mikecowhey
Plastic
- Joined
- May 7, 2021
So I have a couple of lowers that aren't right and I am looking for some thoughts on repairs.
The first one, from what I can figure, was damaged during the trigger pocket milling procedure. the best explanation I can come up with is that either I didn't have he mill clamped tight enough to sufficiently hold the work piece, or that the modification I did to the milling fixture to hold the lower didn't perform as intended. Basically what I figured happened was that that the mill clamp came loose just a little and the lower rotated in the vice so it took a deeper cup than I wanted, by the time I realized what happened the cut was about 3/8 of an inch deeper that it was suppose to be. I had the the mill head tightened down so that it wouldn't move up or down on its own so I don't think the quill dropped on its own. So the floor plate of the trigger pocket is about 50% non existent and the cut goes into the trigger guard frame just in front of the grip. Even with the trigger spring sticking out of the bottom of the receiver next to the trigger everything still functions.
I would like to try to fix it if i can, so here are my options that I have come up with for repairs.
1. Buy new lower, easiest and potentially the cheapest, plus it will give me a messed up lower to give to the ATF if it comes down to it.
2. Tig weld, probably the best option but I do not have access to one nor have ever used one so I would have to rely on someone else. I do have access to a spool gun that I can practice with so that could potentially be an option.
3. Low temp solder/braze like bernzomatic or hobart
4. I have a friend said he has used JB weld, not necessarily an option I would like to go with but if others have had success with this than I may be willing to give it a shot.
5. leave it as is and drop in a self contained trigger pack so that I don't have the trigger spring sticking out of the bottom of the receiver, or possibly in conjunction with JB.
Sorry I am having trouble getting the photos to upload from google.
Google Photos
Google Photos
Google Photos
The other receiver not damaged during the trigger pocket, I found out after putting the rifle together that the buffer tube threads were cut at an angle causing the buffer to bind up when it cycles locking it open. The bolt isn't locking open with the bolt catch, all it takes to release the bolt it to put a little bit of pressure at the back of the buffer tube and the bolt slams home like it is suppose to. I put a straight edge across the top of the upper and measured from the top of the tube at both ends and found the back of the tube is a tad over .010" difference, just enough to cause a problem. I put a new lower on the firearm and everything cycles fine. I haven't measured the tube yet but I might to see if it is flat.
So my question on this one is how would one go about straightening out the threads on something like this? Obviously the best method would be to strip the coating and fill in/weld the threads, re-boar the hole and cut new threads. Are there any other options for a repair for this or is it time to invest in a welder and start practicing?
The first one, from what I can figure, was damaged during the trigger pocket milling procedure. the best explanation I can come up with is that either I didn't have he mill clamped tight enough to sufficiently hold the work piece, or that the modification I did to the milling fixture to hold the lower didn't perform as intended. Basically what I figured happened was that that the mill clamp came loose just a little and the lower rotated in the vice so it took a deeper cup than I wanted, by the time I realized what happened the cut was about 3/8 of an inch deeper that it was suppose to be. I had the the mill head tightened down so that it wouldn't move up or down on its own so I don't think the quill dropped on its own. So the floor plate of the trigger pocket is about 50% non existent and the cut goes into the trigger guard frame just in front of the grip. Even with the trigger spring sticking out of the bottom of the receiver next to the trigger everything still functions.
I would like to try to fix it if i can, so here are my options that I have come up with for repairs.
1. Buy new lower, easiest and potentially the cheapest, plus it will give me a messed up lower to give to the ATF if it comes down to it.
2. Tig weld, probably the best option but I do not have access to one nor have ever used one so I would have to rely on someone else. I do have access to a spool gun that I can practice with so that could potentially be an option.
3. Low temp solder/braze like bernzomatic or hobart
4. I have a friend said he has used JB weld, not necessarily an option I would like to go with but if others have had success with this than I may be willing to give it a shot.
5. leave it as is and drop in a self contained trigger pack so that I don't have the trigger spring sticking out of the bottom of the receiver, or possibly in conjunction with JB.
Sorry I am having trouble getting the photos to upload from google.
Google Photos
Google Photos
Google Photos
The other receiver not damaged during the trigger pocket, I found out after putting the rifle together that the buffer tube threads were cut at an angle causing the buffer to bind up when it cycles locking it open. The bolt isn't locking open with the bolt catch, all it takes to release the bolt it to put a little bit of pressure at the back of the buffer tube and the bolt slams home like it is suppose to. I put a straight edge across the top of the upper and measured from the top of the tube at both ends and found the back of the tube is a tad over .010" difference, just enough to cause a problem. I put a new lower on the firearm and everything cycles fine. I haven't measured the tube yet but I might to see if it is flat.
So my question on this one is how would one go about straightening out the threads on something like this? Obviously the best method would be to strip the coating and fill in/weld the threads, re-boar the hole and cut new threads. Are there any other options for a repair for this or is it time to invest in a welder and start practicing?
