ammo limitation

Question
GCH,  I have a Colt Cobra 2" bbl. that I bought new back in the 70's. It's in like-new condition. I load my own ammo. What maximum load or FPS can I go with this weapon. I have several loads available for 900 FPS, but is this exceeding the limits of this weapon and if not, how far can I go safely?  

Respectfully,

mike

Answer
Mike,

Any answer to question that would require more data. 900 FPS of WHAT? Driving a 110 gr projectile out of that gun at that velocity MAY be OK, driving a 158 gr projectile that fast would likely be a short trip to the scrap metal pile.

The issue isn't really velocity, it's pressure, but home hand-loaders, unlike factory ammunition producers, can't afford the equipment it takes to measure pressure, so we have to rely on velocity and "signs" to guestimate what pressures may be.

The Colt's were beautiful old revolvers, but they always were on the "dainty" side compared to the Smiths. The D-frame alloy Cobra is not a particularly robust gun.

The reported problem with the alloy guns is that the frames elongated under use of heavy loads (unless, of course, they were heavy enough to break the frame outright).

There are a few confusing factors here. In the first place, better pressure testing and better powders have made it so that modern (factory) ammunition can generate velocity while keeping pressure down. The Corbra was approved for standard pressure .38 Sp., but because of more accurate measurements today, the "standard pressure" of the 70's exceeded the +P pressures of today (+P+ .38 Sp is a wildcard, with no established parameters).

Colt approved the Cobra for 1,000 rounds of the +P ammunition of the day, but that doesn't tell us anything. It was good marketing. They knew that the gun would be carried much and shot little, and that making such a claim would boost sales enough to cover the occasional gun that was send back to them for repair or replacement.

Back in 1995, the last year of it's production, I picked up a Detective Special (which I wish I still had). It had a beautifully blued steel frame, and explicit instruction NOT to use +P ammunition. My guess is that this is because Colt learned something about +P ammunition in their D-frame guns.

Reloading one's own ammunition is a valid activity (I do it myself) for three, and only three reasons: 1)To tailor the accuracy of a bench-rest rifle without regard to power, 2) for hunting, to generate a particular power and performance, and 3) cheap fodder for handguns.

A 2" barrel will never be "accurate" and was never intended to be. You won't hunt with such a gun. What's left for hand-loading is to produce the cheapest rounds possible that will be easy on both the shooter and the gun.

If you keep the gun for self-defense, get factory ammunition for that purpose. You can't produce anything on your loading press anywhere near as effective as modern factory ammunition, but Mas Ayoob has documented the many people sitting in jail cells today who have tried. It usually goes like this at the trial, "Ladies and gentlemen: unsatisfied with the current ammunition used by the military and police, this man set out to make a round so devastating to human life that you can't buy it in stores, even among items restricted to law enforcement only." The argument works very well, as a number of prosecutors will tell you.

Colt doesn't make the Cobra anymore, as you are aware. I think I'd treat a 2010 Toyota Corolla a little differently than I would a 1927 Model T (if I actually had either of them). Regardless of what the original claims for the Model T were, I can't replace it easily or cheaply.