If your rifle is running an h2 reliably it should work with the rifle length stock system. I use H3's in my rifles because of suppressed shooting now but all of them run fine without the suppressor.

That said, the only time I ever tried an A2 stock in a rifle it was not reliable whatsoever until I put back on a carbine buffer and buffer tube. I would not run a carbine buffer or spring in the A2 tube. The carbine buffer and spring are too short and would cause even more problems.

I'll add that there are also a lot of options for solid stocks on a carbine tube. Magpul makes a few and so do some other manufacturers. They retain the adjustable LOP but can be locked in tight like a fixed stock once you put them where you want them.

Your best way to see if the A2 stock will work on your rifle is to bow wow someone's lower with one already on it and mount your upper to it.

 

I would not run a carbine buffer or spring in the A2 tube. The carbine buffer and spring are too short and would cause even more problems. Your best way to see if the A2 stock will work on your rifle is to borrow someone's lower with one already on it and mount your upper to it.

I'd never use a carbine spring in the longer buffer tube. I did that once, and had a piece of steel pipe in the bottom of the buffer to compensate for the difference in the length of the springs. The rifle functioned so poorly that I had to take it to a gunsmith whose primary work was with ARs. Upon return, he told me the problem was with the carbine spring and carbine buffer being in the longer tube, even though the difference in the lengths of the differing springs had been compensated (or so I thought). I never had another problem with that gun once everything had been corrected by someone who knew a little something more about the AR platform than I did.

The question is, Can I use the heavier carbine buffer in the longer tube? The amount of gas coming back will be the same, the Spikes buffer will still feel the same energy but that energy will be absorbed by a spring that is longer and therefore, can absorb more energy by virtue of its longer length. Now I'm asking myself if the longer tube (and shorter buffer) will allow the bolt group to want to shoot its way back into the buffer tube, possibly ruining my $57 Bravo Company Machine charging handle...

 

Your gas key and your charging handle would definitely be making contact. I'd heavily advise against it. It may not even be safe for you as the shooter but in the least it will start causing the rifle to damage itself. Your Bolt Carrier would just have too much room to move back and it wouldn't be bottoming out on the back of the receiver extension but on the charging handle or the lower where the receiver extension/buffer tube mounts to.

I think the rifle will still run fine with the rifle buffer. I use a 5.4oz buffer in my rifles and they work. But that's my rifles, yours may be a little more picky, here is another idea.... you can take out and change the weights in an AR15 buffer. There is a roll pin in the back that can be romoved and you can add or remove weight to what you want. You can turn a regular carbine buffer into an h2 if you wanted/needed to. Or vice versa. It just wouldn't have the correct markings on the face. You can do some work on the A2 buffer and with a scale alter it to the weight you need...

 

. . . you can take out and change the weights in an AR15 buffer. There is a roll pin in the back that can be removed, and you can add or remove weight to get what you want.

I had that idea come to me not long after I made my previous post. I know ARs can be "timed" to spit the brass where the user wants it to land for easier gathering and policing by varying the weight of the buffer. If that's possible, should also be possible to make one cycle correctly with the long stock and some mysterious combination of spring and buffer. I have no idea how to do it myself, and I'll be dam-ned if I'll take it to Silver Bullet and have it set there for six months until they get around to doing such a small job...

 

This is a stock I recommend for people wanting a fixed stock feel and performance but retain an adjustable LOP still. It's very solid and locks in place once you get it where you want. It still uses a carbine buffer and spring as well so no issues there.

https://www.magpul.com/products/ubr-collapsible-stock

It is not cheap though but is a complete unit including the proprietary buffer tube and all. Just put it on and drop in your spring and buffer.

Edit. Here is a video of a guy doing an in depth look at the UBR. It does mount a lot more like an A2 stock. The buffer tube actually looks like a short A2 tube.

https://m.youtube.com/watch?v=fh4bOmH0iaM

 

Thanks for the links, Trent. I'm looking to put the plain, drab, dry, old A2 stock on just for getting the rifle to group. The collapsing Daniel Defense stock just does not set in the rear bag well, and I believe that poor setting is a large part of the rifle's inaccuracy. The load I was using may also be, but to replace the stock eliminates what I believe to be a large question. In looking around the web last night, I was able to find complete stock kits for anywhere from fifty dollars to just over one hundred. Before I spend some money, I must first find a job. I've been out of work for almost four months. I chose to be; my last job had me in the Bay Area six days a week. I can't believe I did that for almost three and one-half years. My next job will not have me there at all. Experience is the best teacher...

 

My rule of thumb has always been use the buffer and spring that matches the stock, never had a problem.
As far as collapsible stocks go I've never been able to get a AR to group consistently with one, not to say it can't be done, I just can't do it.
Being somewhat of a traditionalist when it comes to AR's I like the A2 stock
Optics planet carries every AR part known to man as far as I can tell, I get most of my stuff from them.
Leapers UTG Model 4/AR15 A2 Fixed Stock Assembly RB-T469D $2.00 OFF New Product

 

I've shot my cheapo collapsible from a Caldwell lead sled and it shoots great so I don't think the stock will make your gun shoot better, but if you wanna run an A2 just use all rifle parts in the rifle tube. I've run two different carbine uppers on my Colt A2 lower without any problems. If for some reason the rifle buffer is too heavy you can open it and take some weight out, but it probably won't be.

 

While the actual volume of the gas tube on a rifle is more than a carbine tube, that is for a given pressure. The port pressure for a carbine is much higher than a rifle, so it could be argued there is more gas in a carbine tube. If its a 16" barrel (vs 14.5") there is a lot more dwell time and pressure. Add to the matter the inconsistency in port sizes and you have several different variables. It is very common to have an over gassed carbine, usually addressed with a heavier buffer as that is the easiest fix. The violent cycling from being over gassed and under buffered is most likely the reason for accuracy issues with a carbine stock. Soften it up and you will see a lot better accuracy since the bolt wont be slammed with high gas pressure while the round is still in the barrel. Next up is an adjustable gas block, but those suffer from gas cutting since the actual port pressure isn't being reduced. I've also blown a very lightweight adjustable gas block apart for that very reason, the manufacturer re-engineered it after that. My best experience has been with a gas block that uses hardened bushings in the underside of the block directly over the port in the barrel. Once you have a known in spec port, you can begin fine tuning with the buffer. Most carbines shoot best with an H2 weight. For pistols I like an H3. Hope that helps put things in perspective a bit better.

 

If you are using a rifle butt stock and tube, I would say use the rifle spring and buffer.

Call the maker first and see what they say about it. There may be some differences in gas pressure.

 

NV Shooter: "I am wondering if the lower volume of gas generated in the carbine barrel versus that volume in the rifle barrel will be enough to reliably operate the rifle buffer and rifle spring. Maybe use the rifle spring and the carbine buffer?"

I am not sure which you mean by lower volume of gas generated in the carbine. When a round ignites you get a pressure curve and the closer the gas port in the barrel is to the chamber the higher the port pressure delivered to the operating system is generated because the pressure spike is still high when the bullet passes the port.

Now that being said the velocity from a 16" barrel is normally lower than a 20" barrel as the bullets from the short barrel clears the muzzle before full velocity is achieved. That is why on my RRA Varmint Rifle I ordered the 24" barrel.

In a full length barrel the port pressure is much lower.

Per my contacts at RIA when the first M4s were fielded the port pressures were out the roof which exhibited extraction forces on the case rim much higher than the pressures in the M16s. The result is the case rims were ruined on millions of cases as the cases would not go into a shell holder.

I had similar issues with a AR Carbine. It had a 16" barrel but the short handguards and close mounted front sight. What I had was the worst of both worlds. Close sight radius, big port, etc. Also the first M4s had the same size gas port as the "real" AR barrels so that made for a bad combo, high pressures + large gas ports = overdriven gas system. I had a friend who wanted it and I explained what the problem was with it and he said he did not care because he was never going to get into reloading so I let him hold it.

What do you consider "hitting the broad side of a barn" to be in relation to group size at 100 yards? Rejection with ball ammo is 7.2" at 100 yards insofar as the spec is concerned and to a competition shooter that is not acceptable. For a target rifle I am looking for no more that 1 1/4" (= barrel comes off) at 100 yards with my handloads with good barrels and under a inch as new.

When I conducted the M16A1E1 Test at APG. As new the barrels averaged 3.5" at 100 yards. I started seeing a slight increase in dispersion at 2400 rounds (about 4") At 3600 rounds it was in the 6" range and at 4800 rounds it was right at rejection and at 600 yards could not be kept on a 8FtX 12ft target beyond 600 meters. Of course those are chrome lined barrels and chances are good a non chromed will shooter better initially but will become worn quickly. At 6000 rounds the chrome in the tops of the lands of the "new design heavy barrel" was gone for two inches down bore.

Bottom line is a rack grade barrel combo is not generally a nail driver and add a season shooting might not be a barn hitter in the competition world.

Now bear in mind the M16A1E1 test was with 62 grain bullets (M855 experimental). I have a sectioned M16 barrel that was subjected to 20,000 round run and the chrome is only worn away for 1" forward of the chamber. The same propellant was used in both and since ball propellant is noted for eating barrels for breakfast the results are not surprising.

Of particular interest the bullets in the experimental M855 were made by FN and were the same they loaded in FN made SS109 and when we tested that ammo the groups reduced from 3.5" range to 1 .25" range. Different propellant was used in SS109 and barrels were still "in spec" at 12,000 rounds.

 

What do you consider "hitting the broad side of a barn" to be in relation to group size at 100 yards? Rejection with ball ammo is 7.2" at 100 yards insofar as the spec is concerned and to a competition shooter that is not acceptable. For a target rifle I am looking for no more that 1 1/4" (= barrel comes off) at 100 yards with my handloads with good barrels and under a inch as new.

FWIW, that one made me even happier with my PSA uppers. The three I've built so far, 1-carbine length and 2- midlength gas systems are all in the 1.25"-1.5" range from a rest. All are scoped, (I'm not doing that with the irons).

 

NV have you ever used the Magpul MOE SL carbine stock ? Its a pretty tight fit... I use it bench shooting several of my ARs and seems to work great . About 60 bucks.

There is another one that locks with an adjustable throw lever to make it rock solid, I THINK its made by Safariland , i have one on an AR somewhere around here ! I may just have to open 17 hard cases to find it ! I bought mine through Midway....

 

Dang it Humpy ,,,,I just love my encyclopedia, Humpanica !!!!

 

I've never anyone say that ball powders are harder on barrels than extruded powders with the same burn rate, in fact exactly the opposite, the lower flame temperatures and less abrasive shape of ball powder should make the barrels last longer.
Also it would seem to me that if you have scoped AR with a free-floated forend and decent ammunition the accuracy expectation should be well under an inch@100m in an experienced AR shooters hands.
OP never said if he tested the gun using optics but if your vision isn't perfect don't expect your groups to be either especially with standard military sights.

 

OP never said if he tested the gun using optics but if your vision isn't perfect don't expect your groups to be either especially with standard military sights.

At 66yrs of age, my vision is better than my memory, but not by much.