Cold barrel shot always a flyer.

My M77 Hawkeye "All-Weather" 308 groups around an inch at 100yds. However, with it sighted in @100yds the first shot hits 4" high at 1:00, then the rest are right in there. If I let the (now dirty)barrel cool for 15 minutes, first shot will hit at 1:00 again.
Can I adjust a screw somewhere or do something with the plastic stock?

Cold barrel shots are often "off". Jack O'Connor used to tell of an old friend who said he only fired "one shot" groups. He'd go to the range and fire one shot from a cold barrel on different days and use those to determine where a bullet was going to hit when fired - from a cold barrel - on an actual hunt. Not normal, though, to be that (4") far off!

One of my neighbors had a Savage that did that.
Turned out to be the barrel. Something was wrong with how the steel was made.

Me myself, I've found that while properly bedding the stock may not fully cure a "cold shot" problem, it will often greatly reduce how far from the group the fliers will be.

DGW

I agree,the bedding is the next step in the journey if you want to fix it.
The three B's of accuracy are barrel , bullet and bedding. I think you can rule out the bullets as you get great groups after that first shot. That almost always means the barrel is OK also. That leaves bedding, or something is moving or loose. Have you tried another scope on it? Rings and bases tight?
I had a Rem. 700 .243 that did that before glass bedding the recoil lug and freefloating the barrel. After that it was dead on every shot, clean or dirty,
Hot or cold. Good luck and let us know what you find.

Check the barrel to stock fit when it's cold and after the barrel is hot. If the barrel is not floating when hot or has a tight spot to the stock this may be you issue! Good luck! George

George said:

Check the barrel to stock fit when it's cold and after the barrel is hot. If the barrel is not floating when hot or has a tight spot to the stock this may be you issue! Good luck! George

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+1 - lots of times folks think because a rifle has a synthetic stock that the action and barrel are automatically "bedded" properly but that's not always, maybe not even often, the case.

OldePhart said:

George said:

Check the barrel to stock fit when it's cold and after the barrel is hot. If the barrel is not floating when hot or has a tight spot to the stock this may be you issue! Good luck! George

Click to expand...

+1 - lots of times folks think because a rifle has a synthetic stock that the action and barrel are automatically "bedded" properly but that's not always, maybe not even often, the case.

Click to expand...

Absolutely true!

I just noticed the same thing this year after forty years of revolver shooting. It is....a great idea to sight in at the temperature that you wil hunt in and use the first or fouling shot to set your sights.
The first round will usually be close by, but outside the others at the ten o'clock position. A different twist rate or direction might get you something different, but it may be consistent for that gun.
For my load research and accuracy testing of cartridges. I load four and document the spacing of the remaining three.....not all will agree, but it is fast and will get you in the ballpark quicker. You can always go back out and try to proove the results wrong.
Question is....which chambers to load, though always the same ones.
There are differences in throat dimensions in the same cylinder of many revolvers. Those can be found with plug guages and remedied. Testing which chamber aligns best with the bore of factory guns can take a lot of testing. Line boring is worth the extra money if you worry about such things.
My New Model Flat top .44 spl and my stainless .45 combo are very very good with all of this. I wish my SP101s were too.

Is that first shot from a clean barrel? I can live with a 1st shot variance of an inch or so but not 4".
I'm retired and have my own range right outside the yard gate so my methods may not be do-able for others. After I have my rifles zeroed, I shoot one shot a day for 3-4 days to get that cold bore zero. Then I clean the bore and shoot one shot per day if it looks like that is going to be a problem. I want to know where that first bullet is going to land with various scenarios. I already know where the POI will be from a warm,dirty bore from the original zero session. I will often add the use of a bore snake to the mix(1 or 2 pulls) just in case I get caught in rain/snow and need to wipe the bore.