+p or P+P in a colt Mk4 mod 70?

badbot · December 12, 2017, 01:24 AM

I wanted to ask if anyone knows if the colt bbl is safe with the P loadings.

DPris · December 12, 2017, 02:43 AM

It's not the barrel you need to worry about, as such. You won't blow one, if that's your concern.
Denis

Slamfire · December 12, 2017, 07:22 AM

Quote:

It's not the barrel you need to worry about, as such. You won't blow one, if that's your concern.
Denis

I agree the barrel is not going to blow. There are other issues such as frame peening and failures to feed and failures to eject. Overpressure ammunition will be hard on the gun and function may not be as reliable with standard pressure ammunition.

Basically, what to you think you are going to get with +P or +P+ ammunition? Do you feel safer because you think the extra oomph is going to give you better lethality?, does more always mean more?

Dfariswheel · December 12, 2017, 08:22 PM

The standard 16 pound recoil spring is good for standard load 230 grain ammo at 800 feet per second.
Going to a 17 to 18 pound spring "may" improve operation and lessen battering, but it's hard to argue with John Browning and Colt who designed the gun to use a 16 pound spring.

If you use hotter ammo you need to up the strength of the recoil spring.
For hotter ammo over 800 fps you may need a spring of 20 to 22 pounds.

Remember, the stronger springs also cause the slide to slam shut harder, and that too causes battering of parts.
The law of diminishing returns holds here, and while you can use +P ammo with a stronger spring, using +P+ ammo is rarely justified and definitely will cause the gun to wear much faster.

If you're facing a human, +P+ isn't really going to make a real difference, but will wear out your pistol.
If you intend to face a grizzle or polar bear, then you'd be better with a more powerful type of gun, possibly a 10mm.

Bill DeShivs · December 12, 2017, 10:07 PM

+P+ kills them deader!

**Aguila Blanca** · December 12, 2017, 10:10 PM

Quote:

Originally Posted by Dfariswheel

Going to a 17 to 18 pound spring "may" improve operation and lessen battering, but it's hard to argue with John Browning and Colt who designed the gun to use a 16 pound spring.

Actually, they designed the M1911 for a 14-pound recoil spring. (With a small radius firing pin stop.)

badbot · December 12, 2017, 11:30 PM

I just wanted the information, not trying to kick over the beehive.
I have a buffer installed and the poly washer under the recoil spring for the slide to bash instead of the frame. I can't remember if I went up on the spring tension back then.
I would never argue with Mr. Browning about gun design.

I assume that my old bowling pin loads exceeded any +P currently made.
I did what I could to mitigate any extra wear and tear.

5whiskey · December 12, 2017, 11:52 PM

The occasional range session with +p is fine Imo. Keep a 16lb recoil spring, ditch the shock buffer, and get a square base firing pin stop. Going up in mainspring weight will help a lot... At the expense of trigger pull weight. Which is why I quickly discarded the idea of hotrodding 45 in a 1911.

Don P · December 13, 2017, 07:31 AM

+P+P+P will be just fine

Have to love the gimmick of +P having people jump all over it. It will kill them even deader than regular ammo plus your follow up shots will be nowhere to be found

Johnny Guest · December 18, 2017, 05:14 PM

I messed around with all sorts of .45 ACP loads for decades. After spending a lot of time and money with various bullet shapes and weights, both factory and handloads, I finally decided to become realistic.

Standard stuff is usually best---certainly simpler. I measure factory ammo against 230 gr. hardball at standard velocities. Unless doing the most precise possible methods, it is difficult to tell which target was shot with Federal,R-P,or Winchester ammo.

Many years ago, I adjusted my practice handloads, 230 RN cast, 230 RN plated, and 230 RN jacketed, so that they all hit pretty much the same point of impact as the factory ammo. Happily, I found that Speer Gold Dot 230 HP standard velocity impacted right in there with that same ammo.

I sometimes have to look for the GDHP which is NOT the Plus-P load. No problem. I'm retired and kind of enjoy shopping at ammo suppliers. The
GDHP (and factory FMJ) standard velocity loads are adequately powerful without the max velocity "advantage." They are easier to shoot well and don't batter my pistols as much.

A five-inch Government Model or even a 4.25-inch barrel Lightweight Commander are sufficient with standard velocity ammo. Yeah, when I pack a snubby .38 Spl or a compact 9mm, the +p ammo is something of a comfort, but I don't feel the need with a .45 ACP.

For whatever its worth, my handloads are for practice or hunting. I carry factory ammo when I go out in public.

Best regards
JPG

Model12Win · December 18, 2017, 05:49 PM

Should be safe for reasonable P+P loads, provided you install a stiffer spring. Should be fine with P+ stock.

otasan · December 19, 2017, 05:25 PM

My CCW load in my Glock17 is the Corbon 9mm 115gr JHP +p load. I have read that the G17 can handle +p and +p+ loads, but I don't shoot this stuff very often at all. I can highly recommend the Corbon load. I chronographed it at 1400 FPS.

otasan · December 30, 2017, 03:49 PM

It's +p and +p+. I shoot them without problems in my Glock 17.

December 12, 2017, 01:24 AM	#1
badbot Member Join Date: November 26, 2017 Posts: 18	+p or P+P in a colt Mk4 mod 70? I wanted to ask if anyone knows if the colt bbl is safe with the P loadings.

December 12, 2017, 10:07 PM	#5
Bill DeShivs Senior Member Join Date: April 7, 2006 Posts: 10,981	+P+ kills them deader! __________________ Bill DeShivs, Master Cutler www.billdeshivs.com

December 13, 2017, 07:31 AM	#9
Don P Senior Member Join Date: December 17, 2005 Location: Swamp dweller Posts: 6,187	+P+P+P will be just fine Have to love the gimmick of +P having people jump all over it. It will kill them even deader than regular ammo plus your follow up shots will be nowhere to be found __________________ *NRA Life Member, NRA Chief Range Safety Officer, NRA Certified Pistol Instructor,, USPSA & Steel Challange NROI Range Officer, ICORE Range Officer, ,MAG 40 Graduate* *As you are, I once was, As I am, You will be.*

December 18, 2017, 05:14 PM	#10
Johnny Guest Moderator in Memoriam Join Date: August 28, 1999 Location: North Texas Posts: 4,123	+p or no +p I messed around with all sorts of .45 ACP loads for decades. After spending a lot of time and money with various bullet shapes and weights, both factory and handloads, I finally decided to become realistic. Standard stuff is usually best---certainly simpler. I measure factory ammo against 230 gr. hardball at standard velocities. Unless doing the most precise possible methods, it is difficult to tell which target was shot with Federal,R-P,or Winchester ammo. Many years ago, I adjusted my practice handloads, 230 RN cast, 230 RN plated, and 230 RN jacketed, so that they all hit pretty much the same point of impact as the factory ammo. Happily, I found that Speer Gold Dot 230 HP standard velocity impacted right in there with that same ammo. I sometimes have to look for the GDHP which is NOT the Plus-P load. No problem. I'm retired and kind of enjoy shopping at ammo suppliers. The GDHP (and factory FMJ) standard velocity loads are adequately powerful without the max velocity "advantage." They are easier to shoot well and don't batter my pistols as much. A five-inch Government Model or even a 4.25-inch barrel Lightweight Commander are sufficient with standard velocity ammo. Yeah, when I pack a snubby .38 Spl or a compact 9mm, the +p ammo is something of a comfort, but I don't feel the need with a .45 ACP. For whatever its worth, my handloads are for practice or hunting. I carry factory ammo when I go out in public. Best regards JPG

December 12, 2017, 02:43 AM	#2
DPris Member Emeritus Join Date: August 19, 2004 Posts: 7,133	It's not the barrel you need to worry about, as such. You won't blow one, if that's your concern. Denis

December 12, 2017, 08:22 PM	#4
Dfariswheel Senior Member Join Date: May 4, 2001 Posts: 7,478	The standard 16 pound recoil spring is good for standard load 230 grain ammo at 800 feet per second. Going to a 17 to 18 pound spring "may" improve operation and lessen battering, but it's hard to argue with John Browning and Colt who designed the gun to use a 16 pound spring. If you use hotter ammo you need to up the strength of the recoil spring. For hotter ammo over 800 fps you may need a spring of 20 to 22 pounds. Remember, the stronger springs also cause the slide to slam shut harder, and that too causes battering of parts. The law of diminishing returns holds here, and while you can use +P ammo with a stronger spring, using +P+ ammo is rarely justified and definitely will cause the gun to wear much faster. If you're facing a human, +P+ isn't really going to make a real difference, but will wear out your pistol. If you intend to face a grizzle or polar bear, then you'd be better with a more powerful type of gun, possibly a 10mm.

December 12, 2017, 11:30 PM	#7
badbot Member Join Date: November 26, 2017 Posts: 18	I just wanted the information, not trying to kick over the beehive. I have a buffer installed and the poly washer under the recoil spring for the slide to bash instead of the frame. I can't remember if I went up on the spring tension back then. I would never argue with Mr. Browning about gun design. I assume that my old bowling pin loads exceeded any +P currently made. I did what I could to mitigate any extra wear and tear.

December 12, 2017, 11:52 PM	#8
5whiskey Senior Member Join Date: October 23, 2005 Location: US Posts: 3,652	The occasional range session with +p is fine Imo. Keep a 16lb recoil spring, ditch the shock buffer, and get a square base firing pin stop. Going up in mainspring weight will help a lot... At the expense of trigger pull weight. Which is why I quickly discarded the idea of hotrodding 45 in a 1911.

December 18, 2017, 05:49 PM	#11
Model12Win Junior member Join Date: October 20, 2012 Posts: 5,854	Should be safe for reasonable P+P loads, provided you install a stiffer spring. Should be fine with P+ stock.

December 19, 2017, 05:25 PM	#12
otasan Junior member Join Date: April 17, 2005 Location: Hartford, Vermont Posts: 519	My CCW load in my Glock17 is the Corbon 9mm 115gr JHP +p load. I have read that the G17 can handle +p and +p+ loads, but I don't shoot this stuff very often at all. I can highly recommend the Corbon load. I chronographed it at 1400 FPS.

December 30, 2017, 03:49 PM	#13
otasan Junior member Join Date: April 17, 2005 Location: Hartford, Vermont Posts: 519	It's +p and +p+. I shoot them without problems in my Glock 17.