I recently bought a preban colt sporter lightweight. While shooting today I started to get a couple failures to go into battery. After changing mags it occurred to me it was a rifle issue. Took the rifle down and found the buffer tube detent had fallen out and was behind the sear block (thanks for the sear block colt). Looking at it compared to my 6920 it appears the buffer tube wasn’t installed completely causing the detent to wear through the small amount of tube holding it in place. Am I correct with that assessment? Would simply reinstalling the buffer detent and screwing the buffer tube in some more fix my issue?
Was this a new Colt? Any signs of someone being a YouTube armorer?
Bought it from the original owner that bought it back in '91. When I asked him if he removed the buffer tube his response wen’t something like “I might have to see how an adjustable stock fit”. Nice, now need to clean up his mess. Should I replace the tube or just tighten it up? Any idea on where to get a buffer tube detent spring?
They come in standard lower parts kits, some even come in “oops” kits designed for people that lose detents and springs.
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That buffer tube was not installed by the factory.
All sporter lightweights came with fixed stocks.
So my guess is the castle nut was not staked properly, if at all and it came loose.
It still has a fixed stock. I believe he took off the stock and buffer tube and installed an adjustable stock. When he returned the rifle back to stock he didn’t install it correctly. He’s a family friend which makes for greater frustration.
Other than no bayonet lug and the fixed stock, the Lightweight Sporter is identical to the Government Carbine, as far as the examples of both I have owned were concerned.
YMMV and Colt is not necessarily consistant in their models.Colt Sporter Lightweight is designated as a 6530 I believe. No bayonet lug, A2 stock, rollmarked Sporter Lightweight and the serial number prefix is probably SL.
Someone modified that. That endplate also has a weird color to it. It almost looks black. In any case I wouldn’t be blaming Colt for something that happened on something that is over 20 years old and probably been messed with.
Yeah, I learned the hard way, to only “sell” to family friends.
Easy now, I never said colt installed it incorrectly. I love my 6920, I explained the previous owner admitted to removing the buffer tube.
Order a new detent spring and detent. I looks like the receiver extension needs to be installed in 1 more revolution. Easy and cheap fix
He can’t thread it in any more past the flange. It is a rifle tube, not a carbine tube.
Ordered a magpul armorer tool and a new detent spring. Hopefully I can get it running right again.
Is there a gap between the receiver and extension flange or buttstock? If so, it should definately be screwed in all the way. If no gap, you will need a new receiver extension.
For rifle extension, I don’t think the armorer tool is needed.
You are 100 percent correct. It would seem he tried installing the stock without removing the tube from the stock. I broke it down completely and when screwing the tube in by itself, it had a solid half turn more before bottoming out. All I need is to wait on a new detent spring and I should be good to go, no tool required besides a flat head screwdriver. Thank you M4carbine.net. Maybe if he was a member here he could have done it right the first time. Measure twice, cut once and all that…
double post
nof555 - I’m not real clear, this has an A2 stock on it it, correct? If I’m thinking correctly, you may be hosed. The A2 rifle extension has a shoulder on it and it screws all the way into the receiver. From my point of view, it should have had a little more metal holding the detent in place. If the guy didn’t tighten it correctly, you may be in luck. Take the stock off, hopefully you have an armorers wrench, it should have a fixture/cutout for the protrusion on the end of the tube, torque it down good against the shoulder. I’m not sure what size open end would work, but if all else fails a crescent. If it was left a little loose by your friend, hopefully it will move enough to get away from that ate out section.
Oops, looks like you solved it while I was messing around. Good.
If you want official Colt: AR15A4 Buffer Retainer Spring or if you don’t care about that Buffer Retainer Spring
ETA: Never mind looks handled.
Thank you very much good sir. I checked midway and all they had was dpms retainer springs (which I cringed my teeth to consider buying). Honestly, it probably doesn’t matter but I’m going to go with the colt instead.
I think he will need a new lower receiver extension. But without seeing it in person, I wouldn’t be sure.