Cold Bore Problems

[BAJ]

I have a barrel that I suspect doesn't shoot well with a with a cold bore. Are there any characteristics in general that barrels with cold bore problems exhibit besides not grouping well? Will shots generally go high or low? What makes a barrel have a cold bore problem? Does it have anything to do with how tight the bore is?

Thanks,
Brian

 

[DonMatzeder]

How many rounds does it take to warm up? If it's less than 5, it is just the lack of lube in the bore. Just learn to always shoot that many foulers before going for score. Most all rimfires are like that.........

 

[Brian_K]

I have a barrel that I suspect doesn't shoot well with a with a cold bore. Are there any characteristics in general that barrels with cold bore problems exhibit besides not grouping well? Will shots generally go high or low? What makes a barrel have a cold bore problem? Does it have anything to do with how tight the bore is?

Thanks,
Brian

I have just completed a test using a Broughton 4c 25” barrel and Eley Match to try and determine at what point the barrel starts to shoot accurately and at what point this falls off.

The barrel was thoroughly cleaned (nylon, bronze brush, JB bore paste). I shot a total of 98 rounds. It took two rounds to set a zero and after twelve rounds the rifle started to shoot accurately but had moved two clicks high (at 25yds). I reset the zero and continued the test, by the 98th round the rifle had not lost any accuracy.

I cleaned the bore with two wet and three dry patches, I intend to run the test again to see at what point the rifle starts to lose accuracy.

Each barrel will be different but I hope this helps.

Brian

 

[Hambone]

How many rounds does it take to warm up? If it's less than 5, it is just the lack of lube in the bore. Just learn to always shoot that many foulers before going for score. Most all rimfires are like that.........

+1

 

[Bolero]

My Anschutz 1411 always takes 10 or 12+ shots to warm up and start shooting accurately...I don't clean the bore after that unless I change ammo for some reason or accuracy starts falling off...
same with my Suhl 150...

Brian if you've cleaned the bore after your 98 shot test you lose your frame of reference don't you...??? wouldn't you have to start over again or is that what you mean...???

Bolero

 

[Brian_K]

Bolero,

I figured, as with any test you need a fixed repeatable base point. When the testing started the bore was as clean as it gets no carbon or crud anywhere, bright as the day it was born. During a match I use two wet and three dry patches between each card (or at least I try my best to). I don’t believe this gets the barrel back to the fully clean stage so by running the test again from this point, I’m somewhere near real world match conditions. This time I expect the barrel to take fewer rounds to settle down and possibly lose accuracy before 100 rounds are shot, but we’ll have to see. If it doesn’t lose accuracy I’ll repeat the test until it does (I need the practice anyway). I hope to be able to determine when two wet and three dry are insufficient and a deep clean is required.

Brian

 

[alan k]

It can also depend on what you use to clean/oil the barrel. When I was using a 50/50 mix of Kroil/rinfire blend it took 15 or 20 rounds to settle/foul the barrel. Kroil was the problem. I have run a few tests and to my thinking every cleaner acts different as to how many foulers it takes for the lube to build in the barrel.

Al Kunard

 

[Brian_K]

Good point Al, I found a supplier of Rimfire Blend over here in the UK so that’s what I use. I do however give the bore a final swab with Kroil if I’m not going to use it for a while. I think the main thing is to be consistent whichever way you do it.

Brian

 

[alan k]

Good point Al, I found a supplier of Rimfire Blend over here in the UK so that’s what I use. I do however give the bore a final swab with Kroil if I’m not going to use it for a while. I think the main thing is to be consistent whichever way you do it.

Brian

I use Kroil in every firearm I own when storing for any length of time.

Al Kunard

 

[Hambone]

One of the best .22 riflesmiths I have ever encountered always said. "More .22r/f barrels have been trashed by over zealous cleaning than have ever been shot out".