OK, you're right - that's just a fancy way to say glued. Well I decided, against my better judgement and the advice of my peers, to make a guinea pig outta myself and try out a JB Weld unitizing job.
Lacking the means to buy a unitized gas system, and the skill to pull off either of the accepted methods (tig welding or screwing and gluing) I figured the worst that could happen is I'd scrap the factory Norinco parts and be forced to upgrade (secretly hoping that's what happens).
The rifle is a 2009 22" Norinco M305. I just picked it up on here about 2 weeks ago and I'm totally hooked - big time m14 fever. Anyway, here's how it went.
First I scuff sanded the contact areas with 80 grit sand paper. I decided the best spots for the glue would be a drop between the flat of the gas cylinder where it contacts the front band, and between the cylinder and the front band from behind. After sanding I thoroughly degreased all places that would receive glue. I spent a lot of time prepping the glue surfaces knowing that there wouldn't be much surface area, and wanting to achieve the best possible bond.
One area concerned me, the section just forward of the barrel shoulder - I was worried the front band might lodge in there after the glue had set and I'd have a hell of a time getting it off. I haven't heard of that being a problem but decided to do my best to avoid any surprises.
I filled the gap with regular teflon tape and made sure the front band would fit over it while still being able to press snugly against the barrel shoulder without any tape getting in the way. This way the front band would not be in direct contact with the barrel - just the barrel shoulder - once the gas system was glued up. Just to be safe I greased the barrel so no glue would stick.
I mixed up the JB weld and started by applying a small amount to the outside of the front band where it contacts the gas cylinder making sure to keep it away from the barrel. I used many Q-tips along the way to clean away unwanted glue. I pressed the parts together and then pulled them apart again before moving on to make sure no glue had squeezed against the barrel
At this point I put the gas cylinder in place, tightened down the gas cylinder lock and screwed in the plug. I positioned the front band so that it was properly centered on the cylinder. In order to keep the glue from seeping through the cracks and making a mess on the outside of the front band I used some scotch tape to make a barrier.
Then it was time to apply the bulk of the glue. I used a small brush to dab it on the back of the front band making sure to get it all around the cylinder. I tried to stay away from the section of the front band where the stock ferrule would be.
Once I was satisfied that I'd gotten it in all the cracks I cleaned away any excess glue with Q-tips and set it aside for the night. The next morning with a few taps from a mallet the unitized gas cylinder slid free. It now fits more snugly than before but still has a bit of play in the barrel splines. There is plenty of room for the stock ferrule and it only contacts the front band at the lip. Overall the job turned out pretty clean and the bond seems very strong.
Only a small amount of the JB Weld is visible from the front but the color matches the parkerizing pretty well I think.
I'll be taking it out to the range this weekend to see how it holds up and if I can shrink my groups. Before the job I was able to shoot 2 MOA at 50 yards. I'm just hoping I haven't made it worse
I'll get back to you after a few hundred rounds.
Lacking the means to buy a unitized gas system, and the skill to pull off either of the accepted methods (tig welding or screwing and gluing) I figured the worst that could happen is I'd scrap the factory Norinco parts and be forced to upgrade (secretly hoping that's what happens).
The rifle is a 2009 22" Norinco M305. I just picked it up on here about 2 weeks ago and I'm totally hooked - big time m14 fever. Anyway, here's how it went.
First I scuff sanded the contact areas with 80 grit sand paper. I decided the best spots for the glue would be a drop between the flat of the gas cylinder where it contacts the front band, and between the cylinder and the front band from behind. After sanding I thoroughly degreased all places that would receive glue. I spent a lot of time prepping the glue surfaces knowing that there wouldn't be much surface area, and wanting to achieve the best possible bond.
One area concerned me, the section just forward of the barrel shoulder - I was worried the front band might lodge in there after the glue had set and I'd have a hell of a time getting it off. I haven't heard of that being a problem but decided to do my best to avoid any surprises.
I filled the gap with regular teflon tape and made sure the front band would fit over it while still being able to press snugly against the barrel shoulder without any tape getting in the way. This way the front band would not be in direct contact with the barrel - just the barrel shoulder - once the gas system was glued up. Just to be safe I greased the barrel so no glue would stick.
I mixed up the JB weld and started by applying a small amount to the outside of the front band where it contacts the gas cylinder making sure to keep it away from the barrel. I used many Q-tips along the way to clean away unwanted glue. I pressed the parts together and then pulled them apart again before moving on to make sure no glue had squeezed against the barrel
At this point I put the gas cylinder in place, tightened down the gas cylinder lock and screwed in the plug. I positioned the front band so that it was properly centered on the cylinder. In order to keep the glue from seeping through the cracks and making a mess on the outside of the front band I used some scotch tape to make a barrier.
Then it was time to apply the bulk of the glue. I used a small brush to dab it on the back of the front band making sure to get it all around the cylinder. I tried to stay away from the section of the front band where the stock ferrule would be.
Once I was satisfied that I'd gotten it in all the cracks I cleaned away any excess glue with Q-tips and set it aside for the night. The next morning with a few taps from a mallet the unitized gas cylinder slid free. It now fits more snugly than before but still has a bit of play in the barrel splines. There is plenty of room for the stock ferrule and it only contacts the front band at the lip. Overall the job turned out pretty clean and the bond seems very strong.
Only a small amount of the JB Weld is visible from the front but the color matches the parkerizing pretty well I think.
I'll be taking it out to the range this weekend to see how it holds up and if I can shrink my groups. Before the job I was able to shoot 2 MOA at 50 yards. I'm just hoping I haven't made it worse
I'll get back to you after a few hundred rounds.
) demonstrated on my rifle the right application of a punch and the BFH to peen the spline channels to get a nice tight fit. Tightened things up nicely but there is that pucker factor every time I get to hammering on the rifle.
