Grand Power P40 10MM

[StopPolloition]

@StopPolloition

Agreed with all that, except on the P-07. Mine has been pretty good. I did update mine with the Cajun 'defensive carry' package, but it was still pretty decent before I updated it. Maybe I got lucky. I do agree that having the option for people to convert to cocked/locked vs. decocker is a good idea by CZ.

I'm not sure how best to describe the issues had with my P-07. Excessive stacking and gritty feeling all the way through. I had hoped that it would break in but it didn't after hundreds of rounds and dry firing. The shape or contour of the trigger also rubbed my finger raw. I had considered sending it to Cajun for trigger job but decided against it for a potential carry piece as I prefer to carry stock or mostly stock triggers. In the end I just gave up on it in favor of the Beretta PX4 or Beretta 92 Compact in the rare event I need a reduced size DA/SA pistol.

 

[StopPolloition]

I've thought about an XD, even though I don't prefer a striker-fired, as it sounds promising. Needs a bit longer bake for me - too early in the release to trust it.

I'd been considering whether the grip safety feature on the XD 10mm is a decent alternative to the Tau Development Group SCD for Glocks. Basically the only way I'd consider routine carry of a striker fired is to have some type of additional passive safety feature since I typically AIWB carry. The SCD on a G20 will prevent the trigger from being pushed if your thumb is firmly engaged on the rear of the slide as well as give you feedback much like an external hammer would when you are holstering. I wonder if the XD grip safety will prevent the trigger from being pushed, or if it will merely prevent the striker from being released. Theoretically, what if your trigger was caught on an obstruction in your holster, and you holstered with your grip broken in a way to not engage the grip safety. Would it just discharge later when you placed your hand on the grip and contacted the grip safety?

Sig makes a P220-10 that has decocker and is DA/SA that isn't the Legion

I'd seen the Elite Match or Emperor Scorpion models but they were all still quite pricey. There's also the problem of being only 8+1 compared to 15+1 in much more affordable alternatives.

 

[MrRob96]

I'm not sure there are affordable 15+1 options unless you mean the Witness series, which as you pointed out is manual safety.

Those of us that want double stack 10mm with DA/SA and decocker are kind of SOL. That's why I grabbed the GP P40 to begin with. There are bugs in the guns, but perhaps you'll get a good one like Zathras.

Seems like the P40 magazines are suspect all around. BTW I think the GP P40 mags are dimensionally the same as large frame Witness mags except for the location of the mag latch. My large frame Witness magazines(9mm) fit the mag well and appear to be in a good place to feed the P40, but they don't stay in. That suggests to me that Witness mags may be as bubblegumty to load with 10mm as this P40.

So far I've tried these 10mm formats:
Single stack 1911
Double stack 1911
GP P40
S&W 3rd gens
Glock 20/40
Sig P220-10 SAOs
Sig P220 Legion

Each has their issues.

Not sure what else is available at a lower price point. I'm hoping one day Sig will make a P227-10.

 

[Zathras]

@Zathras

After your suggestion, it seems like lateral pressure on the trigger can change the behavior of the decock. If I push the trigger to the left while pulling, it drops hammer reliably. If I pull the trigger to the right, it decocks the hammer ~75% of the time. I will see if I can do anything to remedy this.

Interesting. You might have trigger bar spring issues like I had on my CZ. I haven't busted open the GP to the same extent to know how they compare, but the 'hold left' bit makes me wonder.

Good luck.

 

[Zathras]

@MrRob96

Thanks for the input on the other 10mm guns. Also, the Witness mags compatibility thing I've heard before, so thanks for giving me the confidence to try it. Whenever I can get some ordered I'll let you know how it works (or doesn't).

 

[Zathras]

@MrRob96 and @StopPolloition

As promised...

Just got a few Witness mags and busted out the drill press. I only altered one so far to try it out. I got 1 actual EAA one (the only one this place had) and 4 MecGar ones. I altered a MecGar one and, though there are probably videos on how to do it and what to alter, I didn't go by any of it. I merely looked at the original GP mag and the new one and observed for differences. I can get you guys photos if you want, but can't do it from my workstation right now. Let me know.

A couple notes though, if you're considering doing it...

(1) Was the easy (or at least fast) part. (2) Took more work/patience/testing.

1) The hole can be circular (ie. doesn't have to be a square cut) - or at least it does work on my GP40. I used a 5/32" drill bit and went slow. When I do it again, I think I'll up the speed of the drill press another notch (think it was 760 on mine as the lowest, and I was under the impression with metal to go slow at first, so that's what I did). I was careful on the vise to not crush the mag, but I might think of a better way to do this to generate more upward pressure. I used a bit of cardboard crushed up inside the magwell to help, and also to let me know when I got through all the way so I didn't hit the other side.

2) I was glad to see the mag inserted, held in place and ejected fine with the hole. Then, while testing with some snap caps, I had the pesky last round not cycling properly. I (more closely) inspected the notches on the follower and saw an extra bit was taken off on the GP one. I filed that guy slowly and eventually had to use my small set of chisels (though I suppose you could go with a razor blade or utility knife, I'd urge caution there). I didn't want to go Dremel yet, as that seemed like I'd slip somewhere or cut too much too quick. I nickel-and-dimed my way to success with the mini chisel and got it to look pretty close, trying it every few shavings and eventually got it to cycle properly. I took some videos of the differences between the original, the modified, and a new, unmodified MecGar to show how the follower alterations worked.

I'm not sure if it's endemic to all GP's, but mine will auto-chamber with a firm insert of a loaded mag, and that works still with the MecGar, so figured I'd mention that in case people cared.

A mag for half-the-price (and more easy to find)... glad it worked.

 

[MrRob96]

@Zathras

This is awesome info. How is the loading of the MecGar mag compared to the provided GP mags?

Did you post the video anywhere?

You didn't have issues with your mag dropping out under recoil, correct? I imagine the problem is based on where the latch is located, but perhaps the notch shape may help.

 

[Zathras]

@MrRob96

Mag inserts seem fine. I don't feel anything loose or slipping.

Have not tested it under fire yet. I intend to before I alter any other equipment. However, I have not had mag-drop issues out of my gun as of yet. I've shot the 1400 fps Corbon stuff and it didn't seem to mind it. I've mag-dumped it before and not had an issue.

The videos/pictures I have not posted, but can try to do that when I get to my other computer, can hook up my phone photos, etc. The videos I had were to demonstrate the differences in behavior of follower types - unaltered Witness ones without the follower notched down will just lock the slide back with a round still in the magazine and no attempt to chamber it. The photos are to display the subtle differences in followers and where I put the 5/32 hole.

I've also not attempted to load the full 14 rounds vs. the 13 I get stuck with on GP to test differences in spring tension. Will followup when I get a chance.

I hope to make it to the range tomorrow on my day off, test some factory vs. handloads and this new mag alteration, but we'll see.

 

[Zathras]

@MrRob96

Here are the photos and my shoddy attempts at videos/video editing.

Sorry: GP40 - YouTube

The filenames describe what each is, so hover over each. Let me know if anything's insufficiently clear.

 

[Zathras]

Witness mag worked fine. A bonus is that I could even get all 14 rounds into the mag (by hand - without a UpLula). I can't currently get more than 13 in my 2 GP mags even with an UpLula (like many people seem to experience), so my Witness mag is my 'high-capacity' mag apparently. Here's some evidence at 7yds, though it looks like I could use some practice with my 'low-left' issues . I intend to update my other magazines, when I get time.

 

[MrRob96]

More great info, @Zathras

I think I'm gonna have to mod a few mags. If I could get this GP40 running right, it will be my new carry 10mm. A lot cheaper option than the 3rd gen Smiths and a lot higher capacity.

Ordering mags now.

 

[Zathras]

Glad it helped. Let me know how the drilling goes. I was going to try to fashion a wood block that was fitted closely enough to the mag cavity and see if that helped prevent potential mag crushing/warping in the vise and allow for decent upward pressure when drilling.

I looked into ordering just follower replacements to make that part easier, but was unsuccessful. The chisels I used, in case you're interested (these look close enough to what I got at least)...

https://www.amazon.com/Delicacy-Pro...&qid=1550336958&sr=8-1&keywords=small+chisels

They're cheap, but work well for this project, with a good soft mallet/hammer.

 

[DavidTN]

I have a Grand Power P40 10mm. Bought it about a year ago. I have shot 350 rounds of Underwood Xtreme Penetrator ammo thru it; 140 grains at 1,500 fps -- 700 ft lbs energy. No FTFs. No signs of gun stress that I can see. I don't do much blogging. I'm not a gun expert. I used to deer hunt a lot, and shoot a fair amount. I'm not a reloader or a gun smith. I don't have the "tech vocabulary" most of you guys on here have. Just wanted to relay my personal experience with my Grand Power 10mm, since many of you were curious about them in recent months. I've never had a mag drop out, or a trigger squeeze fail to drop the hammer. I did have some FTFs with Underwood cast lead ammo, but not any other of various types of ammo I tried. So, I settled on the Underwood Xtreme Penetrator as my bear defense load, which has run flawlessly in this gun. In handguns, I have several 9mm, 22mag, 44 mag, and an 11 oz Smith 357 mag titanium, so I have felt a wide variety of handgun recoils. My 11oz Smith 357 (with 500 ft lb loads) kicks like a mule. My ported 38 oz Taurus Tracker when shooting over 800 ft lbs rounds is worse,, even with fat soft Pachmayr rubber grips. The recoil of my 14+1 shot 27 oz Grand Power 10mm with Underwood Xtreme Penetrator 700ft lb loads is MUCH less than my 357 or 44 mentioned above. It's unbelievably easy on the hands. It's like it "shoves" you a little, instead of "slaps" you. No sting. Me and sev of my friends are amazed at how nice/managable the recoil is. It's apparently true that the "rotating barrel" design transfers some of the recoil out to the sides, rather than back into your hand. My 38oz ported Taurus Tracker 44mag is recoil much more unpleasant than the Grand Power, even when loaded with about the same ft lb loads. In fact, my Grand Power 10mm recoil is absolutely not unpleasant at all. Many times I have shot 50--100 rounds of the Underwood 700 fl lb loads in a session and not felt any discomfort, then or later. HOLSTER: It's true that some of the Sig p320 holsters fit the Grand Power. After trying 2 or 3 diff, ones, I lucked into a Kydex LAG Tactical Defender holster, OWB, 2 loops. It's made for "Sig P320 Full Size 9/40", and my Grand Power 10mm fits it nicely. I think I used a heat gun and flared the holster's edge out a little further from the mag release button, to prevent unintentional mag release. That's all it required for a great fit as I recall. In that LAG kydex holster, I carried this gun all over Colorado in 2018 on a family trip, and it was a pleasure. Couldn't stand the thought of a moose, mountain lion, or bear attack on one of my granddaughters, and me being defenseless. I also carried bear spray. I carry the gun chambered and UN cocked, with the safety OFF. This way, my first shot is either double action, or I could cock it before shooting. I like this method, because in an animal charge situation, I don't have to fumble with a safety. If I simply pull the trigger, it will go boom. That's just the way my brain works. You can carry this gun cocked and locked if you prefer. I also carry this 10mm when hiking in Tennessee black bear country. No problem to carry. By putting one pant's beltloop in between the holster's loops, I can slide the 2-loop holster around to 3-4 oclock for driving or squatting down, and then slide it around to 1-2 oclock when hiking. I can do this sliding "invisibly", in public, under my untucked shirt. I bought this gun solely as a woods protection gun, a work gun. So, I'm not really concerned about it's looks, or about holstering marring the finish. Look closely at one of the pics, and you'll see where I etched S, F, D into the gun to remind my 64 year old brain which position is Safe, Fire, and Decock. I added a "Hogue Rubber Grip Handall Fullsize" grip sleeve to the gun. Fits perfectly, works well, and make it look better. (At least one company is making stick-on grips for it now). The Grand Power P40 10mm to me is a rather utilitarian looking gun, like the older Volvo cars, but by golly it just keeps impressing me with it's performance, features, light weight, capacity, and versatility. I keep enjoying this gun more and more. - DavidTN

 

[Zathras]

@DavidTN Thanks for the post and all the info.

One of the things marketed for the GP is the rotating barrel, so that helps with recoil. Based upon your experience, it sounds like it's not just marketing when comparing it to your other magnum calibers. If you like that style and want a 9mm option, the Beretta PX4 Storm pistols (Compact and Full - not sub-compact) have the rotating barrel.

It's good to know about the holster situation. I just have a generic sub-par nylon one to just cover up the trigger, but not having a decent holster keeps me from carrying it around. Thanks for the tip about the Sig P320 LAG one. I have several similar style holsters I like to carry OWB under an untucked shirt for my CZs.

Your DA/SA chambered and decocked carry method is pretty standard and the exact reason some people (like myself) keep going back to the DA/SA handguns over striker-fired. I'm not a real fan that it has a safety at all, but it's kind of like the Beretta in that way.

I do reload and have tried the lighter projectiles (some Nosler 135gr and 150gr JHP) and have had good results for accuracy, but have no means of testing their energy or speed - no chronograph and that'd be difficult to test at the always-hot indoor range I typically go to anyway. However, 10mm has a lot more options than it used to for ammo, and I've only scratched the surface.

Again, thanks for the post and the pictures... and welcome to the forum. I got a lot of kin (most dead now) from TN. Beautiful part of the country.

 

[DavidTN]

Thanks for the input Zathras. And FYI, the gun hugs nicely to your side with that LAG Defender holster, which has very sturdy loops. The gun does not lean out or flop around any, and doesn't print badly at all.