Fixing and pillar bedding a cracked CZ527 7.62x39
Materials Used:
- 2x 5/16"x5/16" Brass Hose Barbs (Home Depot)
- 2x 1/8" Wood Dowel (Dollar Store)
- JB Weld, Original Cold Weld (Canadian Tire)
- 11/32" Drill Bit
- 9/64" Drill Bit
- Small Flat File
- Nail Polish Remover Pads
- Latex Free Tourniquet
- Painters Tape
- Wood Clamp
- Dremel Tool with Burr & Grinding stone
- Black Marker
- Torque Screwdriver
- Hacksaw
- Plumbers putty or crafting putty
- Mold release agent, Pam, Oneshot, or whatever you like.
Here is the crack going from the top tang hole extending 3" with a slight curve to the right forgrip.
I used two of the "5/16"x5/16" Brass Hose Barbs" and removed the middle ring using a drill and a large flat file.
I simply put the barb in the drill and held the file against the ring until is was the same diameter as the rest of the barb.
Now remove all the hardware from the stock.
The stock is new and has no oils or dirt on it so I don't bother using any acetone to clean it.
I use the 11/32" drill bit to enlarge the front action bolt hole, being careful to keep it centred.
As the crack was the main issue I needed to deal with it first.
I clamped the stock in the middle of the crack before making the holes to make sure the crack remained clean and the hole was the right size.
I couldn't drill a hole straight through the crack so I opted for two diagonal holes using a 9/64" drill bit, stopping before going all the way through the stock.
After cleaning out the hole I used the 1/8" dowel and marked the end to show how far it should be pushed in.
Then I removed the wood clamp.
At this point I dry fit the brass hose barb and marked the length with a marker. (I held the trigger guard in place so the barb would sit directly on the metal.)
I then taped all around the top rear tang so no epoxy would get on the wood.
Putting the barb back in place I checked it was close enough to bed and not to short, corrections made with a flat file.
After mixing equal parts of JB Weld I confirmed it was runny enough to use in the crack drill holes.
I used one 1/8" dowel as a tool to scoop the JB Weld into the holes and I would stop to pull the crack open, working it, before adding more.
When the holes seemed full I put in a dowel and pushed it all the way to the end. (I found my hole was a bit to big and would use a smaller bit in the future.)
After doing this a few times, also spinning the dowels to help with air pockets, I wipe off any that comes out the crack or spills back into the stock.
Now I let this set and move on to the rear tang and post.
With the remaining JB Weld now thicker and less prone to running I used the dowel to put the epoxy on the sides of the hole, just enough to paint the inside walls.
I put a small amount of putty in both ends of the barb and then put epoxy up and down the sides.
Then I pushed the barb into the hole making sure to catch and clean off any that came out the other end.
Next I remove the putty and clean the ends of the barb.
Now I spray the trigger guard with the release agent and hold it in place with the rubber tourniquet.
At this point I also put the wood clamp back on the forend and watched for any epoxy that was pushed out and wiped it off with the Nail Polish Remover Pads.
The clamp was then left on for the next 30 hours to ensure it was well set while I worked on the rest of the stock.
The dowel has been set for 6 hours so I break them off and clean the area with the dremel and burrs.
I removed the rubber band and trigger guard, making sure to clean any epoxy off the stock or guard with a Nail Polish Remover Pad.
I also remove the tape from the crack area as no more epoxy is coming out.
I continue to clean the stain, make lines, and small holes all around the area the crack is for a better bond.
I make this about an inch longer that I think the crack goes to help prevent future issues.
I then wait until the next day to proceed.
The next day I remove the wood clamp and tape the forend so no epoxy gets on the outside wood.
As my second hole to fix the crack had to exit inside the bolt hole I had to file the epoxy and dowel down a bit before ry fitting the barb.
I then use the second brass barb and mark it for length before cutting with a hacksaw, then finish with a flat file.
I mix more JB Weld to do the bedding and front barb/pillar.
I make a small dam with the putty so the epoxy won't run outside the repair area.
While still runny I fill the repair area and all the way back to the barrel recoil lug.
My barrel is free floated so I don't make this very deep, just enough to stay under the barrel.
I then wait a bit until the epoxy thickens and repeat the above steps used on pillar one to ensure it sits on the metal trigger guard firmly.
I then make sure to apply my release agent liberally over the barrel and chamber.
After cleaning any epoxy that runs I wrap the trigger guard and barrel with the rubber band and let it sit for 6 hours.
After the epoxy has set for 6 hours I remove the barrel and have a look to see what needs to be fixed up or removed.
A small amount of epoxy was moved so I use a dowel to push things back in place before spraying my release agent again.
Then I put the barrel and trigger guard back in place and bolt it to 25psi, I then let it sit until the next day.
The next morning I remove the barrel and trigger guard and use a dremel to remove any high areas and slope the area where I made the dam with putty.
Make sure to remove all the putty from the bolt holes as mine didn't all come out on it's own.
Then I put the rifle back together after cleaning and oiling it one last time.
Here is the finished project. I won't be shooting it for a few more days at least so it has plenty of time to dry.
Here is the old stock and the new stock together while I worked on them.
CZ declined to provide the proper inch pounds to use on the action bolts so I used what I thought would be okay. (25psi.)
CZ declined to answer if my bedding the new stock would void my warranty, so I only did the old one for now.
CZ did say that using blue loctite was okay on the bolts.
I did things this way for a few reasons;
1. The crack needed to be fixed properly as it went through the bolt hole and 3" into the forend.
2. Glue and working from the outside in wasn't going to stop the crack from spreading over time.
3. I needed a runny epoxy to get into the crack and dowel was a great way to deal with the problem.
4. Home Depot, Rona, Lowes, and Canadian Tire only carried LePage and/or JB Weld epoxies. (WTF? They have a deal in my area?)
Feel free to substitute or change things to meet your needs. I just used what I had that I thought would work well. Time will tell.
Zen
Update: May 29th
Took the CZ 527 with the repaired stock to the range with my new M&P15. I fired 5 rounds left, over corrected, fired 5 right, corrected, and the last 10 went nicely into the #8 ring. As I only had the 20 7.62x39 that was all the sighting in I could do for the day. So I proceeded to blast away with my new AR until another 200RNDS vanished.
Materials Used:
- 2x 5/16"x5/16" Brass Hose Barbs (Home Depot)
- 2x 1/8" Wood Dowel (Dollar Store)
- JB Weld, Original Cold Weld (Canadian Tire)
- 11/32" Drill Bit
- 9/64" Drill Bit
- Small Flat File
- Nail Polish Remover Pads
- Latex Free Tourniquet
- Painters Tape
- Wood Clamp
- Dremel Tool with Burr & Grinding stone
- Black Marker
- Torque Screwdriver
- Hacksaw
- Plumbers putty or crafting putty
- Mold release agent, Pam, Oneshot, or whatever you like.
Here is the crack going from the top tang hole extending 3" with a slight curve to the right forgrip.
I used two of the "5/16"x5/16" Brass Hose Barbs" and removed the middle ring using a drill and a large flat file.
I simply put the barb in the drill and held the file against the ring until is was the same diameter as the rest of the barb.
Now remove all the hardware from the stock.
The stock is new and has no oils or dirt on it so I don't bother using any acetone to clean it.
I use the 11/32" drill bit to enlarge the front action bolt hole, being careful to keep it centred.
As the crack was the main issue I needed to deal with it first.
I clamped the stock in the middle of the crack before making the holes to make sure the crack remained clean and the hole was the right size.
I couldn't drill a hole straight through the crack so I opted for two diagonal holes using a 9/64" drill bit, stopping before going all the way through the stock.
After cleaning out the hole I used the 1/8" dowel and marked the end to show how far it should be pushed in.
Then I removed the wood clamp.
At this point I dry fit the brass hose barb and marked the length with a marker. (I held the trigger guard in place so the barb would sit directly on the metal.)
I then taped all around the top rear tang so no epoxy would get on the wood.
Putting the barb back in place I checked it was close enough to bed and not to short, corrections made with a flat file.
After mixing equal parts of JB Weld I confirmed it was runny enough to use in the crack drill holes.
I used one 1/8" dowel as a tool to scoop the JB Weld into the holes and I would stop to pull the crack open, working it, before adding more.
When the holes seemed full I put in a dowel and pushed it all the way to the end. (I found my hole was a bit to big and would use a smaller bit in the future.)
After doing this a few times, also spinning the dowels to help with air pockets, I wipe off any that comes out the crack or spills back into the stock.
Now I let this set and move on to the rear tang and post.
With the remaining JB Weld now thicker and less prone to running I used the dowel to put the epoxy on the sides of the hole, just enough to paint the inside walls.
I put a small amount of putty in both ends of the barb and then put epoxy up and down the sides.
Then I pushed the barb into the hole making sure to catch and clean off any that came out the other end.
Next I remove the putty and clean the ends of the barb.
Now I spray the trigger guard with the release agent and hold it in place with the rubber tourniquet.
At this point I also put the wood clamp back on the forend and watched for any epoxy that was pushed out and wiped it off with the Nail Polish Remover Pads.
The clamp was then left on for the next 30 hours to ensure it was well set while I worked on the rest of the stock.
The dowel has been set for 6 hours so I break them off and clean the area with the dremel and burrs.
I removed the rubber band and trigger guard, making sure to clean any epoxy off the stock or guard with a Nail Polish Remover Pad.
I also remove the tape from the crack area as no more epoxy is coming out.
I continue to clean the stain, make lines, and small holes all around the area the crack is for a better bond.
I make this about an inch longer that I think the crack goes to help prevent future issues.
I then wait until the next day to proceed.
The next day I remove the wood clamp and tape the forend so no epoxy gets on the outside wood.
As my second hole to fix the crack had to exit inside the bolt hole I had to file the epoxy and dowel down a bit before ry fitting the barb.
I then use the second brass barb and mark it for length before cutting with a hacksaw, then finish with a flat file.
I mix more JB Weld to do the bedding and front barb/pillar.
I make a small dam with the putty so the epoxy won't run outside the repair area.
While still runny I fill the repair area and all the way back to the barrel recoil lug.
My barrel is free floated so I don't make this very deep, just enough to stay under the barrel.
I then wait a bit until the epoxy thickens and repeat the above steps used on pillar one to ensure it sits on the metal trigger guard firmly.
I then make sure to apply my release agent liberally over the barrel and chamber.
After cleaning any epoxy that runs I wrap the trigger guard and barrel with the rubber band and let it sit for 6 hours.
After the epoxy has set for 6 hours I remove the barrel and have a look to see what needs to be fixed up or removed.
A small amount of epoxy was moved so I use a dowel to push things back in place before spraying my release agent again.
Then I put the barrel and trigger guard back in place and bolt it to 25psi, I then let it sit until the next day.
The next morning I remove the barrel and trigger guard and use a dremel to remove any high areas and slope the area where I made the dam with putty.
Make sure to remove all the putty from the bolt holes as mine didn't all come out on it's own.
Then I put the rifle back together after cleaning and oiling it one last time.
Here is the finished project. I won't be shooting it for a few more days at least so it has plenty of time to dry.
Here is the old stock and the new stock together while I worked on them.
CZ declined to provide the proper inch pounds to use on the action bolts so I used what I thought would be okay. (25psi.)
CZ declined to answer if my bedding the new stock would void my warranty, so I only did the old one for now.
CZ did say that using blue loctite was okay on the bolts.
I did things this way for a few reasons;
1. The crack needed to be fixed properly as it went through the bolt hole and 3" into the forend.
2. Glue and working from the outside in wasn't going to stop the crack from spreading over time.
3. I needed a runny epoxy to get into the crack and dowel was a great way to deal with the problem.
4. Home Depot, Rona, Lowes, and Canadian Tire only carried LePage and/or JB Weld epoxies. (WTF? They have a deal in my area?)
Feel free to substitute or change things to meet your needs. I just used what I had that I thought would work well. Time will tell.
Zen
Update: May 29th
Took the CZ 527 with the repaired stock to the range with my new M&P15. I fired 5 rounds left, over corrected, fired 5 right, corrected, and the last 10 went nicely into the #8 ring. As I only had the 20 7.62x39 that was all the sighting in I could do for the day. So I proceeded to blast away with my new AR until another 200RNDS vanished.
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