 PM
Looks like RRA 2-stage trigger.
Yes Sir

supersonic
07-25-2007, 5:21 PM
[QUOTE=BossHogg;688930]Not sure about what cut out your talking about. I have a RRA upper rec and it fits my stag oll like a glove. Here is a pic of my Stag TE]

Yeah, +100%! When I received my brand new RRA upper and first "tried" mating it to my Stag, it was almost "too" tight. CLP+opening/latching/closing(wash;rinse;repeat)+100rds downrange later & they seem like one piece. I've never had an upper & lower do that before: aggravate me @ first , then pay me back tenfold w/ PERFECT fit AND great accuracy! (good thing my next build consists of same upper/lower combo!:))
S.S.:43:

mecam
07-27-2007, 9:35 AM
FWIW, my DPMS rifle upper is a very tight fit with my Stag15 lower.

383green
07-27-2007, 11:41 AM
Dumb question time: Does that RRA 2-stage trigger eliminate the disgusting scratchy creep feeling that I've come to expect from AR triggers? It seems to me that moving the sear surface farther away from the hammer pivot point should reduce the bearing pressure at the sear, thus making it harder to feel any roughness there. I always guessed that much of the difference in feel between AR and Garand triggers was because the AR's sear engages very close to the hammer's pivot, while the Garand engages at a much larger radius.

bwiese
07-27-2007, 11:48 AM
Ramcharger,

A 'tight' fit between upper and lower receivers is perhaps perceptually or cosmetically nice. It's functionally useless, however.

Even some slop in upper/lower fitting on ARs does not really affect accuracy. The lower in an AR really doesn't do much work other than hold the mag and the trigger group - everything else done from time of firing til bullet leaves barrel is done in the upper.

You can take the crappiest wiggliest lower with a tack-driver upper and still have a damn accurate rifle.