QUESTION ABOUT BLACKHAWK CONVERTIBLES.

I have been looking at a Ruger Blackhawk convertible, the 5 1/2" 38/357 with the extra 9mm cylinder. My reason for interest in this model is that it is the only 5 1/2" version currently available. I do not need or want the 9mm cylinder. My concern is this:
38 special and 357 magnum bullet diameters are .357 for jacketed and .358 for lead. Nine mm bullets measure .355 and .356 by comparison. So I wonder about the groove diameter of the barrel. It cannot shoot both 38/357 and 9mm well. It is either too big for 9mm or too small for 38/357 (I suspect the former is the case). Any insights that you could provide would be welcomed.

The throat of the 9mm cylinder of my convertible tapers from .355 at the end of the chamber to .357 at the front end of the cylinder. I think the 9mm bullets are supposed to expand a little bit from pressure while in the throat to fully engage the rifling. And if they do the taper then gets them centered to the bore when going into the forcing cone. I have not slugged the barrel. I think it is a standard .357 barrel. I shoot a lot of 9mm 124 gr BBHB in it and they seem as accurate as similar loadings in .357 cases with 125 grain .357 bullets from the same company. I like the 9mm for reduced loads since the case is almost full and I am not worried about powder position or double charging. 9mm brass is dirt cheap. easy to load.

I think you will like that gun.

I've had the 9mm/357 convertible for a number of years. Before my last move-the 9mm cylinder disappeared-I shot the 9mm for accuracy. I am better set up to reload 9mm and find it cheaper, swells more accurate.

Yeah. I am on my 2nd 9mm cylinder. They must have a way of making off on their own. I did not shoot 9mm for years. Lost the cylinder. Got mad at myself for loosing it and bought another 9mm cylinder for the gun. Shot it. Like it a lot. Bought dies, plated bullets, and a box of range brass in 9 mm. Fairly cheap shooting.

Over the years I've had lots of Blackhawk convertibles and they've all shot better than pretty much any 9mm semi auto I've ever owned. I currently have the stainless flat top in 4-5/8" and it is fabulous in every way.

They use the .357 barrel. They work better than one might suppose, some a little better than others as with any gun.

The relatively cheap 9mm ball ammo makes for fun "plinking".

If you find that you simply cannot abide the 9mm cylinder you would be able to sell it in the Classifieds here.

:mrgreen: :mrgreen: :mrgreen:

It's not that I don't want the 9mm cylinder. It's just that I'd be paying more to get it. I am mentally locked into the 5 1/2" barrel, which means the extra cylinder. Maybe I should consider the 4.62" barrel.

NOTE THIS : Nearly all european 9MM PARABELLUM BBL's are of .357" ID. My Browning HP is .3572" and shoots like a million bucks. YOU can toss a horse through my Walther P38's BBL and it shoots like ten million bucks.
IT is the throats in the 9MM cylinder that REALLY matter. THEY will determine how STRAIGHT the projectile will enter the rifling
ALL of your assumptions are essentially wrong , Sir !
And so it goes...

I just ordered a 4.62" stainless flat top convertible in .357/9mm. I should have it by next Wednesday. Thanks to all for your input.

I've had an OM .357 Blackhawk for many years that I actually purchased while I was till in the army stationed in California. About 10 or 15 years ago, I got curious about having a convertible revolver that could shoot 9 mm ammo. I manged to find a almost new 9 mm Blackhawk cylinder online at a very reasonable starting price and I bought it. It took a minor amount of end to end fitting, but now I had a .357/9 mm revolver. To this day, it will shoot 2 1/2'' groups at 25 yds. no matter what I feed. One of the smartest gun moves I've ever done!

grobin said:

I've had the 9mm/357 convertible for a number of years. Before my last move-the 9mm cylinder disappeared-I shot the 9mm for accuracy. I am better set up to reload 9mm and find it cheaper, swells more accurate.

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Is your .357 a large frame or the medium frame? I believe I have a large frame 9mm cylinder if you are interested.

If you shoot cast 9mm you may need to have the throats opened to .358.

I have one of these and both cylinders shoot equally well. I was concerned also that the 9mm might shoot a little loose, but doesn't seem to be the case with mine. The only issue I have with the 9mm cylinder is that the step where the neck of the cartridge rests to headspace gets crudded up after about 50-75 rounds and the next rounds are hard to seat in the cylinder. I tossed a small cleaning rod with a 9mm mop in my bag to swab the cylinder out periodically. Seems to help.

TfflHndn said:

I have one of these and both cylinders shoot equally well. I was concerned also that the 9mm might shoot a little loose, but doesn't seem to be the case with mine. The only issue I have with the 9mm cylinder is that the step where the neck of the cartridge rests to headspace gets crudded up after about 50-75 rounds and the next rounds are hard to seat in the cylinder. I tossed a small cleaning rod with a 9mm mop in my bag to swab the cylinder out periodically. Seems to help.

Click to expand...

Sometimes I have difficult extracting a 9mm case. Even on the first cylinder full.