JTPinTX
Custom Call Maker
I bought this CZ 527 in 2008 with the express intention of shooting the barrel out of it over the next 10 years. It was a 12 twist .223 to take advantage of cheap ammo and components. It was the gun I taught my young daughter to shoot centerfire with. She killed her first deer and first coyote with it, she put a lot of rounds through it and had a lot of kills learning to shoot and learning to hunt. I used it for practice as well. Often it was shot hot, sometimes very hot. I knew it was killing the barrel but that was its purpose in life back then.
3-4 years ago the round count was getting up around 4K and though it still shot OK, accuracy was for sure going downhill. I contacted James Calhoon and he had a brand new 9 twist factory takeoff barrel. I got it for $125 and put it on the shelf for whenever I had a chance to swap it out. Life got busy, I got distracted, my daughter started shooting my 6.5 Grendel AR, so it sat.
A couple weeks ago I decided I needed to get it out and get the barrel swap done. I had a lot of components on the shelf I could use in it and with the shortages going on I felt it was a good time to take advantage of that. We got a nice big lathe at work a year or two ago and I have been teaching myself to thread, been making my own jigs and fixtures, studying up on rifle work and practicing, all that good stuff. I spend quite a bit of time watching videos and then going out to the lathe and doing what I just watched.
The old barrel was on very tight and I had to be careful not to tweak the action getting the old barrel off. Right before I thought I was going to have to give up it broke free. I set the new barrel up in the lathe, indicated it in, and just barely, barely touched the rear face to true it up and take off a couple of burrs from the original factory install. I screwed it on the action and headspace was right where I wanted it. Probably a couple thou tighter than factory but still good to go.
I pulled the barrel back off the action and set it up in the lathe to thread the muzzle for the ASR brake for my suppressor. Indicated in the bore to about .0005 with my long stem dial indicator, cut 1/4" off the barrel to get a clean new crown, and threaded it 1/2x28. I took it slow and cut the threads to a nice snug fit all the way down.
I took it home and cleaned it real good and then coated the bore with Dyna Bore Coat. I let that set for 24 hours. The next day I shot 10 rounds of factory stuff hot and fast to set the DBC and got a solid zero at 50 while I was doing it. On the last round I intentionally shot the tack out of my target. I knew at that point it was going to be a shooter.
Now to the good part. That new factory takeoff is probably one of the best shooting factory barrels I have ever personally seen. I had a bunch of old various reloads on the shelf from the old barrel. It will shoot anything I put down it under 1/2 MOA for 3 shots, and most of it under 3/8". It did shoot one group with factory loads over 1/2 MOA, but it has not shot a single group of reloads over 1/2" at 100 yards.
2 groups with a 50 VMAX load, .279" and .326", a group with 50 Blitzkings, .382", a group with 52 AMAX, .218", a group with 55 Barnes TTSX, .498". This barrel is amazing. Cold windy shooting conditions and it keeps throwing bullets into little groups. And not only that, POI for the different loads is very close. To me that is also usually a sign that a barrel is going to be very consistent.
I think I have used up a years worth of the Rifle Gods luck on this one.
A couple of pictures of groups:
3-4 years ago the round count was getting up around 4K and though it still shot OK, accuracy was for sure going downhill. I contacted James Calhoon and he had a brand new 9 twist factory takeoff barrel. I got it for $125 and put it on the shelf for whenever I had a chance to swap it out. Life got busy, I got distracted, my daughter started shooting my 6.5 Grendel AR, so it sat.
A couple weeks ago I decided I needed to get it out and get the barrel swap done. I had a lot of components on the shelf I could use in it and with the shortages going on I felt it was a good time to take advantage of that. We got a nice big lathe at work a year or two ago and I have been teaching myself to thread, been making my own jigs and fixtures, studying up on rifle work and practicing, all that good stuff. I spend quite a bit of time watching videos and then going out to the lathe and doing what I just watched.
The old barrel was on very tight and I had to be careful not to tweak the action getting the old barrel off. Right before I thought I was going to have to give up it broke free. I set the new barrel up in the lathe, indicated it in, and just barely, barely touched the rear face to true it up and take off a couple of burrs from the original factory install. I screwed it on the action and headspace was right where I wanted it. Probably a couple thou tighter than factory but still good to go.
I pulled the barrel back off the action and set it up in the lathe to thread the muzzle for the ASR brake for my suppressor. Indicated in the bore to about .0005 with my long stem dial indicator, cut 1/4" off the barrel to get a clean new crown, and threaded it 1/2x28. I took it slow and cut the threads to a nice snug fit all the way down.
I took it home and cleaned it real good and then coated the bore with Dyna Bore Coat. I let that set for 24 hours. The next day I shot 10 rounds of factory stuff hot and fast to set the DBC and got a solid zero at 50 while I was doing it. On the last round I intentionally shot the tack out of my target. I knew at that point it was going to be a shooter.
Now to the good part. That new factory takeoff is probably one of the best shooting factory barrels I have ever personally seen. I had a bunch of old various reloads on the shelf from the old barrel. It will shoot anything I put down it under 1/2 MOA for 3 shots, and most of it under 3/8". It did shoot one group with factory loads over 1/2 MOA, but it has not shot a single group of reloads over 1/2" at 100 yards.
2 groups with a 50 VMAX load, .279" and .326", a group with 50 Blitzkings, .382", a group with 52 AMAX, .218", a group with 55 Barnes TTSX, .498". This barrel is amazing. Cold windy shooting conditions and it keeps throwing bullets into little groups. And not only that, POI for the different loads is very close. To me that is also usually a sign that a barrel is going to be very consistent.
I think I have used up a years worth of the Rifle Gods luck on this one.
A couple of pictures of groups: