forearm screw


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pre'64 Dan
May 10, 2006, 02:17 PM
I have some 3/4 inch loads worked up for my 1949 model 70 30.06...why does the first shot (no matter what) shoot 2 inches high? The only thing I can think of is the front screw. can anyone help? Thanks:fire:

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Thefabulousfink
May 10, 2006, 02:29 PM
I assume that after the first shot the rest drop 2" and group in 3/4". Is your barrel the factory stock or have you added a bull or fluted barrel? On many rifles the POI (point of impact) will change as the barrel heats up. When I shot small-bore rifle in college, we would put 3-5 "sighting rounds" through the gun before we began shooting at the scored targets. Most of our groups would shrink by half once the barrel got warmed up.

My other question is does the first shot hit the same place every time or is it a 2" group? If it is allways hitting 2" high at 12 o'clock, just remeber that and adjust your sights/scope up for your "cold shot" then adjust them down once the barrel is warm.

USSR
May 10, 2006, 02:43 PM
I have some 3/4 inch loads worked up for my 1949 model 70 30.06...why does the first shot (no matter what) shoot 2 inches high?

pre'64 Dan,

That's what's known as your "cold bore shot". Now you know why sniper rifles have heavy contour barrels.

Don

pre'64 Dan
May 10, 2006, 02:45 PM
it is always the first and maybe the second shot. I'm figuring that is a cold barrel problem, but have been told it's probably the front screw. I don't mind shooting at the range, but try to get a deer or elk to understand that I need to compensate. My other 70's have never had this problem. I am loading 53.3 grains of IMR4350 behind a 180 grain partition standard winchester primers, federal brass. thanks again:banghead:

Thefabulousfink
May 10, 2006, 02:58 PM
Do some reading on snipers (especially police and swat), they allways have to make a cold shot and make it hit (no time for warm-up shots in a standoff). They practice by sighting their rifles for that first shot and let their guns cool down between each shot. If you are going to do a lot of target shooting or range shooting then sighting your gun for warm barrel shots makes sense. However, the first shot is the one that matters for snipers (and hunters) so sight your rifle where that first bullet goes.

Sharps Shooter
May 10, 2006, 04:05 PM
Is your "first shot" always through a clean barrel?

hoghunting
May 10, 2006, 04:15 PM
Do you clean your rifle after each range session? Do you oil your barrel after cleaning? The first shot could be off because of oil or cleaning solvent in the barrel. Even pushing a dry patch won't remove all the solvent or oil, but it gets out the excess. The first shot usually takes out the oil or solvent.

Onmilo
May 10, 2006, 06:15 PM
Cold barrel, clean bore, dirty bore,,,,,

This is where cyrogenic treatment really shows its value.
Barrel stress is different between your cold shot and your subsequent shots.

Cyrogenics coupled with firing from a prefouled bore has been shown to improve the ability of the first shot to hit point of aim.
These two things remove the most problomatic variables or at least reduce those variables to inconsequential levels.

Some serious shooters have taken the science to the level that they can shoot first shot point of aim, point of impact from a clean bore, a fouled bore, or a smoothbore,,,, ok,,,,just kidding on that last one.

Clean bore shooters tend to mirror finish the lands and grooves with hand lapping and careful measurement.
Runout and dimensions on their barrels run .0005" or less.
Pretty amazing really.
If you watch them on the line, they decopper the barrel every three shots.
Some decopper every shot.
Worse than black powder shooters in fastidiousness but the groups they cluster speak for themselves.

Chawbaccer
May 10, 2006, 08:02 PM
Back the screw out and float the barrel with a piece of card under the action see if that helps.

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