AR gas systems

[tombogan03884]

When I assembled my Ranger AR I ordered a buffer and spring, then I ordered the Carbine buffer and spring that I actually needed   
I understand that tube length and gas port diameter are all variables, but can some one give me a layman's education on rifle, carbine, and pistol gas and buffer set up's ?
How would they impact switching between a pistol caliber like 9mm and a rifle caliber like 5.56, or .300.
Would I need to switch buffers as well as uppers to change caliber ?
I want access to several guns, but I only want to buy 1 trigger group .   

[les snyder]

Tom... from my experience with a 16" mid length gas 5.56 carbine,  a 10.3" 5.56 SBR, a couple of 5.56 10.5" "pistols"... I'll clarify,,, my pistols were new manufactured lowers marked "other" on the ATF4473, and they both have a carbine length spring system that is in a KAK buffer tube that is slightly longer (8 1/2") than a carbine tube but has similar internal dimensions... it gives me nose to charging handle length of pull... the SBR is a LMT Mk18 upper that made the trip to Iraq... the SBR, and both of the pistols run with H2 buffers and stock carbine springs... I think the 10.5 in barrels have around a .072" gas port, but you have to check with their specifications... I've never played with a "pistol" length system that uses a 1911 spring... the factory buffer tube from PSA houses a carbine spring... I helped barrel a .300BLK, and other than sticking a barrel in an upper, seemed to work with the OEM 5.56 spring... I wasn't around it for any fine tuning

the mid length AR is a competition rifle that uses a full length (short) GI A1 stock... it ran originally with a 4.2oz rifle buffer and rifle spring... it now uses an Enidine hydraulic buffer (don't know the actual weight

the AR9 PCC  competition was a 16" blow back with a 6.2oz buffer and rifle length spring... it also is housed in a G1 A1 stock, total weight of bolt and buffer was around 22oz.....

the AR9 PCC now uses a CMMG radially delayed bolt and the Enidine hydraulic buffer with rifle length spring

the AR9 7.5" pistol is a blow back and uses the KAK buffer tube, stock carbine spring and a H2 buffer

a 10in 9mm upper was used for a short time with the registered SBR lower.. it used a Macon Armory mag well block and Colt/Metalform magazines... the other 9mm lowers are made by New Frontier and are Glock format

there is considerably more recoil with a 9mm than a gas 5.56... unless you are a PCC competitor, I really wouldn't recommend the radial delayed system unless you purchase the entire carbine as I had numerous tolerance/interference problems... shot the .300BLK only sparingly, but my friend at SOCOM says that they have been very effective suppressed by the SF users... it is his choice for home defense

good luck... Les

[tombogan03884]

      It was a video on the CMMG action that got me wondering about recoil springs and ejection issues .   


https://www.youtube.com/watch?v=GJTQOhh7KX8

CMMG prices are why my 10mm is a TNW   

When I was retrieving that video I saw another one that might interest you.


https://www.youtube.com/watch?v=TytgA4OkFJs

[les snyder]

Tom... I watch Forgotten Weapons daily... the Palmetto State 9mm AK-V (very similar in size to the Vityaz copy) looked pretty reasonable a couple of weeks ago, but I think it jumped a couple hundred dollars...

I'm extremely happy with the brace on the G34, and hopefully the announced front sight mount will be available soon, if not, I'll make an aluminum mount

[tombogan03884]

A friend of mine bought a Glock for a camping gun, I was telling him about that the other day.
The ones in the ads look to busy and bulky, but the pictures you posted looked real good.

[Sponsor]

[les snyder]

I received a reply from Recover Tactical on the front sight mount availability which is a 1913 rail near the muzzle... pre-order end of June, delivered in August... Tom, I'm impressed with the brace for what I want it for.. it is not a range toy, if it were I'd mount one of the dot scoped pistols... the taller co-witness Dawson sights make it easier to shoot. and if I were to do it again, I think I'd get the tallest ones...again, mine is the basic brace with charging bridge

[tombogan03884]

My purpose was basically an" SBR" stand in .
The strictly "pistol braces" are more dependent on your purpose .
I need my pistol focused more toward Discreet carry so it wouldn't work for me.
Unless I start camping again of course.
Because I think it is the perfect solution for my buddy who just wants something for the tent at night.
He's not a "gun guy" so I suggested the Recover to him.

What as a USER, do you think of these full caliber AR and AK "pistols" ?
I've shot 223 in Contender's so I know the 556 AR pistol should be OK to shoot.
But .300 or 7.62 X 39 seem Intermediate to me.
To big and powerful for a handgun and to small for a shoulder weapon .
But if your interested in the ACTIONS, rather than the guns you have all the working bits without unneeded barrel and furniture.

[les snyder]

Tom... sent you a couple of e-mail pictures of my short guns...I get nose to charging handle with that length buffer tube... while a OEM factory buffer tube is about 1.5" longer... I milled the end of one flat for a 10/22 project... Les