What kinds of ammo are hardest on the gun?

[Scoundrel]

The back story which prompts this question is here, in case you are interested: http://kahrtalk.com/showpost.php?p=124224&postcount=56

So now I want to know what kinds of ammo are likely to break fragile little guns.

Is it the velocity that make them beat up the gun more?
Is it more related to the bullet weight?
Is it some magical formula of pressure, weight, and barrel length?

When I get the mini-revolver back, if they have done what I asked (and their customer service person said was totally do-able), I'll be getting back a .22 LR model instead of the .22 Magnum. It is my intention to try and maximize its life by taking it easy on the thing when practicing with it, and find something to put in it when carrying it in "deep cover" mode that will be as effective as .22 LR can get without destroying the gun.

Charter's manual/website says that their mini-revolver should be able to handle high velocity rounds. But then again, it also says it should be able to handle .22 Magnum, and we saw how that turned out.

These are the 4 choices I am considering.
Note that these measurements are only what I could find posted, and I do not know what barrel length was used to measure them.

1. Aguila Super Colibri
Bullet Weight: 20 grains.
Muzzle Velocity: 500 fps.
Muzzle Energy: 11 ft. lbs.
Bullet Composition: Solid Lead Waxed (looks like a .177 pellet in shape, almost)

2. Aguila Sniper Subsonic
Bullet Weight: 60 grains.
Muzzle Velocity: 950 fps.
Muzzle Energy: 120 ft. lbs.
Bullet Composition: Solid Lead Waxed

3. Federal (no fancy branding; 550-round value pack)
Bullet Weight: 36 grains.
Muzzle Velocity: 1260 fps.
Muzzle Energy: 125 ft. lbs.
Bullet Composition: Copper Plated Hollow Point

4. CCI Stinger
Bullet Weight: 32 grains.
Muzzle Velocity: 1640 fps.
Muzzle Energy: 191 ft. lbs.
Bullet Composition: Copper Plated Hollow Point

Some notes about these rounds:

1. I am well aware that the Aguila Super Colibri is useless for anything except putting holes in paper and killing rats at point blank range. I would use this only for making sure the gun works and showing it off at the range. This stuff tends to leave a ring of tar-like black goo in the cylinder that makes it difficult to load/unload anything else, but that's OK, it would get cleaned after a range trip.

2. I am well aware that the Aguila Sniper Subsonic would not stabilize, and would keyhole badly. That's OK, because the effective range of this gun is about 15 feet, and I really wouldn't care if the bullet was traveling forward, backward, or sideways when it hit its target 1/63rd of a second after the hammer falls. I do care that it weighs 60 grains. I am worried about whether that bullet weight is more damaging to the gun than a lighter, faster bullet.

3. The Federal value pack ammo is "the old standby". When I was having difficulty with my S&W 317 AirLite revolver, this was the stuff that I could shoot all day without jamming up the cylinder. Also, when I was having trouble with rounds jamming up in the aftermarket Black Dog 50-round drum for the S&W M&P 15/22, this is the stuff that would feed through that drum all day with no issues. It shoots kind of dirty, but it works. It is an excellent "middle ground" when you want copper plated hollow points that cost $0.04/round and feed/shoot reliably, and you aren't too worried about accuracy or how dirty your gun gets.

4. This stuff gives the most satisfying bang, but it jams up my 317 AirLite revolver. The casings do a half-circle bulge near the rim because the ejector gives way allowing the casing to expand. The mini-revolver has solid round cylinders all of the way to the back, and no ejector, so this might not be a problem. But the Stinger ammo feels like it kicks the 12-ounce 317 around a lot, so what will it be like in the 6-ounce mini-revolver? Will it damage the gun?


So there it is. I await your carefully considered input...

[CJB]

The slide velocity is proportionate to the bullet velocity, when considered in terms of momentum.

That is, the Law of Conservation of Momentum, tells us that mass (weight) x velocity will be the same for both the bullet, and the moving parts.

To calculate this, take the weight of the slide, and the weight of the barrel, and half the weight of the recoil spring (not the compression, but its physical "heaviness" in weight).

Lets say (I'm making this up) that a PM9 slide weighs 7.25 ounces, the barrel weighs 7.5 ounces, and the recoil spring weighs .5 ounces (half of which is .25 ounces). Total weight - 15 ounces.

Lets say we have a 115g bullet moving 1120fps, and a 124g bullet moving 1065fps through the PM9.

Ok, now its time for the math. There are 437.5 grains per ounce, so lets take 437.5 x 15 ounces and we get - 6562.5 grains for the moving gun parts.

Now lets look at the bullet momentum - 115g x 1120 = 128800grain-feet seconds

Divide that by 6562.5 and we get an initial slide velocity of 19.6266 feet per second.

Now lets do the other cartridge.... and we get 20.1234 feet per second initial slide velocity.

So, you can see, in the example above, the 124g bullet and its load, will beat up the gun slightly more than the 115g bullet and its respective load.

All of that is made up numbers - not Gospel truth. You'll have to run the real life numbers to get real life results.

Its momentum when figuring velocities of the parts, not energy. Energy would be 1/2 x mass (weight) x velocity-squared. Fortunately that is so, because if it wasn't, who would get hurt more, the shooter or the bad guy!

[Scoundrel]

OK, CJB wins the prize for the "propellerhead" reply. :)

Who's going to go for the "practical" reply?

[ltxi]

But to simply answer your question, high energy/high pressure rounds. In most center fire handgun calibers ammunition is grouped into std pressure, +P, and no standards +P+. Guns are rated to what they can handle without undue wear, damage, or destruction.

.22 rimfire isn't rated like that. But they're all relatively low energy rounds. Any handgun that can't handle anything .22 within it's appropriate loading....short/long/long rifle/WMR....should be thrown into deep water or be buried six feet in the back yard.

Rohm RG22 comes to mind.


Edit....

Sorry about your Smith issues. That's just wrong!

My NAA Mini Mag weighs 7 oz loaded. Ammo I guess makes up an ounce or two of that. Been carrying and shooting it for about 15 years. Handles well and no wear. Quality speaks.

[Scoundrel]

Any handgun that can't handle anything .22 within it's appropriate loading....short/long/long rifle/WMR....should be thrown into deep water or be buried six feet in the back yard.
Rohm RG22 comes to mind.

Well, that's a good black and white answer if we're talking absolutes, but there are many cases where people say you just want to find what works best in your gun, rather than saying you should toss your gun off the ferry halfway across the river.

This was true for my S&W 317, which doesn't like stingers, but functions very well with lower velocity ammo.

The problem is, with the very small number of shots it took to rattle the derringer apart, I want to try to get an idea what might work well before I rattle another one apart. I'm not sure how far Charter's goodwill and customer service go and I'd rather not overextend it.

It's pretty obvious that using the 20 grain subsonics for playing with it on the range is the way to go. But what do people think about the other three rounds listed, and how likely they are to damage the gun?

I selected a "low, medium, high" spread - slow 60-grain rounds, standard velocity 36 grain rounds, and high velocity 32 grain rounds. Which one will beat up the gun the least, do you think? And, do you think that one will have a decent amount of energy when it hits the target?

I will, of course, be having this discussion with their tech support guy when I get my gun back. But, I want to have it here first, objectively.

[Scoundrel]

Sorry about your Smith issues. That's just wrong!

My NAA Mini Mag weighs 7 oz loaded. Ammo I guess makes up an ounce or two of that. Been carrying and shooting it for about 15 years. Handles well and no wear. Quality speaks.

Thanks. I have considered sending it back to S&W repeatedly until they finally send me something that can shoot Stingers without jamming up.

I have also considered having a smith put a shim on the ejector rod to make it stop wiggling. There's a local smith who's interested in doing that for me, but I'm not sure I want to spend the money for that. I'm not sure I even really want to fire Stingers through it.

So it's not really worth the effort/money of doing either. I'd only be doing it out of sheer stubbornness. So I just run Federal or Winchester bulk ammo through it, and it does fine with those. With a 1.5" barrel, I can't expect much from that gun anyway.

I do recognize now that I should have spent more for the NAA version. Maybe I'll sell the Charter one when it comes back and buy an NAA. How many rounds do you figure you've put through it? What ammo do you typically use in it?

[ltxi]

This was true for my S&W 317, which doesn't like stingers, but functions very well with lower velocity ammo.



Yeah, I could go with that. Especially if it's the original, aluminum cylinder version.

Functional equivalent would be my older 442 designed for standard pressure .38. I'd never think of shooting +P+ through that one.

Or my old, original Charter Undercover. Stretched the frame on that one with hot handloads back in the '70's before I became semi-sane.

But neither of these ever locked up with over pressure ammunition because of unsupported case bulging.

[CJB]

ok, cjb wins the prize for the "propellerhead" reply. :)

hah!!! Thank you!!!!~

[ripley16]

Or my old, original Charter Undercover. Stretched the frame on that one with hot handloads back in the '70's before I became semi-sane.

I did the same thing at the same time - ruined a Charter Arms Undercover by shooting +P in the '70s. The reason I switched to a auto.

[ltxi]

I did the same thing at the same time - ruined a Charter Arms Undercover by shooting +P in the '70s. The reason I switched to a auto.

Ha,ha....I still have that gun, and actually shoot it occasionally. It has, at best, a one pound single action trigger pull.

Other than SuperVel, by inference, did we even have +P in the '70s?

[CJB]

I should note.... if you simply take the weight x velocity of each load, the ones with the highest forward momentum (what you just calculated) will give the highest oomph to the parts on the gun. Thought that was maybe self evident.... but just sayin' for clarity sake

[Scoundrel]

Thought that was maybe self evident....

Didn't want to make any assumptions about that. I'm not a physics whiz, or a gun whiz.

[CJB]

Wella.... as long as yer not a cheeze-whiz, it'll do.

Its all relative, and directly proportional. You really dont have to "know" how fast the parts are moving. You were concerned with "relative" properties of the various ammo. So, for any given gun, the projectile with the most MOMENTUM (not energy) will impart the most counter-momentum to the parts.

[les strat]

All I know is Marlin's manual tell me not to use hyper velocity ammo, even though I do when I shoot squirrels because of the accuracy (CCI stingers). I usually use just high velocity at the range and haven't had any noticable wear.

[muggsy]

Tracers and Jocko's hand loads. :)