Ok, so I put together a rifle a few months back, and it runs just fine, but it takes an inordinate amount of force to seat a P-Mag, even when they are loaded down. My other rifles do not have this issue with the same magazines, so I gather it’s probably the magazine catch.
My question is this… Does the amount of revolutions you screw the catch into the Mag Release button have any bearing on how tough it is to seat a magazine? It doesn’t seem that it would, but I can’t think of anything else that would be causing it. Unless of course the mag catch is just out of spec.
looks like you need a couple more turns on the mag release. I usually do mine where the end of the latch is flush with the mag release button, never had a problem.
When I install my mag catches I turn it until it is just below flush with the button. That seems to be the best bet. Yes, depending on how you have it set can affect its’ operation.
Might be the spring, but could also be the mag catch that’s out of spec, or if you’re unlucky it could be the receiver out of spec - slot for the catch machined too high up on the well. Wouldn’t take much.
That was the Pueblo dust, and yes I’ve cleaned it. It was the only pic I had handy to post at the time. I hadn’t made any changes to it since that picture was taken so I figured it would suffice. It’s much cleaner now. hehe
I’ve seen a couple of upper receivers in the last year that were so goofed up, the cut in the upper that “stops” the mag was very low, and would not allow the mag to get high enough for the mag catch to catch the mag.
The second one, I had the opportunity to actually measure it against three other uppers from known sources (two from Stag and one from M&A). The upper in question, its bore and other cuts were .035 - .040 too low (and tight, and rough). The guy could not seat a mag because it was stopping hard in the upper. This misalignment also lead to a binding of the carrier in hand cycling, which caused frequent malfunctions in shooting.
Insult to injury, the mag catch itself was poor. The top edge of it was very rounded off, so it would not retain a mag even if it had been able to get high enough to click in. Mags hammered in hard enough to where the mag catch could engage, could be yanked out due to the roundy edge on the mag catch.
This rifle had a ton of other problems. In the FSB, the relationship between the hole receiving the gas tube and the gas tube retaining pin hole was way off, to where the retaining pin had been just mashed into place. This jinked the gas tube enough to where its hole for receiving gas was 40% or more shut off from the gas pass-through hole in the FSB. Maybe not such a big prob as the gas port in the barrel (16") was well oversized!
The buffer tube bore was undersized and not straight, and rough as a cob. The trigger group was goofed up to where the disconnector almost would not release the hammer on trigger let-off, and, of course, the carrier key screws were staked by the girliest man in the place with the smallest hammer available.
I thought I had seen the last of such poor parts 15 years ago. Looks like they’re making a comeback!
With the new upper receiver I had to adjust the Eotech 50 clicks in elevation, was relieved to find it had that much. Probably had been dialed to the edge of its range to compensate for the misaligned, original upper.
I had a similar problem, and post but I also noticed shaved metal and bare aluminum in the upper. I attributed this to being an “off” brand. I bought a used BCM upper from a fellow member. This new one is way worse. I just figured it was normal at that point. I really have to press hard to lock a magazine with the upper installed.
It was a Frankengun. Guy said the parts came from some place I had never heard of, so I didn’t retain the name. Is there a ________ Armory or something like that?
NOTE:
Edited to remove the name as it was speculation. In light of the actual place having now been named (see Spt. 5 posts), I wanted to make sure I was not impugning any outfit that did not deserve it. Although I don’t believe an AR parts house exists with my postulated name, again to be on the safe side I have removed it. Thanks- Ned
This was one of the very few AR’s I’ve seen where the headspace was off… on the short side. No wonder, the bolt face recess was .007 shallower than any I’ve seen. I’ve never seen this dimension vary more than a thousandth either way. Reamed for headspace, although that makes this a one-bolt gun. Replace the bolt with one to spec and it’ll have .007 too much headspace.
After changing nearly everything but the lower receiver, barrel and bolt group, extraction problems started(hadn’t seen this before as the gun would not run long enough to show it). Dammit! Forgot about that oversized gas port. The area of the gas port is over double. Brass cases were getting rims nearly pulled out by the extractor. I have restricted the hole in the gas block, thinking that’ll do it…yes, the extractor has a good spring, black buffer, and D-ring.
“If I’d known then what I know now”… I’da told the guy let’s flatten the upper, bend the barrel double, weld the bolt to it, box it up with the bent buffer tube, and send it back with some Vaseline. Oddly though the 16" barrel is a decent shooter… 3" at 100, EoTech with no magnifier, Hornady steel-cased training ammo.
Oh yeah, even the buffer tube castle nut was cheezoid. About 1/16th shorter, with a big chamfer on the ID, so it had maybe three fewer threads at work.
Gun went for 250-plus today with no probs. Should have another 750 through it in the next few days.
Another gun with parts from the same outfit would not retain mags; same roundy mag catch… same fix: replace with mag catch made right. These bad ones, the flat catch part was stamped and not machined, causing the rounded edges.
This gun went 1100-plus rounds this week, not one single problem. Still no guarantees, I told the guy… who knows when the bolt might break, trigger pin might separate, etc. This gun was so bad that one just can’t tell about the parts.
This guy and his partner brought four more rifles to class Thursday to have them checked out by Pat Sweeney and me… they came from the same source, a guy who has built a few AR’s but has a ways to go in terms of how to put them together right (and none of us were born with the knowledge), where to get the parts, and essentially, how the AR gets used and abused in training.
I don’t know much about Airsoft but I’m starting to wonder if these were Airsoft-ish parts on these guns. Many of them had a Made-In-China feel to them. Pat and I took two guns each and we each saved one and basically called the other “unsalvageable”. Good Lord they were bad. All had the Cheezoid castle nut. All had the Cheezoid mag catch. All had short headspace, and being “in the field” as it were, all I had was the headspace gage but I’ll betcha headspace was short because they all had the same rejected bolts with .007 or-so-short bolt face recesses.
Some parts appeared to have black paint as the only finish.
Right, a buffer tube castle nut wannabee, as found on these six carbines.
1-wrench doesn’t fit (maybe why they were loose)
2-close to 1/16" shorter
3-huge chamfers on inner diameter, which combined with 2, reduces thread count to about 1/2
4-finish is black spray paint
After Ned and I overhauled the ones that actually wanted to work, they went 100+ rounds each in the next five minutes without a problem.
Still, told the LEO who had brought them that they were best used as training guns, and not duty guns.
The list of what was wrong with them was long, inclusive, and impressive. including things like the buffer weights being bare turned aluminum, not having been andodized. When Ned went to drive out the retaining pin, to see what kinds of weights were in them, he could push the pin out by hand.
