PDA

View Full Version : Upper/Lower best fit list?


workinwifdakids
04-25-2008, 9:14 PM
I read somewhere that perhaps some uppers and lowers do not go well together, produce ugly gaps, have too tight or too loose of tolerances, or cause leprosy.
:icon_bs:
OK, I made that last part up, but still.

Is there a list of lowers that correspond to nice upper fits?

I used the search function first.

Help me, or my next post will ask which lower is better, or how I heard from a friend at the range who knows this LEO who says all .223 rifles are illegal, or...
:rofl2:

UncleJohnny
04-25-2008, 9:46 PM
Got a stag arms lower, then bought a stag 2h upper, and they fit sooo good. no slop, the take down holes were really snug, and no ugly gaps between the lower and upper. My light can bareley shine through it, lighting from the opposite side. The .223/5.56 is not banned. The .50 are banned.

scfast
04-25-2008, 9:49 PM
cmmg+cmmg.....stag +cmmg ...cmmg+adco/whiteoak...stag+stag.....lower+upper.From what i have herd all .223,7.62x39,.308,30.06,300wm,7.62x54r,6.5,6.8,.50 ,.22,.17,12 gauge,.410,9mm,.40,.44mag,10mm,45.cal,.38,.177 .22 .25 pellets etc are illegal in california were all criminals.

aplinker
04-25-2008, 10:35 PM
All of them fit with all of them, unless they're out of spec.

somecallmetim
04-25-2008, 10:42 PM
My Stag lowers + RRA uppers fit VERY tightly (I can't assemble or disassemble without tools, but they still have yet to be fired).

BP88
04-25-2008, 11:12 PM
Stag upper and Stag lower? Mine fit fine. :)

Jicko
04-26-2008, 12:34 AM
Theoretically, they should ALL FIT.

"produce ugly gaps" <- ONLY happens if you are cheap S, and get bottomfeeder parts....

pklin1297
04-26-2008, 8:11 AM
Mega and Mega... Sun Devil and Sun Devil... Stag and Stag... See a pattern?! :D

Ballistic043
04-26-2008, 8:20 AM
unfortunately 'gaps' can't always be attributed to quality. sometimes even if you go with the same company you can have some jiggling of receivers. alot of it has to do with finishing methods that can ultimately determine the fit. too thin and you get play, too thick and the rifle is difficult to disassemble. even having and upper+lower from the same company 2 years apart could produce loose fit. ive seen it before and its not a big deal

if you think yours is bad you should handle a GI issue rifle... hand me downs with more play than a 5 dollar whore..

Ech0Sierra
04-26-2008, 8:24 AM
RRA+RRA might cause jail time.

mltrading
04-26-2008, 9:39 AM
Basically, all upper and lower receivers are made with one specification. Ideally, they should fit very well. However, once there's a spec, there's error.

I'd say there's no best fit on the market. Whatever receivers "mate" together without noticible play is a good fit.

By the way, RRA used to sell "hand-picked" "super-tightly-fit" receiver sets. They might be what you are looking for. But RRA is on the list.......:mad:

Jicko
04-26-2008, 9:51 AM
You can *always* add an Accu-Wedge ($2?) if you found that your upper and lower got too much play.

http://www.cactustactical.com/osc/images/accuwedge2.gif

apbrian112
04-26-2008, 9:54 AM
Got a stag arms lower, then bought a stag 2h upper, and they fit sooo good. no slop, the take down holes were really snug, and no ugly gaps between the lower and upper. My light can bareley shine through it, lighting from the opposite side. The .223/5.56 is not banned. The .50 are banned.

+1 my stag lower/upper combo is as tight as a frog's butthole.

however, my stag, dpms, colt uppers had a little slop when mated to a spikes tactical st-15 lower. (not enough to worry about, and it still went bang when i pulled the trigger)
my bohica arms FAR50 510dtc upper fits snug on my spike lower though.

i have 2 unbuilt DSArms lowers that i yet to see the fit on different uppers
and i have a bushmaster varmint upper coming to me, and i'll check the fit on my stag, DSArms, Spikes lowers and update.

mltrading
04-26-2008, 12:16 PM
You can *always* add an Accu-Wedge ($2?) if you found that your upper and lower got too much play.

http://www.cactustactical.com/osc/images/accuwedge2.gif


It's a good thing. However, for fixed-mag-and-break-open ARs, it's a pain to put upper half back.

Jicko
04-26-2008, 4:48 PM
It's a good thing. However, for fixed-mag-and-break-open ARs, it's a pain to put upper half back.

If you choose to go the "break-open" to load route (it is now 2008, am i right? not late 2005 anymore...), I don't think you want a TIGHT upper/lower combo.... tight one generally translate into pretty tight "takedown" and/or "pivot" pins....

BTW, I think biwese or TechTed suggested an "O-ring" in the pivot pin trick.... that works well too...