What to get for my first bolt gun?

[Absocold]

Recoil is linear, true. But in actual practice, because of the way rifles are built (bore axis above the butt of the stock) and the way people are shaped (rifle braced well above the body's center of mass), the recoil effects are partly to the rear and partly upward. They combine into a circular motion. What happens when you fire a rifle? You feel some kick and the barrel goes upwards. The more powerful the round and the lighter you and the gun are, the more felt recoil and the bigger an upwards arc the gun travels before recoil ends. That arc is part of a circle. Circular acceleration (or acceleration around a pivot, the pivot being your shoulder) is known as torque.

Ok, the easiest way to explain this is to over-exaggerate the problem. Small things aren't as easy to see as big ones, so we go big:

Imagine the scope mounts are six feet high. Now does the scope see some torque? Yep. Plenty. Well, simple math shows if it sees torque at a large distance, it will see some at *ANY* distance. And the forces involved with some of the larger/snappier calibers can be rather large, even when the scope is mounted low.

Good glass will take a lot of recoil with no problem. But nothing lasts forever, entropy always wins. If you raise the scope further from the bore axis, thereby increasing the forces it is subjected to, you will shorten its life span. Maybe a little, maybe a lot.

You may not think it's a big deal, but that's your call to make and your money to spend. My goal is to help people and hopefully prevent the repeating of problems I've encountered.

[Stlhead]

Instead of wasting my time I will recommend a book. Applied ballistics for long range shooting by Bryan Litz.

[Absocold]

Does this book argue against Newton's Laws of Motion (specifically #2 and #3) and/or ignore physics? I'm betting that's a no. The author may have computed the rearward motion and upwards motion together to compute a single force vector, this might lead to some confusion or misinterpretation. But torque is undoubtedly one of the forces experienced by a rifle scope (the entire rifle actually, except for the moment center) and the farther an object is from the center of motion, the more acceleration force it experiences from torque. These are pretty simple facts.

If you took the barrel off the rifle, inserted a round into the chamber, placed the chamber flat to a wall with the barrel aiming away from the wall at a perfect 90 degree angle and fired the cartridge electrically, because the barrel has symmetrical resistance to the force vector and a stable platform it would recoil directly to the rear and have no other movement forces and therefore no torque. But rifles aren't symmetrical and shooters aren't immovable objects. Because of the shapes, angles and mass involved, upwards is the secondary motion you get.

On another note, a bit off topic, anyone here know what centerfire rifle scopes *aren't* braced for? If you said, "Forward recoil", you are correct. Try mounting an expensive rifle scope on a magnum spring piston pneumatic rifle and see what happens. A silly little springer air rifle will absolutely demolish a scope not built for it in very short order. Springers recoil rearward as the piston moves forward, compressing the air that pushes the projectile down the bore, but when the piston reaches the end of its travel the rifle recoils forwards very sharply - most scopes are not built to handle this force. Ask me how I learned this one and how many scope builders I talked to about this issue. On second thought, don't ask me, I'd rather not be reminded again. It was a painful lesson. I also learned that match-quality airgun scopes are not terribly common and are not cheap.

While we're here having fun with guns and physics, here's an interesting one: When you fire a gun, where does the force from that recoil actually go? What absorbs the recoil? You? Nope. You're just a conduit that transmits that force into the ground. It's the earth itself that absorbs the force.

[Stlhead]

Absocold, you should write a book full of your whimsical musings about rifles and long range shooting, or possibly start a blog.

[jameslee1223]

Back on topic, here's a group I shot today. It would've been 0.45" if I wouldn't have pilled that last shot.

[perttime]

Did you manage to call your shots ... and knew it was off before you looked?

You must be doing something right

[jameslee1223]

Thanks, I'm trying. Yeah, I call my shots. I'm still not used to the recoil. I doesn't kick any harder than my 12g Mossberg but it's still different. And the only experience I've had with rifle cartridges bigger than 5.56 was when I was in the Army. And then I was shooting an M60, so a little different. lol I need to do some serious dry fire. Fifteen minutes a day, every day.