AR Sponsor
Posted: 7/9/2015 10:18:25 PM EDT
| I have a RRA complete lower and a BCM 16 inch middy w/Troy rails and I'm having problems trying to snap them together. I can get one of the takedown pins in but the other will not go through. It's either one or the other. I tried putting oil on one but that didn't work. Any other suggestions? |
| I had this problem with Spike's lower and upper. If I placed the two receivers together, only the back one would go in. If I put the front one in first and swung it down, I'd have to push down really hard to get the rear pin in. I discovered some extra material right behind the front pin hole on the upper. Once removed, it went together very well and made a good fit. |
| I have 3 or 4 BCM uppers and 2 RRA lowers. They all fit tight together. Just seems to be how the tolerances of the two brands fit. I place the upper 90deg to the lower and push the front pin in then lever the two closed. The last quarter inch or so is very tight but I just push them together. One or two I have to lightly mortar to get the rear pin to push in. I've done this many times with all of them and I don't see any damage at all, not even a scratch. They also all function fine when assembled. |
|
I know it may sound weird but, my Noveske SPR has similar issues but, if I cock the hammer on the trigger, both pins will slide in fine. I still have to use a bullet tip or something similar to get the front pivot pin pushed out enough to get it apart. I've had the rifle for close to 6 years now and it's still the same. It was a special run of 50 rifles that were cerakoted so, I didn't want to mess around with filing out the holes.
I also used to have a Noveske VIS upper that was a total pain in the ass to get mated. It never failed that I had to use a punch get that one apart also. I want to say that my 762 OBR is the same way where it's a little tough to get both pins in with the hammer up so, maybe give that a try to see if works. |
|
Quoted:
LIGHTLY hone the hole on the receiver....lightly mind you...until it goes. First I'd use a bright light and look real close at everything. Find out what is going on. I've ran into an issue where the rear of the upper was hitting the top part of the lower where the buffer tube mounts. See if the holes are off for / aft or upper / lower. If everything between the upper and lower looks good and you can get the front in, try removing the rear pin and detent and running a drill bit through it SLOWLY, with the upper and lower heald tightly together. I've done this my self before. I think it's a 1/4" bit. Keep in mind you'd be voiding any warrenty or whatever and you're on your own. ETA: I recently installed another upper that was very tight to get the rear pin in, I tried hinging it on the front pin and repeatedly slamming them closed... actually worked. I think it kinda commpressed whatever high spots it was hitting on. |
|
Quoted:
No more insulting or GD type comments in tech. Warning sent. To the OP sorry for the comment, was just having a little fun and wasn't trying to get anyone's panties in a bunch lol As stated above......give It a good whack with a mallet just work it back and forth a few times and hopefully it loosens up |
|
I have never had an upper and lower not go together but I have had them be really stubborn. What I have done is to remove the pivot pin and buff the end (the chamfered edge) up with a brillo pad and run that same brillo pad through the pivot pin take down lugs. It smoothed out the surfaces enough for the pins to slide in easier. I have read where people sand/ file the take down lug hole but I prefer not to do that. This may be your only option if none of the other options work.
Check the take down lug hole for nicks/ dents at the edge. If that hole has a raised edge, it can make it hard to insert that pin when pressure is on it. |
|
Quoted:
Had a chance to look at it with a flashlight and I think the rear holes don't line up correctly. I'll have to try to run a drill bit through there or find a file. Hi- before you do that get a small punch or something smooth that will fit in the holes snugly as they line up now and just verrrrrry gently work them around a bit if you can then see if they lined up just enough to insert pin. Do it very gently and gradually |
|
Quoted:
Had a chance to look at it with a flashlight and I think the rear holes don't line up correctly. I'll have to try to run a drill bit through there or find a file. I have the same problem on one of my rifles on the takedown pin (rear pin) I have to use a hammer/punch to get it out and muscle it to get it in. Pain In the arse but manageable at least. |
|
Make sure the buffer isn't pushing the receiver out of alignment. Sometime the buffer tube could be threaded on a little more, and the buffer catch bends, which allows the buffer to push on the receiver which prevents the rear pin/hole from lining up.
Please post a picture first before you go screwing up something. While you could have an out of spec part, this might be easily solved without drilling or filing. |
|
Quoted:
I have a RRA complete lower and a BCM 16 inch middy w/Troy rails and I'm having problems trying to snap them together. I can get one of the takedown pins in but the other will not go through. It's either one or the other. I tried putting oil on one but that didn't work. Any other suggestions? This is of no surprise. I first found out about this about 10 years ago. Rock River Arms has typically made their uppers and lowers to fairly tight tolerances. As a pair, they fit nice and tight with little to no wiggle. The RRA lowers have always been an issue with most other uppers. The fit is so tight that the takedown pin cannot slide through when the pivot pin is already in place. In order for this to happen, the upper will need to be fitted to the RRA lower. |
|
Some can be extremely tight. Sometimes the buffer will rest against the BCG and you have to push the upper back, but it shouldn't be difficult. My Sig M400 has a really tight takedown pin. If you have some sort of tensioning device to eliminate receiver slop, it can make it difficult sometimes. |
|
Quoted:
I fiddled with the dam thing more and the fricking pin went through. Both of them are a pain to get in and out but I'm assuming that will get better. Great. Yeah sometimes the pins are a bit hard to put in. I had a BCM upper that I put together and yes, they make it with slightly tighter tolerance. The idea is that it'll give the upper a longer life. |
|
Quoted:
I have the same problem on one of my rifles on the takedown pin (rear pin) I have to use a hammer/punch to get it out and muscle it to get it in. Pain In the arse but manageable at least. Quoted:
Quoted:
Had a chance to look at it with a flashlight and I think the rear holes don't line up correctly. I'll have to try to run a drill bit through there or find a file. I have the same problem on one of my rifles on the takedown pin (rear pin) I have to use a hammer/punch to get it out and muscle it to get it in. Pain In the arse but manageable at least. Same, but I wouldn't go as far as honing any holes. It's annoying, but it's not a problem - just like having a bit of wobble between lower and upper isn't an issue either. |
|
Quoted: I fiddled with the dam thing more and the fricking pin went through. Both of them are a pain to get in and out but I'm assuming that will get better. From what I've heard, RRA tends to be tighter fits to many others. I've also heard they will become easier over time. Stick with it! |
|
Quoted:
From what I've heard, RRA tends to be tighter fits to many others. I've also heard they will become easier over time. Stick with it! Quoted:
Quoted:
I fiddled with the dam thing more and the fricking pin went through. Both of them are a pain to get in and out but I'm assuming that will get better. From what I've heard, RRA tends to be tighter fits to many others. I've also heard they will become easier over time. Stick with it! I was told the same thing back in 2009 when I posted the same issue about my Noveske 10.5. Still need a punch or similar along with a small hammer to get the pins loose after taking it apart more than I can even remember. |
|
Quoted:
I fiddled with the dam thing more and the fricking pin went through. Both of them are a pain to get in and out but I'm assuming that will get better. Good deal! A few hundred rounds fired will probably work wonders, make sure to lube the pins good when you back them out. |
AR Sponsor