AR platforms

[Panman65]

 

 

Ive just signed on so greetings everybody. I hope this is the rite place for this topic? I was reading a question earlier about the difference between the A-2 buffer and spring, and the carbine length buffer and spring. Yesterday I was out test firing a new .223 Wylde carbine upper matched with an A-2 fixed stock with matching buffer and spring. The results ended in a .223 single shot. Duh. I've got a carbine length buffer, but should I use the buffer and matching spring? Or can I change out just buffers. This is my new hypothesis. Also, for .223, 5.56, and .300 aac overall case length should be 2.060" (+-.003) I've made some subsonic 230 gr lead bullets. My results are not all blackouts have the same headspace. Any takers? Or have I just answered my own question? It happens......

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[Nugget]

You may already know this but I couldn't really tell for sure from your post. Be sure to use a rifle buffer and spring with a rifle buffer tube and a carbine buffer and spring in a carbine tube. Do not use a carbine buffer in a rifle buffer tube.

Edited August 16, 2017 by Nugget
Complete

[Flatland Shooter]

1 hour ago, Nugget said:

Do not use a carbine buffer in a rifle buffer tube.

 

Why?

[Panman65]

I know there's a difference in length and weight that comes with the A2 buffer tube. I have one in my .308, there's also one paired in my 6.8 spec ll. But for a 5.56 I'm thinking that I need a lighter buffer and spring. I'm using a mid length gas tube, for such a light load as the 5.56 I just don't think there's enough gas pressure to cycle the next round? The other day, I didn't think to swap out lowers with the .300 aac I had with me. Duh. I'm positive that would've fixed my single shot 5.56 issue. I want to keep the A2 stock on it cause the length of pull is perfect for me, and I don't have the rattle of the 6 position. I've probably just answered my own question here. Thanks to thinking out loud with other shooters. Thanks.

[Nugget]

6 hours ago, Flatland Shooter said:

 

Why?

You can do it if you use a spacer otherwise you will receive damage to your lower from the gas key slammming into it.

[Flatland Shooter]

2 hours ago, Nugget said:

You can do it if you use a spacer otherwise you will receive damage to your lower from the gas key slammming into it.

 

Good to know.  I've never tried running a carbine buffer in a rifle tube so never really thought about it.  Makes perfect sense.

[Panman65]

I understand the idea of a spacer in order to use a carbine spring and buffer. But what if I used the A2 heavy buffer with the lighter carbine spring? At this time I've got both carbine spring and buffer in a rifle tube. I can definitely tell the difference! Also with the carbine spring I can hear the rattle of the spring in the tube. This I believe is the only reason why this rifle isn't cycling. I've never tried this setup before. Everything else in this build is functioning properly. A spacer would have to be approx 1-1/2" in order to take up the slack of the lighter spring. But what if the problem is the 5oz buffer? Using the heavier A2 full length spring with a 3-4oz buffer, but I think the lighter buffer won't have the mass needed to compress the spring? This has become a bit of a conundrum I think? I was using an 8x8x24" chunk of wood to

testfire in my basement, but I've blown it to smitherines. Lol. I'm setting up a safety discharge sand barrel like the ones that were kept on base at building entrances to safely unload a weapon prior to entering. I've got the steel drum, cut out a 10" hole in the center for the muzzle. Now I just gotta get 4-5 bags of sand to fill it with. Then I can do some actual live fire test to make sure we're cycling and or which combination works better? Does anyone know of any other reason why this action isn't cycling? With the A2 spring and buffer the action won't even move to cycle the next round. I've run into all kinds of issues with dozens of builds, just nothing like this. Im open to any and all suggestions. However, I still think it's in the buffer assembly..... tanks everybody for the input. I'm feeling kinda dum at the moment and not liking it at all.

[Eviljarv]

To me sounds like you have a very under gassed rifle or using very weak ammo. What ammo are you using? I would remove a weight from the rifle buffer and see what it does

[Panman65]

American eagle 5.56 is what I was running, but I also roll my own. This has got to be a buffer issue? Everything else is the same same carbines with mid length gas tubes and std gasblocks as my others except for the A2 rifle stock. Although I do use the A2 length tube, spring and buffer on a .308, and a 6.8 spcll. It just all points to the buffer. Tanks

[Eviljarv]

1 hour ago, Panman65 said:

American eagle 5.56 is what I was running, but I also roll my own. This has got to be a buffer issue? Everything else is the same same carbines with mid length gas tubes and std gasblocks as my others except for the A2 rifle stock. Although I do use the A2 length tube, spring and buffer on a .308, and a 6.8 spcll. It just all points to the buffer. Tanks

Try removing one of the weights inside rifle buffer. I wouldn't run a carbine buffer in an A2 tube, the gas key will hit the receiver extension, you match the buffer/spring to the buffer tube not the barrel

Edited August 17, 2017 by Eviljarv

[Eviljarv]

And if everything is brand new sometimes it takes a few mags to break in everything, I would run the bcg wet and some 5.56 ammo since it's higher pressure and see if it gets better. 

[Panman65]

Funny you should mention that. Cause that's just what I did. Lol. There must be some great minds out here eh. I sprayed the hell outta it also checked the gas rings. What I should've done was swapped lowers with the blackout I had with me. I didn't think of it till I got home. 

[Panman65]

Ok, so I put the A2 buffer on the scale 5.4 ozs, then the carbine 2.9 ozs. I lowered the A2 down to 2.8 ozs and still using the heavy A2 spring.

Just did a test firing. It will eject the spent shell but won't feed the next round. Hmmm? Bcg maybe? Tried another, no diff. Tried mine in another rifle, worked fine. Then the lil lite bulb in me head come on about spacers!

Kudos to Mr Nugget!

I started thinking about the spacer idea in order to use a carbine buffer in the A2 stock. Since I reduced the buffer weight on the A2 buffer it dawned on me that it would act as a spacer paired with the carbine spring. I just ran 2 full mags thru it, and except for the smoke cloud it worked just peachy!!!!!!! Lucky for me that I remembered that I had a green 2'x16" thick log of Osage orange out back that I was going to use as an anvil stand but made a different type of stand instead. It's a super hard chunk of wood. Average penetration was 4" deep. Almost 9" with a fmj 300 aac. Thanks to all for reading all my babbles and helping me answer my own questions with your input. Stay safe out there, n keep ur powder dry n downwind. The PanMan

[DesertTortoise]

Don't mess with the springs and buffer. As said use rifle buffer and spring with an A2 receiver extension / stock. You probably have a gas problem if this persists with the correct springs.

Look at the gas block, gas tube, gas key, and gas rings (especially if you assembled the rifle yourself). If you think you are undergassed, try and solve this before changing the buffer system. More than likely the gas block is not aligned...

The best way to tune the action of an AR is with an adjustable gas block, not the buffer and springs.

[Eviljarv]

29 minutes ago, DesertTortoise said:

Don't mess with the springs and buffer. As said use rifle buffer and spring with an A2 receiver extension / stock. You probably have a gas problem if this persists with the correct springs.

Look at the gas block, gas tube, gas key, and gas rings (especially if you assembled the rifle yourself). If you think you are undergassed, try and solve this before changing the buffer system. More than likely the gas block is not aligned...

The best way to tune the action of an AR is with an adjustable gas block, not the buffer and springs.

Listen to this man, all you are doing by mismatching buffer parts is masking the underlying problem, if it won't cycle right with a rifle buffer/spring then you have a gas problem

[Panman65]

I checked all that. Gas block, tube, key and rings. Everything checked out. I also tried a new bcg, then I put the upper on a carbine lower and it ran fine. I also tried a different upper on the A2 lower and it wouldn't feed another round. That's when I took out some buffer weights and tried it with the longer and heavier A2 spring. No luck on either of the uppers. That's when I decided to try the carbine spring, I stretched it out a lil bit, but it all worked fine. I took it back apart and checked for any unusual wear or shiny spots. Everything looks clean. The A2 stock, tube, buffer and spring were originally from an AR-10 .308. Idk if that's the reason for the cycling issues? But I ran 2 full mags thru it just as fast as I could with the 2.8oz A2  buffer and carbine spring. All I know is that it works great now.

[Eviljarv]

Then that's mostly likely your issue, buffer and spring are not interchangeable between AR-15 and AR-10, just get a rifle buffer and spring for a .223/5.56 and should work just fine