Long Range Hunting Online Magazine


Go Back   Long Range Hunting Online Magazine > Hunting > Long Range Hunting & Shooting

Long Range Hunting & Shooting Nightforce Optics


Reply

Cold Bore Improvment

 
LinkBack Thread Tools Display Modes
  #1  
Old 07-24-2012, 11:14 PM
Gold Member
 
Join Date: Nov 2011
Location: Saratoga Springs, Ut
Posts: 512
Cold Bore Improvment

Im sure this has beaten to death already... But I have done about everything i can think of about my cold bore shot. many changes have been made to my gun with not much change... (CZ 452 Scout, .22lr) My cold bore shot used to be all over the place. Now after all the things i have done to my rifle over the last six months... stock, trigger kit, bedded action. tried different cleaning techniques. I am now down to this... My cold bore is half a mil high at 25 yards. If I let the gun sit for just a few min the first shot is half a mil high.... and the rest of the shots are spot on! WTF! any input would be appreciated.
Reply With Quote
  #2  
Old 07-24-2012, 11:42 PM
Gold Member
 
Join Date: May 2009
Posts: 738
Re: Cold Bore Improvment

That is a hard one to work out.
Try the gun with a normal magazine and not the single shot adapter.
Try different brands of ammo .
Try not cleaning as much as rimfires don't need to be cleaned very often like centerfires do.
It is strange that letting the gun sit a while causes a high shot . That would indicate heat is an issue but rimfires don't get that hot anyway and one would think the zero would go up with sucessive shots if heat was an issue.
Does your CZ have a screw under the forend infront of the reciever ring ?
If it does then maybe you should try altering the tension on that front screw to see if anything gets better or worse.
Also some CZ's have no support between the stock and the action under the middle screw and if this screw is too tight it bows the action and stock .
I am guessing here because I am not familiar with that specific American scout model . It may be different to my Brno Cz's over here .
.5 Mil at 25 yards is only about .45 inch . Are you sure you are shooting well enough to see that .45 inch difference all the time.
Don't ignore the scope either they do some crazy things.
Reply With Quote
  #3  
Old 07-24-2012, 11:50 PM
Gold Member
 
Join Date: Nov 2011
Location: Saratoga Springs, Ut
Posts: 512
Re: Cold Bore Improvment

I am using a 10 round mag,
No barrel tension srew. it is free floated.
I have shot it clean cold bore, and not cleaned in 1000 rounds, and it is the same
I am shooting CCI SV, it has proven to be very accurate ammo in this rifle
Reply With Quote
  #4  
Old 07-25-2012, 12:19 AM
Gold Member
 
Join Date: May 2009
Posts: 738
Re: Cold Bore Improvment

It can't hurt to try some other ammo .
If the ammo and the scope are ok then it has to be either a bedding issue or something strange about the way the bullet chambers when the gun is cold or weird barrel vibrations when the barrel is cold .
It may be one of those weird issues that can't be easily identified.
If all else fails and you have done lots to fix the problem then maybe you should think about selling the gun or if you still want to keep it get an inch cut off the barrel tos ee if it changes the harmonics . Rimfires don't usually have much barrel harmonics due to the low pressure round but who knows what this gun is doing.
CZ's sometimse have very tightly fitted barrels . They put them in at the factory with a machine that locks them up very tight . Well mine are that way. I removed the barrel from one of my Brno Cz's and it was as tight as hell. In the end I reckoned it was so tight it was distorting the action . So I lapped the barrel threads to a nice even and better fit and accuracy did improve some what . It was quite accurate before but it got better after releasing that tight barrel stress on the action ring.
Reply With Quote
  #5  
Old 07-25-2012, 03:40 AM
Platinum Member
 
Join Date: Feb 2011
Location: Halfway between Lubbock and Dallas
Posts: 5,140
Re: Cold Bore Improvment

Quote:
Originally Posted by Clayne B View Post
Im sure this has beaten to death already... But I have done about everything i can think of about my cold bore shot. many changes have been made to my gun with not much change... (CZ 452 Scout, .22lr) My cold bore shot used to be all over the place. Now after all the things i have done to my rifle over the last six months... stock, trigger kit, bedded action. tried different cleaning techniques. I am now down to this... My cold bore is half a mil high at 25 yards. If I let the gun sit for just a few min the first shot is half a mil high.... and the rest of the shots are spot on! WTF! any input would be appreciated.
Simple, always fire at least 2-3 fouling shots after a good cleaning before you go back to shooting for accuracy. If anything that's what the CCI SV's are good for.

If you do a little reading you'll find it's some of the worst .22lr ammo on the market for consistent velocities.
__________________
Without the First and Second Amendments the rest of The Constitution is Meaningless.
Reply With Quote
  #6  
Old 07-25-2012, 03:42 AM
Platinum Member
 
Join Date: Feb 2011
Location: Halfway between Lubbock and Dallas
Posts: 5,140
Re: Cold Bore Improvment

Quote:
Originally Posted by Clayne B View Post
I am using a 10 round mag,
No barrel tension srew. it is free floated.
I have shot it clean cold bore, and not cleaned in 1000 rounds, and it is the same
I am shooting CCI SV, it has proven to be very accurate ammo in this rifle
Have you bedded the action?
__________________
Without the First and Second Amendments the rest of The Constitution is Meaningless.
Reply With Quote
  #7  
Old 07-25-2012, 04:21 AM
Gold Member
 
Join Date: May 2009
Posts: 738
Re: Cold Bore Improvment

Quote:
Originally Posted by WildRose View Post
Simple, always fire at least 2-3 fouling shots after a good cleaning before you go back to shooting for accuracy. If anything that's what the CCI SV's are good for.

If you do a little reading you'll find it's some of the worst .22lr ammo on the market for consistent velocities.
In the initial post he says it shoots high after being left unused for a short time even after firing many shots ? So after it cools down the first shot is high each time . A fouling shot will not fix that scenario because many shots have been fired.
I am also thinking that any ammo change might be worth a try .
Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes


Similar Threads for: Cold Bore Improvment
Thread Thread Starter Forum Replies Last Post
Cold Bore, Time Clayne B Long Range Hunting & Shooting 1 01-08-2012 12:22 AM
Cold bore accuracy? 284 Win. Long Range Hunting & Shooting 8 09-25-2011 10:15 AM
cold bore fliers bigjake Long Range Hunting & Shooting 11 07-26-2011 08:17 PM
Cold Bore POI tracker12ga Rifles, Bullets, Barrels & Ballistics 5 10-15-2010 06:49 AM
How is your cold bore shot different? teddy12b Long Range Hunting & Shooting 7 01-12-2009 09:59 PM


All times are GMT -5. The time now is 05:00 PM.


Powered by vBulletin ©2000 - 2014, Jelsoft Enterprises Ltd.
Content Management Powered by vBadvanced CMPS
All content ©2010-2014 Long Range Hunting, LLC