delta_echo

The chamber of the weapon supports the brass casing and prevents most movement of the round before and during firing. Improper spacing of chamber in the radial direction results in bulging or even destruction of the brass, while improper headspacing (in the axial direction of the round) can also destroy the brass, as well as eject primers into the operating mechanism of the weapon. Both cases have the possibility of dramatically raising pressures inside the weapon as well.

There was a firearms board I was part of that tried to help control the spam by instituting a 5 posts minimum before you could start your own topic. Seemed to have worked pretty effectively. Simply reducing the requirement to 1 post (which could be done in the introduction of new members thread) might be enough to to put an additional halt on the spammers without discouraging new members with legitimate questions.

I've always just used small amounts of 70/30 flash encased in small tubes with a electric match attached. They are great for ground hits and body hits (with a blood pack attached and the appropriate safety measures), but not so much on tree hits due to the telltale flash. The quick remedy for this is simply just to cut a frame out during editing, however. Ideally I would like to eliminate the flash all together, but without the heavy smoke produced by other compositions.

Any idea as to the formulation of the professional "bullet hits" that you are using? Do they produce much smoke or flash? Not trying to change the subject, but I am curious.

I have had great success with 50:50 Potassium Chlorate/Antimony trisulfide bound in ping-pong NC laquer. Reliably ignites with a standard 9 volt with almost no delay. I hate to say it, but I don't know the wire gauge of the nichrome as I bought so much of it so long ago. Pretty thin, though. I've used these with a 300 ft. 12 gauge cord with no problem as well. The power source in this case was a 12V car battery, however! I've lit off about 250 of these with only one failure (later found out to be a broken bridgewire), so as long as you pre-test them, you shouldn't have any failures.

As has already been mentioned, this mix contains a chlorate and a sensitizer/fuel, so care must be taken. Bound in laquer, however, seems to desensitize the mix from pressure and friction.

I can't tell enough from looking solely at the course overview, but I'm not sure it necessarily covers much in pyrotechnics. Though sometimes incorrectly lumped under "special effects" pyrotechnics is classified as a visual effect (along with miniatures, camera tricks, etc.). Special effects is typically about computer generated effects. Having many friends in the film industry as well as having done some pyro for various small films, I've been around the terminology. Like I said, though, not sure on the course - check it out and let us know.