CZ452 American Chopped and Threaded

| October 4, 2015 | 0 Comments

Awhile back the question was brought up whether or not there was sufficient diameter to thread a 452 American barrel 1/2x28tpi.

I got around to threading my recent purchase from Whittaker’s.

Shot a 10 shot group the other day to get a baseline. The rifles bore had 2 dry patches run though it. That’s it other than mounting a scope and shooting 5 rounds to sight it in.


This evening I got around to threading the muzzle. Coaxially indicated the barrel to .0002″. The tenon was cut to .438″ long, .498″ diameter with .475″ pitch diameter. The shoulder left measured .575″ so it’s .0375″ to the side.

After the threading was done I assembled the rifle an torqued the action screws to 29inlbs, mounted the scope and shot another 10 round group with a thread protector only. It’s the middle target.

You will notice a slight POI shift but it was still close considering the rifle was in pieces earlier.

A suppressor was then installed and another 10 round group was fired. The results are below on right hand target.


The rifle was shot in the same manner each time, a front rest and rear bag.This isn’t very scientific but it shows that the threading on this particular barrel wasn’t effected.

Tomorrow I will cut the barrel down to just a tad over 16″ and shoot it again.

Well it’s to late to turn back now I suppose.

At the factory length I left the crown alone. Will be putting the same style on the muzzle when I am finished.


It was a long day for me between projects and getting some shooting in.

As promised I cut the barrel down to 16.25″ and cut a crown similar to the factory job.


I went ahead and made a thread protector and blued it and the muzzle/threads.

I shot these in the same manner after cutting the barrel down. Pretty much the same results. Notice the POI shift. Guessing the barrel is a little stiffer. Again nothing was done other than mounting the scope and torquing the action.


I went ahead and shot the rifle just before dark to help confirm if the shorter tube would shoot after the work I did on it.

Looks like it’s going to be fine for my wife’s squirrel gun.

DubbleA thank you for the detailed work and review. Now we?see if done right by the right gunsmith with the right rifle, shortening and threading a barrel can be done.

Courtesy of DubbleA on rimfirecentral.











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