ok people so I ordered an 18" barrel with a rifle length Gas system...

it is chambered in .223 wylde...

so I figured this would be a Good choice to do a MK12-ish type build...   I am not going for a totally "to spec" type build...   just an SPR in 18" length with the components to my liking/budget...  


so here are a few questions I have...

- what is the original gas system for a Mk12...??

- is this 18" rifle length gas system going to give me problems or be finicky about ammo...???

- what type of buffer should I use..???

- is there anything I should know about this type of setup...???



please feel free to give me all suggestions and or advice...  pics, comments and all that jazz... will be greatly appreciated...

thanks in advance...

Rifle

Probably not. Make sure your gas block is installed correctly (as with any barrel).

What kind of stock are you using?

Mine is not finicky at all. It cycles everything from hornady 75gr match to 55gr PMC, even starting loads with 60gr hornady ballistic tips and H335. I'm running a homemade non adjustable titanium gas block, carbine stock and buffer.

I've got a 16.5" voodoo barrel with rifle length gas system, zero cycling issues.

I have an 18" with a rifle stock and buffer, sweet shooter, zero problems.

I also have an 18" barreled upper with rifle-length gas system.

It has an 1:8 Rifling Rate and is made of 410 SS.

Works perfect with standard buffer and buffer spring.

Of course, mine was built by BCM, so I can't claim any credit
on why it works so well.

I'm sure they put it together correctly.

I've shot more than 250 rounds thru it and have not had
any issues with it.

Easily shoots 1 1/4" at 100 yards with my "first try" handloads.

I'm sure factory "Match" loads will get under one inch....

Probably, as long as you're shooting pretty much standard ammo it should work fine.

I had issues with mine using reloads with TAC (they didn't work well in my 20" rifles either, but worked fine in my 16" carbines with mid length gas system) and my favorite load with IMR4198.  IMR4198 is supposed to be on the edge of too fast (burn rate) for ARs but it works in every rifle/carbine I have except that 18".  I opened up the gas port just a little on mine and now it works great.

Oh, worked fine with H335 powder, BLC 2 powder and CFE223 powder.

yes...

I am going to be using a Magpul STR stock...

I ordered the parts form PSA...

I ordered the 18" freedom upper 416R SS 1-7 twist .223 Wylde

I also ordered there lower build kit with the Magpul moe w/ STR stock and enhanced trigger group...

I went with a NIB BCG from Aim... and still need a charging handle....

I'm going to change out the stock handgaurds on the upper with a Cheap Ebay FF slim Keymod handguard...

I will probably change out the A2 birdcage for a brake of some sort...

so I think this build should be ok...

however I was concerned with the Gas System...  

I Guess the lower Build kit should most likely have a standard milspec Carbine Buffer Tube, buffer and Spring...  I should be receiving on Monday or Tuesday the parts from Palmetto....

Geez its taking them a long time....   I got caught it the transitioning phase of their mailing system... received an Email the otherday that they were doing some type of upgrade to their mailing system and that I should be receiving the order soon,,,,,,,

No issues as yet with my 18" rifle-length .223 Wylde barrel, shooting factory 55 gr. Wolf Gold and 55 gr. reloads over 18 gr. of W748.

i did an 18" build with a rifle length gas system a while back. it performed flawlessly and was accurate as hell. Even with soft wolf/tula ammo it was reliable as hell. I run it suppressed with 77gr sierra's and it's smooth as silk

18" ballistic advantage 223 wylde bbl.

for 3 guns it was an ass kicker. now it's setup for "distance".

SO, is everybody running the 18" rifle length gas system with a standard carbine buffer...


the one I received with my build kit from palmetto is just a standard Carbine Buffer...


from what I can Assume... ( I know, I know, Ass-u-me)  however I hate to say it... from what I can assume, the rifle length gas sytem was created to run off a rifle length buffer...  and the Carbine Buffer is a little lighter...   so I would imagine that a Carbine buffer would still function,  however... I would want to believe that it will cause the rifle to run a little harder, by it being over gassed... and would eventually cause the rifle to ware faster and or run sloppier in time, by over working the system...

is this not sooooo...???


like I say this is only an assumption...

should I worry about this...  should I be running a different buffer...???

sorry for all the questions...   I just want this build to run smooth, and/or proper...  I would hate to run it like this and then later on find out I should have been using a different buffer, for the setup I have....

1) a reasonable gas system setup should function with any buffer weight; changing weights around being more for fine tuning.

2) the only way to know with certainty what your particular build is going to do is to put it together and try it.

3) if you want to try a heavier buffer later on it's a few seconds to change it.