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View Full Version : gas block removal and replacement (metric and inch variations)


Togakure
August 31, 2001, 15:12
Okay, so I bought an Aussie parts kit from Tapco for 149.00. The kit was quite nice except for the middle 1/3rd of the barrel, it is pitted. So much for Malaysian armouries :) This is what I would like to do, buy a 21", US made, Badger barrel from DSA and take the gasblock off of the Aussie barrel and place it onto the badger barrel. Is this feasible or am I setting myself up for a nightmare. I have an Imbel gear receiver (metric) that I am going to have the kit built onto. Your opinions are greatly appreciated.

chuck1
August 31, 2001, 18:43
I have in my hand one metric and one inch gas block. From what I see the major differance as far as swithing them is that the inch has the gas port drilled at what looks to be a 45 degree angle. There is a slight differance on the inside diameter which is .002 by my caliper.
I am sure that is just production tolerances so it looks like it will fit.
The biggest problen I can see is where the pin is installed. You will have to go through the orginal hole with out enlarging it so be careful with that area. Your best bet on that will be to use an slightly undersize carbide endmill on a mill and then ream the hole to final size. I am sure there are other ways to do it but that looks to be the most precise.
The gas port you will have to drill through the new barrel so that is no problem with the angle. Hope this helps

Dwalton
August 31, 2001, 19:22
You mean like this ?
http://www.hunting-pictures.com/members/Dwalton/dsabrl.jpg
The DSA barrel came without gas port , cross pin groove , and the groove for the hand guard screw .
I turned the front swivel rings down to look more like a L1A1 . I also milled a flat on the top of the barrel at the breech . I used my wore out Aussie barrel as a pattern . Still needs to be re-parked , but I'm happy with the way it turned out .
I don't think this is something to try without equipment , as indexing the gas block to the barrel was a head scratcher !
Also , make sure you know what O.D you need ,for the mounting area of the gas block , on the barrel . The first one I got from DSA was 0.002" UNDER-SIZE . I needed 0.692 " O.D on the barrel , 0.6915" I.D of the gas block , made for a nice heat/shrink/press fit .

DJW

Togakure
August 31, 2001, 23:14
Thanks gents! Here is another possible fix. I am considering using a Arggie gas block, with open ears. I will have to use an Izzy front sight post which will be no problem. It seems that I am having a bit of difficulty in removing the pin which hold the gas block in place on the Aussie barrel. Any suggestions?

chuck1
September 01, 2001, 02:32
To remove the pin try heating the gas block and use a very short punch that is just slightly smaller in diameter than the pin. If you can lay the barrel on a peice of aluminum with a hole through to give the pin room to come out that will help with out damaging the block or barrel. It will take a few good wacks with the hammer and punch to get it moving. I bent a good punch removing mine which is why I suggest a short punch.

Dwalton
September 01, 2001, 06:43
Just in case you don't know , the pin is a taper pin . You need to drive it out from the right to left ( viewed from the breach ) .

DJW

Togakure
September 01, 2001, 08:06
Thanks for the advice! I will give it a whack today :D.