How difficult to fit a 9mm cylinder to a BlackHawk?

[bczrx]

I have a NM Blackhawk [1974 model, I believe]. I found a 9mm cylinder for it and now want to see about fitting it. It is ok fore/aft motion. However, the bore/chamber alignment needs to be tested.

I can't find the proper chamber guide/rods for 9mm that are long enough for the 6 1/2" barrel. I am guessing I'll need to turn a .357 rod down to .355 to check the chamber/bore alignment.

Since I want to go back/forth between cylinders, am I right that I need to hone down the pawl/star lip on the cylinder face equally to get each cylinder to line up properly? Once I verify my .357mag cylinder is lining up properly, of course.

Just checking. I can't touch the hand/lifter, or the .357mag cylinder will be out of alignment.

thanks in advance.

 

[loaded round]

I fitted a 9mm cylinder to my OM 357 Blackhawk many years ago. It originally was a very tight fit and I needed to hone it done slightly with emery cloth on a tongue depressor. Very little metal needed to be removed for the perfect fit. Checked the alignment with a Brownell's range rod and my new 9mm shot perfectly. Bear in mind that you won't get the same accuracy as you would with quality 38/357 ammo because of the Ruger's bore dimension. However it's accurate enough to shoot both surplus ammo and emergency use.

 

[Chuck 100 yd]

The pawl/hand rotates the cylinder but the cylinder latch holds it in alignment. The way you talk,it sounds like you have machining capabilitys. Turn a gage rod as you spoke of and check your cylinders. I bet you will find that they are both good. Most cylinders that fit for and aft and have reasonable barrel cylinder gap also time very well. Check it and report what you find.

 

[woodperson]

You might just try the .358 rod. That is about what the cylinder throats are on my 9 mm cylinder. They are sure bigger than .355.

 

[bczrx]

Thanks all. I will follow your advice.

I was aware that the cylinder latch holds the alignment, but also thought that the hand/pawl pushes up on the cylinder. as the trigger is pulled and held back [firing conditions]. This could cause a slight mis-alignment of the cylinder to the bore, even though it was 'locked' in alignment by the cylinder latch.

or am I over thinking it?


As to getting back, that I will do. However, it may take awhile. I could explain why, but you all have lives and don't need to be bored about the distractions of another. I just don't expect to have time for this for a couple of months, unfortunately.

When I DO check it, I will report back as to what I found/did.

Thanks again!

 

[Chuck 100 yd]

The instant the trigger releases the hammer the pawl/hand no longer is in contact with the cylinder as it retracts as the hammer falls. The cylinder latch/bolt is the only thing holding the cylinder in alignment with the bore during firing.

 

[bczrx]

The instant the trigger releases the hammer the pawl/hand no longer is in contact with the cylinder as it retracts as the hammer falls. The cylinder latch/bolt is the only thing holding the cylinder in alignment with the bore during firing.

Ah. Ok. Thanks!

 

[Aqualung]

Dredged up an old thread.

When measuring for a 9mm cylinder, the main measurement for OAL is from face of the "star" to the face of the "flange", correct?

I'm assuming that slightly larger is better, so it can be machined* to fit.

If machining* needs to be done, can the star be machined*? Or will it affect function?

What other considerations are there?

* Meaning removal of **very little** metal with sandpaper or file...no 9" angle grinder

Every now and them, I get the idea to give my .357 Blackhawk "convertable" capabilities...

Thanks

Aqualung

 

[GeezerD]

In making a range rod to check cylinder alignment, the rod has to be bore diameter which on a 357 would be about .350. This diameter is still less than the throat diameter on a 9mm cylinder.

Generally, Ruger holds their cylinder dimensions close enough to allow most cylinders to interchange with minimal fitting. ------------------------- GeezerD

 

[Acorn]

Just a little suggestion. If I were making a range rod I'd cut the end off at an angle. That way if there is mis-alignment you can rotate the rod to see if is up-down, or lateral. Not my idea but I think a good one.