Anyone here into firearms?

Wolfenstein

I've got a few guns myself....mostly pistols.

Kimber Stainless Pro Carry II 1911 .45
Kimber Ultra TLE II 1911 .45
Springfield A1 Loaded with all kinds of custom goodies 1911 .45
Glock 19 9mm
S&W Bodyguard .380
Ruger SR9C 9mm
Sig Sauer P229 Extreme 9mm (my favorite)

I also have a old .243 breach load (cant remember the name brand)
Mossberg 500 with a pistol grip

and some others which I cant remember off of the top of my head.

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Ghostvette

I've got an assortment of rifles & pistols, (just a few):

ParaOrdnance SSP (full size government model) .45
Colt Combat Commander .45
Colt Officer's Model .45
Kimber Ultra Carry II .45
SIG P229 in .357 SIG w/.40 extra barrel
Beretta Mini-Cougar .40 (for sale or trade)
Ruger Mini-14
AR-10 D9 Firearms custom build .308
AR-15 D9 Firearms custom build in 6.8 SPC w/300 Blackout extra upper
M-14
1903A3 Springfield .30-06

and several more...

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2015 Magma Red 6MT Sport Tech/2012 Fairlady MB 6MT Base (RIP 08032018)https://www.nicoclub.com/FSM/370Z/Coupe/

synolimit

actually i was wrong too with the 200fps per inch. but i just saw a guy cut a 24" barrel to 16.5" at every inch. the 24" was the fastest. like Hilters V-3 cannon you do get the fastest rounds out of the longest barrel. im sure a 5.56 will eventually slow but i dont think we'd know when, when most only go to 24". i believe him since most 24" barrels like the tester guy shot, was almost 3500fps out of a reminton 700 with a normal 5.56 55gr round. the guy that shot through the ar500 had a "bull something" barrel that was chrome lined or something, adding to the speed he said. he seemed to know his stuff so id guess he did 3700fps with a chronograph at some point.

regardless of m.v., at 50 yards he punched straight through it while none of us could.

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13 370z-

synolimit

heres a good read....

He was probably not lying, nor using AP rounds. It seems counter-intuitive that a much smaller bullet would do so much more damage to the plate, but that is how it works. In fact, in the world of steel shooting, this is very common. Many ranges that have range-owned steel will not let you fire anything at it with a muzzle velocity over about 3000 fps. The smaller and faster they are, the more harmful they are to steel. Rounds like .221 Fireball, .204 Ruger, and stuff like that are the reasons for rules like this. They easily blow clean holes in AR500 even at several hundred yards. I can't find too much outside source information on WHY this is, so I'll go ahead and take a physics stab at it.

While I knew that this was the case, I never REALLY investigated why, so you asked a great question . I pondered a few different possible solutions. Impulse, power, sectional density, kinetic energy, just to name a few.

There is no question that the rifles you were shooting at the plate had a great deal more kinetic energy than his 5.56, even at 3700 fps. Kinetic energy is RELATED to my analysis, but it does not end there.

In the end, I came up with the conclusion that the power transferred to the plate is what is killing it. When I say power, I'm referring to energy per unit time, the physics power. (I say this because the word, "power," is thrown around quite a bit in the shooting community, with a very loose and often incorrect definition). Many materials have a power density limit, meaning you can only add so much energy, over so much time, before things start to break. For example, if you take a 100 W bulb and plug it in to a standard 110V fixture, you get 100W of power. Plug it in to a 440V outlet, you get 1600 W of power, but the filament will likely fail, and the bulb will burn out. Why? Because there was too much power.

If you leave a 100 W bulb on for an hour, you have expended significantly more total energy than the very short bright flash of 1600W, but the bulb will operate normally.

An additional example: Consider hammering a nail in to a board. In this case, we want the board to "fail," to allow the nail in. Trying to push the nail in with your hand is near impossible, right? Even if you're using WAY more energy than you would using a hammer, you're applying that energy over too long a time, and you have low power. A hammer, on the other hand, takes less energy, but imparts that energy on the nail and in to the board in a much shorter time, meaning you can deliver much more power with a hammer than you can by pushing with your hands. This "power" only lasts for a split second, but that's all you need

Power = Energy / Time

You can see there are two ways to increase power... Either increase the energy, or decrease the time.

The total amount of KE is just a part of the equation. The other important half is, "over what amount of time did this energy transfer occur?" In the above example, the normally operating bulb expended 360,000 J of energy, over the course of one hour. In the 440 outlet, Just 1600 J of energy were expended, but the filament failed. That is because the normally operating bulb was operating at 100 Joules per second, while the one that failed was operating at 1600 Joules per second. Somewhere in between 100 Joules per second and 1600 Joules per second is the filaments power density limit. Exceed it, and the filament fails.

To get the bullet power, you must first determine the KE of each round.

55 gr, 3700 fps = 1671 ft lb
150gr, 2700 fps = 2427 ft lb

Here's the kicker... Since the 55gr bullet is shorter, and traveling much faster, it dumps that energy in to the plate much faster than the .308 bullet.

To find the impact time, you take the bullet length in inches divided by the bullet speed in inches per second, to give an approximate amount of time the bullet is in contact with the plate.

Next, take your KE divided by impact time for each round, you'll get a power rating in ft lb / s

When you compare those two numbers, you find that the 5.56 round is delivering 1.6 times as much power in to the plate as the .308. Even though it is smaller, lighter, and has less KE, the bullet exceeded the plates power density rating, and punched a hole through it.

While .308 delivers more KE to the target, 5.56 delivers it's energy considerably faster.

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13 370z-

Wolfenstein

How do you like that P229 chambered in .357 sig? I have been wanting to get one for a while now. Do you find it difficult to find ammo for it?

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Ghostvette

I haven't had a problem getting ammo, I bought a bunch before the availability got crazy. The recoil isn't bad, it's a little less than the .40, so that's a bonus. I've been tinkering with my carry gun, and the SIG gives me good capacity and manageable recoil. With the extra .40 barrel, if I don't want to shoot .357 SIG, I swap barrels and use a couple of my extra mags. A few minutes, and I'm banging away with the .40. I like it.

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2015 Magma Red 6MT Sport Tech/2012 Fairlady MB 6MT Base (RIP 08032018)https://www.nicoclub.com/FSM/370Z/Coupe/

Wolfenstein

I need one. I carry my 229 now unless I am wearing a t-shirt then I will carry my bodyguard and in the winter I carry my springfield. A majority of my carry is with my 229 and it would be nice to have the option of 9mm and .357 sig.

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Ghostvette

I don't think a 357 SIG barrel will fit your 9mm frame, that would be a question for SIG. Since the 357 SIG is a necked down 40 (basically), the mags are the same for the 357 & 40. I got my 229 used for about $500, so that might be an option for you. Any excuse for another gun...

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2015 Magma Red 6MT Sport Tech/2012 Fairlady MB 6MT Base (RIP 08032018)https://www.nicoclub.com/FSM/370Z/Coupe/

Wolfenstein

Well I have been going back and forth on whether or not I want a new p229 that comes chambered in .357 sig or if I want to get this which will fit my generation 9mm p229:

Sig Sauer P229 357 Caliber Exchange Kit 12rd

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Ghostvette

That might be a great way to go. I should look and see if they make a kit for mine that I could shoot 22 through it. But i think I'll just pick up a SIG Mosquito...

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2015 Magma Red 6MT Sport Tech/2012 Fairlady MB 6MT Base (RIP 08032018)https://www.nicoclub.com/FSM/370Z/Coupe/

Wolfenstein

I believe there is a kit for a .22 conversion or you could go with a mosquito. Personally I have never been a fan of .22's. They ALWAYS seem to have feeding issues, which I guess is not a problem for going to the range and plinking but I wouldn't want to carry one for protection.

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6MT

CCI stingers for the .22LR feed issues with semi pistols. Usually, after break-in, there's seldom any problems.

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Andrew

2009 370Z Sport/Touring 6MT sold
2013 Honda Civic Si coupe D/D

SouthArk370Z

I use copper-coated round-nose .22LRs and seldom experience a feed problem. I get frequent jams in some guns when using un-coated and/or blunt-nose bullets. YMMV

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Ghostvette

The biggest complaint I hear about the Mosquito is feed issues, then upon questioning the shooter, they just took it out of the box, loaded it up and started banging away. The owner's manual says to thoroughly clean it before shooting to remove assembly lube, which could cause some functionality issues. I've shot a couple different ones and haven't had an issue with feeding, as long as you use good quality 22 ammo. We did have some issues with some of the lower velocity 22, but we passed it off as something we did incorrectly, rather than crappy ammo. It loves CCI Mini-Mags and most other hyper-velocity stuff.

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2015 Magma Red 6MT Sport Tech/2012 Fairlady MB 6MT Base (RIP 08032018)https://www.nicoclub.com/FSM/370Z/Coupe/

6MT

Yeah, cleaning that "goop" off from the factory is a given. My Glock 17 was the same.

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Andrew

2009 370Z Sport/Touring 6MT sold
2013 Honda Civic Si coupe D/D