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Posted: 9/7/2025 10:43:41 AM EDT
I picked up an lpk from a fairly well known vendor. While screwing down the mag catch this happened.  In nearly 40 years of assembling and disassembling these things, I've never seen this happen. WTF? 
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The pic is hard to see clearly but the parts are thread at the shaft end that goes in the plate and plate hole that broke aren't they? Pic makes it look like it was pressed in and swaged instead of screwed in and swaged. If it was pressed in might be why it broke. |
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Originally Posted By j3_: Pic makes it look like it was pressed in and swaged instead of screwed in and swaged. If it was pressed in might be why it broke. Yep, looks to be interference fit, swaged. The thing literally snapped like a Frito while turning. No pressure on the arm as I had a plastic punch on the other side compressing the nut and spring. These were advertised as made in USA, mil spec, cast not mim. I have my serious doubts as to the legitimacy of that statement.  |
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The tdp drawings online showed the spec being pin threaded both ends and the plate threaded to accept the pin. As far as mim the plate portion by the spec is allowed to be mim but still it is supposed to be threaded. You see mil spec in ads all the time nowadays and it just doesn't mean much I don't think. Like seeing grade 8 socket screws listed on carrier sales ads and socket screws are not normally even graded that way. Bad part is that just looking at the part you can't tell which way it is made. Makes me wonder how many I might have made that way. Thought I would check some I had culled out of parts kits for other reasons like out of measurement arm dimensions or angle of the pin not being in the angle limit to the plate. Out of four they were all made pressed in instead of threaded like the spec calls for and snapped easily. |
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Originally Posted By ZastavaGuy: Yep, looks to be interference fit, swaged. The thing literally snapped like a Frito while turning. No pressure on the arm as I had a plastic punch on the other side compressing the nut and spring. These were advertised as made in USA, mil spec, cast not mim. I have my serious doubts as to the legitimacy of that statement. A properly made magazine catch will have the shaft screwed into the plate and the end of the threads peed over for a permanent assembly. Looks like a MIM part . . . |
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I emailed the vendor after it happened just to let them know what occurred. Got an email back today that they were sending out another, so kudos to them. I did reply regarding the fact that it was press fit instead of screw and they might want to check with their supplier. |
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Really disappointed in how many I have out of kits from many vendors most said mil spec. All of the ones of mine with what looks like a small D recessed into the plate were made that way no threads and I broke one today to see that has what looks like a small indented rectangle and it was the same no threads. Colts are 15 bucks each ouch. Wish someone would sell them and state they were made to "real mil spec" with the threaded into the plate pins and the hardness required for the plate. |
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