what causes cold shot flier? weird gun

[okie]

I'm trying to iron a problem out for a friend. model 70 hvy #7 bbl, fully floated stock--the cold shot at 100 is always about 2 inches from the 2nd,3rd,4th etc. The weird thing is that after this "cold" or first shot, the gun shoots very well---until it cools off. any suggestions?? thanks in advance.

 

[6BRonwheels]

Hi Okie,
Have you checked the action screws?
Good luck,
Jack

 

[okie]

yeah-tried running both tight,I think 45 in) and tried leaving rear one loose-- does same thing-- looking for another stock now to try it with---I thought about clamping barreled action in a rubber jawed vise to try to see if it does it without a stock period---I'm a 700/clone man but the action is similar--this has got me purplexed? Exactly what could be heating up other than the chamber/throat in one shot????? stress in barrel or chamber??? maybe someone who has had similar experience will chime in.

 

[Forum Boss]

2" is a lot. Swap scopes and see if that makes a difference.

And, make sure the barrel is rotated tightly in to the action.

 

[okie]

scope changed out when it was first noticed---it is very repeatable---at least in 50degree F or cooler temps.,we're waiting for it to warm up to try at hotter temps) It puts firstshot 2in. to the side and then will stack three or four more in the same spot??---this group is really tight---leave gun for 30 min. and it will print back where the first flier is. barrel is tight---could it be too tight or bound up somehow??

 

[mikecr]

How many shots does your friend need?
If one then;
How does it group at 1shot per hour?
If he needs 5 then;
The first shots a warmup/fowler...

 

[okie]

yeah, thought it would make a good prairie d. rifle---just shoot one up close, then go to work on em. But it won't work for a longer range hunting rifle. thanks anybody know what I'm overlooking???

 

[treeman]

I've noticed that before with 22 lr but never a center fire except from a clean barrel first shot. may just be the barrel.let us know if you find out something.
treeman

 

[RDavies]

I notice it all the time with my various F class barrels. If the barrel has just been cleaned, the first shot will be low,.5 - 1moa) due to velocity being approx 50-100 fps lower, caused by a clean slippery barrel. The 2nd shot will usualy be .3-.5 moa lower then all in the group.
If the barrel is alreay fouled, the 1st cold shot will be higher, I am thinking due to the powder residue hardening, causing higher pressures. This is enough of a problem, that when I am shooting F class, if I have to stop shooting for a cease fire for a few minutes, my next shot wil be a bit high if I dont hold off a bit.
This is with 5-6 different barrels from 22 to 30 cal, but I dont get as much variation as you, maybe as these are custom match barrels.

 

[okie]

it is a custom made by an excellent barrel maker--I have several and they all shoot better than me. It looks perfect in the hawkeye. It does it with a fouled bore---the gunsmith has collaborated with the barrel maker and they have decided to set back and rechamber, and turn a few more threads--they're thinking maybe the threads are bound up or some kind of stress in this area..??? it's too cold in his shop to do anything now.

 

[mikecr]

What are you going to use the gun for?

 

[okie]

looks like it will be used for prairie dogs---I wouldn't trust it for a crow or coyote gun.

 

[glo]

I had this problem with my M70. I lived with it for 20 years. In my case it was both the first and second shots. No one could ever figure it out. I found out while building another rifle, it was the chome-moly barrel. I solved the problem by having the barreled action cryoed.

My gunsmith, James Houge identified the problem as we spoke about a barrel for the,then) new project. Jim says, “moly barrels have memory like an elephant”.

 

[okie]

glo---so after the first two off shots, it shot well?