This here. I'm guessing it wasn't actually the acceleration added by gravity, but the energy remaining from the horizontal vector of the bullet's trajectory. Unfortunately, this is just a guess on my part. Hatcher's work for the .30-06 is of limited use, as bullet shape is going to influence terminal velocity. If this is the case... it is actually safer to shoot straight into the air than just kinda mostly into the air! If we did this, celebratory gunfire might actually be safer than firecrackers!
My post was mainly about the common idea that a .22 bullet will come back down with enough energy due only to gravity that it will hurt someone. My guess is still that it won't hurt someone, and if this is the case, certainly it will not hurt someone if it passes through a 12 ga hull before it even gets to altitude. Obviously this will decrease the maximum altitude, but my guess is that the terminal velocity of a .22 is actually low enough that it doesn't take a hugely high fall to reach that velocity.
Well, 90º is complicated, and would need to be calibrated to deal with the procession of the Earth, too. The trick would be with angles like 80º which are going to be "straight up" for practical purposes. But would yield a high parabolic trajectory.
Right. That and any cosine error from not truly vertical trajectory ignored, what’s the maximum height a 40 grain .22 bullet will reach if muzzle velocity is 1200 feet per second? I’m sure we can get tark to give us his elevation and temperature if we ask nicely, but you might just go ahead and compute this for us at sea level on a standard day. I know you are smart enough to do this off the top of your head. It would seem like work for me to figure it out.
About 600 feet above sea level and temp all over the place from hot & humid to cold and dry. I live in the midwest! Remember, the bullets velocity is unknown after holing the empty shotgun shell. And it doesn't matter if the bullet goes a thousand feet up, or ten thousand. It will fall until it reaches terminal velocity ( or hits the ground first ) and after that point it will not fall any faster. It's all a moot point now, because I discovered a neat trick today. I shove a penny into the shotgun shell before firing. The fired bullet stays inside the shell and it almost doubles the range. With this little trick, using long rifles works better than shorts. More kinetic energy, I suppose.
It's ballistic coefficient is also unknown after holing a shot shell also affecting it's terminal velocity on the way down.
Man there’s always gotta be some haters and worry warts when people are having fun. Next they’ll say it’s illegal to destroy pennies. I think it sounds like a ton of fun.
Oh, good grief. Have you ever seen a non-antique rolling block rifle with socket head screws? My guess is that tark knows what he's doing.
Happy to see blanks and powder actuated tool cartridges recommended for the safest approach to this launcher.
We find too many examples of folks converting or building things that don't comply with regulations to guess about them. Hope, sure. Guess?
Yes, but this thread is not even remotely about that. It seems that this thread was started to talk about chucking 12 ga hulls and has mainly continued by folks telling tark he's doing something wrong. A couple of minutes of searching would show that tark is very good at building rolling blocks. Why must our first response always be "you know that's illegal" when there are several ways it could be legal?
I think folks that were not familiar with Tark's skill and knowledge were just concerned he might have made a mistake that might get him in trouble. The fact that you know his skill and knowledge is great and can help reassure them. I'm sure he'll be along to reassure them he knew what he was doing when he built it.
Thanks for the hand slap. I did not accuse anyone of anything. Working in the "business" I've seen way too many "conversions". I thought my post was tactful and in no way denigrating to the OP.
The moderator did the prudent thing and removed this thread for a day and sent me a PM telling me that some of you guys were concerned about legality. Rest assured, it is not an NFA violation. The pistol was made from scratch using a rifled 22 cal. barrel blank. It is not a smoothbore. I do have a front sight for it when I want to shoot bulleted ammo and it is quite accurate. Everyone's concern was and is appreciated.