I Recently purchased a M14, i want to do the reccomended mods to it to increase accuracy/reliability, in regards to shimming and unitizing, can you/do you do both or one or the other?? im confused on where exactly the shims are placed on the barrel/gas block area. also in regards to unitizing is there anyone in the Winnipeg area able to do this??
M14 Unitizing and Shimming
- Thread starter zombiedfens
- Start date
If you unitize it, you will probably find that it doesn't need shimming, but its possible it still might in order to have the gas lock index so that its tight against the gas assembly when the hole lines up with the gas cylinder. The unitizing really tightens it up and I find it makes it much tighter on the barrel. I did a couple of them, one by tig and one by mig, both done on a spare barrel. They required some firm tapping with a brass drift to slide them off the spare barrel and back onto the original rifles. I did some others simply on the rifle they will remain on, and that's a lot less work. I suspect the heat of the welding slightly distorts the alignment of the hole in the barrel band and makes what was a tight fit, now an interference fit.
I attended one of 45APCKING's clinics, and several gas cylinders that were welded at the clinic were very difficult to remove .....
Looking at it later, it seemed to me that holes in the the barrel band were spaced slightly too close together, and when assembled on the barrel and welded the barrel band was getting caught in the machined groove ahead of the shoulder.
My fix was to lightly dremel the inside of the barrel band for a better fit, and to make a welding jig to keep the parts in better alignment during welding ( not a new idea, I shamelessly stole it from someone else on this board
) The end result of this was that my 'Unitized' gas assembly slides on and off my rifle easily with no binding. The jig belongs to 45APCKING now, so if you need your gas cylinder unitized, one of his clinics would be a good place to get it done.
Nice looking jig. Still working on another clinic in the MB area just like Suprathepeg and Fire organized in April this year. Got a super busy winter lined up.
Confirming a Clinic for January (Barrie, ON), February (Burlington, ON), March (Ottawa, ON), Oct (Halifax, Newfie Scotia), Sep (Northern Ontario)
So that's the schedule so far.... Nothing is cemented in stone (except for Jan, Feb , and March clinics..)
Whooops, I'm digressing!
Barney
Confirming a Clinic for January (Barrie, ON), February (Burlington, ON), March (Ottawa, ON), Oct (Halifax, Newfie Scotia), Sep (Northern Ontario)
So that's the schedule so far.... Nothing is cemented in stone (except for Jan, Feb , and March clinics..)
Whooops, I'm digressing!
Barney
I attended one of 45APCKING's clinics, and several gas cylinders that were welded at the clinic were very difficult to remove .....
Looking at it later, it seemed to me that holes in the the barrel band were spaced slightly too close together, and when assembled on the barrel and welded the barrel band was getting caught in the machined groove ahead of the shoulder.
My fix was to lightly dremel the inside of the barrel band for a better fit, and to make a welding jig to keep the parts in better alignment during welding ( not a new idea, I shamelessly stole it from someone else on this board
Thats a nice looking jig, if you could provide me with the dimensions for it i could turn one down on my lathe ( I grabbed a bunch of 1.5 -2" diameter bar stock out of the recycling bin behind the local college, they just throw it away ) also why the copper pipe? once the parts are welded together does that keep shims from comming out if shimming was done?? im confused on where exactly the shims go.
I didn't record any dimensions .... I had my gas cylinder in hand and turned it to be a close fit .... I also left a small step for a snug fit on the barrel band ID.
The purpose of the copper pipe .... a short length of redi-rod runs through the gas cylinder and tightens against the copper tube to squeeze the barrel band tightly against the gas cylinder shoulder so there wouldn't be a gap when welding. I used copper and brass for the jig so there wouldn't be a danger of welding the jig to the parts.
As for shimming, I didn't need it (I'm pretty much a newbie with the M14 ) but the way I understand it, you only need to shim to ensure the the gas port in the barrel and the associated gas port in the gas cylinder are properly aligned...... I checked this with the shank of a #36 ( ?? ) drill bit. Hopefully someone with more knowledge/experience will chime in here
