[UT] The Great Caselessness Fraud

[Sam Cade]

Originally Posted by lexington

Isn't that an artifact of wanting to make it compatible with the AK-74?

Not really.
Straight blowback submachine guns in service calibers require relatively massive bolts to function reliably. The most efficient place to put the spring to drive the bolt into battery is directly behind and in-line with the bolt.

Reliability is enhanced by slowing the cyclic rate. The most efficient way to decrease cyclic rate (provided that bolt weight is optimum) is to increase the amount of bolt travel.




To wit:

http://files.uzitalk.com/reference/d...i_exploded.jpg
45 is the bolt. 56 is the recoil spring.

http://worldwar2headquarters.com/ima...3GreaseGun.jpg