Ask Ian: Analyzing the Savage Rotating Barrel (at 7500 frames/sec) (ad-free)
Added 2022-08-23 12:01:01 +0000 UTCA question I have been asked by several different people in several Q&A threads is:
"Does the Savage rotating-barrel system actually do anything?"
In his 1905 patent, Elbert Searle specifically claims that his design creates a positively locked breech. He did this, in theory, by having a system where the barrel must rotate before the slide can move rearward (which opens the breech), and where the bullet engaging the rifling created an opposite rotation which would hold the breech closed until the bullet left the barrel.
In reality, Searle's system does not do that. The breech begins to open while the bullet is still traveling down the barrel, as the rearward pressure on the breech substantially overmatches the rotations force created by the bullet on the rifling. However, this system does still provide some delay, and allows the moving parts of the Savage system to be about 20% lighter in mass than those of the Browning model 1900. The Savage may not have a positively locked breech, but it is a safe and reliable design.
Comments
heck camera tech these days are so capable.
Guido Schriewer
2022-08-23 14:21:58 +0000 UTCThe Grand Power line of pistols also use a rotating barrel. Perhaps look at both pistols.
David K. Jernigan
2022-08-23 13:56:23 +0000 UTCPLEASE REPEAT this analysis with a Beretta PX4! I can provide a pistol for this if you like, I have got a .40 on hand. The above suggestion by John Dallman re: a "witness mark" on barrel to help analyze rotation is a good one, the blur from high frame rate makes it tough to be sure about rotation. Also, minor note: The muzzle flash which appears as a red glow rather than discrete sparks is not so much from "unburned powder" as it is from the air burning of Carbon monoxide produced by a somewhat negative Oxygen ballance powder, these powders produce carbon monoxide among the propellant gasses. The old "town gas" used for gas lighting & gas stoves before natural gas was used is a mixture of Carbon monoxide and Hydrogen, CO burns rather well in air...
Robert Rowe
2022-08-23 13:29:46 +0000 UTCAnother design which uses a rotating barrel is the Beretta PX4 Storm full-sized and compact models (sub compact is tilt barrel, not enoughroom in the short slide for the rotation). It seems that it is locked breech, perhaps the high-speed camera can determine whether this is true or not.
EyeBall
2022-08-23 13:02:29 +0000 UTCThanks Ian for taking a look at this! Now I wonder if another 5 degrees would have done the job.
W. B. Mike
2022-08-23 12:36:53 +0000 UTCA question and a comment about the experiment: Presumably the slide can move a very short distance before it hits the lug, or it couldn't be assembled or disassembled? Drawing a line with a sharpie on the part of the barrel that's visible through the ejection port would make it easier to tell when the barrel starts rotating.
John Dallman
2022-08-23 12:36:03 +0000 UTC
