PDA

View Full Version : Gas port size for 18" Imbel barrel?


MADMIKE
May 01, 2008, 16:52
I finally have gotten around to building the last two DSA recievers that I bought.
I have two 18" para barrels that I bought from TDW that I put on them, ( I know it's been a while since TDW had these but this "working for a living" thing has cut into my leisure time).

Will I need to drill out the gas ports?
What is the factory spec on gas port size for 21" and 18" barrels?
TIA

MAINER
May 01, 2008, 19:14
Probably not!

Then again, they all seem to do their own thing. Specs for 18" and 21" are the same according to a recent post. Generally .097" is the common size, with .096"~.105" within spec.

gunplumber
May 01, 2008, 21:42
.116" for 18"

Kyrottimus
May 02, 2008, 01:25
I don't have the experience or know-how of GP, but on my one, single, lonely, solitary 18" FAL (with Imbel Bbl, mind you), from what I recall, the gas port is the "normal" size (~.100").

Works great on 4 gas setting with South African surp.

On my 21" Imbel it runs the same ammo on 4.5 or 5 (I tend to keep it on 5, as it is easier on the brass). Its gas port size is the same as my 18".

FWIW, hope you get it working well.

We need a range report and pictures. :fal:

johnny.308
May 02, 2008, 10:05
I just checked the port on my DSA Para Carb. with 16.25" barrel and it measured a minimum .110. There was no way a .116 was going down that hole. It may have been larger than .110 but I don't believe so.

gunplumber
May 02, 2008, 11:16
After shorting somewhere around 1500 barrels, the dimensions I found worked best on most of the were .116 for 18" and .118 for 16"

sure, some will work with smaller ports - lot of other variables on your gas block ID, gas piston, etc, but the ones I gave work most often on most guns.

Kyrottimus
May 02, 2008, 14:29
Originally posted by gunplumber
After shorting somewhere around 1500 barrels, the dimensions I found worked best on most of the were .116 for 18" and .118 for 16"

sure, some will work with smaller ports - lot of other variables on your gas block ID, gas piston, etc, but the ones I gave work most often on most guns.

FWIW GP, I wasn't claiming otherwise or trying to contradict you. I've not even looked at any other gas ports aside from my own rifles.

I was stating that I probably got lucky with the rare exception, not the rule. :fal:

gunplumber
May 02, 2008, 14:59
my factory SAR-48 para has a 17.35" barrel and a .098" port. And it works with gas all the way open. I don't know why. It just does.