View Full Version : Has anyone ever moved the gas block

September 21, 2001, 15:32
aft and shortened the handguards? I want to make a 16" LW with my Williams, but think moving the gas block and making the HGs shorter would look neat. Better then a AR shorty. What size do you think the gas hole would be? .144?

September 21, 2001, 15:56
We do it here. We make a sleeve that is brazed onto the barrel for the new gas block location. The barrel is turnded to locate the sleeve. The new gas port should be drilled at .125 and stepped up as needed until you get consistent cycling. We generally end up anywhere between .141 and .156 diameter. Tig the original gas port shut and turn down on the lathe. This is the condensed version. If you need more details and dimensions, give me a call or email.

September 21, 2001, 18:04

I shortened my R-1 about 4" overall. Some/all at the M/D shoot that saw it and/or shot it made positive comments.

Handles like a "real" carbine. The balance is a little off, but that will be remedied when the Alumilite gets here! :D

This was strictly a WECSOG project. The only power tools (other than the Dremel!) I used were a belt sander, electric drill and a 4" disc grinder. Much!! hand-filing and more test fitting and mic'ing.

Length was determined by where the handguards were cut!, as they were done first as a separate project. Then, while longingly looking at the un-cut bbl, I mic'd it out and found that there was enough dia. at the required area to "stop" the block.

After a week of peeking in the workroom to see if the FAL-fairies had done the job (rats, they were'nt here!), I took the plunge, and fired up the hacksaw and Dremel.

CAUTION: At NO TIME was any consideration given to twist rate, land/groove placement vis the gas port/new, or whether the dammed thing would actually work! just wanted to see what-in-the-hell it would look like ;)

Some prudent filing of the new flat for the GB, slide it on, and whack the hell out of it w/a BFH and a mod'd old cold chisel. Granted, I started out gently tapping and wound up smackin' the sh*t out of it, to get it to seat. Mk 1 eyeball and Mr.Starrett got it square to bbl.

The balance of the gas sys was just "cut and paste" to fit. Ground/filed the spring keeper knob off the rod and let the spring ride to the rear piston back, to get travel required.

Closest garden-variety drill I could find was a TiN 3/32...close enough for Jazz (you do the conversion) :D. Never did weld/fill the old holes. Now I have a "comp'd" FAL! Cycles on 3.5-4.5 !

Put the darned thing together and let it sit for a few days, to let all the part's wounds heal. That W/E, I just couldn't stand it anymore, and bound and determined, set to test firing the monster. All the usuall disclaimers aside, I tied the thing to the reloding chair, handcycled one round, and pulled the lanyard from behind a stout wall!


O.K. nuttin's broken. Load TWO in the mag. Same proceedure .

BANG, clink; Bang, clink (brass rattlin' off the walls/floors)!

Repeat process w/o the lanyard, but with serious eye/ear/face/hand protection.

WOO-HOO! Now three-four in a row R-F. Zippity-do-da-day! Five thru ten, same result. Bigger grin!

Many rounds later (Couple or three hundred?), the G/B has set back (front?)a couple of thou, but I never did get the securing pin in, just let the H/G bolt do the job :( I guess I'll hafta re-set the bugger and file another half-round in the BBL. New meaning of the FAL files :) ; it was the toughest part of the job, filing that perfect 1/2 rd. groove, now I gotta do it again!

If I were to do it again; the only change I might make, is to try to index the gas port to a groove, and THEN cut the H/G :D.

I do have a photo of K.Funk firing the thing, if you want to see how bad a photog I am w/a cardboard camera. From a distance it looks (sorta) like a FAL, till you start lookin' real tight, then the WTF look will pass across you puss, and the grin will begin!

Best of luck in your endeavours,

BTW; I can see George, Derek, Mark, and others "cringing". Once again, I DO NOT recommend any of the above practices to anyone. Strictly for my own edification and your enjoyment! For educational purposes only :D , Paul

September 21, 2001, 18:33
Originally posted by Lawrence/Entreprise:
<STRONG>The new gas port should be drilled at .125 and stepped up as needed until you get consistent cycling. We generally end up anywhere between .141 and .156 diameter.</STRONG>

What is the length of the barrel with this size hole?
If you want to give me a more detailed description, please email me, I'm very interested.
Thank you, Bill

PS Do you still have the new-in-the-wrap Izzy mags? I would like to get more, the ones I bought from you are beautiful.

[ September 21, 2001: Message edited by: idsubgun ]

September 21, 2001, 22:24
Originally posted by Deltaten:

I shortened my R-1 about 4" overall...WOO-HOO! Zippity-do-da-day! ...Strictly for my own edification and your enjoyment! For educational purposes only :D , Paul</STRONG>

I like the way this man operates!

derek huffman, azexarms
September 22, 2001, 02:25
I've done a couple like this.

Started with a new medium contour DSA bbl. Turned much of it off and turned a new "bed" to seat the gasblock on. Drilled the holes and "voila".

New DSA shorty handguards and a new DSA shorty piston were required.

Only had to open the port up to .118

Ran like a champ on "4".

D. www.azexarms.com (http://www.azexarms.com)

September 22, 2001, 06:59
See! Derek even does it! Albeit, w/a real machine shop and some serious tools, I'll betcha :D

I guess I just got lucky with the "balance" of all the operating parts. Sort of the like the restaurant trade's "if it looks good, it tastes good" reasoning.

I originally started just to see if I could duplicate the $575 ;( DSA front end. Hell!, I don't have that in this thing, even w/all the sect.922 parts. "$60.00 just for the HGS?", no way! $3.75 worth of JB Weld and off we go!

But Derek, why the DSA bbl? Dinch'a have an old R-1 or Steyr laying about....AHHH!, that's right, you actually want to SELL these things. :D So how bad could I bugger it up, trying to drill the BG pin thru, rather than the "file" method? Would the bit 'run' into the GB, rather than cut the bbl? The local power eqip. shop is getting tired of requests for off-the-wall-sized chain saw files! ;)

Stay tuned for the continuing saga.... "Alumilite meets Shorty". No 'butts' about it, a short story, if I ever heard one.


Timber Wolf
September 22, 2001, 10:17
I wish you guys would let this thread die or I am going to have to do one. I did several ARs barrels like this back years ago making CARs but I cut them off at the original gas port and tig welded a long flash hider on to make up the 16". Used the original short no-trap door buttstocks for a good looking and handling package.

September 22, 2001, 14:54
I plan on having the barrel turned down and moving the gas block aft about 3 1/2", barrel cut at 13" and a piece of chrome-moly tubing welded on to make it legal. Using wood HG/BS I got cheap for century. With a Williams receiver, should be light and handy :D