Reddit reviews Understanding Firearm Ballistics

This guy right here. I read it while I was bored in Air Force tech school and it was a great resource.

Soft is a relative term. As for literature you can try looking up this book in the library. I've not read through this particular one so I wouldn't say buy it.

>The data for foot-pounds of force is taken from expected use: a 9mm round through a Glock 19, a .308 through a 24" barrel, etc. It should be noted that you'll lose muzzle velocity the shorter your barrel gets. I believe this also increases felt recoil, right?

A little more complicated, but true enough in practice. A shorter barreled weapon usually has faster burning powder. So if you run a .45acp through a long rifle barrel (20") you might end up with less muzzle velocity.

The only thing (if the cartridge is the same) that increases felt recoil is the weight of the weapon, and the way the firearm deals with recoil. If you fire a .308 in an ultralight guide rifle - it is going to hurt. If you have a shorter barrel, there will be less recoil entering the firearm but negligible as to what you feel. Once the gasses exit the barrel they aren't acting on the gun that much anymore. That is why silencers and muzzle breaks reduce recoil - because the gas that used to just flow away is now pushing forwards on the gun, reducing recoil.

If the weight of the gun is the same, the way that the firearm deals with or uses the recoil becomes very important. In a very rigid firearm (say an ultralight scandium/titanium revolver) there is no energy absorbed and slowed by the frame - it ALL goes into your hand (ouch!). If you get a polymer frame, the firearm flexs a bit and slows the recoil making it more comfortable.

If the firearm actually makes use of the recoil energy (autoloaders) then part of that energy is being used to cycle a new round. This reduces the recoil delivered to you, and makes it slower and more comfortable. Roller locked delayed blowback designs (MP5, G3, etc) do a great job of transferring the recoil impulse into a lighter weight bolt and using acceleration to absorb the energy instead of mass. Personally, I think this was one of the greatest systems there was (and is to a far less degree) for shooter comfort - but there are wear issues that are more of a concern (100k rounds or something) than in locked bolt designs.

When you get into the more recent guns, they start to use most all of the above. My FN FS2000 shoots like a dream. Polymer frame, somewhat heavy gun, lighter bullet, piston driven locked bolt, longer rearward travel of the bolt group, and everything hits flexible on flexible, energy absorbing stock. My wife can shoot this and doesn't find it much different than a .22lr 10/22.

Then you get into the designed for recoil guns, and I know of only one - the KRISS. I read about this thing a long time ago, and it seemed ingenious, but although it popped up in the magazines from time to time it never "took." But they are real now (as in you can buy them) and while I haven't shot one yet, apparently the hype lives up to the performance. In these guns you take all of the above, and add purposefully engineered methods of reducing to eliminating recoil. The idea is that you take the recoil energy and make it go up and down instead of back, in a basically mutually exclusive waste of energy.

http://www.kriss-arms.com/technology

From the one guy that I have met that has shot one (an owner of a very large gunshop) he described it as "irrelevant."


>Do you have any good information on the upper limits for this sort of thing? I made the mistake of shooting a hand-loaded .45-70 I wasn't ready for -- that was at least 3,000 ft/lbs (yeah, I know, "I swear it was this big"). How much more could you load a .45-70, for example, before it's unsafe? How little energy could you pack in a 9mm before it will fail to cycle (I know this is very dependent on the gun, and many cheap handguns won't cycle even with solid factory ammo)

This is something you have to find bit by bit, and with the help of advanced hand loaders. There are people who use "cups" (I can't remember the exact name, but I think that might be it) to load up rounds and then they can determine chamber pressure by the deformation of the cup. If you are willing to be more patient, and a little more risk taking you can slowly work your way up and see how the brass performs.

So unfortunately, no help there.

>Very true. The reason I think muzzle energy is a great indicator of a firearm's power is Newton's 3rd Law. Two cartridges with equal muzzle energy but a different bullet shape (or weight to speed ratio) may have different stopping power, but two cartridges with equal muzzle energy will have equal recoil. Since most "I'm interested, tell me more" type shooters are interested in getting experience with firearms -- not getting information on how best to take down an animal -- I think that set of statistics is the most valuable.

For sure, for sure. I really was just trying to fill in some of the blanks you left. As I said your post was great.

>I definitely agree with that and every point you've made seems like it's deserving of a post -- 'beginners guide to safe, humane, effective hunting', perhaps. I was more interesting in the mechanical, experiential explanation of general firearms terms. Personally my only real interest with firearms is in target shooting, so it's clear why I didn't focus on hand loads, stopping power, etc. Out of my realm of (amateur) expertise.

I can tell you aren't going to remain in that "amateur" (let's be real, you know more than 98% of people at LEAST) stage for long. Once you get bitten - people usually go nuts on it. I went way overboard, but hey - it is fun learning about it. :)

This is the ballistics book that got me more interested in it -http://www.amazon.com/Understanding-Firearm-Ballistics-Robert-Rinker/dp/0964559854/ref=sr_1_1?s=books&ie=UTF8&qid=1370674745&sr=1-1&keywords=ballistics

As a warning - you have to really enjoy it because it is like 500 pages and it doesn't read like a mystery novel. LOL

Don't edit your post, because it was great and factual - it just provided an incomplete picture. For most people purchasing a lower powered round is actually quite a bit more helpful in practice.

Sorry for barraging you with text again. This is just a topic that I really enjoy, so I probably ramble off point and write more than I need to. :)