View Full Version : Buffer detent pin broke
It finally happened—I broke a Colt detent in my 1980 16” SP1 carbine. Nothing major was damaged, but my range trip was cut short. I was using Federal XM193, but I don’t think it matters.
Now I have a spare parts kit (never had one before that I took to the range) but have looked at HK & Leitner-Wise “Heavy Duty” detent.
Anyone with any experience with the heavy duty or HK version? I’m not sure the HK will work with Colt.
Alternatively, I replace springs every 5k rounds, but never had a maintenance schedule for pins—anyone with insight on this matter?
It finally happened—I broke a Colt detent in my 1980 16” SP1 carbine. Nothing major was damaged, but my range trip was cut short. I was using Federal XM193, but I don’t think it matters.
Now I have a spare parts kit (never had one before that I took to the range) but have looked at HK & Leitner-Wise “Heavy Duty” detent.
Anyone with any experience with the heavy duty or HK version? I’m not sure the HK will work with Colt.
Alternatively, I replace springs every 5k rounds, but never had a maintenance schedule for pins—anyone with insight on this matter?
The only time the buffer touches the pin is when the receivers are open or separated. All the pin does is retain the spring. It serves no other purpose. I' can tell you the quickest way to break one... Break open the gun with the bolt locked back.
I was shooting & the gun locked up.
Did your buffer tube loosen causing the pin to pop out?
The detent pin should not be contacting the buffer during shooting, but in some rifles it may which can cause this breakage. Maybe this happened to the OP. You can check for this, when closing an upper onto a lower, you should be able to see the rear of the bolt carrier contact the buffer, pushing the buffer off of the pin. With this in mind, the buffer detent pin isn't a part that should wear out or need PM replacement schedule, or to be heavy duty. Does your buffer have evidence of hitting the pin over and over?
If I understand correctly, the detent in your gun lasted 38 years. I am unaware of how many rounds have been through it or if it is modified. However, if my 1978 SP1 detent broke, I would order a new colt detent and spring from brownells for $9.00 and carry on. Actually, I have a few detents and springs in my spare parts.
Cheers, Steve
vicious_cb
06-24-18, 15:10
FYI, the buffer detent, or lack there of, does not impact function of the rifle at all. You just have to remember to catch the buffer with a finger everytime you shotgun the upper and lower.
FYI, the buffer detent, or lack there of, does not impact function of the rifle at all. You just have to remember to catch the buffer with a finger everytime you shotgun the upper and lower.
Unless the tit ended up somewhere that it wouldn't fit. I am not sure we have heard the rest of the story yet.
Unless the tit ended up somewhere that it wouldn't fit. I am not sure we have heard the rest of the story yet.
I agree. I can't see how that locked up the gun.
titsonritz
06-25-18, 03:20
This thread makes me think of this...
https://truenortharms.com/products/ar-15-offset-buffer-retainer
Yeah, the buffer detent isn't needed like said before.
It shouldn't have tied up the rifle, unless the little tit got some place it can't fit into like the FCG.
I had a National Match Service Rifle that for some reason, never discovered by me the liked to break them, four times. Everytime the little tit would end up in the FCG, of course during rapid fire.
I sold that rifle, without the detent, full disclosure to buyer. It ran fine without the buffer detent.
I never did figure out what was causing the breakage.... everything looked fine. But I can tell you that it ran without the buffer detent and after going down in a lag match, that's how I ran it until I sold it.
Some of you guys are full of crap, if the buffer doesn't run against the buffer detente then how can you close the AR when it is put together? How can you open the AR without the buffer flying out? How do you explain the detente marks on the buffer? No some of you need to go back to GS class/school. Yes the buffer detente does and will stop the buffer and will break/bend the detente.
rngr1
Some of you guys are full of crap, if the buffer doesn't run against the buffer detente then how can you close the AR when it is put together? How can you open the AR without the buffer flying out? How do you explain the detente marks on the buffer? No some of you need to go back to GS class/school. Yes the buffer detente does and will stop the buffer and will break/bend the detente.
rngr1
So you are repeating the same thing 4-5 of us said (different words) after calling us out for doing it??? BTW, what is your first language? Maybe it's a translation thing.
Some of you guys are full of crap, if the buffer doesn't run against the buffer detente then how can you close the AR when it is put together? How can you open the AR without the buffer flying out? How do you explain the detente marks on the buffer? No some of you need to go back to GS class/school. Yes the buffer detente does and will stop the buffer and will break/bend the detente.
rngr1The hinge point is below the buffer and carrier plane of alignment. This allows the carrier to close onto the buffer face while simultaneously pushing the buffer rearwards and off of the dentent.
In simpler words, the detent holds the buffer when the ar is open. The bolt carrier holds the buffer when the ar is closed.
The sheared off detent got mentioned in one of the Inrange videos and I think one or both of them stopped using the detent to eliminate the chance of it ending up in the fcg. Think they also were trying a JP captive unit, but can't recall of they had used it enough to form an opinion.
I had a similar problem with the detent pin. I've had my 6920 for many years. Last time I took it to the range it 'locked up. Turned out the detent just popped out. Once I got it opened up found the pin in the lower receiver. The buffer tube was not loose and had to loosed the castle nut and move the buffer tube back to get the new detent pin back in. The old detent pin showed no signs of wear around the edges that retains the spring, strange.
MountainRaven
06-26-18, 13:29
The sheared off detent got mentioned in one of the Inrange videos and I think one or both of them stopped using the detent to eliminate the chance of it ending up in the fcg. Think they also were trying a JP captive unit, but can't recall of they had used it enough to form an opinion.
Not only did they run it enough to have a solid opinion of it, they ran it enough to give it the IRTV Stamp of Hubris.
https://www.youtube.com/watch?v=e7XiLjVDs38
In any event, part of the why was because they have seen the detent break often. And because they don't even bother with the detent in their builds, they like having the captured action spring.
Some of you guys are full of crap, if the buffer doesn't run against the buffer detente then how can you close the AR when it is put together? How can you open the AR without the buffer flying out? How do you explain the detente marks on the buffer? No some of you need to go back to GS class/school. Yes the buffer detente does and will stop the buffer and will break/bend the detente.
rngr1
You are wrong. Everyone else is correct. Marks on the buffer face are from the back of the carrier. The detent is only under load when the back of the carrier pivots off of it when the receivers separate.
Now I have seen some out of spec trash lowers that have the detent incorrectly located. And those with self destruct fairly quickly.
You are wrong. Everyone else is correct. Marks on the buffer face are from the back of the carrier. The detent is only under load when the back of the carrier pivots off of it when the receivers separate.
Now I have seen some out of spec trash lowers that have the detent incorrectly located. And those with self destruct fairly quickly.
Mark, I don't remember if it was here or not but someone had a rifle busting pins because the hole was drilled too far forward. His buffer looked like a steel toothed badger chewed on it!! I doubt that is the OP's problem on his old SP1. He is probably one and done and we'll never see what stopped the rifle.
Straight Shooter
06-26-18, 16:05
Some of you guys are full of crap, if the buffer doesn't run against the buffer detente then how can you close the AR when it is put together? How can you open the AR without the buffer flying out? How do you explain the detente marks on the buffer? No some of you need to go back to GS class/school. Yes the buffer detente does and will stop the buffer and will break/bend the detente.
rngr1
Thats a hell of an F-ED UP first post.
Mark, I don't remember if it was here or not but someone had a rifle busting pins because the hole was drilled too far forward. His buffer looked like a steel toothed badger chewed on it!! I doubt that is the OP's problem on his old SP1. He is probably one and done and we'll never see what stopped the rifle.
Yep.. just a fluke or something.
Do yourself a yuuuuge favor. Check yourself befo' you wreck yourself.
Some of you guys are full of crap, if the buffer doesn't run against the buffer detente then how can you close the AR when it is put together? How can you open the AR without the buffer flying out? How do you explain the detente marks on the buffer? No some of you need to go back to GS class/school. Yes the buffer detente does and will stop the buffer and will break/bend the detente.
rngr1
titsonritz
06-26-18, 19:20
Some of you guys are full of crap, if the buffer doesn't run against the buffer detente then how can you close the AR when it is put together? How can you open the AR without the buffer flying out? How do you explain the detente marks on the buffer? No some of you need to go back to GS class/school. Yes the buffer detente does and will stop the buffer and will break/bend the detente.
rngr1
You've been around four years and this the best first post you can come up with? Maybe try reading some more (comprehension helps) and come back in another four years try again.
The tit was mangled & got wedged under the rear of the trigger—at least that’s where I found it after breaking things down. The buffer is a new H buffer I installed because I thought the original Colt carbine buffer must be evil—otherwise why would they sell H, H2, H3? :confused:
The original buffer looked barely used. The gun is quite cherry—a steal at $1500!
The first time I shot it, the gun locked up as the springs from the hammer weren’t seated in the trigger pin groove. My fault—I didn’t check. I assumed the gun was 100% from a fellow gun guy.
It was a used gun, the original owner said there was under 1000 M193 (National Guardsman, got ammo “free”).
Is there any benefit to the heavy duty HK or Lietner Wise detents?
In reading responses, I think not. I futzed around with the detent out—maybe that’s the easier answer vs a $20 souped up part.
bamashooter
06-27-18, 06:23
Do yourself a yuuuuge favor. Check yourself befo' you wreck yourself.
Respectfully request to use that line sometime. ;)
Respectfully request to use that line sometime. ;)
Ice Cube hereby grants permission.
Ice Cube hereby grants permission.
Just correct the yuuuge spelling to Huuuuge. Just kidding:D
Does anyone know if HK buffer retainer will even work in a regular AR?
I tried one & it doesn’t work. It sits too high & needs to be modified.
Thanks for the great info!
I tried one & it doesn’t work. It sits too high & needs to be modified.
Some of you guys are full of crap, if the buffer doesn't run against the buffer detente then how can you close the AR when it is put together? How can you open the AR without the buffer flying out? How do you explain the detente marks on the buffer? No some of you need to go back to GS class/school. Yes the buffer detente does and will stop the buffer and will break/bend the detente.
rngr1
When I first read this, I suspected it was just trolling. Could it be real?
Some of you guys are full of crap, if the buffer doesn't run against the buffer detente then how can you close the AR when it is put together? How can you open the AR without the buffer flying out? How do you explain the detente marks on the buffer? No some of you need to go back to GS class/school. Yes the buffer detente does and will stop the buffer and will break/bend the detente.
rngr1
Whether it's trolling or not, let's address this:
Detente: variation of détente. the relaxation of strained relations or tensions (as between nations)
Detent: a device (such as a catch, dog, or spring-operated ball) for positioning and holding one mechanical part in relation to another in a manner such that the device can be released by force applied to one of the parts
I have seen it alleged that some semi auto bolt carriers are shorter than proper carriers; I've never measured or compared, and cannot attest to the veracity of this claim. OP, can you measure your carrier, or compare it to a known good one? If this theory holds up, and someone swapped an undersized carrier into your rifle, I could see how the short carrier would allow the buffer to impinge on the detent with the rifle in battery. Even without measuring, you can watch carefully as you close the upper to the lower, to see if the carrier pushes the buffer back or not. If everything is in spec you should see just enough movement to get the buffer off the detent. If it does not, expect more broken detents.
Powered by vBulletin® Version 4.2.5 Copyright © 2024 vBulletin Solutions, Inc. All rights reserved.