HELP ! Cold bore vs Warm in Hunting Rifle

[bubbaonpc]

What's going on? First shot out of my cold hunting rifle is PERFECT. Inch and a half high at 100 yards. The next shots, 2-3-4-5 are high right and about a 3-4 inch group. I can let the rifle sit, pick it up cold the next day and PERFECT shot, next shots are high right. I've changed nothing from last year. Same powder, same box of bullets, primer, brass ect. I even double checked OGIVE. I've heard of "one shot rifles"...but it was perfect last year. I'm not on the edge of twist rate...bullet weight...but I am shooting Reduced Loads for Wife. 1-10 twist .308, 165 gr RL15 41gr at 2500 FPS, .02 off lands. I would think "SCOPE" if it wasnt dead on when cold the next day. Any Thoughts ?

 

[dfanonymous]

I don't see the issue...your rifle has a cold barrel shot...that happens to be perfect. Cold barrel deviation is a thing. I know the argument that "it's not a cold barrel, it's a cold shooter" that causes deviation and sure...but as far as internal ballistics are concerned some rifles have cold barrel shot deviations. The only concern is the 3-4 inch group. Did you get a SD an ES on this load?

 

[robert l]

What's going on? First shot out of my cold hunting rifle is PERFECT. Inch and a half high at 100 yards. The next shots, 2-3-4-5 are high right and about a 3-4 inch group. I can let the rifle sit, pick it up cold the next day and PERFECT shot, next shots are high right. I've changed nothing from last year. Same powder, same box of bullets, primer, brass ect. I even double checked OGIVE. I've heard of "one shot rifles"...but it was perfect last year. I'm not on the edge of twist rate...bullet weight...but I am shooting Reduced Loads for Wife. 1-10 twist .308, 165 gr RL15 41gr at 2500 FPS, .02 off lands. I would think "SCOPE" if it wasnt dead on when cold the next day. Any Thoughts ?

Maybe speed the load up a little. Or have you cleaned the barrel really well.

 

[LongWalker]

My primary hunting rifle has a different POI on a clean cold bore shot than a fouled barrel cold shot. About an inch high and left. Drove me crazy for a bit and now I put about 20 down the tube then go back to the range the next day to confirm. As long as it's fouled it's dead on.

 

[bubbaonpc]

I don't see the issue...your rifle has a cold barrel shot...that happens to be perfect. Cold barrel deviation is a thing. I know the argument that "it's not a cold barrel, it's a cold shooter" that causes deviation and sure...but as far as internal ballistics are concerned some rifles have cold barrel shot deviations. The only concern is the 3-4 inch group. Did you get a SD an ES on this load?

5 shots in order...2500..2505...2513...2508...2487. I'm happy with first shot..should be all she needs. It just baffles me why it changed from last year. Sub MOA 5 shot gun last year. Pain in *** waiting for barrel to cool. Maybe 50 shots since new...shouldnt need good cleaning??? Maybe I'll speed em up a bit?

 

[bubbaonpc]

Maybe speed the load up a little. Or have you cleaned the barrel really well.

50 shots since new...shouldnt need good copper cleaning??? I'll try your suggestion...along with others... I'll clean it good...I'll speed em up and get the barrel fouled and see. Shot like a dream outta the box...maybe it likes a clean bore. Thanks for your help !

 

[bubbaonpc]

My primary hunting rifle has a different POI on a clean cold bore shot than a fouled barrel cold shot. About an inch high and left. Drove me crazy for a bit and now I put about 20 down the tube then go back to the range the next day to confirm. As long as it's fouled it's dead on.

Thank you. My 204 Ruger shoots better after fouling barrel.

 

[PBramble]

I've had rifles that take about a hundred rounds to settle in. Factory rifles are different critters than customs. I've had to run them slightly hot to get them shoot. I'm in the 47 grains of Varget neighborhood.

 

[emp1953]

Further on you say there's maybe 50 shots through this rifle. Shoot it some more. Some barrels need 80-100 to break in. So you haven't removed the stock to clean the rifle. Since it is fairly new, did you mount the scope or did it come with the scope mounted. If the latter, recheck their work. Depend on yourself, not the guy in the store, or factory.

 

[RetiredSniper]

What's going on? First shot out of my cold hunting rifle is PERFECT. Inch and a half high at 100 yards. The next shots, 2-3-4-5 are high right and about a 3-4 inch group. I can let the rifle sit, pick it up cold the next day and PERFECT shot, next shots are high right. I've changed nothing from last year. Same powder, same box of bullets, primer, brass ect. I even double checked OGIVE. I've heard of "one shot rifles"...but it was perfect last year. I'm not on the edge of twist rate...bullet weight...but I am shooting Reduced Loads for Wife. 1-10 twist .308, 165 gr RL15 41gr at 2500 FPS, .02 off lands. I would think "SCOPE" if it wasnt dead on when cold the next day. Any Thoughts ?

I went through this years ago with the Remington 74 and 76. First shot dead on out of both then the shot would walk up the target after that. My best guess was the lighter barrels were warming up and point of impact was changing. I went the a heavier barrel 308 with 165 grain bullets and have no problems any longer!

 

[Just an Old Cowboy]

Over the years, I've had a number of customers bring their rifles into the shop complaining about poi shift after the first round. It can sometimes be caused by a pressure point in the barrel channel causing a shift as the barrel heats and expands. Another potential area is improper bedding which again causes pressure points because of heat expansion when fired.
The third thing I find that causes this problem is stress in the barrel and action from cutting and machining, most particularly in factory rifles.
I've sent a number of these to 300 Below for cryrogenic treating, and had excellent results in either eliminating, or greatly reducing poi shift, and in many cases accuracy has also been improved, as a result of relieving these stresses, and the cost of this process is relatively inexpensive for the result.
Hope this helps give a little insight of a few areas to start looking to resolve your issues. One or a combination of these three things will almost always resolve this problem.

 

[maximini14 223]

Try shimming up the barrel at the fore end of stock. Cut pcs of credit card to fit in barrel channel. Shoot a group, add a shim. Shoot a group add a shim and see if that helps.
But check scope bases and rings for uniform tighness first before changing anything

 

[Radman]

What's going on? First shot out of my cold hunting rifle is PERFECT. Inch and a half high at 100 yards. The next shots, 2-3-4-5 are high right and about a 3-4 inch group. I can let the rifle sit, pick it up cold the next day and PERFECT shot, next shots are high right. I've changed nothing from last year. Same powder, same box of bullets, primer, brass ect. I even double checked OGIVE. I've heard of "one shot rifles"...but it was perfect last year. I'm not on the edge of twist rate...bullet weight...but I am shooting Reduced Loads for Wife. 1-10 twist .308, 165 gr RL15 41gr at 2500 FPS, .02 off lands. I would think "SCOPE" if it wasnt dead on when cold the next day. Any Thoughts ?

Perhaps you are doing what I had to learn for myself after a wasting a lot of time and ammo. IMO: if you are a hunter Zero on that cold shot! If you are a target shooter don't worry about your first shot, then Zero on anything after that first shot. It made a world of difference for me. There are others here who can better explain it but I do know it has to do with things like copper smearing your rifling and barrel crawl. (Me personally? The latter was always much more evident with a stainless barrel than with black.)

 

[RAGGED EDGE]

Exactly what rifle are we talking about?