I recently installed the choate mount on my chinese military.
I learned alot doing this, which can be translated that I did lots of things wrong, wasted plenty of time and money in the process.
But I can tell you if you want to do it yourself, there are a few things/costs to consider:
1. choose screw size. the choate comes with 4 #8-40 socket head capscrews.
you won't find this tap in most sets, so will likely have to buy it at a gunshop. cost $28 for package of 5 bits at p&d. I should have probably bought 4 #8-32 capscrews, would have saved about $25.00.
2. you need two good smaller clamps to place the mount on the receiver before transferring holes. Most of us already have this.
3. after clamping the mount on the gun, ensure that the open sights point to the cross hairs of a centered scope. then remove the scope to ensure you can install the bolt, etc parts, since the scope mount will be semi-permanent when you're finished. When I did this, I noticed that if I shaved off some metal from choate mount on the underside where the bolt has to go under, I could lower the overall height of the scope. So, off to my grinder, where I removed a fair bit of material. Trial and error later, you'll see where I ended up at. WARNING: if you copy my setup (photos), you will have to grind the bottom of the choate mount or the bolt won't slide into the action. Of course, if the scope you use has its eyepiece beyond the mount, you may have to remove the scope before you can get the bolt out. That was a compromise I was prepared to live with.
By the way, after grinding the bottom, I touched up the bluing with Brownells blue. (about $15). Don't forget, add the cost of a grinder if you don't have one. A hand grinder will do a messy job. You should use a bench grinder if you do this.
3. you'll need a center punch and a drill press is preferred. The centerpunch has to be a high quality hardened one. The one I bought from Napa was too soft. The Princess Auto transfer punch (comes in the kit with the plastic base) flattened out on the receiver. A good punch like this will cost you at least $10-15.
4. After center punching, you can drill on size with a 9/64 (0.140") bit. I strongly suggest getting a cobalt bit from Napa or Canadian Tire (more money), cost around $6.
5. If you want to drill a small hole and work your way up, you have to know what you're doing. I drilled one hole with a very small bit (1/16) then went to the next size, 5/64. Very bad idea, I now know that the second bit will break off and had a very miserable time getting out the broken bit. Only a cobalt bit would could drill it out, but by the time I was done, the bit was toast. If you are going to do the stepping drill thing, you need to make larger sized jumps, so that the cutting flutes on the next drill are outside of the max od of the previous hole. Otherwise, you'll break the bit and then heaven help you.
6. By the way, you'll need cutting oil/tapping fluid. You can find it at Napa, Canadian Tire didn't have it. Cost: about $10. If you don't have that, you can use motor oil as well, but it apparently isn't nearly as good.
7. by the way ver. 2, the centerpunch that was hard enough to mark the receiver was too large (not tapered enough) to fit inside the holes on choate base, so I had to use a metalic marker and fill in the holes, then put a small red mark at the center of that. Then place the punch directly on the red mark. Kind of tricky, with four holes and all. In hindsight, if I had a mill, I would have made a template that clamps onto the receiver.
8. After doing all this I installed the scope and saw it was going to get whacked by the shells coming out of the gun. Since this gun is very accurate, I decided that I wanted a more serious, gopher capable scope, i.e. my vortex 4-12. Enter the next part of this project, a shell deflector. Well I found an old square in my garage and decided it was up to the job. Will some measuring, bending (using two vices) hacksawing and more drilling and tapping on the choate mount, I had my deflector, neatly tucked in to take advantage of the overhanging choate mount for extra stiffness. Of course, in making my scope decision, I kissed the stripper clips goodbye. I'll miss you, stripper clips.
9. Ok, so I get it all back together and excitedly go to the range to shoot it. Guess what, it was click, no bang. Long story shorter, the excess metal from my tapped holes for the choate were stopping the bottom portion of the bolt from traveling forward to encase the back of the cartridge. The result was light primer strikes. When I found this, I took out my dremel and very carefully ground away the offending material.
--------
In summary, then if a gunsmith quotes a relatively high price for doing this job, it's probably still going to be cheaper and certainly faster than doing it yourself, if you have to buy all that stuff.
So, after all that, here is my baby, ready to go for gophers next week.
I learned alot doing this, which can be translated that I did lots of things wrong, wasted plenty of time and money in the process.
But I can tell you if you want to do it yourself, there are a few things/costs to consider:
1. choose screw size. the choate comes with 4 #8-40 socket head capscrews.
you won't find this tap in most sets, so will likely have to buy it at a gunshop. cost $28 for package of 5 bits at p&d. I should have probably bought 4 #8-32 capscrews, would have saved about $25.00.
2. you need two good smaller clamps to place the mount on the receiver before transferring holes. Most of us already have this.
3. after clamping the mount on the gun, ensure that the open sights point to the cross hairs of a centered scope. then remove the scope to ensure you can install the bolt, etc parts, since the scope mount will be semi-permanent when you're finished. When I did this, I noticed that if I shaved off some metal from choate mount on the underside where the bolt has to go under, I could lower the overall height of the scope. So, off to my grinder, where I removed a fair bit of material. Trial and error later, you'll see where I ended up at. WARNING: if you copy my setup (photos), you will have to grind the bottom of the choate mount or the bolt won't slide into the action. Of course, if the scope you use has its eyepiece beyond the mount, you may have to remove the scope before you can get the bolt out. That was a compromise I was prepared to live with.
By the way, after grinding the bottom, I touched up the bluing with Brownells blue. (about $15). Don't forget, add the cost of a grinder if you don't have one. A hand grinder will do a messy job. You should use a bench grinder if you do this.
3. you'll need a center punch and a drill press is preferred. The centerpunch has to be a high quality hardened one. The one I bought from Napa was too soft. The Princess Auto transfer punch (comes in the kit with the plastic base) flattened out on the receiver. A good punch like this will cost you at least $10-15.
4. After center punching, you can drill on size with a 9/64 (0.140") bit. I strongly suggest getting a cobalt bit from Napa or Canadian Tire (more money), cost around $6.
5. If you want to drill a small hole and work your way up, you have to know what you're doing. I drilled one hole with a very small bit (1/16) then went to the next size, 5/64. Very bad idea, I now know that the second bit will break off and had a very miserable time getting out the broken bit. Only a cobalt bit would could drill it out, but by the time I was done, the bit was toast. If you are going to do the stepping drill thing, you need to make larger sized jumps, so that the cutting flutes on the next drill are outside of the max od of the previous hole. Otherwise, you'll break the bit and then heaven help you.
6. By the way, you'll need cutting oil/tapping fluid. You can find it at Napa, Canadian Tire didn't have it. Cost: about $10. If you don't have that, you can use motor oil as well, but it apparently isn't nearly as good.
7. by the way ver. 2, the centerpunch that was hard enough to mark the receiver was too large (not tapered enough) to fit inside the holes on choate base, so I had to use a metalic marker and fill in the holes, then put a small red mark at the center of that. Then place the punch directly on the red mark. Kind of tricky, with four holes and all. In hindsight, if I had a mill, I would have made a template that clamps onto the receiver.
8. After doing all this I installed the scope and saw it was going to get whacked by the shells coming out of the gun. Since this gun is very accurate, I decided that I wanted a more serious, gopher capable scope, i.e. my vortex 4-12. Enter the next part of this project, a shell deflector. Well I found an old square in my garage and decided it was up to the job. Will some measuring, bending (using two vices) hacksawing and more drilling and tapping on the choate mount, I had my deflector, neatly tucked in to take advantage of the overhanging choate mount for extra stiffness. Of course, in making my scope decision, I kissed the stripper clips goodbye. I'll miss you, stripper clips.
9. Ok, so I get it all back together and excitedly go to the range to shoot it. Guess what, it was click, no bang. Long story shorter, the excess metal from my tapped holes for the choate were stopping the bottom portion of the bolt from traveling forward to encase the back of the cartridge. The result was light primer strikes. When I found this, I took out my dremel and very carefully ground away the offending material.
--------
In summary, then if a gunsmith quotes a relatively high price for doing this job, it's probably still going to be cheaper and certainly faster than doing it yourself, if you have to buy all that stuff.
So, after all that, here is my baby, ready to go for gophers next week.
