PDA

View Full Version : Problem with bolt release install


wild_wild_wes
02-18-13, 00:54
I was assembling a couple of lowers using parts I bought from Fulton Armory, and when I got to installing the bolt releases, neither would fit into the slot in the reciever. Close inspection of the latches showed that the castings were pretty rough, and had numerous bumps that are enough to prohibit them from fitting in right. How do I smooth the surfaces or otherwise abrade the raised areas enough to get the parts to fit?
markm
02-18-13, 08:16
Those parts are a pain because they're head treated. If they're so tight they won't even fit in snug... that's a pain.

I'd try to find someone local who has a spare part you could just try to confirm that it's the part and not the upper.

You can file on it, but it's a slow process because of the hardness.
wild_wild_wes
02-18-13, 11:44
Right, I tried a file, but only seemed to take the finish in the high parts off.

Both lowers are Fulton Armory (and, consecutive serial numbers), so the machining is probably identical.
MarkG
02-19-13, 10:53
If memory serves me, the slot in the upper receiver should be 0.155 +0.002.

I measured a couple of Colt bolt catches. Both came in at 0.152 with dial calipers.
Joe Mamma
02-19-13, 13:21
If memory serves me, the slot in the upper receiver should be 0.155 +0.002.

I measured a couple of Colt bolt catches. Both came in at 0.152 with dial calipers.

According to a Colt drawing I have (which may or may not be correct), the slot should be 0.167 +/- 0.010. The hole diameter for that detent and spring is 0.156 +/- 0.003.

Joe Mamma

Edited to correct typo in spec!
Donut
02-19-13, 15:14
According to a Colt drawing I have (which may or may not be correct), the slot should be 0.167 +/- 0.100.

Joe Mamma

You mean +/- 0.010.
patrick sweeney
02-19-13, 15:29
You mean +/- 0.010.

We sure hope.
Joe Mamma
02-19-13, 19:39
You mean +/- 0.010.

Yes, I just edited my original post for clarification. Thanks for picking that up!

Joe Mamma
Donut
02-19-13, 19:47
Yes, I just edited my original post for clarification. Thanks for picking that up!

Joe Mamma

No problem. I saw it and thought, "Hmm, that's a lot of variance," and had to go check my schematic. :)
sinister
02-19-13, 21:55
Blueprint (for reference):

http://biggerhammer.net/ar15/cad/ar15_lowerblueprints_unknownorigin.pdf
Joe Mamma
02-19-13, 23:41
Blueprint (for reference):

http://biggerhammer.net/ar15/cad/ar15_lowerblueprints_unknownorigin.pdf

and another:

http://www.biggerhammer.net/ar15/cad/ar15_receiver.pdf

Joe Mamma
wild_wild_wes
02-23-13, 20:29
Well I got a couple of noname bolt releases from my LGS, and they fit in with no problem. Apparently, Fulton Armory parts don't fit into Fulton Armory recievers.
Litpipe
02-23-13, 23:12
Glad it Worked out. FA has dissapointed me lately.
Shao
02-24-13, 07:08
If you don't mind me asking, were the bolt catches from Fulton marked in any way?
wild_wild_wes
02-24-13, 08:41
No, there were no markings of any kind on these bolt catches. The parking was a very light grey, for what it's worth.
DirectDrive
02-24-13, 08:55
I recently found one of this type to have an undersize RP bore.
Would have been a cluster had I not attempted to dry-fit it for a function check, prior to driving the RP.
It had a "coarser" than typical, tactile (not tactical) surface on the paddle as pictured...

http://palmettostatearmory.com/media/catalog/product/cache/1/image/9df78eab33525d08d6e5fb8d27136e95/b/o/bolt_catch.jpg


For reference, typical "finer" tactile paddle surface...

http://www.brownells.com/userdocs/products/p_160308100_2.jpg
Safetyhit
02-24-13, 09:02
I recently found one of this type to have an undersize RP bore.


You're referring to FA, correct?
DirectDrive
02-24-13, 09:17
You're referring to FA, correct?
No, this one in particular was shipped by PSA.

If you dry-fit the assembly as standard practice, using the correct diameter drill bit shank for a temp pivot, you will find this crap.
I tape the drill bit in place and let the roll pin chase it out as well.
wild_wild_wes
02-24-13, 12:30
I recently found one of this type to have an undersize RP bore.
Would have been a cluster had I not attempted to dry-fit it for a function check, prior to driving the RP.
It had a "coarser" than typical, tactile (not tactical) surface on the paddle as pictured...

http://palmettostatearmory.com/media/catalog/product/cache/1/image/9df78eab33525d08d6e5fb8d27136e95/b/o/bolt_catch.jpg


For reference, typical "finer" tactile paddle surface...

http://www.brownells.com/userdocs/products/p_160308100_2.jpg

My FA looks like the top one, and the noname one looks like the bottom one. I did not test fit the pin in first, but I will now. They could not be forced into the recieve slot anyway, so is a moot point though.
FSTRN
02-24-13, 17:11
I had the exact same problem the other day. The bolt catch from a PSA kit had function problems until I reamed out the rolling pin bore by hand with a drill bit. Very frustrating.

ETA: Belay that last. I did need to apply power to that bit in order to open the bore. Flexeril fogs the intellect.
wild_wild_wes
02-24-13, 18:04
Additionally: I had a Gieselle DMR trigger in another reciever, and switched it to the Fulton I was building. The hammer wouldn't disengage, because the selector lever shaft was blocking the rear of the trigger bar from rising far enough. So I took the Fulton selector lever out and put the one from the other reciever in: now it works. I installed an SSA in the other reciever, and the Fulton selector works with it; so the Fulton selector lever is slightly out of spec too, I think.