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post #5 of Old 02-13-2007
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Ballistics and firearms are my bailiwick (my company is a member of SAAMI and I instruct); so here goes:
the The Sporting Arms and Ammunition Manufacturers’ Institute specs specify maximum of pressures in PSI (pounds per square inch) or CUP (copper units of pressure); a typical chamber pressure for a 2 3/4" 1oz load at 1400 feet per second (that's at the fast end of the scale) will generate 11,500 PSI; and if the load is compressed and the barrel oiled then pressures will get even higher.
Self-defense or hunting rounds use a combination of factors to push the pressure curve even higher.
Much of the velocity comes from the length of the barrel, the load actually accelerates the whole lengthe of the barrel and only stops speeding up once it leaves the higher pressure of the barrel.

I looked at the flare specs and they are fired with no powder, the primers alone provide enough energy to propel the charge out of a 3" barrel with a velocity of about ~200fps. Just looking at the construction of the Orion flare you can see that the design is for low weight and small size and not for higher breech pressures. If higher powered flares are used the Orion even needs an additional breech safety holder.

Even if a 2 3/4" shell could fit into a flare gun, firing one will probably result in what shooters technically call a "KB" (KaBoom) and the risk of damage from flying pieces of the breech is quite high. Say goodbye to your hand.

Also, it seems that from the flare makeup it will probably also be bad to fire it from a normal shotgun since the the magnesium flare might ignite while the charge is still travelling down the barrel, either exceeding pressures or melting the barrel of your Purdey or Holland & Holland.

Shooting a shotgun shell out of a plastic or polymer flare gun chamber is a sure-fire way of injuring yourself.

On the subject of using a shotgun for self-defense onboard - belowdecks any long-gun (rifle or shotgun) is quite unwieldy but no matter where used a shotgun (with as short a barrel as possible) is a formidable firearm. No matter what you load the shotgun with, be it rock-salt or birdshot or Cayenne pepper seasoning, the round will be lethal at close range. At muzzle contact even an empty shell with just a primer will do the deed. This is due not to the firearm's projectile but to the effect of expanding gases. There is no such thing as "shooting to wound" with any firearm. The common legal approach in the US for justifying lethal self defense is if you, or a reasonable person in your position, is "in fear for their life" by an attacker. If the answer is not "yes" then you don't use lethal force. Someone stealing my dinghy or boarding to rifle the cockpit area doesn't merit a "yes" - but being armed while doing so certainly would merit a warm response. And I won't have permanent sleep problems thereafter, either.

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Last edited by Zanshin; 02-13-2007 at 04:38 AM.
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