Cold bore shot load development.

[cjmac]

So i have a new factory barrel hunting rifle that was given to me . Ruger American in 308 . Never worked up a load for a thin wall factory barrel before . I mentioned a few times I'd like to have a cheap light weight scouting / hunting rifle and this was given to me lol ..
I want to have a consistent cold bore shot that will land within 1.5in radius at 100 yards . I have some 165 Sierra game king btsp and varget powder . How do I work up a load that will give good cold bore shots ? Done plenty of load development on heavy barrel guns but only worried about tye groups not the cold bore shot .. thanks !

 

[dryhumor]

You might load a span of charge weights, and have several targets to shoot one cold bore shot at each trip. Make notes of temperature, wind, RH, time of day, etc for each shot along with charge weight on the target.

 

[Bill Norris]

So i have a new factory barrel hunting rifle that was given to me . Ruger American in 308 . Never worked up a load for a thin wall factory barrel before . I mentioned a few times I'd like to have a cheap light weight scouting / hunting rifle and this was given to me lol ..
I want to have a consistent cold bore shot that will land within 1.5in radius at 100 yards . I have some 165 Sierra game king btsp and varget powder . How do I work up a load that will give good cold bore shots ? Done plenty of load development on heavy barrel guns but only worried about tye groups not the cold bore shot .. thanks !

Cold bore shots are not actually controlled by the load per say. IMO each rifle has it's own approach to cold bore shots. Not to say that changing the load may or may not help the cold bore shot to be more closer to the group but I'm not so sure that would completely control the cold bore shot as things do change concerning the rifle and not load related.

 

[jmkasza]

For my Tikka t3 in 308, I did my load development then set zero with a cold bore. Why over complicate the ole deer getter?

 

[TSFineGuns]

For my Tikka t3 in 308, I did my load development then set zero with a cold bore. Why over complicate the ole deer getter?

This. Right. Here.

 

[CJ6]

I do 3 shot groups, noting the impact of the 1st round with sporter barrels. As mentioned above keep track of the atmospheric conditions and try to do your load development in the temp range you plan on hunting in.
With a good load you'll rarely be more than a 1/2" out of center.

 

[cjmac]

For my Tikka t3 in 308, I did my load development then set zero with a cold bore. Why over complicate the ole deer getter?

How do you do your load development for a thin barrel hunting rifle?

 

[cjmac]

I do 3 shot groups, noting the impact of the 1st round with sporter barrels. As mentioned above keep track of the atmospheric conditions and try to do your load development in the temp range you plan on hunting in.
With a good load you'll rarely be more than a 1/2" out of center.

Shoot 3 shot group , let cool completely then repeat?

 

[Doom]

Cold bore is somewhat of a misnomer. While temperature is part of the equation, what can be the greater influence is a clean and/or lubricated barrel. Try and not hunt with the barrel in that condition.

 

[Bill Norris]

Cold bore is somewhat of a misnomer. While temperature is part of the equation, what can be the greater influence is a clean and/or lubricated barrel. Try and not hunt with the barrel in that condition.

Non-floated barrels vs. amount of action screw torque can hamper the cold bore shot as well.

 

[B Nettesheim]

Try 3 shot groups but an hour between each shot
Hopefully you have time on your hands

 

[jmkasza]

How do you do your load development for a thin barrel hunting rifle?

3 shot groups, plenty of time in between for the barrel to rest. I usually do this when I have half a day to spend at the range and bring a few other guns along to stay active. Most of my 22lr practice sessions is on a break during load development.

 

[cjmac]

Cold bore is somewhat of a misnomer. While temperature is part of the equation, what can be the greater influence is a clean and/or lubricated barrel. Try and not hunt with the barrel in that condition.

I normally foul the barrel before I hunt. Learned that the hard way on targets lol

 

[Sandstorm]

I use Lock-Ease on my barrels after I clean them as my last patch and my cold bore shots land in the same place as my competition shots...so really no cold bore at all anymore. The Graphite and alcohol in the liquid
in a well soaked patch seems to help with the cold bore shot placement for me.
YMMV. however so testing on your equipment required and may not work on all barrels..don know.?

 

[CJ6]

Shoot 3 shot group , let cool completely then repeat?

Yes.
I also cleaned the bore between groups. This is how I'd take a hunting rifle hunting (clean bore ). Everyone has their opinion on the cleaned bore vs fouled, I prefer a cleaned bore.

 

[Orr89rocz]

I’ve done two shot groups as of late to save components. Thin model 7 barrel and also my super grade model 70. Couple of sporter type barreled 338 win mags. It gets hot after two shots.
Need cooler days to do this and a barrel cooler helps. Also can bring a cooler with a towel in ice to help bring barrel down faster.

When working thru charge weights i note the best two shot groups. Revisit with 3 shots. It takes a while. If it repeats thats what i load with, may play with seating but depends how accurate you need this to be? I also may shoot a rapid group to see how heat affects the group.

 

[cjmac]

I’ve done two shot groups as of late to save components. Thin model 7 barrel and also my super grade model 70. Couple of sporter type barreled 338 win mags. It gets hot after two shots.
Need cooler days to do this and a barrel cooler helps. Also can bring a cooler with a towel in ice to help bring barrel down faster.

When working thru charge weights i note the best two shot groups. Revisit with 3 shots. It takes a while. If it repeats thats what i load with, may play with seating but depends how accurate you need this to be? I also may shoot a rapid group to see how heat affects the group.

If i can get my cold bore shot to land within 1or 1.5 in radius of zero at 100 it will be fine . Just need to find a consistent load first probably. But never done load development for a thin lightweight barrel before . Seems like 2shots will group good but not 3 or 4

 

[Orr89rocz]

If i can get my cold bore shot to land within 1or 1.5 in radius of zero at 100 it will be fine . Just need to find a consistent load first probably. But never done load development for a thin lightweight barrel before . Seems like 2shots will group good but not 3 or 4

You certainly can get 3-4 shots to group. It just can take a while for the gun to cool abit depending on ambient obviously. I just look for sub moa type accuracy and if two arent close then three is gonna be a waste lol

 

[cjmac]

You certainly can get 3-4 shots to group. It just can take a while for the gun to cool abit depending on ambient obviously. I just look for sub moa type accuracy and if two arent close then three is gonna be a waste lol

Say I load 3 rounds for each charge weight .
Would you let the barrel cool completely between all 3 rounds ? Or try to just group the 3 slowly

 

[Orr89rocz]

Up to you, kinda need to see how the gun behaves. Generally i shoot slow. And feel the barrel to get an idea when i can shoot again. Note where the cold first shot of the day goes relative to the others. Wait a few min between shots esp for shot 3 as two shots will warm the barrel up a good bit. Use a barrel cooler and try to keep barrel a consistent temp. You could even get scientific with it and get a temp gun lol but i shoot next round when the barrel feels relatively cool for me. It sucks cuz it takes a while esp on warmer days but i try to do development nearer the temps i expect in hunting seasons.
But 98% of my hunting is 120 yards and in. Single hole target groups dont apply here. The other guns i use for field hunting 300-700 yards is possible and it matters wayy more there