Topic: Automag V questions

Retrieved: December 07, 2013

Can anyone tell me the diameter of the breech end of the Automag V's barrel? And maybe a picture of the underlug and cam track?

Luc V.
Oct 26 2012

I hope this is what you need:

TRX302
Oct 27 2012

Thank you Luc, that's exactly what I was looking for!

Can you take a few more measurements for me? I'd like to know the width across the chamber area, and the dimension from the bottom of the chamber to the bottom of the lug.

XP001
Oct 27 2012

hey Luc,
Just be done with it and send him the barrel, lol. You might as well mic everything and maybe make a drawing to scale for future ref. of others. I got an idea, start making a blueprint and file them for us. I would do it but don't have a mic, lol.

Just need to know so I'll ask, why do you want to meassurements?

Luc V.
Oct 27 2012

TRX302, here are the requested measurements.

and one extra, but now you have to tell us what you're upto!

Oops sorry measurements are in inch, I forgot to switch to milimeters

If you need any other, my pistol is still stripped laying on the kitchen table for the next hour...

To XP001, you just gave me an idea, I start to ask money from now on for the measurements and pictures, send payment trough paypal...

Nah, serious, I'm glad to be of some help.

TRX302
Oct 27 2012

Thanks again, Luc. I appreciate you taking the time.

XP: the picture of the cam track tells me the AM-V barrel slides back more than is common and has a very gentle disengagement angle compared to other designs. The other measurements tell me that is is rather thin around the chamber area.

XP001
Oct 28 2012

I never thought about the thickness around the chamber and I never had or heard anything about crack chambers/bbl's before. I never used or made handloads in mine and have about 1000 rds thru it without a issue. Have you seen any? I perfer mine AMT V over my Desert Eagle brick, love them ports!

Luc, you realize that Paypal is anti-gun right?! Just so you know you should only ask for Postal Money orders, they are good as cash, lol.

I think you should make prints for e-files for all us as long as you have it in pieces. I would do it if somebody sends me a electronic mic, hint hint.

TRX302
Oct 28 2012

Some things, you can design from the equations in the handbooks. Other things, "industry standards" may diverge quite far from what the books say. According to the formulas in Kent's Mechanical Engineer's Handbook, the rod bearings in your car should beat themselves to death before the engine warms up the first time. In practice... some of those equations are extremely conservative, and often have the hidden assumption that the service life is "forever." So sometimes you get a better feel about the design of specific things by looking at what others have done.

> I perfer mine AMT V over my Desert Eagle brick

I have big gorilla hands, and hanging on to a friend's Desert Eagle is still awkward.

I'd love to see one of the LAR Grizzlies stripped down; unlike the AMT-V, it appears to be a 1911 variant. But Automag Vs are common as dirt compared to the Grizzlies.

Oddly, LAR seems to call everything they make a "Grizzly"; I've seen it stamped on their Maadi-Griffin clone .50 caliber single shot rifle, too.

Luc V.
Oct 28 2012

Conserning thickness around the chamber, just think about the following:

This picture below is to what I believe the thinnest area of the chamber from the V in .50 caliber.

And this is the picture from the cylinder of my brothers Ruger Super Redhawk in caliber 454 Casull.

The "walls" of the cylinder are much thinner as the chamber from the V.

The Casull works at 56.565 psi or 3900 Bar and the 50 AE AT 33.359 OR 2300 Bar.

I guess thickness is relative, it depends or the materials you use...

To XP001, I know about the paypal (hypocrit) policy, but I treat them the same way, I use it because it the easiest and fastest way to transfer money overseas.

If it is payment for gunrelated items, I use the policy don't ask don't tell...

TRX302, sorry no help here, my Grizzly is 'only' 45 WinMag.

TRX302
Oct 28 2012

Luc V. wrote:
my Grizzly is 'only' 45 WinMag.

Is it the same as the .50 otherwise?

Luc V.
Oct 29 2012

Sorry, I can't answer that question. I never saw or had a .50 Grizzly in my hands.

TRX302
Oct 29 2012

I'm crushed. I was beginning to think you were omniscient.

TRX302
Nov 27 2013

So, I'm looking at the AMT-IV/V again, and now I'm really, really impressed with Larry Grossman's work.

Like so many others, I dismissed the IV as a souped-up 1911 because it looked much like one, and none of the gun magazines of the day had any pictures of one disassembled. Not that I would have understood what I was looking at back then, without a helpful editor pointing things out. also I was put off by the "gravel-blasted" finish, the ugly slide stop lever, and the ugly grips. I didn't care much for the round "buttocks" and chipmunk cheeks on the slide, either.

Anyway, the AM is less like a 1911 than a Tokarev or a Smith 59. It's way different in there.

note: One of TRX's Laws is "Everything looks like something else." I'm just trying to give you an idea of things that are similar to Larry's design as examples.

The first thing, and the least important, was the use of a ramp instead of a link to pull the barrel down. Browning himself came up with that one for the High Power, and most "1911 style" pistols use that method instead of a link nowadays.

But when you look at the barrel and slide, there are no locking lugs. The back of the barrel has an extension (called the "hood" on a 1911) that contacts the breech face. The ejection port is opened up, and the back of the barrel is block-shaped, and engages the port to form a single huge locking lug instead of having grooves and ridges cut inside the slide and on the barrel like a 1911. As far as I know SIG came up with that, though Glock popularized it. This saves a lot of machining, which makes it cheaper, and the big port reduces ejection issues, and puts more metal around the breech, making it stronger.

Browning didn't do it that way; he used complex tooling and cut lugs farther foward, up inside the slide. He was likely fully aware of using the breech face, but if you look at the original .38 and early .45 designs, you'll see really small ejection ports. This was probably to minimize entry of dirt. Some 1800s designs even had sprung sheet metal covers over the ejection ports, like an M-16. Nowadays we don't worry much about it. Browning may not have worried either, but a lot of the 1911's design was by request of the Army. Browning usually offered several options when the Army nitpicked something, the Army decided which one they wanted, and Browning went with that. In general, the Army committees chose well...

Anyway, I've looked at pictures of AMV bits for years, and never noticed they used that locking method. A clear case of "can't see the forest for the trees", I was so curious about the ramp geometry, I didn't even notice.

He used a "conventional" pivoted extractor hook, but the front of the hook doesn't go around the corner of the ejection port. Instead, it fits into a closed slot on the slide. This strengthens the area around the port considerably - the large SIG-style port makes a weaker slide than the small 1911 style. I haven't noticed any other guns that did that; Larry's design looks like a worthwhile improvement.

Larry kept the 1911 barrel bushing and recoil spring system. Many newer guns dispense with the bushing entirely, and most like fancy captured spring assemblies. I think the bushed barrels are located more precisely, and some of those fancy recoil spring systems are a pain in the butt.

The largest divergence is the fire control group. To fit the longer cartridges, Larry needed more room. He got rid of all the grip safety and hammer spring bits that a 1911 uses, and went with a very Auto Mag-ish pivoted trigger and trigger bar mechanism. He moved the safety up into the slide, and came up with a complete system that was very simple and looks like it would have been inexpensive to make. Those are major wins for a production firearm.

Moving the safety up to the slide simplified the fire control group considerably. I don't know how the ergonomics of that work in the AM, but it feels fine on my FEG .45.

The more I look at the AM-IV/V, the more I like it...