Request help with a .300WM anomaly

DarkGryphon · August 27, 2014, 01:21 PM

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?

big al hunter · August 27, 2014, 01:33 PM

What type of sights do you have on the rifle and how far above the bore is the line of sight?

FrankenMauser · August 27, 2014, 01:37 PM

Not enough information to make a call.

What's your sight height?
Velocity?

Scope?

Bart B. · August 27, 2014, 08:30 PM

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.

Mobuck · August 28, 2014, 07:46 AM

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.

DarkGryphon · August 28, 2014, 10:51 AM

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.

Art Eatman · August 28, 2014, 11:48 AM

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.)

T. O'Heir · August 30, 2014, 04:27 PM

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.

DarkGryphon · September 2, 2014, 09:05 AM

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.

August 27, 2014, 01:21 PM	#1
DarkGryphon Junior Member Join Date: August 25, 2014 Posts: 3	Request help with a .300WM anomaly 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?

August 27, 2014, 01:33 PM	#2
big al hunter Senior Member Join Date: March 12, 2011 Location: Washington state Posts: 1,558	What type of sights do you have on the rifle and how far above the bore is the line of sight? __________________ You can't fix stupid....however ignorance can be cured through education!

August 27, 2014, 01:37 PM	#3
FrankenMauser Senior Member Join Date: August 25, 2008 Location: In the valley above the plain Posts: 13,424	Not enough information to make a call. What's your sight height? Velocity? Scope? __________________ Don't even try it. It's even worse than the internet would lead you to believe.

August 27, 2014, 08:30 PM	#4
Bart B. Senior Member Join Date: February 15, 2009 Posts: 8,927	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. Last edited by Bart B.; August 27, 2014 at 08:36 PM.

August 28, 2014, 10:51 AM	#6
DarkGryphon Junior Member Join Date: August 25, 2014 Posts: 3	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. Last edited by DarkGryphon; August 28, 2014 at 10:58 AM.

August 28, 2014, 07:46 AM	#5
Mobuck Junior member Join Date: February 2, 2010 Posts: 6,846	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.

August 28, 2014, 11:48 AM	#7
Art Eatman Staff in Memoriam Join Date: November 13, 1998 Location: Terlingua, TX; Thomasville, GA Posts: 24,798	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.)

August 30, 2014, 04:27 PM	#8
T. O'Heir Senior Member Join Date: February 13, 2002 Location: Canada Posts: 12,453	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. __________________ Spelling and grammar count!

September 2, 2014, 09:05 AM	#9
DarkGryphon Junior Member Join Date: August 25, 2014 Posts: 3	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.