Cold bore blues.

[Rhovee]

Went and shot my best group to date. But my cold bore isn't looking so hot. Is there anything that could be done to try and bring this closer? I don't think the first shot was me but I need to check. I'll attach a picture for reference. First shot to right is cold bore. Left is a 3 shot group. Gun has about 30 rounds since last cleaned
27" rock creek blank carbon wrapped
N570 powder
Fed 215
28 nosler
195 Berger.

 

[ShtrRdy]

you'll have to repeat the test and see if this consistently happens. I would like to believe a good barrel chambered and threaded properly would not have this happen.

That is a very nice 3-shot group you have there.

 

[Wild Bill G]

How could you be proud of that 3 shot group it looks like one hole. As a act of kindness I will take that rifle off of your hands. Nice group you should be proud. As for the cold bore have you noticed this before or is it just this load. Not sure how long a gun has to sit to be considered cold bore but maybe try a 3 shot cold bore group. May just be some minute fine tuning to solve issue. Maybe something in the bedding someone here will have the answer.

 

[Barrelnut]

Might also try dry firing a few times before the first shot of the day with the rifle. I think it helps me be a little more consistent with the first shot.

Awesome group.

 

[Rhovee]

Trust me, i am surprised at the group. I have shot quite a few in the .3-.25 range. That is a good idea with doing some dry firing to get a good feel for the trigger. I am going to try it again today.

 

[Greyfox]

you'll have to repeat the test and see if this consistently happens. I would like to believe a good barrel chambered and threaded properly would not have this happen.

That is a very nice 3-shot group you have there.

I agree with this, and comments about dry firing practice. I will test for cold bore accuracy at least 6 times on separate days before I am confident of the actual performance. While I have rifles that will print sub .25MOA groups in controlled warm bore conditions, expecting cold bore performance to this level may be unrealistic. I'm happy when I can get at least .5MOA on different days, temperatures, etc. Most of my rifles require a bore that is fouled at least 10 shots to do this. If a rifle doesn't produce cold bore accuracy but is reproducible, I will set up for the first shot POI (for hunting) and adjust for follow-ups if required. This all assumes the bedding, mounts, scope has checked out OK and cold bore vs warm bore velocity is within 10-15FPS. If first shot performance continues to be erratic/problematic(+.5MOA) I go back to basic load development. Last point. I have found that some barrels need 100-200 rounds through them before they stabilize and produce stabile velocity and cold bore consistency.

 

[adam32]

From what has been posted on other threads...that should only happen with a button rifled barrel...a cut rifled will have the same cold bore POI as warm...

 

[Rhovee]

Funny you mention that. Yesterday I also shot my 6.5 wsm with a benchmark button barrel and the cold bore with 3 following shots was .4" group. Center to center.

 

[Rich Coyle]

Okay.

 

[odoylerules]

From what has been posted on other threads...that should only happen with a button rifled barrel...a cut rifled will have the same cold bore POI as warm...

I don't understand the difference, but if that's true, why would anyone ever use button?

 

[adam32]

I don't understand the difference, but if that's true, why would anyone ever use button?

It doesn't make a difference...just some people here say they will only use a cut rifled barrel on hunting rifles since buttons won't shoot cold bore...I was just poking fun at their "opinions".

 

[odoylerules]

It doesn't make a difference...just some people here say they will only use a cut rifled barrel on hunting rifles since buttons won't shoot cold bore...I was just poking fun at their "opinions".

I don't know that manufacturing differences at all. I was sincerely asking. I'll have to do some research

 

[Greyfox]

It doesn't make a difference...just some people here say they will only use a cut rifled barrel on hunting rifles since buttons won't shoot cold bore...I was just poking fun at their "opinions".

+1.....on both counts!

 

[Geno1112]

I shoot only cut rifling barrels in competition, and some of them take up to 8 shots to settle down until they group well from a clean barrel.