I purchased a IDF M14 kit from Wolverine, and a barrelled M305 receiver from another vendor (johnone). I have removed the M305 barrel and cut receiver stub from M14 barrel. I have built many garands so to time the barrel looks straight forward and will not be over indexed like the factory install. I noticed the op rod does not slide into track on the M305 receiver so I assume I need to remove some material from the tab not sure top of tab or bottom?? When I install the bolt into the stripped receiver with no barrel it does not drop in fully so I feel some material needs to be removed (lapped) to allow bolt to drop in?? Also I had to drill out the barrel set screw as it was impossible to remove, I assume this is not necessary to replace as it does not appear a M14 had this. Any information on fitting op rod and bolt to this receiver would be greatly appreciated, I have read some of the stickies on M14 and I did not see these answered or photo bucket pictures.
M14 IDF build help
- Thread starter crogers
- Start date
I did a big tutorial on fitting oprods some years ago but "they" didn't seem to want to sticky it.
sometimes all you need to do is break the top two corners of the oprod tab stightly with a Stone.... not a file.
In fact, you are best served to alter any tab dimensions with stone files and not metal/diamond ones.
without seeing the problem, it's hard to give advice on your particular oprod.
color the whole tab black with a jiffy or machinist blue and try inserting it.
remove it and take some good pics showing the binding marks...… post those and I'll see if I can help you from my keyboard.
We are in the same province but I'm in the interior so probably can't help you in person.
don't worry about the set screw
make sure you have 80 to 90 ft pounds of torque being required to seat your barrel to index.
sometimes all you need to do is break the top two corners of the oprod tab stightly with a Stone.... not a file.
In fact, you are best served to alter any tab dimensions with stone files and not metal/diamond ones.
without seeing the problem, it's hard to give advice on your particular oprod.
color the whole tab black with a jiffy or machinist blue and try inserting it.
remove it and take some good pics showing the binding marks...… post those and I'll see if I can help you from my keyboard.
We are in the same province but I'm in the interior so probably can't help you in person.
don't worry about the set screw
make sure you have 80 to 90 ft pounds of torque being required to seat your barrel to index.
too be honest I kinda missed that in the first read and was mentally engaged in the oprod discussion hehehe
Take a picture with your bolt as far as it will close too , then we can say whether it might be lappable.
you'll need headspace gauge(s) if so and will need to disassemble the bolt if not already.
OP are you near 100 mile house?
Thanks 45ACPKING for all the info I am on the Island. I will get the marker out and see where the contact is being made on the lugs, it looks like I could force it down so it's close. I will use a hone and soften the top of the op rod tab corners. I was thinking of getting the op rod and bolt issue sorted out before I install the barrel. Pictures..... I am one of them guys to lazy to figure out how to attach, but I will investigate posting them. I will need to get 7.62 headspace gauges from my buddy down island. I am in no rush I just noticed these issues and thought I would ask for advice before I got to deep in it, and read these were common issues with Chinese receivers.
Thanks for the direction. Although I will use the marker and see were it is making contact before the barrel install, nothing more than the marker (I promise lol). The barrel was over indexed that came off and it looked like it went back too far as I thought the barrel was the issue for the bolt not fully engaging, but after barrel removal still did not drop in as far I would like. I will get the head space gauges (pull thru reamer??)and lapping equipment then work on the stripped bolt after barrel installation. If the head space is too little can these IDF barrels be reamed using 7.62 pull thru reamer? Chromelined???
can't ream those without a special reamer that nobody sells.
as far as I know anyways.
on that subject you might want to send m14 medic a pm, he has seen a lot more of the recent IDF kits than I have. if it's a standard usgi barrel it can't be reamed
as far as I know anyways.
on that subject you might want to send m14 medic a pm, he has seen a lot more of the recent IDF kits than I have. if it's a standard usgi barrel it can't be reamed
m14medic.ca
Expried Business Member
- Location
- Regina SK Canada
OP,
Couple of questions for ya...
Is your bolt disassembled?
Is the IDF barrel “protruding” into the receiver?
As far a fitting the op-rod, if 45acp’s advice allows you to get the tab into the take down notch; and if it still won’t move through it’s field of travel, then you may need to lap the op-rod to the action.
John
Couple of questions for ya...
Is your bolt disassembled?
Is the IDF barrel “protruding” into the receiver?
As far a fitting the op-rod, if 45acp’s advice allows you to get the tab into the take down notch; and if it still won’t move through it’s field of travel, then you may need to lap the op-rod to the action.
John
speaking only about the .308/7.62 rifles as I have not dared touch a x39 version..... The set screw typically found on norinco receivers is a funny thing the Chinese added to the design. I guess it was intended to keep the barrel from rotating by jamming the thread, which it does do. That said, if the barrel is attached to the receiver correctly, that set screw is not needed.
Now these newer rifles are foreign to me so I can really only speak with experience to rifles imported before say around 2015 but in all cases in the past, the presence or absence of the set screw should not affect the barrel. Also, the set screw is in no way to be used to accommodate for lack of proper torque seating the barrel, which is commonly accepted to be 80 to 90 foot pounds to top dead center.
If your barrel is spinning and you did not use tools to loosen it to that state...… yes, that is very bad.
Now these newer rifles are foreign to me so I can really only speak with experience to rifles imported before say around 2015 but in all cases in the past, the presence or absence of the set screw should not affect the barrel. Also, the set screw is in no way to be used to accommodate for lack of proper torque seating the barrel, which is commonly accepted to be 80 to 90 foot pounds to top dead center.
If your barrel is spinning and you did not use tools to loosen it to that state...… yes, that is very bad.
I just noticed the bit at the end of your post.
When an m14 barrel is made , at the shoulder where it tightens against the receiver there is an undercut to the barrel. This commonly referred to as a torque shoulder. What happens is that this undercut shoulder is designed to crush fit against the receiver. To achieve the correct draw against the receiver, the design calls for 80 to 90 foot pounds of torque at top dead center.
So for the guy at home building his rifle what does this mean?
How does a guy know if his barrel is gonna work?
hand fit the barrel and observe where the top dead center rotates to. Ideally you want to see it stop turning by hand somewhere between 15 and 20 degrees to the left of top dead center if you are looking down the action from the back.
If it is 20degrees or over...… a smith or machinist will need to consult the barrel drawings and reset the torque shoulder. The Jerry Kunhaussen 30 caliber service rifle shop manual details this process.
If it is under 15 degrees, the torque shoulder will need to be roll peened or swaged in a lathe. Again, the 30 caliber service rifle shop manual details this process.
roll peening the shoulder back towards the threads is pretty easy but it takes an understanding of what you are doing and the right surface to work on. Not everyone wants to put their barrel on an anvil surface and start tapping away with a flat hammer as they rotate the barrel evenly but it is the way to get it done if you need to massage the torque shoulder to get the correct draw.
