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Post by HMC710 on Jan 7, 2017 15:23:47 GMT -5
I picked up a used Just Right Carbine in 45 ACP at a show last year because I like the modular design and it would make a great platform for the Uzi calibers we do. Sadly, the rifle didn't function (after shelling out $30+ for a Glock mag) so it sat in the case until a time when I could do an autopsy........ Pics to follow.....
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Post by HMC710 on Jan 7, 2017 18:29:42 GMT -5
I started to pull the carbine apart and someone had beaten me to it.... There is a buffer tube extension that a std AR tube fits on and someone had not loosened the castle lock nut enough to remove the locking ring and stripped some threads.
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Post by HMC710 on Jan 7, 2017 18:41:59 GMT -5
Let try another photo This one came of photobucket instead of an attachment
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Post by HMC710 on Jan 7, 2017 22:12:50 GMT -5
OK, the photobucket pics work much better..... I have sent all this info to Just Right for their information. I know I would like to know any issue there is with my stuff. I have no idea what the round count on this rifle was when I bought it used last year. I bought a Glock 45 ACP mag and went to test fire and had about 2 rounds out of 20 tries go off. At that point I packed it up and put it in the "When I have time" pile. I pulled it apart today and here is what I found: When a gun won't go bang, its either an ignition issue or a chamber issue. The JRC has a pretty cool modular bolt assembly. I bet New Frontier liked it too..... On the left end of the firing pin is a "pin stop" for lack of a better term. It lets the FP float in alignment in the bolt body. I was not getting ignition so either the headspace was bad or the FP assembly was bad. First thing I found was the end of the FP was mushroomed and would not slide into the "pin stop". So, when the hammer fell, there is no way it would hit the FP. Here's the FP Now logic would tell you that when the bolt closed, with the FP too far fwd, it should move the FP back into position. Or, light off the round..... This didn't happen. But before we get to that, here is a new 9mm bolt assembly on the left... you can see the FP protrusion from the pin stop. The next thing I checked was the chamber: Protrusion from the chamber was .090". When I do an AR blow back I usually target about .135"..... Then we check the bolt face.... The bolt face is recessed .108, so with the chambered round we have .018" of headspace. A bit much. All of this put together leaves a serious FTF issue. I'm going to tune up the end of the FP and probably bevel it a bit to account for any more mushrooming. Then I will probably shorten the breach of the barrel a bit to reduce head space. Then I'll look for that $30+ glock mag I bought....... Anyway, the main reason I got the JRC was to see how the barrels mounted so I could do one of our Uzi conversions
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Post by paulsblackrifles on Jan 9, 2017 9:15:08 GMT -5
I have a JRC in 9mm, no problems with it at all! It was a Gunbroker buy, not real cheap but cheaper than a 9mm AR.
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Post by HMC710 on Jan 10, 2017 9:51:54 GMT -5
I got a call from Canandaigua, NY! Thanks Tom, I appreciate that very much. Now I really have to find that 45 glock mag....
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Post by HMC710 on Jan 12, 2017 16:31:28 GMT -5
Placed an order for some parts the other day so I reluctantly added a 45 Glock mag.......
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