20" A2 build going featureless... receiver extension (tube) and buffer required?

[the86d]

(This is not on the books, so I can't see why I would let it be.)
I want something I can hold onto, so I went with a Thordsen FRS-15 Stock.

Since I have a 20" barrel, and this stock will not accept a full rifle-length A2 buffer, I need to change the buffer tube(, and get a carbine buffer too).
This is what I believe to be called DI (Direct Impingement), and I don't want any bolt short-stroking.

Can someone give me some info on what will work, if I can use a carbine tube with just a certain-weight buffer, OR direct me to a thread that would help me out (that apparently I can't find the correct keywords for)?

Thanks!

[the86d]

I AM seeing that there are different weights of buffers:
Carbine Buffer (Avg 3.0 oz)
Heavy (H) Buffer (Avg 3.8 oz)
H2 Buffer (Avg 4.7 oz)
H3 Buffer (Avg 5.6 oz)
Rifle Buffer (Avg 5.0 oz)

Is that what is needed, just the right buffer, or go through each one, like this guy mentions (get a whole bunch of them), or special springs?:

https://www.youtube.com/watch?v=YwvcWgNBu2Y

This chart says I should use something like a 5.3-5.4oz buffer:

[Jimi Jah]

Install an adjustable gas block and you can run any of them. I like the powdered tungsten buffers here, no clang, smoother cycling.

[the86d]

Welp, I got me a 7075-T6 aluminum (almost double the strength of 6061-T6?) extension set w/buffer, spring, end plate, and castle nut.

I can do more research if the buffer doesn't work, as it doesn't state what weight the buffer is, but at least I will have my re-build complete and be able to use the mag release button as it was intended.

/#StillOffTheBooks
/#BuckOfama
/#BuckJerryAndDroogs.

[kcstott]

Everything I can find says standard weight buffer just carbine length parts, But there is always the option to tune a bit with lighter or heavier buffers. but you really need to know WTF you are doing. AR's don't operate they way one would typically guess. There's a lot going on under the hood and i am by no means an expert on the AR platform.

[the86d]

Everything I can find says standard weight buffer just carbine length parts, But there is always the option to tune a bit with lighter or heavier buffers. but you really need to know WTF you are doing. AR's don't operate they way one would typically guess. There's a lot going on under the hood and i am by no means an expert on the AR platform.

Well, I COULD tune my ammo I shoot in it, but then worry about if it will cycle my lady's too (A2 rifle length vs carbine). Then again, I did put my lower together, roll-pins and all. The non-A2 is where I had no experience (until recently), aside from assisting my lady slap her's together (roll-pins and all).

I am just talking about swapping a buffer here, which I removed and replaced thousands of times cleaning one issued by the USMC, it isn't rocket science. I may just have to buy a few to test if there is an issue.


Since I don't use an AR-15 bolt carrier, but a full nickel boron bolt carrier and bolt, this might be a factor too. Just thought of that.

[oleg114208]

i got 24 inch ar build with carbine buffer tube and h3 buffer cycles no problem. if you reload use slower burning powder if i reload using like 4198 it cycle 7.5 and 16 inch but not 24 due to gas block to far not enough pressure cfe 223 works perfect on all of them, it makes 7.5 nice flame thrower. i also notice in my experience all buffers work on 24 inch starndard buffer just little more recoil but they all cycle. carbine h h1 and h3.

[the86d]

i got 24 inch ar build with carbine buffer tube and h3 buffer cycles no problem. if you reload use slower burning powder if i reload using like 4198 it cycle 7.5 and 16 inch but not 24 due to gas block to far not enough pressure cfe 223 works perfect on all of them, it makes 7.5 nice flame thrower. i also notice in my experience all buffers work on 24 inch starndard buffer just little more recoil but they all cycle. carbine h h1 and h3.

Thanks for the info!

As of late, I usually get what I can get as far as powders go, with all the new AR owners pressing ammo. I've got 8lbs of IMR 4064 to work a load up when I rejoin my shooting club (range membership required, so I have fewer AKs pointed at me at a public range by people who pretend not to understand English, like others have mentioned). I haven't gone to the range in like 9 months, as I let it expire with other things going on.

Since the lady has hers built, I assume we will hit the rifle range more! She is now more enthused, as I bought her her lower before registration too (she DROS'd, of course), she has been saving up and she just finished it ON the afternoon of 12/31!

[oleg114208]

Thanks for the info!
Since the lady has hers built, I assume we will hit the rifle range more! She is now more enthused, as I bought her her lower before registration too (she DROS'd, of course), she has been saving up and she just finished it ON the afternoon of 12/31!

my understanding if you bought lower before 2017 you can build it as BB with all "evil features" before 2018?

[the86d]

my understanding if you bought lower before 2017 you can build it as BB with all "evil features" before 2018?

The way I understand it, but you must register any legally owned BB rifle with "evil features" as an AW before 2018, even if not currently registered (DROS'd long/shot gun 2014 or later are all registered). If owned pre-2014, it isn't officially registered. I ain't registering crap, if I don't have to.

If I had a BB registered rifle (DROS >2013), I would register it as an AW before 2018, as it would already be registered, rather than go featureless. Jerry Brown and his droogs can put that in their pipes and smoke it.

Now in the future, when all this BS gets overturned because the commies in this state's legislature shoot themselves in the foot due to over-regulation (due to court-ruling prescient) I will be a happier camper, IF I am still here, instead of in a free state where we aren't treated like criminals... and a rifle is just a rifle(, and my lady can pack legally without a permit).

[kcstott]

my understanding if you bought lower before 2017 you can build it as BB with all "evil features" before 2018?

Technically no.. as you were supposed to be in possession of the complete evil featured rifle prior to 2017. But who says you weren't??

[kcstott]

Well, I COULD tune my ammo I shoot in it, but then worry about if it will cycle my lady's too (A2 rifle length vs carbine).

Yeah screw that. I build ammo for one semi auto only and thats my Garand, I use starting loads and 150gr bullets, need to run them over the Magneto speed to be sure i'm in safe operating range. But they don't recoil or report any worse then the Lake city ammo i have.

My AR308 has an adjustable gas block as i just want to use as close to one load as possible for my .308 loads. I don't want multiple loads, recipes, screw that.
I have brass for each rifle i keep it separated, and just load all my 308 with 175gr Bergers or SMK's and call it good. I don't plink with these as they are set up for long range. Good adjustable gas blocks are not cheap but you get what you pay for.

[oleg114208]

If I had a BB registered rifle (DROS >2013),

if i bough just lowers after 2014 have they been registered too?

[kcstott]

if i bough just lowers after 2014 have they been registered too?

Registered? Yes, Registered Assault weapons?, No.

Big difference.

[the86d]

It's almost like it isn't scary anymore, so it's function must have been altered with the removal of the scary EBR features...