switching buffer system .223

[rugerdawg]

I have an ar-15t (24" cut 1o 18")and obviously a rifle gas system. It is presently set up with a std. a2 stock,rifle buffer and spring and I would like to change it to a lmt sopmod (carbine buffer). Do I need to use something other than a std. h buffer or heavier?

I built an ar-10t which I did the same thing (24" to 18")and after I switched to the ar-10 carbine buffer tube , spring and buffer I experienced serious ftf's and fte's from short stroking. I redrilled the gas port to the next size up and it has functioned perfectly since.

Hopefully someone here has done the same thing and can chime in here. I would have to assume all you 3-gunners running 18" barrels with carbine stocks would have a take on this, although mid-length gas systems seem to be more in vogue.

Edited May 6, 2010 by rugerdawg

[Graham Smith]

Good luck finding an answer. I've asked the same question here and in other forums and cannot find an answer. I switched to an EMOD stock which came with a standard carbine buffer and found it to be a bit "snappy", so I bought an H2 buffer to test. I just got it and won't know till Friday if it makes a difference.

[rugerdawg]

I can't figure out why no one will address this issue. Is this stuff top secret or is the answer so obvious that only a dummy like myself can't figure it out?

How did the heavier buffer work out for you?

[Graham Smith]

Apparently, it's on a need to know basis. Anyhoo, I used the H2 buffer this weekend while sighting in a scope. It is a lot smoother for me than the standard carbine buffer is.

I should also mention that I'm using a Levang Linear Compensator (to help reduce noise), which directs all the muzzle blast directly forward and, as a result, I get more straight back recoil than I would with a regular flash hider or compensator.

[00bullitt]

I guess I still do not understand why it is not understood. Please try one more time to describe what you are asking.

[AlamoShooter]

Its close to Rocket science . If as all you did was cut the barrel back after the gas port = it will have little effect on the gas into the buffer.

If all you did was change buffer tube and buffers = we all test and retest with new barrels, new stocks, new anything = test it at the range.

A friends new 308 will not push the bullets any thing close to his other guns, so he makes several trips testing and looking for loads.

You do know not to put a Rifle buffer in a Carbine tube? or a carbine buffer in a rifle tube ? rite?

Edited May 13, 2010 by AlamoShooter

[EkuJustice]

The heavier buffers definately smooth it out quite a bit. I originally ran a carbine buffer in my SBR but replaced it for a spikes tactical which makes a world of difference

[rugerdawg]

Thanks for the replies, I will do some testing with some different buffers as suggested. The original question came about due to my previous experience with my ar-10 and having gas problems. I haven't even shot the ar-15 yet and was just hoping to avoid the same issues. I have built 10 ar's over the past few years of all sorts of configurations (legos for big boys)with great success. I know this isn't rocket science but it is sure nice to have people who have been there to help others avoid mistakes.

[Graham Smith]

Here, in a nutshell, is the question - at least as I see it.

You start with an AR-15 with a rifle length gas system and an A2 stock with a rifle buffer.

You replace the A2 stock with a carbine stock with a carbine buffer. The buffer is now lighter, the spring is shorter, and the buffer tube is shorter.

It would seem to me that the "logical" thing would be to try and restore some of the "balance of forces" by increasing the weight of the buffer to something closer to that of a rifle buffer. Problem is, this doesn't seem to be common practice and I have no idea why not.

I just cannot seem to find any explanation as to the relationship between buffer weight and everything else; despite the fact that there are three gas tube lengths and I don't know how many common barrel lengths, and "tuning" the gas volume and BCG weight are often mentioned. It just seems like there is this big hole in my knowledge base that I cannot seem to fill.

[bushmeat]

I'm running an 18" with rifle length gas tube. Started out with using a standard carbine buffer and it ran OK. But installed an H3 on a buddy's advice. It does feel smoother and is marginally more accurate. When chronoed, I found velocity spread significantly lessened. Guess the bolt is locked for a longer period and this has an effect.

[tt350z]

I actually prefer a regular old carbine buffer on mine. My rifle seems to nose dive more when I'm using an H3 buffer as the bolt closes.

Using a 18'' rifle gas with SJC Titan on the end.

[sierra77mk]

I like the recoil impulse of the 20" AR, and I liked my full weight standard buffer setup with midlenght gas.

When I went to an adjustable stock, The standard carbine buffer was way to light and fast cycling and bouncy.

I went to a 9mm buffer in a 16" midlength and love it.

Another thread here:

http://www.brianenos.com/forums/index.php?showtopic=101982

In my research it is really an individual choice on how the recoil feels to you. That of course depends on the weight of the gun, what comp, barrel weight (balance), the type of matches you shoot, type of ammo, your physical size, how you hold the rifle etc...

I don't think you could go wrong with an H2 but in theory you could add a buffer the same weight as the rifle buffer you are replacing and have the same reliability.

[chp5]

The combo of barrel length, gas port size, comp and ammo is unique to your rifle. IMO the best thing to do is to buy a few buffers - H, H2 (or Spike) and run it for yourself and decide. Sell the unused buffers if you want to recoup part of the cost.

[benny hill]

What is your goal, less recoil?

[rugerdawg]

My primary goal was to reduce recoil but I just also happen to prefer the cheekweld and compactness of the sopmod stock and was hoping to retain the softer recoil of the rifle system.

[benny hill]

A very lightened carrier & buffer will take lots of recoil out of it. I run mine & others w/o any problems.

[olp73]

A very lightened carrier & buffer will take lots of recoil out of it. I run mine & others w/o any problems.

I have heard that you lighten standard carriers with forward assist serrations to the same weight as JP low mass carriers.

Is this true? I am a potential customer looking for a new carrier!! Picture? Tell me more!!

[StealthyBlagga]

The standard CAR buffer is indeed lighter than the rifle buffer, but travel distance is the same (buffer is shortened by the same amount as the buffer tube) and the spring is stiffer to compensate for the lighter buffer weight. I would suggest you start with a standard bolt carrier and a standard CAR buffer/spring, and see how the rifle runs. In particular, you want ejection to be in the 2-4 o'clock range; extreme forward ejection can be a sign of overgassing (unlikely with your chopped barrel, of course). If you want to try other buffer systems, you can try an H1, an H2 or a 9mm buffer, but I would be surprised in you even needed an H1, let alone the heavier buffers. Personally, I would NOT suggest you use a lighter carrier/buffer unless you also have an adjustable gas system to dial down the gas, and that approach brings its own complications (like greater environmental sensitivity).

When assessing performance, run through a standardized course of fire typical of what you shoot in matches, and let the shot timer tell you which is the best buffer system. Do NOT rely on how a rifle "feels", which can be highly subjective. Your match placement will depend on how fast and accurate your shooting is... there is no space on the score sheet for the RO to grade how your rifle feels .

Edited July 2, 2010 by StealthyBlagga

[fastshooter03]

With all the different gas hole sizes, throat lengths, powder burn rate, bullet weight, and rifling characteristics there is no scientific way about tuning your gas system for a particular stock/barrel/gas system length.

Like StealthyBlagga said just run a standard carbine buffer and spring and see how she works.

If tuning is needed you can get RP spring weights as well as different buffer weights.

From what I've seen it seems the lighter weight you go with the BCA/Buffer system, the more the spring can overcome said system.

I.E. get too light and the spring may short stoke you if there's not an over-abundance of gas(extreme case). Say the stock carbine buffer and spring won't fully cycle(not a likely case but you know...). You could either go with a lighter spring as long as the BCA closes properly or you could add weight(heavier buffer).

On my 3-gun rifle I run a rifle length stock ARFX with a carbine length buffer and a custom spacer with RP stand length spring and shims(3/8",1/2",etc) as needed. I can vary the spring preload over 2" IIRC.

Let us know how it turns out.

Nick

Edited July 3, 2010 by fastshooter03