Perplexed, need some pro advice

[RuninL8]

Yes, thanks for the clarification for others.

Don't waste your money on anything other than a lab radar chrono. As you say you want to improve long range skills. Then spend the money otherwise you are gonna be chasing your tail.

Thanks a TON for the questions and areas to consider everyone! Guess I'm out to make another purchase (chrono). Worse problems to have.
Some great advice on things to consider in shooting form.

 

[Chieftan]

Kind of a theory out in the weeds here, but do you have really tall scope mounts on the 308 compared to the 300WM?

Also recheck your zero at 100 with the 308. Sometimes scopes shift zero.

2.1" to center on the .300 and 1.9 on the .308. Not much clearance to the barrel on either. They're both big scopes.

 

[Chieftan]

Don't waste your money on anything other than a lab radar chrono. As you say you want to improve long range skills. Then spend the money otherwise you are gonna be chasing your tail.

Appreciate you!

 

[Reemty J]

Are the ring height and scopes same on both rifles

 

[Chieftan]

Are the ring height and scopes same on both rifles

No, Leupold rings on the .308 with Zeiss Conquest V4. Spuhr mount on the .300 with Mark 5HD.

 

[powermax]

Don't waste your money on anything other than a lab radar chrono. As you say you want to improve long range skills. Then spend the money otherwise you are gonna be chasing your tail.

This ^^^^^^^^^^^^^^^^^^^^^^^^^^^

 

[Chieftan]

At 300 yards your gonna have a real tough time doing the "reverse math". With the 150 gr 50 Fps difference is worth .6" in point of impact at 300. So unless you shot a group with zero vertical then it's pretty impossible to get a accurate measure on velocity.

I used this method 15 years ago and it's a tough way of doing things. Like Lance said, beg or borrow a chronograph. If you can't then make sure your truly zeroed at 100, then shoot as far as possible (500 yards+) without dialing anything on a target tall enough to catch your impacts and then try the math again.

The group of 5 that I shot had about a 1.5" vertical. Appreciate the advice!

 

[bowhunter123456789]

I agree on the chronograph.....but here's some other food for thought when getting started shooting. You said that you where shooting mostly sub MOA, Which I'm reading into a little bit here so bear with me and don't think I'm fault finding at all.
I'm using inches for ease of example...... Let's say your groups are between 3/4" and 1 1/4" that's a 1/2" variable which translates to 1 1/2" variable at 300. If your spread is worse the variable goes up. All of these add up at some point and I think it's easy to get hung up on what apps and charts say we should be at when there's a ton of other variables. I think it was easier in the old days when we didn't have all the modern technology distraction. You shot, shot and shot more, built your dope card and went with it. I'd say keep shooting and use apps/charts to get you on paper. With shooting comes consistent confidence......I'm envious of the guys that can confidently shoot a Ladder work up at 500 yards without doubts of their shooting errors inducing bad data.
One other thing......I used to shoot alot of 100 yard groups and was very confident in my ability to shoot sub Moa, however when I begin shooting longer range the Sub MOA didn't immediately translate out. Most of it was me and I had to realize this and work on my shooting fundamentals instead of chasing my loads or rifle!

Well said, I experienced the same and concentrated on my shooting fundamentals and saw major improvement at longer yardages

 

[Chieftan]

This thread went from "why did I shoot a 3" MOA group at 300 yards with a 7.3" drop vs an 8.2" drop with a .300Wm" to "why this guy sucks at shooting" pretty fast.

 

[RuninL8]

This thread went from "why did I shoot a 3" MOA group at 300 yards with a 7.3" drop vs an 8.2" drop with a .300Wm" to "why this guy sucks at shooting" pretty fast.

Confidence, confidence in your equipment and yourself is everything. You can't become a confident shooter until you are confident in your equipment. I have sat down with countless people put them behind a rifle that will shoot a 1/4 inch at 300 yards, show them what the rifles capabilities are and then let them shoot. You would not believe how many can shoot under an inch at 300 when they have never shot that well at a hundred. They had confidence that they could. Alright I'll step off my soap box, point being chasing your tail in a rifle that isn't precise, well you'll get nowhere fast.

 

[Shane Lindsey]

How refined is your aiming point at 300 yards?

I used this target at 600 yards and found out it was too big (12"). Based on your math of 3-4" high, that could be just your aiming point differing slightly.

First groups were aiming center of bull.

Second groups were aiming where the orange and the white meet. I had to do this before I had a chrono to reverse engineer my velocity and it worked out better. Was just interested in vertical dispersion. No wind calls(at least that let me sleep better)

FWIW-my 20" 308 with 175gr launched at 2465 FPS calls for 5.2 MOA or (21) 1/4 MOA clicks at 300.