Request help with a .300WM anomaly

DarkGryphon

Inactive
So i just recently broke out my late granddads winchester model 70 in .300WM. I took it out to sight in and in two trips to the range now i have run across something thats making no sense. Wanted to put it out there and see if anyone can help me sort it out.

My knowledge base is as follows: I have been shooting since I was 5yrs old. I have shot competitvely for 5yrs and have been a military firearms instructor for the last 6yrs. I have shot rifles for sport and competition but this is my first step into the dicipline of long range shooting. Thus I ask: What am I doing wrong here?

From the prone position firing off a bag rest at 100 yrds my 5 shot 2" groups are 4" above point of aim. At 200 yrds from the same position they are almost 9" above point of aim. Both days elevation from shooter to target was minimal. While several people I spoke with seem to think the bullet is still climbing out, the data tables for 150gr soft points suggests the bullet impact should be lower not higher.

Any suggestions?
 
A scoped .300 Win Mag shooting 180-gr. factory loads that print 4" high at 100 yards will be 5.3" high at 200 yards when its zeroed at 330 yards. If zeroed at 410 yards, bullets would be 9" high at 200 yards and 5.9" high at 200 yards.

Therefore, something's not right with your numbers. I don't know what's causing the issue but it may be the way you're holding the rifle; perhaps different at each range.
 
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adjust your sights unless you really need the long range zero
My experience with using the 300 Win mag has been that consistent recoil attenuation is the biggest problem and leads to vertical stringing or zero shift. I owned and used a 300 Win mag target rifle for years until I simply couldn't stand the recoil(or handle it within use parameters). I dropped back to 308/30-06 target rifles and still use them occasionally.
 
The rifle has an older model Weaver scope on it. All the screws are tight and the scope mounts are solid. Ill have to look at how tall the rings are.

Thank Bart for the bullet data. That helps make more sense than the base tables I was seeing. It would suggest the rifle is sighted in around 300-400 yards. Ill have to bring it down some and try it.

I had considered it was something in my position or hold of the rifle with regard to the recoil. I will look at that next range day.

Thanks for the input Ill post any changes after the weekend range.
 
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Like Mobuck said, adjust your crosshairs. Two inches high at 100 should be roughly dead on at 225 to 250 yards.

Older Weaver? Likely, down eight clicks. (They generally were 1/4" clicks.)
 
Condolences on your loss.
I suspect you see much better results with a heavier bullet for a .300 Mag. Knew a guy who regularly won 1,000 yard matches(also shot prone. No rest though, I think.) with a 17.5 pound, custom rifle, built on a Win M70. He used 190 grain match bullets.
Mind you, sighting in for you will matter.
 
Thank you all for the help. 8 clicks down got me within 1" of center at 200yrd. Now if I can just master the flinching on follow up shots Ill have a good base to practice on.

Right now Im shooting what I have which is hand me down 150gr soft points. I plan on picking up some newer ammo when I get done with this stuff and data it as well.

Also considering swaping out the scope for a newer one that is a much better optic. Figured I can get used to the scope I plan on using on my new rifle when it comes in.

Again thank you all.
 
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