Blowback action?

[BountyHunter]

what goes on in a "blowback action" pistol? thanks

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My bulldog was ran over by a car last week therefore I joined AUTOMOBILE CONTROL INC. those damn cars should be taken off the street

 

[Rex Feral]

In a blowback action, the strength of the recoil spring and the weight of the slide are the only thing holding the shell case in the chamber until the pressure susides to a safe level for extraction and ejection.

There is no mechanical lock up of parts to hold the chamber closed, so blowback actions are generally less powerful calibers. I think Detonics made a pure blowback 9mm at one time but that is the largest I have personally heard of. The weight of the slide and strong recoil springs would make larger calibers impractical.

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Cry "Havoc!" and let slip the dogs of war.

 

[Stephen A. Camp]

Hello. Rex Feral told you right. You will seldom see above .380ACP in blowback. The Detonics Pocket Nine and the old Astra 300 and 400 pistols come to mind, but that's about all. Most all the rest use some kind of locked breech or delayed blowback systems.
Best.

 

[James K]

Hi guys,

The whole idea is to "keep the lid on" until the pressure within the case drops to a point where the case will not blow out when it comes out of the barrel. This is usually after the bullet exits the barrel. A high pressure round in a blow-back pistol can back out too soon and burst, spraying brass fragments and letting gas loose in the action.

The Astra 400 (9mm Largo) and 600 (9mm Parabellum) were both blowback. So are the High Point pistols. The Astras used a little trick of putting the hammer cocking at an extreme mechanical disadvantage to give almost a delayed blowback effect. The High Point depends on a massive slide.

The most common type of locked breech is the recoil operated pistol. In this type, the barrel and breechblock (often part of a slide) are locked together until the recoil from the moving bullet causes the barrel-breechblock unit to move to the rear. Contrary to what is often believed and published, it is not the gas pressure which causes this, but the motion of the bullet. If the barrel on, say, a Model 1911 type pistol, is plugged so the bullet cannot move, the gun will not unlock.

Jim

 

[johnwill]

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by Jim Keenan:
If the barrel on, say, a Model 1911 type pistol, is plugged so the bullet cannot move, the gun will not unlock.

Jim[/quote]

Well, if the barrel is plugged on most any .45ACP gun that I'm familiar with, you wouldn't even know that the gun didn't unlock, since it's likely that the resulting explosion in your hand would distract you!