Cold barrel-warm barrel

[Pyno&dyno]

I am just beginning to test the performances of my1917, when the barrel is warm the gun is very precise, my problem comes when the barrel is cold, the POI is higher about 2,5" and gradually decrease with the following shots, actually I use the following reloads: 55grs of IMR4350, lapua167 scenar moly, CCI br2, Sellier&Bellot brass. Is there any way to contain or eliminate the problem or should just try to controll it by using leaner starting shots?

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[kragluver]

Clean, cold barrels on average will typically shoot higher than a hot, fouled barrel. Your M1917 is not unique in this regard. A lot of people I know at the range only test their handloads in clean/cold barrels - i.e., they clean after every shot and let the barrel cool. I've never gone to that extreme.

All my rifles will do as you described. The first shot is usually an inch or two high at 100 yds. They group well after that. I always throw the first shot out of the group when load testing. I also use the Optimal Charge Weight (OCW) method of shooting one of each test load at a target and rotating through all the various loads. That way, each test group is equally affected by barrel heating and fouling.

[browningautorifle]

In the Canadian army we used to fire two warming shots before zeroing. ????

[emmagee1917]

I would figure it tends to be colder up there , so maybe it takes two to reach " operating" temperature?
Chris

[jmoore]

I would figure it tends to be colder up there , so maybe it takes two to reach " operating" temperature?
Chris

In Italy or Canada?


Zero shift can be influenced by quite a few factors- have you ensured the bore and chamber are perfectly free of oil before shooting? Do you disassemble your rifle between trips to the range?

Sometimes there's not much you can do about cold bore POI changes except to learn the rifle, though.

[Pyno&dyno]

Does the barrel pressure on the stock have any influence? Because in competition are not allowed warm up shots, I guess will have to learn how to compensate

[kragluver]

As previously mentioned, condition of the bore at the cold shot (oil, cleanliness, etc) and stock bedding can make a significant difference where the first couple shots go.

NRA High Power competitions allow two sighting shots not only for sighting purposes, but to also foul and heat the barrel.

There is good reason to know where your first "clean/cold" shot will go as that is typically the condition of the bore in a hunting scenario.

[Calif-Steve]

I was at Perry in the Vintage Match when my M1917 started climbing off the target. I had about 20 rounds into the match when all of a sudden I was a goner. The barrel was a JA 2 groove barrel and when I got back from Perry I sold the rifle. Pity, a near mint bore, but a disaster after 20 rounds.

[Dan Wilson]

Yes the upward pressure on the barrel has a lot to do with the accuracy, but it seems at 5 lbs your stock is right on where it needs to be.
You are probably going to have to learn to compensate that first shot during a match unfortunately.