M4/AR15 Barrel drawing?

[Bamban]

One data point on port in the groove.

I have chambered AR15 barrels, never intentionally timed the port in the lands
This one came about by accident. It was melonited l, has 10,741 round count. I literally had to coerce by buddy that we swap the barrel before headed out to Perry. He was reluctant because the last 600 he shot was 198. The 8 came on #20. Jitters with the thought of cleaning the target. Mind you the shooter was 2 years into being a grand senior at that time.

 

[LVLAaron]

I'm missing an extension wrench (currently in the USPS system being lost I'm sure) - As soon as I get some other stuff cleared out of the shop backlog I'll start on the AR15 barrel project. I can't wait to get it going.

 

[GenePoole]

I just found a R700 223 varmint take-off in my box-o-barrels and I'm gonna give it a try too. Done a few, but my goal here is to get the gas port aligned between lands, then get the extension timed to the port. @DaveTooley any advice?

 

[LVLAaron]

I just found a R700 223 varmint take-off in my box-o-barrels and I'm gonna give it a try too. Done a few, but my goal here is to get the gas port aligned between lands, then get the extension timed to the port. @DaveTooley any advice?

I'm working with the same thing. At first I didn't think it would be a challenge because timing is just some math and measuring... but... how to measure to/from the gas port location has me scratching my head.

 

[LVLAaron]

Finally got around to doing this

 

[GenePoole]

Finally got around to doing this

View attachment 1643307

They say a picture tells a thousand words, but in this case I disagree. What are we looking at and how does it work?

 

[LVLAaron]

They say a picture tells a thousand words, but in this case I disagree. What are we looking at and how does it work?

The bar is something from the trash heap; Bored a 1 inch hole in it with a set screw to hold the barrel extension. It's just to extend the barrel so I can work on it in the headstock

 

[msalm]

I just made a 6.5 Grendel bbl today out of a shot out 30” 6.5-284…cut 10”off the breech end of the 3 groove Pac Nor (or Lilja?) and the bore looks new. I timed the port dead center in a groove by just making three marks on the bbl shank using a borescope at the proper distance for the port. Had to face off .012” the shoulder to get the extension timed properly to the nearest groove after threading.

 

[LVLAaron]

There are a lot of 30 inch barrels that get turned into tomato stakes because they're "worn out" - But like you found there's certainly an excellent 18-20 inches in every one of them.

I might need to buy my old AR10 back from my buddy

 

[msalm]

There are a lot of 30 inch barrels that get turned into tomato stakes because they're "worn out" - But like you found there's certainly an excellent 18-20 inches in every one of them.

I might need to buy my old AR10 back from my buddy

I speculate they are even better than new as they are fully seasoned/broke in with no real wear. This one made an excellent 18.5” barrel as I nipped off some at the muzzle also. They’ve always shot extremely well. After a rough contouring I also cast a lap and do a light lapping on them…visually you wouldn’t know it was a used barrel. This one was for the son of a good friend for his first deer rifle.

 

[SKWERLZ]

Would like to try and build an AR15 barrel from scratch. I have some barrel extensions from White Oak already...

Looking for dimensional drawings of some barrels.

I suppose the only critical dimensions are the barrel extension and gas port location, yes?

Which gas system you interested in?

 

[SKWERLZ]

Finally got around to doing this

View attachment 1643307

Awesome
I really enjoyed doing an AR barrel

 

[LVLAaron]

Which gas system you interested in?

If I'm being honest I don't know a whole lot about the pros/cons of different length systems. For this one I just cloned a WOA varmint barrel. They use their own length gas system - It was 11.125 from the extension to the gas block shoulder

 

[SKWERLZ]

There are a lot of 30 inch barrels that get turned into tomato stakes because they're "worn out" - But like you found there's certainly an excellent 18-20 inches in every one of them.

I might need to buy my old AR10 back from my buddy

I’m turning my old 338 edge barrel into a 338 arc barrel possibly this year.

 

[SKWERLZ]

If I'm being honest I don't know a whole lot about the pros/cons of different length systems. For this one I just cloned a WOA varmint barrel. They use their own length gas system - It was 11.125 from the extension to the gas block shoulder

Sounds like rifle has length
Excellent for 18”and longer 223’s.
My 24” 22ARC is a +1 so 1” longer than rifle gas system

 

[Sniperhandle]

Awesome
I really enjoyed doing an AR barrel View attachment 1643608View attachment 1643610View attachment 1643611

Me too! I also do my own Parkerizing. This is one I did in 300 BLK from the drop of a Pac-nor I did for a friend and had the drop left over.

 

[GenePoole]

Me too! I also do my own Parkerizing. This is one I did in 300 BLK from the drop of a Pac-nor I did for a friend and had the drop left over.

Don't forget DIY anodizing.

 

[LVLAaron]

Me too! I also do my own Parkerizing. This is one I did in 300 BLK from the drop of a Pac-nor I did for a friend and had the drop left over.

Just did some googlin - I didn't realize this was something I could do at home!

 

[Sniperhandle]

Just did some googlin - I didn't realize this was something I could do at home!

I used to have real USGI parkerizing fluid a long time ago that did the most beautiful green parkerizing. That ran out after many pieces got refinished. Now I use Brownells Parkerizing fluid and it's good, But it just doesn't give that deep rich green color.

I even made my own fluid at one point which works, But not the greatest.

 

[ORjeff]

One thing that I have wondered about for a long time is how do you deburr the inside of the gas port?