Cold bore flyers

[teamja2]

Was out doing final checks on sighting in deer rifles this weekend and noticed cold bore flyers fromboth Remington 700's one in .270 and the other in 300 mag. On the .270 it was about 1" lower and.5" left. Next 3 shots 2 touching and one about 1/4" away. 300 mag shot 2" low 2" right from the next 3 which cut a nice connected line. Both rifles bedded and shoot well but never noticed the flyers before

450 bushmaster first 3 within 1" 2 touching. No coldshot flyer. Was doing great until mount shot moistens groups went to 6" plus. Got it tightened back and sighted so it's ready.

My question is what causes cold shot flyers. Is it fixable.

[slash2]

Are your cold bore shots from a clean barrel or a fouled barrel?

[teamja2]

Rifles have dirty bore.

[slash2]

Rifles have dirty bore.

That shoots my theory down, but then if I had reread your post and noted that you're cold bore shots are hitting lower than you're subsequent shots, I wouldn't have opened my mouth. My cold bore shots from a clean barrel are always higher than the subsequent shots.
Clean bore, less friction, higher velocity, less time to target, less drop, higher point of impact. But then again, maybe it's clean bore, less friction, less pressure build up, lower velocity, longer flight time with more time to drop, lower point of impact. I dunno, hurts my head thinking about it.

[Hoot]

Rifles have dirty bore.

That shoots my theory down, but then if I had reread your post and noted that you're cold bore shots are hitting lower than you're subsequent shots, I wouldn't have opened my mouth. My cold bore shots from a clean barrel are always higher than the subsequent shots.
Clean bore, less friction, higher velocity, less time to target, less drop, higher point of impact. But then again, maybe it's clean bore, less friction, less pressure build up, lower velocity, longer flight time with more time to drop, lower point of impact. I dunno, hurts my head thinking about it.

Actually, in a powder/bullet combination where you need resistance to bullet travel down the barrel to drive up the pressure and hence the velocity, the resulting shots do not get up to speed on a cleaned, oiled barrel until your fouling shot burns and scrapes that off. My experience has been the fouling shot almost always goes low and slightly off to one side or the other. It's obviously an anecdotal observation as it varies from one person to the next and that makes declaring an absolute conclusion nigh impossible. Also, if he had said his barrel was not bedded and free-floated, my first guess would be temperature walking from expansion. In that case, dirty or clean is not the arbitrating factor. Those kind of issues are confidence killers when hunting on a cold morning as you never feel sure the first shot, which is often an important one, will go where you want it to.

Hoot

[teamja2]

Thanks all for the input - not overly concerned but if it was something easy I would look into it. Have to say the 450 did not experience the concern. May have to hunt with it this year.

[MOUNTIN DU]

ditto what hoot sed... i always store my guns with wet bores. about a month before the season, i dry patch them well several times over the next couple weeks. i make my fouling shot on paper and then dry patch and let gun rest several hours. i follow up with a confidence shot and dry patch again. my gun is ready for hunting. subsequent shots during the season get "dry patched" only; after each shot. i've never seen 1st shot flyers using this method.
personnally i'd never fire a shot down a wet bore... especially with hot loads. i've seen extreme pressure signs on spent cases, from "knuckleheads" at the range, thinking a well oiled bore contributes to accuracy. in fact, just the oposite is the case. even a fine film of oil on the bore surface will pile up in front of the bullet's bearing surface as it screams down the barrel. this effect actually causes an "over run" or "hydraulic wedge" condition as the bullet out runs the oil wedged between it and the bore. almost always, the pressure signs can be seen on the cases. most often though, it's the unseen effects of "wedging" that cause the bullet jacket wall to distort as the bore diameter is redused momentarilly when the bullet "over runs" this wedge producing a less than perfect bullet to bore contact for the rest of it's trip down the barrel. worst case scenario, this can leave pressure dimples in the bore, especially in featherweight barrels. if you've ever slugged a barrel before you know what kind of pressure we're dealing with here. now, imagine slugging it in a micro second at pressures of 50,000+psi. scarey stuff
it's been my experience that there's only one way to work with a cold barrel flyer... and that's sight it in cold!
i've had a browning lever action 308 with a 4x leupold scope for over 30yrs, that's a one shot gun! i've taken more deer with it than all my other guns combined. but it will not put two shots together at 100yds. it's so temperature sensative, that i had to shoot it (from a solid rest) make my scope adjustments and put it away until my next shooting session and repeat the process until it would shot point of aim at 100yds with the first shot. needless to say, this was very time consuming, but i can pick it up tomorrow and know it will hit within a 2" bullseye at 100yds on the first shot. not a tack driver but a killin' machine non-the less. for this reason i have only one handload developed for it using a 150gr Speer Grand Slam.

good luck... and post your results.

[teamja2]

Thanks all. I read " sight it in cold " and thought to myself sight it in for shot 2 or 3 the way the last few seasons have gone. Have a tendency to have to shoot more than once - 2 years ago that meant group of 5 deer that ran right at us ehen walkin across a pasture and between father in law and me we tagged out (3 total). Last year that meant shooting 3 times but hitting poorly 1 of the 3.

I'll let you know after season how it wOrks with dry patching just don't have time to start over this year.