120 class powders

[LRRPF52]

In this same train of thought, wouldn't rifle weight have more of an impact than shooter weight?

D. All of the above.

Shooting technique helps a lot as well, with firm rearward pressure and the only disturbance to the rifle is straight back and to the rear on the trigger.

For the AR-15, shooting with Bull Bags close up to the receiver, as well as a heavy rear bag, helps a lot to maximize grouping potential.

What I was saying is that positional factors can manifest as erratic muzzle velocity. The tiny changes to the position shooting from the same place, but at different dots on paper, can show up as groups opening or closing if the position isn’t re-built and settled well. There are some rifles that match your body just right, along with being extremely well-built, that turn out to be hummers and you know when you get one: It feels like you can’t miss with that particular rifle.

I used to do a lot of accuracy testing as one of the final QC processes for a manufacturer who specializes in high-end bolt guns, with multi-caliber barrel/bolt change capability. The chassis were all the same, and I would shoot through multiple .243s, .308s, .300 Win Mags, and .338 Lapua Magnums all-day at the range, from a sled. The rifles didn’t ship unless they had a 1/2” printed group at 100yds.

I remember one particular .300 Win Mag that I fell in love with, Krieger-barreled, that just shot so well for me no matter what I did. I had no intention of getting into .300 WM at that time or any time since, but I still think about it. It was already ordered/spoken for.

My first ArmaLite AR-10 was a hummer as well, 1/3rd MOA gun even without a 2-stage trigger.

There was a Bartlein 20” 6.5 Grendel upper I tested for Precision Firearms after a customer sent it back saying it wouldn’t shoot. I put at least 7 rounds into a bughole at 100yds, before opening the group to 1/2” when another guy at the range touched off a round with his tank muzzle brake right next to me as I broke the shot. I told Mark if the customer didn’t want it, I would buy it off them. They wanted it back ASAP.

I’m still trying to determine how the formula works for a perfectly-fit rifle to the shooter that makes a hummer. Top-end barrels are a starting point as a general rule, but I think there’s something to be said for rifle balance, and how it positions for a shooter. Heavy target rifles work around the balance formula with brute force in the weight/mass department. My interest is more in as light of a rifle as possible, while enjoying repeatable accuracy from various positions.

I want the best downrange performance from the lightest weight, easy-handling rifle as possible. This makes me pat more attention to little things that go on with shooting from positions, and slight variations to the position going from dot-to-dot on a paper target.