SMLE hit by AP round !!

[Emri]

I've been thinking about it and can't fully grasp how the AP core "ignited" the cartridge in the chamber. I can see how the AP core might drive the projectile into the case and cause an "obstruction" that would lead to the burst barrel if the trigger were pulled and the primer ignited. I'm sure no one will ever know for sure, but....

Any thoughts on that Peter?

Thanks,

Emri

[Peter Laidler]

Just thinking off the top of my head, ignition would be simple. The hard and pretty fast AP bullet would tend to crush the chambered .303" round and the crushing/compression of the cordite might tend to cause it to self ignite but I'm not a chemist but a mechanical engineer. Maybe someone else could comment on that. But even if it didn't self ignite under the extreme compression, this compression would have a tendency to drive the anvil back into the cap and that would certainly ignite!

Theories aside, I wasn't there but ignite and explode it certainly did as the pictorial evidence shows!

I have been asked a couple of times regarding use of the picures. You are free to use them but the photo credit must state 'UK MoD (SASC) Army'. Maybe Badger will require a Forum credit. Badger.........

[jmoore]

Diesel principle, yes?

[Peter Laidler]

Off the subject a bit JM, and putting my part time Physics teachers hat on............. what would cause it to self ignite and why? With aplogies to Emri, I deliberately side swerved the dieseling bit of the question because I couldn't UNDERSTAND why

In the next few weeks I'll add pictures of some of the other damaged weapons

[jmoore]

Whilst supposedly the Cordite, being a non-gaseous substance in non-ignited form should not compress and heat, might there not be enough air in the cartridge to compress and heat to a temperature sufficient to fire the round?

Additionally, I reckon the incoming round's energy would largely be converted to heat as it RAPIDLY decellerates in the chamber.

If the incoming bullet obturated the bore well, there ought to be plenty of "fairly" hot air rushing into the case as well! (What's the compression ratio for THAT scenario?!!!)

[Peter Laidler]

Got that JM and thanks. When the point is dicuseed next time its raised here at Warminster, I'll throw that in. Thanks again

[jmoore]

I'm not so velly sma't... If I was, I'd have remembered somebody already made a working firearm using this principal. It was a rifle sold by Daisy in the sixties!

Quote stolen from Pyramydair.com's blog below:

"In 1968 Daisy, brought out a really strange gun. It was a .22 that fired caseless ammunition, which was ignited by the adiabatic heat of a conventional spring-piston airgun powerplant. That's right, a pellet rifle that shot a 40-grain lead bullet at 1100 f.p.s. It was a firearm, of course; but, because Daisy built it, it had a plastic stock. The Daisy VL was never popular with anyone, and they're still sluggish on the used market today. By the way, if you're wondering if one could be used as a spring-piston air rifle - you can forget it. The bore is sized for the standard .22 rimfire caliber of 0.222"-0.223" instead of the airgun size of 0.218." Pellets shoot at 300 f.p.s. or less because of the excessive blowby. Daisy ceased selling the gun in 1969."