We are moving from Illinoisastan to Georgia. NO! I will not be bringing liberal BS politics and policies along for the ride. Question for the crowd..... I have heard threading a small bore barrel can cause accuracy issues. Supposedly the machining can cause the bore diameter to increase slightly near the muzzle. I am considering threading my CZ457 MTR for a suppressor but am hesitant to do so because of accuracy concerns. This barrel shoots really well and I'd hate to mess that up. Anyone with personal experience that can advise whether this is a good or bad idea? We dipped pretty deep into the piggy bank for this house and a new threaded barrel may not be in the budget for some time. Let me know your thoughts.
Barrel Threading
- Thread starter jpjulian
- Start date
hoz53
Gold $$ Contributor
i hope your move works out well for you. ive heard the same thing often enough i believe there is at least sometimes some truth to it. i wouldnt thread a 5/8 muzzle on anything. i dont want to go below 3/4.. they do make clamp on brakes and suppressors ithink. have safe trip
Where are you moving in Georgia?
timeout
Silver $$ Contributor
I don't have the answer to your question but wanted to make sure that you know what it means when the locals say "well bless your heart".
Walt Krafft
Gold $$ Contributor
If it was me and I wanted a suppressor, I would thread that sucker. It may alter its accuracy, maybe make it better. Congrats on the move!!!
ELR LVR
Silver $$ Contributor
Agreeing here
Thread 5/8-24 and you'll be fine
I have experienced muzzle swelling with 1/2-28, but not with 5/8-24
if your barrel don't have enough meat for a shoulder stop but has at least .623 dia.
use a Nut as a stop for the shoulder
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9/16 would even be better than 1/2 threading
Skattergun
Silver $$ Contributor
I’ve threaded hundreds of muzzles and own multiple rimfires with 1/2-28 threads. They shoot just fine. The only time you might notice this is if you have a very capable benchrest rig where you can actually shoot the difference. Another option is to back bore the barrel and have the crown at or behind the shoulder of the threads so there is no bore where the threads are.
I was gonna suggest that. I saw Mark Novak do that on an old surplus rifle. Had a pristine bore except massive rust near the end of the barrel. He counterbored it and unless you actually looked in the muzzle, you'd never know it was done.
Don’t stress it. You will have to get it threaded to 1/2-28 if you are using a .22 can as a vast majority come in that thread pitch. My rifle is threaded at 1/2-28 and has shot great for me since 2017. Know many others with them too who shoot matches and no issues. Get it threaded and have fun.
Also smart move and glad you aren’t bringing those terrible politics with you. Unfortunately too many moving to NC aren’t doing the same.
Also smart move and glad you aren’t bringing those terrible politics with you. Unfortunately too many moving to NC aren’t doing the same.
Did not read responses. Threading will indeed increase bore size, i have confirmed it.
That said there are work arounds for this. Dont run 1/2"threads and run 5/8" or bigger if possible. Needs to have a shoulder to seat against.
Have the threaded portion back bored so the loose portion doesnt exist.
Even though I know you can increase bore size by a wee I have not peronally seen any instances where it was noticably detrimental to accuracy if the work is performed correctly. (Bench guys might tell another tale) You have to cut threads concentric and square to the bore basically the same way you set up to chamber. Many if not almost every barrel will not be true OD to bore... and some are stupid off. Many "gunsmiths" will just chuck up a barrel indexed on OD and cut threads. That idea will not be concentric nor square to bore. I have never seen a suppressor run true either so its a stacking tolerance game at some point. The culmanation can cause baffle strikes and improper pressure distribution causing potential accuracy issues.
And another food for thought. Adding weight will change harmonics and POI shift usually. May be okay or may not be depending on what your gun likes. Do load development with several lots and different velocity ranges and you will probably overcome this.
Rimfire cans are nasty dirty. Buy a servicable can. I shot a very short part of a PRS season with a suppressor and you will have powder and flim flam running back into the action when you go to port arms or muzzle up. This will manifest almost immediately.
Sounds like a lot of negatives but I would tell you to go for it. Suppressed rimfire will put a boyish smile on your face!
That said there are work arounds for this. Dont run 1/2"threads and run 5/8" or bigger if possible. Needs to have a shoulder to seat against.
Have the threaded portion back bored so the loose portion doesnt exist.
Even though I know you can increase bore size by a wee I have not peronally seen any instances where it was noticably detrimental to accuracy if the work is performed correctly. (Bench guys might tell another tale) You have to cut threads concentric and square to the bore basically the same way you set up to chamber. Many if not almost every barrel will not be true OD to bore... and some are stupid off. Many "gunsmiths" will just chuck up a barrel indexed on OD and cut threads. That idea will not be concentric nor square to bore. I have never seen a suppressor run true either so its a stacking tolerance game at some point. The culmanation can cause baffle strikes and improper pressure distribution causing potential accuracy issues.
And another food for thought. Adding weight will change harmonics and POI shift usually. May be okay or may not be depending on what your gun likes. Do load development with several lots and different velocity ranges and you will probably overcome this.
Rimfire cans are nasty dirty. Buy a servicable can. I shot a very short part of a PRS season with a suppressor and you will have powder and flim flam running back into the action when you go to port arms or muzzle up. This will manifest almost immediately.
Sounds like a lot of negatives but I would tell you to go for it. Suppressed rimfire will put a boyish smile on your face!
hoz53
Gold $$ Contributor
ive heard of back boring and even barrels with different chambers on each end that shot ok. ive done a couple drill and tapping the muzzle to put an extension on it so it would make it to the outboard cat head and didnt bother to cut the threaded part off but im still not gonna thread a skinny muzzle. mabie someday—- thanks for the info
If and how much a bore expands depends on how much stress was in it before machining and/or how much was induced when machining/threading. If it has zero stress, it ain't growing. That's on the bbl maker or steel supplier if it's there before machining. That said, the more meat you can reasonably leave around the bore is a good thing...just not a big factor if it was properly stress relieved when the bbl was made or before it left the mill per the specs for the bbl maker. People often consider cut bbls to have less stress due to how they are made but the truth is, the cut bbl makers typically rely on the steel supplier to do the stress relieving of the steel in huge batches before they ever get it and before they ever start machining it.
Your PREMIUM button bbl makers MUST do in house stress relief due to the large amount of stress that process induces. If the bbl is properly stress relieved and has a bit of meat around the bore, it does not affect accuracy. The other thing people fail to consider is that the bore grows with pressure every time we pull the trigger. Not only that, but the bullet swells or obturates to fit the bore while under pressure. Frankly, this subject gets more attention than it deserves. Yes, growth is possible if there is stress left in the steel and if that affects accuracy is debatable and will depend upon how much it grows and muzzle pressure. As pressure drops, the bore swells less, giving a natural choke, too. This isn't a cut and dry thing.
Your PREMIUM button bbl makers MUST do in house stress relief due to the large amount of stress that process induces. If the bbl is properly stress relieved and has a bit of meat around the bore, it does not affect accuracy. The other thing people fail to consider is that the bore grows with pressure every time we pull the trigger. Not only that, but the bullet swells or obturates to fit the bore while under pressure. Frankly, this subject gets more attention than it deserves. Yes, growth is possible if there is stress left in the steel and if that affects accuracy is debatable and will depend upon how much it grows and muzzle pressure. As pressure drops, the bore swells less, giving a natural choke, too. This isn't a cut and dry thing.
My mother was from Texas...... I sure do.I don't have the answer to your question but wanted to make sure that you know what it means when the locals say "well bless your heart".
Pine Mountain north of Columbus.
I think you’re going to like that area. I’m down southeast just below Americus.
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