What gun finish best thermal barrier?

[m21sniper]

Im getting a HK P7 PSP tommorow that needs a finish for cheap. I need a finish that has good thermal dissipation or heat transfer because the PSP model does not have the American P7's heat shield in the trigger guard.

If i can find a nice silverish finish that has good thermal properties(like jet hot coating or something one would use on engine headers) id be a damn happy camper.

Any suggestions?

Here's a pic of a P7:


(this is actually the P7M8 with the heat shield)

The wood grips cost about a $100, i'll lay out another $100 for night sights and another $150 for mag-na-porting. If i can end up getting the frame done for about $150 i should be able to get the P7 ive always wanted for about a $1000 total investment.

That would make me a very happy camper.

[Schumi]

If by finish you mean the difference between blued, black, or polished? What is the frame made of, aluminum with a stainless barrel? All Stainless?

The finish is most likely just an e-coating or anodizing. Anodizing does affect the thermal conductivity on the surface of the material, but only on the oxide layer of the coating, which is about 0.001" thick. The rest of the material will have the same K value, and therefore thermal conductivity as any other.

Unless its a composite frame, you won't be able to tell a difference in thermal properties between the finishes of say stainless or gun metal. The heat transfer properties between aluminum and stainless are far different (stainless will conduct heat slower, and hold heat longer, than aluminum) but I take it the slide/frame is all the same base material and they just coat it differently. I'll admit, I'm an engineer; I don't know a lot about pistol construction.


*Edit- radiation doesn't apply to the above, and it based on emmisivity/absortivity of the material. In this case, black would be worse than stainless, if it is out in the sun. but I doubt you're going to be leaving this out to bake in the heat.

[azasadny]

Parkerizing?

[Rick Lee]

My first P7 was hardchromed when I got it, I believe by Tripps.



I had Robar redo my second one in NP3, which is especially nice on these guns, because NP3 does away with the need for any lube and you can wipe all grime off with just a paper towel. Its lubricating properties are awesome and it's impervious to any kind of sweat corrosion or tarnshing.



Unfortunately, unless you have it redone locally, you need to add about $75 to the price for round-trip shipping. I now live down the street from Robar, so they're very convenient for me.

[Rick Lee]

BTW, I'm not aware of a finish that makes the PSP any cooler to shoot. Their inherent design just makes them get real hot after a few mags. That's fine for carry duty, but you'll need to let it cool for a while if you're shooting at the range. I always bring at least three handguns to the range anyway and the P7 is super easy to strip and let cool while I shoot something else. Otherwise, spend the bucks and get the P7M8. There's a local guy with a P7M10 in hard chrome for $2400. I lust after that gun.

[WilsonTC]

Originally Posted by Rick Lee

BTW, I'm not aware of a finish that makes the PSP any cooler to shoot. Their inherent design just makes them get real hot after a few mags.

What's so different about that gun that makes it too hot to handle? I never recall having to let a gun cool in all my years of shooting (but I've never shot a squeeze-cocker, either).

[RPKESQ]

Originally Posted by WilsonTC

What's so different about that gun that makes it too hot to handle? I never recall having to let a gun cool in all my years of shooting (but I've never shot a squeeze-cocker, either).

It is gas retarded blowback.

Gas from propellant combustion is syphoned off from the barrel slightly ahead of the chamber and used to keep the action locked until the projectile is out of the barrel and the bore pressures are within safe limits for action unlocking.

The gas cylinder is located under the barrel and over the trigger gaurd area. Since very hot gases are fed into this area it becomes very hot. Hot enough to burn flesh in short order with rapid fire.


Robar it.

[m21sniper]

Wilson TC:

The P7 is gas operated, almost all pistols are delayed blowback or blowback operated.
The proximity of the gas piston to the trigger guard causes it to get very hot.

I'm thinking that a thermal barrier like a jet-hot ceramic coating, like you'd get done to engine headers should be effective. If not, i'll probably pay a gunsmith to silver-solder or epoxy a custom heat shield onto it for me.

A used P7M8 is another $500 over what i want to spend just to get a conventional mag release and heat shield. I cannot justify the expense. I cannot possibly imagine it would cost anywhere near $500.00 to have some sort of small custom heat shield installed, but i'd prefer to get a finish that would provide a thermal barrier if at all possible.

Here is a good pic of the P7M8 heatshield just above the trigger:

[GO DAWG GO]

Snipe,

I haven't read all the posts so forgive me. But, you can trust this rule. If the surface is matte or flat in luster (parkerizing) it has more surface area and will dissipate more thermal radiation than any reflective finish (blueing) regardless of material. In some cases regarding micro inch finishes, it is calculated almost twice the surface area...and appreciably more dissipation.

My 02 cents

Bob

[jyl]

What does a PSP run nowadays? Are these the police refurbs?

[Rick Lee]

CDNN had them for $599 when I got my last one. I hear they're even cheaper now. Mine was a police turn in, but looked unfired and uncarried.

[m21sniper]

Originally Posted by jyl

What does a PSP run nowadays? Are these the police refurbs?

I'm getting it for $500.00, and yes, it's a police refurb with a 95% finish.

Rick: CDNN?

[m21sniper]

Originally Posted by GO DAWG GO

Snipe,

I haven't read all the posts so forgive me. But, you can trust this rule. If the surface is matte or flat in luster (parkerizing) it has more surface area and will dissipate more thermal radiation than any reflective finish (blueing) regardless of material. In some cases regarding micro inch finishes, it is calculated almost twice the surface area...and appreciably more dissipation.

My 02 cents

Bob

Can you give me an example of a finish that has 2x the surface area vs bluing? If so i'll try and use that specific finish.

[BlueSkyJaunte]

Originally Posted by m21sniper

Rick: CDNN?

http://www.cdnninvestments.com/

Download their PDF catalog, the site itself doesn't have firearms listed.

[Jeff Higgins]

Originally Posted by RPKESQ

It is gas retarded blowback.

Gas from propellant combustion is syphoned off from the barrel slightly ahead of the chamber and used to keep the action locked until the projectile is out of the barrel and the bore pressures are within safe limits for action unlocking.

The gas cylinder is located under the barrel and over the trigger gaurd area. Since very hot gases are fed into this area it becomes very hot. Hot enough to burn flesh in short order with rapid fire.


Robar it.

Interesting. Not being all that into the autoloaders, I wasn't aware that such a small example was gas operated. I thought that only something the size of a Desert Eagle would have the room needed for this method of operation.

Actually, from this situation as I understand it, it may very well be too small of a pistol to make effective use of this action. If overheating the frame above the trigger finger - to the point of causing injury to its operator - is truly a problem, it sounds as though H&K may have forced the issue a bit. Maybe they should have gone with a more traditional method of delaying blowback, like the tried and true toggle link.

Oh well; while I was mildly surprised to learn of this condition, I suppose it will never affect me. My Peacemakers won't ever do this...

[Rick Lee]

Here you can see the gas piston on mine. The barrel is part of the frame and not removeable, as far as I know.





I don't know that it's gonna hurt the shooter when it gets hot. It's not like a sudden thing. You'll put it down and let it cool off before you let it burn you. I can't remember exactly, but you can probably go through four mags before you need to take a break. Obviously, you're not gonna do well in an all out gunfight with one of these, but then the magazines are so expensive, that you probably can't afford to carry more than an extra with you. It's fine for CCW, it's very accurate, easy to break down and just a cool little gun. The PSP's are very affordable. I called it my Hans Gruber gun.

[m21sniper]

After firing 90 rounds in pretty short order today (using 2 mags and reloading quickly over and over), i think the heating issue is a non factor. It got hot, yes, but not hot enough to not shoot, and certainly not hot enough to not shoot in a crisis situation.

IMO, this is for the most part a non-issue. If i ever get into a situation where the thing is so hot its burning my finger that will be the least of my problems. To be honest, based on my experiences, i doubt you'd even notice it at all until a couple minutes after the situation calmed down.

Originally Posted by Jeff Higgins

Actually, from this situation as I understand it, it may very well be too small of a pistol to make effective use of this action. If overheating the frame above the trigger finger - to the point of causing injury to its operator - is truly a problem, it sounds as though H&K may have forced the issue a bit. Maybe they should have gone with a more traditional method of delaying blowback, like the tried and true toggle link.

Oh well; while I was mildly surprised to learn of this condition, I suppose it will never affect me. My Peacemakers won't ever do this...

The fixed barrel makes the P7 an EXTREMELY accurate weapon, and the gas operation noticably reduces recoil. Combined with the unique squeeze cocker action, i really view the P7 to be a near perfected example of an (all-steel) compact autoloading pistol.

I've wanted one of these for 20 years, and now i have one. I fully suspect i'll have it to the day i die.

It goes out for mag-na-porting and trijicon night sights on the 1st, and the NICE wood grips are already on order.

[m21sniper]

I was looking in my P7 manual, and they list the heat shield of the P7 "M" guns as a separate part, so i'm going to try and see if i can just order one of those for my PSP. That would definitely be the simplest solution.

[charleskieffner]

robars "norton special" (see robars web site) i think is $170 bucks. i have had them do a number of my veapons. check website for specials. last one i did was the POS HK4 .380 slide i got in a deal and another HK4 .380 i got. 15-20% off and it came to like $140 with the special.

if yer gonna buy a HK P9S...................yer gonna HAVE TO BUY TWO (2)!

why ? because when ya shoot the 9mm and see how INSANE FREEKING ACCURATE IT IS and simple to take apart............you will want the .45 HKP9S.

or vicey versa like me.

i have the HK P9S in .45 and i freeking STOLE IT! HK georgia still works on them in 9mm and .45. when i sent mine back they did the UBER WAZOO TAKEDOWN REBUILD/TEST FIRE with (3) different flavors ammo/sent their targets to me/ an HK PIN/multiple steekkkers/various other hk propaganda/ technicians personal note to me on what he did/ free buffer/trigger job/and damn near had me falling over with CLASS ACT CUSTOMER SERVICE! ALL FO FWEEEEE!

[m21sniper]

The P9S is as nice as it is expensive. LOL. I put that one in the Sig P210 category of unobtainium dream guns.

The P7 has been my dream pistol since i was a young US Army Infantry E-1, so i've wanted one for decades. I would have prefered an M8 with the improved mag release, but i can certainly live with the PSP model i got. It's accuracy is otherworldly.