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Posted: 3/3/2004 2:59:08 PM EDT
| Why is it that every RRA lower I build does not fit the upper very well. I hve built two RRA rifles and on both of them the rear of the upper does not fit the rear of the lower. One or the other is out of spec I am guessing but both lowers I have built have been this way. Do you guys have the same problem with RRA? |
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Who made the uppers? I have a bushy A2 upper that won't fit my RRA, but the my slick sided upper from Fulton fits fine. I think the bushy would fit if I worked on it a bit, and I suspect that the tight fit is what RRA is after. I read somewhere else that they have a "high shelf." |
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Ditto that! Mine went to gether great. The fit is good and it shoots well. DO you mean that the two pieces are tight. It seems that RRA does that intentionally to improve accuracy. Some people love it, some don't. To each their own. But mine went together well. Not too tight, not too loose. -Hershey |
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I had a well worn Bushmaster patrolmans carbine upper and a brand spankin new RRA lower receiver built with Cav Arms gear. When I tried to mate it to the only upper I own, I could not close it. I eventually slapped the upper on the A2 carry handle down REALLY hard and it closed. Then I could NOT open it back up. I had to use the barrel as a lever (!) to open it back up! (I know its bad, but I had no more ideas) Then I slapped it closed again. Repeat the above 12 times. After my first range session, it opened and closed very well. No more sticky upper and lower! Just slap it together and go shoot it. |
| I have 2 different Bushmaster uppers and one wont go on my RRA lower that I built and the other does. RRA is supposed have some of tightest specs around. I think they just need time to break in from use and being taken down every once in awhile. I dont think your lowers are out of spec. |
| jnewt you have to fit the rear locking lug on most uppers when using them on the RR lowers. The RR lowers are not quit Mil spec in that area but it makes for a very good tight fit making the use of a Accuwedge unnecessary. It is not much of a problem to fit them just slightly round off the square corners of the rear locking lug on the upper. I believe the reason RR makes the lower like that is so that a DIAS can not be dropped in without allot of machining. |
| What Shooter 505 said. I just built a RRA M4gery all RRA arms parts and had the very same problem with the upper and lower not fitting together. I used some #400 grit wet/dry sand paper and a small wood block and lightly sanded the rear edges of the lug until I had a perfect fit. Then I used some birchwood aluminum black to re-black the area i had to sand down. Zero play and perfect fit Just have to love that. Better than having a sloopy loose fit that's for sure!!! |
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I just got two RRA LE lowers. I ordered a RRA upper, and damn, it was way too tight. I got pissed off and slammed it shut, beat it open, and repeated the process until it opens and closes fine. I noticed that although I can not feel any "wear" where either the lower or upper shaved off aluminum to fit, but there is a loss of the black finish just inside the lower. I have a Bushmaster upper that went on the RRA lower with no problems. I will be getting another RRA upper to mate with the other LE lower, I hope that this pair does not require the ole slam and open routine. If not, well I know what to do:) |
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Hi Jnewt...I'm a fellow Okie living in the Enid Area. I've put together two RRA's, buying the complete lowers and then buying the complete uppers. Both went together just fine. Much tighter than any of the Colt's I've owned. Tight is a good thing. I'd rather they were tight, than have play in them. the pins loosen up after a couple of months worth of use and the upper tilts up off the lower for cleaning just fine. The tolerances on mine are just exactly what I wanted them to be. |
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Shooter505, I am a Littleton native! Yeah the only diamond file I have is round for sharpening knives so I had to use what I had available at the time, #400 WET/DRY sand paper worked great for me. Mine also seemed to be just the thickness of the finish that was making it to tight. With the Birchwood aluminum black I was able to make the unfinished area black again without adding any thickness to the finish. It works just like cold blue but is made for aluminum. |
| Twitchy I am from the Pueblo area. I build about three or four ARs a month. I have had the Rock River sets were I had to remove allot of material off of the lugs and I have had them where I just removed very little. I like the Aluminum black it works great for the lugs and other scratches on AR's. |
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Listen well to Shooter505. He knows of what he speaks. I've done the same thing to the two RRA frankenguns that I have assembled. I like the result. Nice and snug fit with no slop. Although it requires a modest amount of work to fit the RRA receivers together, the result is a much better fit than you would get otherwise. Rejoice in what you have. It's a much better situation than the reverse. |
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xcell Call around to your local gun and sporting supply stores in your area. Otherwise you can find it online pretty common stuff. Brownells has everything under the sun when it comes to stuff like that. As for the bluing stuff ie cold blue is designed for steel and will not work on you upper and lower as they are aluminum. Cold clue works ok for barrel touch up but you have to use the aliminum black on aluminum. |
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