Advice on Parts Selection

[cwouscg]

I’m getting pieces and parts together for a build, bad timing on my part.  Everybody seems to be building guns, parts are hard to find.  As I said in my intro I’ve built a couple 80% AR15s and I’m doing the same with a 308 AR build.  I’m using 5D Tactical for upper and lower, have a LaRue MBT-2S on friggin backorder, might steel one out of an existing rifle.  I think the only thing I’m missing now is a bolt stop pin, after reading its threaded I checked to see if that is what I had.  No joy, no pin either so I’m trying to find one of those in stock.

After reading some threads I’m concerned I may have the wrong buffer parts.  Heres what I have, does anything jump out at any of you that will cause a problem?

  *Barrel - Faxon Match Series, 20” heavy flute, rifle length gas system, putting a VG6 Gamma 762 on it.

  *Gas block and tube - YHM.  I did a quick check and it looks like the tube is the correct length.

  *BCG - Odin Works.  No weight on website that I could find and I don’t have a scale that will accurately weigh this.

  *Buffer - Aero .308 Carbine Buffer Kit, not enhanced kit.  Buffer is 2.5” @ 3.8 oz, spring in 11 7/16” long.  This is the item that concerns me, buffer tube depth is 6 15/16”, OK 7”.

Will this work?  Do I need to get a heavier buffer?  Do I need an adjustable gas block or is it just recommended I get one?

 

TIA

[ARTrooper]

Don’t get adjustable gas block unless you are gonna run a suppressor right away, since you are putting on a vg6 gamma, doesn’t seem like you are. Keep it simple.

as for the buffer and spring, most likely that is where problems may happen. You may get lucky with the aero kit. If you already have it or can’t return it, might as well try. 
 

if it doesn’t work or you can return it, the threads will tell you your two best options: heavybuffers.com or the armalite buffer kit.

[edgecrusher]

Buffer is too light. Should be 5.4 oz

[cwouscg]

On 2/6/2021 at 11:33 PM, ARTrooper said:

Don’t get adjustable gas block unless you are gonna run a suppressor right away, since you are putting on a vg6 gamma, doesn’t seem like you are. Keep it simple.

as for the buffer and spring, most likely that is where problems may happen. You may get lucky with the aero kit. If you already have it or can’t return it, might as well try. 
 

if it doesn’t work or you can return it, the threads will tell you your two best options: heavybuffers.com or the armalite buffer kit.

Thanks, I already have the buffer kit it so I'll keep it, if it doesn't work on this build it will on another.

 

I don't plan on running a can any time soon, I'll modify as needed if I do.

[cwouscg]

23 hours ago, edgecrusher said:

Buffer is too light. Should be 5.4 oz

I was afraid of that.

[shooterrex]

https://www.armalite.com/SACItem.aspx?Item=AR10REKIT01

 

This set up works. If it says out of stock call them they are pretty good about finding another set.

[cwouscg]

4 hours ago, shooterrex said:

https://www.armalite.com/SACItem.aspx?Item=AR10REKIT01

 

This set up works. If it says out of stock call them they are pretty good about finding another set.

Thanks!

[ARTrooper]

On 2/8/2021 at 9:21 AM, cwouscg said:

Thanks, I already have the buffer kit it so I'll keep it, if it doesn't work on this build it will on another.

 

I don't plan on running a can any time soon, I'll modify as needed if I do.

Some guns will run on the 3.8 oz buffer, a lot of it depends on your gas port size. But light buffers does seem to be the number 1 most common issue. 

[98Z5V]

12 hours ago, ARTrooper said:

Some guns will run on the 3.8 oz buffer, a lot of it depends on your gas port size. But light buffers does seem to be the number 1 most common issue. 

.308ARs will only run on a 3.8oz buffer if the manufacturer of that gun cheaped out, and made that bullshiit "in-between" gas port location drilling - not AR15 gas port location, and not Armalite AR-10 gas port location - but IN BETWEEN...  

 

AND, they'll only run on a 3.8oz CHEAP 2.500" long buffer, in an AR15 Carbine receiver extension - IF...  they drilled the gas port diameter TOO SMALL, in order to run that lightass, cheapass buffer...  

Most of the time, for most of the people, with most of the commercial weakass-off-the-shelf ammo.  That seems to be their mantra...  "Send it back to the factory, and we'll look at it..."  And it returns, THE SAME... "We found no problems..."   Of course, you cheapass bastards didn't find a problem... 

Period. 

.308AR buffers cost money.  They need to be 5.4oz, to properly cycle the firearm.  "Enough ASS to control the MASS..."  You've heard it enough - you should know better.  Any lighter buffer is a DOLLAR COMPROMISE from a cheapass manufacturer, and they're cutting corners in other places just to make that work.  Know why?  TUNGSTEN IS EXPENSIVE.  SO ARE STAINLESS STEEL BUFFER BODIES.  Aluminum bodies are MUCH cheaper. Steel weights are MUCH cheaper.

I've already delved into this in so much detail, it's not even funny anymore, and you know where those posts are, Eric.  You should have pointed him directly to those posts.  On your own.  You've been here long enough to know that.

Edited February 10, 2021 by 98Z5V

[98Z5V]

Chief, read this.  It didn't take 15 minutes to write.  It took the better part of 10 years on these things to figure it out.

 

[ARTrooper]

@98Z5V I know the benefits of heavier buffers, and prefer them myself. Helps reduce felt recoil, makes the gun run more smoothly, more reliability with hot loads or suppressed,  minimize wear and tear, and better for more powerful calibers than the basic buffer system was originally designed for. 
 

But with all the threads out there on this subject, we don’t highlight the why we suggest going with a 5.4 oz buffer as much. I know you get tired of the same topic over and over, but it isn’t as black and white as you make it out to be.

SHOULD a 308ar have a a heavier buffer than the “standard” 3.8oz 2.5 in buffer?... HELL YES. 

CAN some 308ar function with a 3.8oz buffer? Depending on the parts (maybe it is because they are made cheaply), YES some can.

Never once did I tell cwouscg his buffer was good to go. In fact I told him if he can return it, than to go with the armalite receiver extension kit or buffers and spring from heavybuffers.com. And I told him problems could come from his choice in buffer. 
 

Tom I have a lot of respect for you and i rarely question your knowledge, not a time even comes to mind. But, if someone already has the parts and can’t get their money back, it isn’t going to hurt to try them out. If they need to change parts than they can, or upgrade later on their own time and budget if it works. $75 can be a lot of money for some people, I know my wife would throw a fit if I spent that without talking to her first since we live on a single income. Just my .02

[98Z5V]

I get it, brother, I do.  Yeah, you can make a light buffer work, and we know one company that does it all the time, by telling their consumers that "they NEED an adjustable gas block..."   They (the company) know who they are...   And they're just putting the band-aid on the wrong cut...  

I get it, brother. 

[DNP]

Hey, it’s not just cheaper...it made that 12lb rifle only 11lbs 14oz. Right?

[cwouscg]

OK, so to sum up I was asking if parts I had on hand would cause a problem.  Thanks to all who pointed out I needed a heavy buffer which I now have on hand.

I am wondering why Aero would sell a kit marketed for a 308AR and have a buffer that is too light.  Oh well, the light buffer won't go to waste as I have a couple of future AR15 builds to do.

Again, thanks to all who answered.

[cwouscg]

On 2/9/2021 at 10:57 PM, 98Z5V said:

Chief, read this.  It didn't take 15 minutes to write.  It took the better part of 10 years on these things to figure it out.

 

Thanks for this!  Lot of good info, learned a lot just in the first paragraph!  

Question about gas tube length.  I saw another picture somewhere on this site showing where the end of the tube lands about 1/4 vs the 1/2 you show in here.  How critical is that 1/8"?  Will the shorter length work with heavy bullets and short cycle with lighter ones?

[98Z5V]

11 hours ago, cwouscg said:

Thanks for this!  Lot of good info, learned a lot just in the first paragraph!  

Question about gas tube length.  I saw another picture somewhere on this site showing where the end of the tube lands about 1/4 vs the 1/2 you show in here.  How critical is that 1/8"?  Will the shorter length work with heavy bullets and short cycle with lighter ones?

The shorter length doesn't deliver the gas pressure needed, for the correct length of time needed, in order to cycle the weapon the way is was designed. That's Gas Timing.    It disengages early, gas pressure isn't delivered for the amount of time that it's designed to do, and you don't have the force driving the recoil system - that you should have.  In that case, it's better to run the Armalite AR-10 gas tubes, which will extend just beyond the center of the cam pin cutout in the upper receiver, and give you just a touch MORE gas timing...

This is just another example of a lack of standards by barrel manufacturers, and a BAD IDEA by barrel manufacturers, that don't really understand the differences between the two gas systems - AR15 gas systems, and the Armalite AR-10 (true) gas systems.  Different lengths of gas tubes, Armalite AR-10 being longer...   So, manufacturers think they can drill gas port locations IN BETWEEN those two gas port positions...   "It'll work for most of the people, most of the time, with most of the ammo.... No matter what gas tube they use..."     This is a cascading mentality, by manufacturers.  "Tolerance Stacking" is what it's called, when you're working with dimensions of parts that have a plus or minus to a size - but this is an oddball way of thinking, in their mentality....  Gas tube is a little short, they put a light buffer in there to save money (because tungsten is expensive), and they just make the gas port too small to run that shiit.   Compromises, based on $$$...  Sooner or later, YOU are the guy that gets a gun that doesn't run...

That's my soapbox on the whole affair... 

 

[98Z5V]

Don't get me started on "why AR15 gas tubes aren't right for .308ARs in the first place, because of height-over-bore issues..."...  

[cwouscg]

Houston, we have a problem.  I did a quick test fit of the gas tube and found out 1- the Faxon barrel appears to be the correct rifle gas length and 2 - the YHM "rifle" length tube is short.  

Armalite has their gas tube as backorder, does anyone know who might have the correct length tube in stock?

 

[98Z5V]

1 hour ago, cwouscg said:

Houston, we have a problem.  I did a quick test fit of the gas tube and found out 1- the Faxon barrel appears to be the correct rifle gas length and 2 - the YHM "rifle" length tube is short.  

Armalite has their gas tube as backorder, does anyone know who might have the correct length tube in stock?

 

 

Check LBE Unlimited.  They make the correct gas tubes, also.   White Oak Armament will make you any gas tube that you want, when you give them the specs. 

EDIT - Did you look at the Armalite website, and see that they're on backorder, or did you call Armalite on the phone, and find out that they're on backorder?  Calling them on the phone makes a difference.  For real.

Edited February 20, 2021 by 98Z5V

[cwouscg]

I looked on the website.  I'll give them a call and see what they say, thanks.  I'll check the others too.  Appreciate the response.

[cwouscg]

On 2/19/2021 at 11:06 PM, 98Z5V said:

Check LBE Unlimited.  They make the correct gas tubes, also.   White Oak Armament will make you any gas tube that you want, when you give them the specs. 

EDIT - Did you look at the Armalite website, and see that they're on backorder, or did you call Armalite on the phone, and find out that they're on backorder?  Calling them on the phone makes a difference.  For real.

Thanks for the tip.  I called and Juan is the man!  I have a couple of the correct gas tubes on the way.

[98Z5V]

4 hours ago, cwouscg said:

Thanks for the tip.  I called and Juan is the man!  I have a couple of the correct gas tubes on the way.

Right on, man - glad it worked out!