Use of +P ammo in colt cobra snubbies?

[megatronrules]

I have two colt cobra snubbies one without the shrouded ejector rod and one with the shrouded ejector,the first w/o the barrel shroud was made in '69 or '70 the one with the barrel shroud was made in 1973 I believe. that being said I know these guns aern't rated for +p ammo but would a few cylinders full through each to see where they are hitting and keeping it loaded with +p ammo for defense/conealed carry hurt anything? I do not shoot a steady diet of +p ammo through ANY of my guns even the ones rated for it so my two cobras being no exception to this rule do you think I'll have any issues with this practice?

 

[Old Fuff]

When Colt was developing the Cobra they chambered one of the prototypes in .357 Magnum, and fired 1000 rounds of the original 158 grain hotter-then-today's-loads with no ill effects except to the shooter's hands.

Years later I inspected one that a police detective had converted from .38 Special to .357. I don't know how may rounds of Magnum he fired, but the revolver was so lose as to be non-functional. However there was no evidence of expanded chambers - which might have been expected. A friend at Colt who was in a position to know told me that the problem was twofold. First, 357 Magnum cylinders (for other guns) were made from a different steel then .38 cylinders and heat treated differently, and second - over time the frame would become distorted because of the pounding. However it was unlikely that the gun would blow up.

Some +P ammunition is truly "plus" while others are "hardly plus" but as a rule I don't use +P ammunition in alloy framed revolvers - even if the manufacturers do rate them for the hot stuff. Velocity numbers aside, I don't believe there is that much advantage when the round is fired out of a 2" or less barrel. What the +P designation does do is give some users a warm and fuzzy feeling, and as such it's a marketing ploy.

In any case, if it makes you feel better, carrying +P ammo won't hurt your Cobra's and limited shooting won't either.

 

[thatguy]

This is my response to the +P question. Note the 1940 Colt ad approving use of the 38-44 Hi-Speed ammo in the Detective Special. The Hi-Speed load was much hotter than current +P and Colt thought this was fine in 1940 made guns. Note the personal policy expressed regarding alloy guns.

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I have been just a little amazed at how many questions are posted on various discussion forums regarding the use of factory loaded +P .38 Special ammo. There seems to be no single answer to the hundreds of inquiries that are posted. Some people base their recommendation on the date of manufacture, or model features (such as model number stampings on S&W revolvers), while others advise following the advice of the manufacturers.

Some time ago I looked into this +P matter and decided that it was much ado about nothing. I am surprised at the mystique that seems to surround +P ammo, with many shooters apparently holding this ammo in awe. I am surprised because all one need do is look at the published ballistics for the +P ammo to see that it is really no great shakes.

Winchester and Remington +P ballistics are identical, with a 125 jacketed bullet moving at 975 FPS and the 158 going 925 FPS. This is only about 50 FPS or so over standard pressure ammo with the same bullets. Hardly anything to write home about.

Now, let’s look at some of the ammo offerings from the past.

I was around and shooting in the late 1960s and 1970s and I recall factory ammo as being much hotter than it is today. It is generally accepted that the SAAMI standards for the .38 Special were reduced in the 1970s and 1980s out of concern for lawsuits by owners of cheap, imported guns who might injure themselves shooting full-power loads. The same thing happened with the .38 Super Colt because of people were loading this ammo into old guns chambered for the .38 ACP round. I don’t have any 40 year old factory ammo to chronograph, but perhaps we can get an idea of what happened by looking at a reloading manual published in 1970.

The Speer Number 8 Manual (1970) lists a top load for the .38 Special using a 125 jacketed bullet of 1,426 FPS. That is nearly 500 FPS faster than the current factory +P ammo. The top load listed for the 158 bullet clocks 1,187 FPS, more than 350 FPS faster than the current +P load for this bullet weight. According to the book, these velocities were achieved by using a K38 revolver with a 6†barrel. The book specifically states that these loads are safe in the K frame revolver but there is a warning that “constant use†will result in the action developing looseness (“constant use†was not defined). They recommended backing off about ½ to one full grain for use in the Charter Arms Bodyguard revolver.

I think the hottest factory load for the .38 Special ever made was the .38-44 “Hi-Speed†designed for the Heavy Duty service revolvers from S&W. As I recall, this load pushed a 158 lead bullet at around 1,150 FPS. Note that the top load in the 1970 Speer manual tops this velocity.

Now, as to what guns are safe with these top-end loads, it appears obvious that in 1970 neither the gun makers nor the ammo companies were much concerned about shooters using this ammo in good quality guns. Between then and now the lawyers stepped in and changed everything. Factory ammo was down-loaded, reloading manuals backed off on their top loads, and the gun makers began issuing all sorts of warnings about using warm ammo. This was all CYA on their part and we can appreciate their position. Have these recommendations from the gun makers changed over the years? Yes, they have. Here is a photo of an ad published in 1940. The ad is for the Colt Detective Special. This is a small-frame revolver, even a bit smaller than the S&W K frame. Note that the ad states approval for use of the .38-44 Hi-Speed load in these revolvers. If Colt thought these to be OK, I assume they would also give the 1970 Speer loads a nod, too.



The bottom line is that each person must decide what power level in ammo makes them comfortable. I routinely use the loads listed above in K and J frame Smiths, but sparingly in the small guns. I don’t trust alloy frames and don’t own any. With a steel gun of good quality I wouldn’t worry at all over +Ps or the above loads. An alloy frame, in my opinion, is another matter. Just my paranoia, perhaps. I am also cautious of guns made before about 1930 because steel tempering was an inexact science before that point.

So, take it for what it’s worth. If you worry at all about factory +P ammo in your gun then by all means eschew the use of it. You aren’t giving up all that much, anyway. But I think it’s time to put the myth of +P load to rest. Compared to what was available in the past, it’s simply not that impressive.

 

[BluesBear]

Over a ten year period I put about 1000 rounds through my Mother's third generation Cobra. It showed no signs of loosening. In fact, after about 4000 additional rounds of standard ammo, it looked nearly new.
My Mother believed in keeping a gun CLEAN.

 

[medmo]

My "Running Gun" is a 1st Gen Cobra. It rides in my fanny pack that goes with me when I go for runs during the week. It's hard to find anything more potent and lighter. I also heard that it is a no-no to shoot plus P's through them. I have run several cylinders full of Federal 158gr SWC +P HP's through it and that is what I carry. My first chamber is snake shot because I believe my number one threat is going to be a dog. I have seen two of the Colt alloy frames cracked. I have not seen any problems with shooting the +P ammo with the gun but also don't plan on pushing the envelope.

 

[Gabby Hayes]

If you scroll down the left-hand side of this page [ http://stevespages.com/page7b.htm ] you'll be able to download a .PDF copy of the old Colt manual that covers the Detective & Commando Special, Diamondback, Police Positive, Agent, Cobra, and Viper. Alloy-frame Colts made after the shroud arrived in the early '70s are certified for limited amounts of +P. The manual lists some recommendations and limitations with +P and warns against using any +P+. Beyond that, I'm with thatguy up above and don't get all excited with today's downloaded ammo.