AR assembly question

[AR1911]

Note that the buffer and spring are not used when shooting .22LR.
You can remove them completely.

 

[Tony Wells]

Well, this setup I think is supposed to use them. It has a much lighter spring and buffer (compared to the .223) that comes with it. I'll try to find a suitable spring for the retainer this weekend and put it all together. I will need to build a spanner wrench. The locking nut was only hand tight as it was, and I'm sure it should be tighter than that.

I was told that with the lighter spring, and shooting the .223, it would fire off bursts of 3 or 4 shots, so there must be some difference in the springs.

 

[Truebane]

A bit late now, but this may help:
http://www.gunpartscorp.com/Manufac...15SporterLowerReceiverButtstockAssy-34694.htm

And if it is doing burst fire like that there is more than a little wrong with it...unless it has military fire control system in it?

Karl

 

[Tony Wells]

Not too late Karl, thanks. I have a dozen active muffs to work on (these ARE kids, after all), so just kind of thinking about the AR. It has a stock FCU, so the bursts are not proper. Probably a worn sear. This thing has seen a lot of use.

I also have a sort of custom rear stock that uses the recoil to fire in a sort of full auto fashion. It's all in pieces, so have to figure out how it is supposed to work. I think the rearmost section slides forward during recoil and when it returns under spring pressure, releases the sear. It's said to be legal.

Thanks for the link.

 

[Tony Wells]

OK, AR, I have a question. With no buffer loaded at all, I get a jamming problem. A single shell will fire, and the next fails to ramp into the chamber, but end up fairly vertical, and bent by the return of the bolt. Is that because of too much spring in the bolt assembly, or because I don't have the spring and buffer in?

 

[cdhknives]

It has a stock FCU, so the bursts are not proper. Probably a worn sear.

A proper disconnector will stop this every time. When you fire and hold the trigger back, the hook on the disconnector catches the hook on the back of the hammer. After the bolt has cycled if you slowly let off the trigger you will hear it click as the disconnector releases the hammer back to be held by the sear. If it THEN fires on its own, you have a worn sear, or more likely a bubba trigger job gone too far. This is eassily checked with the upper removed from the lower...just be careful to not let the hammer free reign to impact the back of the mag well. A strategic piece of wood or even your hand prevents damage there.

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OK, AR, I have a question. With no buffer loaded at all, I get a jamming problem. A single shell will fire, and the next fails to ramp into the chamber, but end up fairly vertical, and bent by the return of the bolt. Is that because of too much spring in the bolt assembly, or because I don't have the spring and buffer in?

The back of the 22lr conversions I have seen appear to be held forward by the front of the buffer. The buffer doesn't move, but is required for support. What brand is yours?

 

[weespeed]

OK, AR, I have a question. With no buffer loaded at all, I get a jamming problem. A single shell will fire, and the next fails to ramp into the chamber, but end up fairly vertical, and bent by the return of the bolt. Is that because of too much spring in the bolt assembly, or because I don't have the spring and buffer in?

I have several AR's and a dedicated AR-22 as well.

22 does not need a buffer or spring, but they are there to keep the 22 bolt in the most forward position when it's in battery.
Without the buffer and spring the bolt is not going back in battery and moving back and forth. The bolt frame shouldn't move at all.
If you were to use the lower without the buffer and spring you need to use a plug. Spike's Tactical sells one.

If you are swapping uppers back and forth between a regular AR15 and your AR22 upper, there is no need to mess with the lower parts. You shouldn't have to swap springs out for 22 either. A plain carbine buffer and spring or H,H2, etc will work just fine.

The buffer tube should not have been moved or removed to just swap uppers.
It should be tightened to about 20-40 ft-lbs. And stake it.
The buffer tube holds the pin in.
If you need to change buffers or springs, just push the pin down and pull the buffer out.

The buffer detent spring is needed to keep the buffer back so that you can remove the upper from the lower. Without that spring tension the pin drops and the buffer would sit too far forward to open up the lower and upper. The buffer would act as a wedge.

I run a taccom reliability kit on mine, and it comes with a plastic/delrin type of pressure plug that goes between the buffer and the bolt and keeps pressure on it.
Here is where I got mine.
http://www.taccom3g.com/22RF_RELIABILITY_KIT.html

I also have a sort of custom rear stock that uses the recoil to fire in a sort of full auto fashion. It's all in pieces, so have to figure out how it is supposed to work. I think the rearmost section slides forward during recoil and when it returns under spring pressure, releases the sear. It's said to be legal.

Sounds like a bump fire stock. Several companies make em. I would look around and see which kit you have.
The two most popular kits are Slide Fire and Fostech DefendAr-15.

I had the DefendAR-15 kit. Really nice and almost all aluminum. The Slide Fire is plastic/polymer.

I hope that helps.

 

[Tony Wells]

OK, AR guys, I have another situation. This upper is a Velocity Firearms brand, and from what I read, is not all that desirable. But I didn't buy it, just trying to make it work. As it stands now, I am getting a very high percentage of OOB, FTF and FTE. Everything seems smooth and I've tried a couple of different magazines with no difference. Once in awhile I get a stovepipe. Any suggestions, other than replace it? I'd like to get this going for the kids to play with at camp. I think I have a couple of weeks to sort it out.

 

[cdhknives]

The first answer to multiple problems like that is cleaning cleaning cleaning...22lr can be extremely dirty. I suggest a complete disassembly and cleaning to like new standards.

The second answer is lube, not too much, not too little, and in the right places.

I know, sounds like a machine tool.:thinking:

 

[trukker]

Some are sensitive to different brands and hp versus round nose. I have needed a hotter 22 load to cycle weapon until it is broken in and then I could use lower velocity loads.