Cold bore shift - help

[nomoa]

First, I'm new to bolt rifles. So please go easy on me.. and I appreciate anyone taking the time to share their knowledge.

I am trying to sight in a new rifle for a cold bore, as the immediate use is for hunting. Hopefully some long range in the future. (Bergara HMR Pro - 300 Win Mag/Nightforce NX8 4-32).

My question is to ensure a cold bore, has anyone used a hand-held blower like the wolfbox (picture below) to blow air through a rifle to cool it quickly? I assume this is fine for the metal, as they heat up quickly so they can probably cool quickly as well..?

I am limited to an outdoor public range with 15min on/off Shooting and a 1.5hr time slot.. So every cold shot is critical. Not to mention i may only get there one more time before the season begins.

 

[spife7980]

I use a fan to cool my barrel in the down time, it’s worth it. Use it.
To get to true cold bore takes time, period. But the fan can keep you away from scorching.

 

[db2000]

Also decide are you going to come bore a clean barrel or have 10 or so shots fired through it when you take it hunting. Once you decide on the specific load or factory ammo you’re going to use you just have to have a true cold bore shot. Unless you’re shooting shit at 500+ yards don’t overthink it. You probably have a decent sized area to hit.

 

[nomoa]

I was not planning on a completely clean barrel. I would call it the equivalent of pulling a dry bore snake through it after a few rounds. Will keep it consistent.

Thanks for the advice. Im currently getting a 1/2" group with a hornady round. I tried a few, remmington and Winchester gave me a 1.5" group

 

[Supersubes]

First, I'm new to bolt rifles. So please go easy on me.. and I appreciate anyone taking the time to share their knowledge.

I am trying to sight in a new rifle for a cold bore, as the immediate use is for hunting. Hopefully some long range in the future. (Bergara HMR Pro - 300 Win Mag/Nightforce NX8 4-32).

My question is to ensure a cold bore, has anyone used a hand-held blower like the wolfbox (picture below) to blow air through a rifle to cool it quickly? I assume this is fine for the metal, as they heat up quickly so they can probably cool quickly as well..?

I am limited to an outdoor public range with 15min on/off Shooting and a 1.5hr time slot.. So every cold shot is critical. Not to mention i may only get there one more time before the season begins.

Have you determined that you have a cold bore shift to begin with?

 

[Baron23]

Chamber Chiller

Chamber Chiller - the ultimate rifle barrel and chamber cooler. Designed to prolong barrel life and help maintain your rifles accuracy potential.

www.chamberchiller.com

Works good and doesn’t make that high keening sound like many others.

 

[nomoa]

Thanks for all of the help!

I'll get out and see if I get a shift with cold / warm/ hot bore.

I decided to print a chamber fan shroud and have ordered a fan off Amazon. I did not know this was a thing..

I appreciate everyone's time!

 

[trob]

I was not planning on a completely clean barrel. I would call it the equivalent of pulling a dry bore snake through it after a few rounds. Will keep it consistent.

1) shoot a fouled barrel. It’s typically more consistent. I will shoot hundreds of rounds without cleaning as long as it is still shooting well.
2) ditch the bore snake. That’s for AR’s. Get a quality rod and bore guide

I like the effort, but you’re thinking too much. Keep it simple.

 

[Wannashootit]

I am limited to an outdoor public range with 15min on/off Shooting and a 1.5hr time slot.. So every cold shot is critical. Not to mention i may only get there one more time before the season begins.

Have you mounted your optic, and boresighted the rifle? With only one, short range trip available you don't want to be wasting time getting on paper. You should be able to boresight at your house to get the first shot on paper at 50 then immediately move out to 100 (assuming that's where you want your zero).

 

[tacoman69]

I'll get out and see if I get a shift with cold / warm/ hot bore.

you wont. shoot a big enough sample size for a solid zero and your cold bore will fall in that cone. its not a thing with good barrels

 

[waveslayer]

What cold bore shift?

 

[JerkyFreak]

From conversations I've had with quite a number if people, most confuse a clean bore shot with a cold bore shot.

I still maintain that if you have a POI shift due to a cold but fouled bore, there is something wrong with the rifle or you.

Clean bore shift is a thing; usually either high or low depending if the bore is either clean and dry or slightly oily.

 

[nomoa]

Have you mounted your optic, and boresighted the rifle? With only one, short range trip available you don't want to be wasting time getting on paper. You should be able to boresight at your house to get the first shot on paper at 50 then immediately move out to 100 (assuming that's where you want your zero).

Mounted and boresighted. I was 2" low at 50. Then moved out to 100 and adjusted from there. This was the best out of 6 different factory rounds. Then adjusted 1.5 down and .5 left.

 

[nomoa]

you wont. shoot a big enough sample size for a solid zero and your cold bore will fall in that cone. its not a thing with good barrels

I always thought it was all firearms.. that's why I'm here... to learn from the pros!

 

[nomoa]

From conversations I've had with quite a number if people, most confuse a clean bore shot with a cold bore shot.

I still maintain that if you have a POI shift due to a cold but fouled bore, there is something wrong with the rifle or you.

Clean bore shift is a thing; usually either high or low depending if the bore is either clean and dry or slightly oily.

Thank you for this... I think this is where I am still confused a bit. If I have 20-50 rounds through the rifle I have been pushing a nylon brush 1-2 times and 1-2 patches..

This is what I intended above where I said the equivalent of a bore snake.

Is this too clean? Should I let it go 100-200 or until I see a change?

In the moment I'm looking to get a deer. Here in AZ shots can be longer. But I am hopefully going to be getting into 300-1000 yard shooting within a year or so.

 

[nomoa]

you wont. shoot a big enough sample size for a solid zero and your cold bore will fall in that cone. its not a thing with good barrels

Would you consider bergara hmr pro to be "good" enough? I feel this was the best my budget allowed, but everyone's "good" and everyone's budget is different.

 

[JerkyFreak]

Unless you are shooting competitive benchrest or have a really bad barrel where fouling increases group size, you do not need to brush and patch very often.

A good rule is to put your rifle in the safe clean. When you go hunting, shoot 2 to 3 shots to check your zero at the start, then only clean again when the hunt is finished. If, for some reason, you believe you need more than 3 shots from clean for the barrel to shoot to point of aim, it is time to change the barrel.

 

[Skeptic1]

I had a rifle that seemed to throw the first shot every time. I bedded the stock to the barrel. I think i remember using Devcon. This resolved my issue. I expected that someone would have mentioned bedding the stock. Chassis systems are pretty popular now. I don't think bedding is necessary when using a chassis but I'm not sure.