5.7mm pocket pistol?

Discuss the FN Five-seveN line of pistols and accessories.

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Valorius
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5.7mm pocket pistol?

Post by Valorius » 07 Apr 2010, 15:13

Hello all. I've been reviewing all the available info on 5.7mm ammo and terminal performance, and i think i'm going to convert my 5.56mm AR carbine into a 5.7mm AR-57, and sell my HK P7 9mm and buy a FN Five Seven.

My question is, does anyone know of any companies that offer a 5.7mm conversion kit for any of the popular pocket pistols on the market today? If not...someone should! :)

It would be nice to have one cartridge that literally "does it all."

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Re: 5.7mm pocket pistol?

Post by Grantness » 07 Apr 2010, 16:41

This has been discussed before...

Keltec may have been considering such a project, but no word yet.

The problem w/ a FsN pocket pistol is that you cant shorten the barrel too much before you start losing performance. Factory ammo is already watered down enough in the FsN; EA ammo or reloads would be needed to get sufficient performance out of a ~4-4.5 inch barrel. Also, the round itself is quite long and requires a long/wide grip. The magazine well could be shortened, as im sure 12-15 rounds would still be plenty for a pocket pistol. To improve "concealability", I dont think barrel length is as much an issue as is the length of the grip.

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Re: 5.7mm pocket pistol?

Post by murphies_finest » 08 Apr 2010, 06:23

maybe a 57 derringer
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Re: 5.7mm pocket pistol?

Post by Rapier1772 » 08 Apr 2010, 16:42

A 5.7 shoe gun!
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Re: 5.7mm pocket pistol?

Post by s-industries » 08 Apr 2010, 17:30

Man, if I had SolidWorks or ProE I would have at least two designs for an FsNc...wherein the 'c' stands for compact :)

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Re: 5.7mm pocket pistol?

Post by PainKillaX » 08 Apr 2010, 17:33

I think someone said "5.7 Deringer" earlier. Man, that would be fun.

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Re: 5.7mm pocket pistol?

Post by murphies_finest » 09 Apr 2010, 05:07

PainKillaX wrote:I think someone said "5.7 Deringer" earlier. Man, that would be fun.
I had said PKX I think it would be pretty slick! set it up like the police backup 357 deringer "pepper boxes" with the 4 barrels.
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Re: 5.7mm pocket pistol?

Post by Grantness » 09 Apr 2010, 05:40

might be cool, but like I said...the barrel will need to be at least ~4 inches long.

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Re: 5.7mm pocket pistol?

Post by GONRA » 09 Apr 2010, 13:23

Since everyone seems to want to shoot
“+P+ Red Blooded American Handloader” handloads,
GONRA suggests what is SORELY NEEDED is a LOCKED BREECH handgun
otherwise similar to than the FN - maybe a little heavier.

Then load the 5.7x28 FN cartridge with Small Rifle MILITARY primers (thicker cups)
to properly operate at the 55,000 PSI (CUP) pressures.

Uncrate your 20mm Solothurn S18-1000 Anti Tank Cannon and note the Stange
rotating sleeve locking system.
A variant of this
(Stange rotating sleeve THREADED onto barrel ahead of chamber, locking into slide)
would be perfect for our small bore 5.7x28 FN cartridge in a handgun.
Careful thread mount PITCH selection provides a
dynamite el cheapo “primary extraction” too.

Bear in mind that with the self loading firearms we are used to shootin’, items such as
“cartridge case / chamber wall friction force” and “axial strength of the cartridge case”
are secondary items (WAY down the list) that govern the self loading mechanical operation.

Current retarded blowback FN pistol is a TOTALLY DIFFERENT BALL GAME.
“Cartridge case / chamber wall friction force” and “axial strength of the cartridge case”
ARE THE MAIN OPERATING CONSIDERATIONS!!!

WATCHOUT +P+ Red Blooded American Handloaders!!!

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Re: 5.7mm pocket pistol?

Post by Grantness » 09 Apr 2010, 14:26

There are lots of locked breech hand guns being produced right now. That might work. The CZ52 (among others) has rollers that allow it to take very high pressure rounds (if Im no mistaken)....but it is heavy. There's a new Russian pistol (sorry, the name eludes me) that is being advertised as a russian combat pistol that can penetrate soft armor w/ high pressure loads from standard caliber cartridges (i think 9mm) and special hardened bullet cores. I think it uses a similar mechanism to the cz52.

somebody stop me if im completely thinking of something else...

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Re: 5.7mm pocket pistol?

Post by s-industries » 09 Apr 2010, 17:41

How about cutting the gun off even with the rail? Will that keep enough barrel length for reasonable performance? Also, if the rail were removable it would make it easier to carry. I was planning on leaving the action as it is...if it will still work on the smaller version. I'm trying to narrow the gun to the current width of the front part of the slide, with single stack mags and a 1911 style trigger. I'm just having a little trouble drawing precise components with my crayons :facepalm:

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Re: 5.7mm pocket pistol?

Post by Valorius » 09 Apr 2010, 18:40

I don't see 4" as a necessary minimum.

There are loads of pocket pistols that have a barrel that is grossly mis-matched to the caliber/cartridge of the weapon.

Like all these .22 and .17 mags, and the .410 snub nose revolvers, etc, etc.

I would rather have a 2" 5.7x28mm than a 2" .22 or .17 magnum, that's for sure.

That being said, the HK P7 has a 4.1" barrel and is virtually identical in dimensions to the new Walther PK-380 .380 and Walther PPS 9mm, so it would very much be possible to greatly reduce the size of the current Five Seven (or better yet, introduce an entirely new platform intended from the ground up to be a subcompact)

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Re: 5.7mm pocket pistol?

Post by panzermk2 » 10 Apr 2010, 09:27

The issue is the recoil impulse. It is VERY high but very short. On a locked breach you destroy the breach face and yet not have enough residual energy to cycle the side and action. This was discovered the hard way many years ago with the BOZ round.

The solution is an aluminum framed FsN with a heavier recoil spring and hammer spring. This will hold the action closed long enough to allow the pressure to drop to a safe level and cycle the action.
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Re: 5.7mm pocket pistol?

Post by Valorius » 10 Apr 2010, 20:42

I mentioned the HK P7 because of it's unique and highly successful gas retarded blow back system, for which all the patents have no doubt by now expired.

I suspect that might solve the 5.7x28mm's "issues" in short barreled guns.

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Re: 5.7mm pocket pistol?

Post by Grantness » 11 Apr 2010, 05:54

panzermk2 wrote:The issue is the recoil impulse. It is VERY high but very short. On a locked breach you destroy the breach face and yet not have enough residual energy to cycle the side and action. This was discovered the hard way many years ago with the BOZ round.

The solution is an aluminum framed FsN with a heavier recoil spring and hammer spring. This will hold the action closed long enough to allow the pressure to drop to a safe level and cycle the action.
I cant tell you how cool that would be. Im almost afraid such a gun would permanetly damage your ears if you ever had to use it in self-defense w/o hearing protection. I get ringing in my ears frequently after shooting reloads WITH hearing protection. ...and of course, if anyone wanted a smaller barrel thats another thing to keep in mind. It will be MUCH louder and the flash will be larger, possibly causing some disorientation.

Right now, as far as concealability goes...I dont have much of a problem with the FsN's size except for maybe the mag well length. The light weight makes up for some of the size issues. The issue I keep having (partially b/c I dont like to use a holster...I feel like holsters add more to conceal) is that it is a difficult weapon to draw b/c of that massive front sight. Also, its almost impossible to draw in a reasonable amount of time if you've added a laser. If a new frame or slide was being designed from the ground up, I think it would be nice to have space for an integrated laser so it can't catch on things.

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Re: 5.7mm pocket pistol?

Post by s-industries » 11 Apr 2010, 10:44

Grant, I'm with you on the integrated laser. My plan is to have a the dust cover shaped like most guns, only instead of containing a recoil rod/spring it will contain the laser. I just haven't decided how I want to actuate it.

I will also have provisions for easy adjustment of trigger take-up and over-travel. I'm a smaller guy so I am working at reducing the FsN size in every area, but overall height is a primary focus. A simple redesign of the trigger guard (to fit with my 1911 style trigger) will allow the hand to sit higher on the gun. Then I can easily trim a little length off the bottom. I planned on an aluminum frame in the first place just because It seems more likely that I could have something machined than molded.

I'm trying to get my brother to go in half with me on Pro/E...if he does I'll start design work pronto.

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Re: 5.7mm pocket pistol?

Post by Valorius » 11 Apr 2010, 11:11

Grantness wrote:
panzermk2 wrote:The issue is the recoil impulse. It is VERY high but very short. On a locked breach you destroy the breach face and yet not have enough residual energy to cycle the side and action. This was discovered the hard way many years ago with the BOZ round.

The solution is an aluminum framed FsN with a heavier recoil spring and hammer spring. This will hold the action closed long enough to allow the pressure to drop to a safe level and cycle the action.
I cant tell you how cool that would be. Im almost afraid such a gun would permanetly damage your ears if you ever had to use it in self-defense w/o hearing protection. I get ringing in my ears frequently after shooting reloads WITH hearing protection. ...and of course, if anyone wanted a smaller barrel thats another thing to keep in mind. It will be MUCH louder and the flash will be larger, possibly causing some disorientation.

Right now, as far as concealability goes...I dont have much of a problem with the FsN's size except for maybe the mag well length. The light weight makes up for some of the size issues. The issue I keep having (partially b/c I dont like to use a holster...I feel like holsters add more to conceal) is that it is a difficult weapon to draw b/c of that massive front sight. Also, its almost impossible to draw in a reasonable amount of time if you've added a laser. If a new frame or slide was being designed from the ground up, I think it would be nice to have space for an integrated laser so it can't catch on things.
Honestly, in high pressure situations, you don't even notice the flash or or the blast until -after- the emergency is over. Ask any troop that's ever fought in a CQB environment (I have, but only in MOUT training, and even in training, when the adrenaline is pumping, it's a non issue. I've fired off belt after belt of 7.62mm blanks in a small room and it didn't even faze me at the time.)

At my size (5'7"), the FN is just way too big to carry concealed. I rarely even carry my P7. My 99% of the time carry gun is my Ruger LCP.

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Re: 5.7mm pocket pistol?

Post by Grantness » 11 Apr 2010, 11:17

even in the dark?

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Re: 5.7mm pocket pistol?

Post by Valorius » 11 Apr 2010, 22:08

In the dark you can't see squat anyway, if anything a big muzzle flash gives you a momentary glimpse of what you're shooting at. Like a strobe light, i guess.

Of course a big muzzle flash can also get you killed cause it gives the other guy something to shoot at. Then again, an M-60 or whatever else rocking and rolling at night also tends to get people's heads down too. People are terrified to begin with in gunfights from what i gather, so a big muzzle flash and blast might actually help you to suppress the BG's fire or cause him to flee. Then again...it might not. ;)

Like many things in life, it "depends" if it's an advantage or disadvantage.

I had a mag-na-ported S&W 9mm with Trijicon night sights that i used to use to dazzle my uncles old timer buddies at their hunting camp at night time by plinking beer cans that would be totally impossible to hit without night sights. The mag-na-porting exhaust gas jets are not really even noticeable to the shooter, but they look mighty impressive to bystanders.

I really view muzzle blast/flash to be a very minor issue in a CCW or home defense weapon. But if i were to let it affect my decision making process i would probably be of the view that more blast/flash in a home defense gun would just scare the living bejesus out of the BG, and probably make them dump in their pants if you onloaded on them with a short barreled AR or something of the sort. :D

Afterwards you will be all disoriented and your ears will be ringing and all that, but they'd be ringing even if you were shooting a .38 snubbie, and you're going to be all disoriented from the stress of the event too, probably. I just feel like my ears ringing are the least of my concerns if i was just forced to use a firearm to defend my life.

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Re: 5.7mm pocket pistol?

Post by Synthetic » 13 Apr 2010, 13:19

Valorius wrote:Hello all. I've been reviewing all the available info on 5.7mm ammo and terminal performance, and i think i'm going to convert my 5.56mm AR carbine into a 5.7mm AR-57, and sell my HK P7 9mm and buy a FN Five Seven.

My question is, does anyone know of any companies that offer a 5.7mm conversion kit for any of the popular pocket pistols on the market today? If not...someone should! :)

It would be nice to have one cartridge that literally "does it all."
How much do you want for your HK P7?

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