[ Does the Savage 1907 Have a Locked Breech? ]
Hi guys, thanks for tuning in to another "Ask Ian" Q&A on ForgottenWeapons.com.
I'm Ian McCollum, and today I have a question that I've been asked a whole bunch.
So I don't have a specific person who asked this,
it's been floating around the Q&A threads for a while.
And that question is: with the Savage Model of 1907 Self-Loading pistol
there is a rotating-barrel delaying system.
The question is what does it actually do? How effective is this?
Or is it just sort of a way to avoid the patents that existed on simple blowback at that time?
So let me begin with a quick quote from the patent.
This was patented by a guy named [Elbert] Searle.
And the patent was licensed to the Savage Arms Company to manufacture.
He says, "One object of my present invention is to provide
a simple and effective positive locking means
to prevent recoil of the breech closure until after the projectile leaves the barrel."
Now, does this pistol actually do that?
Let's start by taking a quick look at the disassembly as a refresher,
and then we're going to go out on the range with a high-speed camera and see what we can find.
So the way this works is when the slide reciprocates backwards it has to rotate the barrel.
Not very much, you can see it's just a tiny bit, it's like 5 degrees of rotation there.
But in theory the slide can't go backwards until the barrel starts rotating.
And if the slide doesn't go backwards, the breech face
(which is right back there fixed to the slide), the breech face can't move backwards.
Which means the cartridge has to stay in the chamber as pressure drops.
Now the way that Searle intended this to work is that the barrel is rotating clockwise as it opens,
and the rifling is rotating counter-clockwise.
And so his intention was that the bullet, as it's travelling down the barrel,
the friction of the bullet against the barrel is going to twist the barrel to the right,
thus providing a force that prevents this unlocking action
until the ... bullet has left the muzzle.
If I take this apart you'll notice that there is a little track there in the barrel
with a little curve at the end of it.
The barrel is fundamentally fixed in the frame, it sits in that little slot there,
but it is able to rotate side to side.
And this little lug on the top runs in this track.
So from this position at rest, notice that the barrel is tilted just slightly over to the left here.
As the slide starts to move, the barrel has to rotate just slightly over to the right.
Now the barrel, again, is fixed in position.
So that's maybe our first hint that this isn't actually a recoil operated gun,
that fundamentally this has a fixed barrel.
And so kind of how could that be a locked-breech system?
Well, let's go take a look at the high-speed footage.
Alright, I started off with the camera set to 2,000 frames per second.
Optimistic that I am, I thought that would be enough
and we'd get some nice video quality. And it does look really cool,
but it turns out we can't really see what's going on.
So if we slow this down, we've got a frame here where we're about to hit.
And then we have a frame here where
we can see flash at the muzzle and the slide has started moving.
But we can't tell which happened first, we need greater resolution.
So I cranked the camera up to 3,500 frames per second.
And by the way, I know the quality is deteriorating here.
The quality of the image goes down linearly as the frame rate goes up.
So at 3,500 frames per second we are getting ...
there we go, that's a much nicer, slower assessment.
Let's break it down frame by frame, we've got the hammer dropping, dropping, dropping, fires.
And once again our first frame that shows any activity
shows the ... slide moving and flash at the muzzle.
So we're going to crank it up again. This time we're at 5,000 frames per second.
Let's see if ... this will be enough to distinguish which of those two things happens first.
So there's the whole activity, now here we go.
Hammer dropping, dropping, dropping, and boom.
Right here we have a little puff of gas,
and we have the slide that has started to move backwards.
You can see just a little bit, but clearly the first thing that's happening
is a puff of gas in front of the bullet and the slide starts moving.
Our next frame we can see muzzle blast, meaning that the bullet has definitely left.
And now we have the excess powder combusting.
So let's slow it down one more time, this is 7,500 frames per second.
And, yeah, this is probably the limit of the usable quality here.
But, slow this down frame by frame again.
And right here we see a small puff of gas come out the muzzle.
Next frame we're going to see a little bit more, and the slide is now definitely starting to move.
Now we have flash, and you can actually see the bullet, it's blurred there.
But in the next frame it's just about off the right edge of the screen.
And that conclusively shows us
that the slide has started moving before the bullet has actually left the muzzle.
And that means that this is definitely not a locked-breech system.
The pressure has not dropped when the slide starts moving.
... I should say it's dropped very slightly
because the space between the bullet and the casing has increased.
But the bullet's still in the [barrel], so none of the propellant gas has had a chance to leave the barrel.
And that's what locked-breech systems do is they hold the breech closed
until the bullet has actually left the barrel
so that pressure can leave ... the barrel behind the bullet,
and significantly drop before the action opens.
So my conclusion here would be that no, the Savage 1907, 1915 and 1917 actions
don't qualify as actual locked-breech recoil operated actions.
They are in fact a ... version of delayed blowback,
because that locking system does not actually prevent the breech from opening.
It's simply a way to add a little bit more delay to the opening,
similar to what one might do with a lever-delayed system,
or a roller-delayed system, or some of the other elements out there.
It's worth pointing out I actually pulled the parts off of a couple of different pistols and weighed them.
And the reciprocating parts on the Savage
weigh in at approximately [20%] less than those of the FN Model 1900.
Which would be ... the first really massively popular civilian .32 calibre pocket pistol like this.
These guys, the operating parts here, the bits that are actually sliding backwards,
weigh 202 grams. On the FN 1900 that same set of parts weigh 250 grams.
So that rotating mechanism that is in the pistol does give it some benefit.
It allows the recoiling parts to be a little bit lighter, and it is definitely a safe system.
It's just not actually a locked system like the patent claims.
Hopefully you guys enjoyed this one. I think this was a lot of fun to go out and investigate.
So if you have questions that are similar to this
that perhaps I can break out the high-speed camera for,
definitely let me know over on Patreon or Utreon.
I have threads going on both of those platforms each month
to get Q&A questions for videos like these from you guys.
Thanks for watching.