UPDATE 300 win mag better accuracy

[NW-GSP]

So I was finally able to get out and shoot my 300 win mag off a bench rest.
 
When I first got there I shot two three shot groups at 100 yards both groups were right at if not under 1inch then my girlfriend shot a three shot group that was a little over 1inch. I did not let the gun cool down so when I went to shoot another three shot group they were all about six inches high and to the left by 8 inches.
My first thought was that the scope got bumped but then I thought about the gun heating up and that it might cause problems. I waited ten minutes and shot again and the gun shot the same three inch group that I had shot when I first got there.

is this caused by heating and the barrel touching the stock? Would pillar bedding help? It is a synthetic stock by the way.

I also shot at 200 yards but my shots were were low left and really no grouping

[addicted]

all rifles will change poi if they heat up. bedding be damned.  the stock is synthetic so it wont swell as much as wood which doesnt swell that much at all under normal shooting conditions.

pillare or glass bedding might help lock the action and stock together making it stiffer and more accurate though. 

sounds like you need to just keep it cool and give it a little break between groups.

if you want to bed

How to Glass Bed a Bolt Action Rifle

[elkinrutdrivemenuts]

You shooting hand loads or factory loads?

[NW-GSP]

You shooting hand loads or factory loads?

Shooting factory federal 180 grain. Its 25 bucks a box.

I was just given a reloading press and now I just need to get primers powder and bullets

[Rick]

So you shot it nine times before the accuracy went to hell. Are you planning on shooting at an animal more than nine times?

If you're shooting 1" or less groups,I wouldn't mess with it.

[NW-GSP]

Rick I'm more then happy with one inch groups at 100 yards I'm more or less trying to figure out why there is no consistancy at 200 yards.
Could it be that its factory ammo?

[Woodchuck]

Did you ever shoot the 200 with a cold barrel? If the gun will group at 100 it will group at 200 all things being equal.

[Alchase]

It is probably the interface between the bench and the trigger...........LOL,
 

If the gun will group at 100 it will group at 200 all things being equal.

Ya that.
 

[NW-GSP]

How much time do you guys give a gun to cool down? I was waiting around 5 min. But either way no I did but yet 200 with a true cold barrel

[jackelope]

Ideally I like to bring 2 guns, shoot a 3 shot group with one, then switch to another gun for a 3 round group...take 15 minutes or so to shoot that group. This has worked pretty well for me.
It was either too hot or you were flinching after too many rounds kicking you. Start fresh at 200 with a cold barrel...go from there. I'd bet you'll find it's not the gun.
 

[Rick]

How much time do you guys give a gun to cool down? I was waiting around 5 min. But either way no I did but yet 200 with a true cold barrel

12 shots from a .300 will have the barrel hot enough to cook on. 5 minutes isn't mearly enough time to get it cooled down. I'd bet you'd need at least 30 minutes to be back to a cold barrel.

I'm with Jackelope. I usually take 2-3 rifles so I can still be shooting as the others cool.

[NW-GSP]

How much time do you guys give a gun to cool down? I was waiting around 5 min. But either way no I did but yet 200 with a true cold barrel

12 shots from a .300 will have the barrel hot enough to cook on. 5 minutes isn't mearly enough time to get it cooled down. I'd bet you'd need at least 30 minutes to be back to a cold barrel.

I'm with Jackelope. I usually take 2-3 rifles so I can still be shooting as the others cool.

thanks for the advice! I will be going back to shoot again in about a week and I have a .22 I have been wanting to shoot

[Woodchuck]

In another thread Jackelope suggested having a partner load it for you after a few shots and have him toss in an empty a time or two, that will tell you if you are flinching. You also might try shooting the .22 after a few rounds to find out as well. 

[Bob33]

I take ice cubes in a ziploc bag to cool down a rifle barrel.

I would not advise anyone else to do this, but I've been known to put a meat/oven thermometer carefully in the muzzle of a rifle...it's surprising how hot a barrel can get, and how long it can take to return to ambient temperature.  If you do this, and you forget to remove it before firing, don't blame me.

[Woodchuck]

P.S. if the gun makes you flinch you need to do something different before it gives you bad habits in all your shooting that will be very difficult to overcome.