OMBH .45 Convertible Help: BOUGHT IT

[meh92]

Found a 7" version with both cylinders that dates to 1971 (no box or papers). I have read that cylinder throats can be a problem with earlier models. Should I be concerend of throat variations given its age? Would this be an issue if I was shooting jacketted bullets or only cast?

I know that value is a matter of condition and location, but could someone put a ballpark value on one in good to very-good condition, 7" bbl, both cylinders, and smooth wood grips (assuming the safety conversion was not done). The owner wants to work a trade and I was hoping to get a general idea on value.

If the safety conversion was done, how hard and expensive is it to convert it back to pre-conversion status?

Thanks

 

[bigbore45colt]

meh92,

I have found that the throats weren't too much of a problem but the only way to know is to measure them.

Value is very difficult to determine without seeing pictures. But, assuming good condition, original condition (grips and lockwork), with matching ACP cylinder, I'd say $750 to $800.

If the safety conversion was done, it is a very easy fix. The parts will run you $150+ (so deduct that amount from the value I gave you above). The hard part is finding them.


Hope this helps,
BB45C

 

[meh92]

Thank you.

If original to the gun, would both be serialized to the gun?

 

[bigbore45colt]

You are most welcome. My only request is that, in return, once you get it, you post pictures of it

Yes, the last 3 digits (sometimes 4 but almost always 3) of the serial number will be elector-penciled (ie scribed) on the face of the cylinder.

BB45C

 

[meh92]

I will gladly do so.

I'm going to look at it on Tuesday and hopefully if all is as advertised, work out some sort of trade beneficial to both of us.

I am mostly a S&W guy and only own an OMBH .357 and OMSS convertible. Is there anything I should watch out for with this gun? Did the .45's have any problems particular to them?

Thanks again

 

[contender]

The only major problem with them is there aren't enough of them to go around. (Of course, if some of us would quit buying & not selling mine,,, eeerrr, theirs.)
I have a few of those myself. I've been tinkering with them a bit too. If you shoot mostly jacketed ammo, you may not have any issues with the throats to barrel dimensions. However, if you decide to shoot cast boolits, then you will want to do a bit more research & measuring.

 

[tom black]

The throats on my home boy short barreled brassie measure .454 and it doesn't shoot .452 cast bullets well at all. However with slugs sized to .454 it shoots like a house on fire.

The throats on my 7.5 measure .452" and it shoots wonderfully with slugs sized either .452 or .454. Jacketed bullets shoot just fine in either revolver.

Tom Black

 

[J Miller]

My71 vintage OM BH .45 had grossly UNdersized and out of round throats. They were so tight I could feel the difference in recoil, and see the additional pressure they caused.

But, if they are undersized, that is an easy fix. Just have them reamed out to .4525" and your home free.
If they are oversized you'll have to use larger bullets as Tom said, or find another cylinder.

Hope it's as advertised and you bring it home.

Contender is right though, the collectors need to quit buying and start selling cos the rest of need some too.

Joe

 

[Wyandot Jim]

My71 vintage OM BH .45 had grossly UNdersized and out of round throats. They were so tight I could feel the difference in recoil, and see the additional pressure they caused.

But, if they are undersized, that is an easy fix. Just have them reamed out to .4525" and your home free.
If they are oversized you'll have to use larger bullets as Tom said, or find another cylinder.

Hope it's as advertised and you bring it home.

Contender is right though, the collectors need to quit buying and start selling cos the rest of need some too.

Joe

Joe,
Eduacate me on this one. I understand about throats being to small and the affect. Please splane why oversize throats has an affect. Barrel is still .452 I always thought a .452 bullet should work fine. Do I need to go check my 45s now
Merry Christmas to ya.
Thanks,
Jim

 

[contender]

J Miller; I promise, I won't buy too many more of them. (Yeah right!) There is just something about 45 OM's that are hard to resist.

 

[Hondo44]

tom black,

I had the same experience w/oversize throats! Once I used 'fatter boolits' it shot like new money!

From what I recall, gas escapes from around the bullet causing inconsistent ballistics.
But mainly they cause bullet cant which allows the base of the bullet to deviate off the axis of the bore and go into the rifling at random angles, ie., cockeyed, distorting the bullet and throwing it out of balance. Therefore how the bullet enters the barrel throat and tapered ends of the rifling (leade) has a very dramatic and predictable effect on accuracy.

 

[J Miller]

Jim,

The problem with over sized throats is that unless the bullet is very soft or a hollow based soft bullet it will not expand to seal the throats. When that happens the powder gases can pass by the base and soften or melt the sides of the bullet causing leading and loss of accuracy.
If the bullet is bevel based the problem is made worse.
Generally the commercial bevel based bullets are very hard and won't expand to seal the throats in anything short of full house magnum loads.

Now, this is not a rule chiseled in stone. Sometimes you'll get a gun that will shoot very well with .452" hard cast bb bullets even though technically it shouldn't.

Also sometimes you'd think a gun with throats reamed to .4525" would shoot great with .452" bullets and it doesn't. My Old Model .45 is that way. Throats are .4525", but it shoots noticeably better with .454" or better bullets. Even though the bore is .452".

Where over sized throats really cause trouble is situations like my S&W 25-5. It's throats are .457". No lead bullets smaller than .454" will shoot good in it. They lead like fiends. If I run them up to .455 to .457" it shoots like a target pistol.

Basically if your gun shoots good, don't fix it.

Joe

 

[Wyandot Jim]

"I SEE" said the blind man
Joe thanks so much. Never really thought about it that way. Good info.
All the guys I shoot with and this is CAS just get .452s, but we don't shoot that accuate Do get blow by on the case with the lighter loads with the 45 Colt and Starline brass. I think a lot of that is due to the case being .006 smaller than the chamber and hard brass.
Thanks for splaneing it :wink:
Jim

 

[meh92]

I have been exchanging emails with the owner and will go take a look at it tomorrow night. I have learned that it has not been converted. Also, judging from the pictures, the grips look original.

 

[Motex66]

Well Joe I'm not hoarding Old Models though I would like to. I have one bought from the original owner. It has been made into a home boy short barreled brassie. Don't have those fancy grips like tom black's. Nice!
I have strayed into the New Models. Really like the new mid frames. While not a three screw they do have a lot going for them. At least if the hoarders, I mean collectors want let go of thiers we now have alternatives.
John

 

[jimbo1096]

meh92- hope you can work out a deal. The OM45's are scarce at a decent price. Looking forward to the pictures if you pick it up.

 

[meh92]

Well, I brought it home today. The owner and I reached what I thought was a very good deal, given it's present condition.



First of all, the gun is far from pristine, and I knew that before making an offer. It has a few issues and that isn't bad news. If it were a "survivor" I would leave it as-is and enjoy shooting it. However, it is far fom any kind of collectible condition so I will not lose a second of sleep making it a project gun. I have wanted to do this for a while and now I have the perfect candidate. My first inclination is towards a Bisley conversion with a 6" barrel and banded front sight... but I digress.

The good news is that the action works perfectly. Both cylinders time just as they should. Both are electro-pencilled to the gun's S/N. A .451 sized bullet stops cold at the throats of all the chambers on both cylinders. My dial caliper is not really good for IDs but mic's ODs just fine.

The gripframe screws appear unturned. Either that, or the owners knew to use a properly sized screwdriver. Usually a good sign.

The grips are in really nice condition and the screw is not buggered.

There is no serious external damage and everything looks like it would easily buff out and refinish nicely.

The gun has some very strange finish wear. Some sort of chemical was used on it that did not agree with the bluing at all! While the picture doesn't show it, the bluing is really bad on the cylinders.

On the roof of the bore right below the front sight, there is a bit of frosting in the grooves. It looks like very light corrosion, but I was wondering if maybe it was caused by the front sight being soldered on. My instinct is that it is rust. It is extremely shallow, but being that close to the muzzle cannot be good for accuracy. Of course, that plays nicely into my shortened barrel scenario.

The rear sight blade is missing. I was planning on a different rear sight alltogether, so this is not a big issue.

Here is a strange one. The ACP cylinder had metal flaking off of the ratchet face. It looks like this part may have been chrome plated at one time. The flaking has the consistancy of chrome plating. This worries me because if it was plated, the dimensions may have been changed after plating. I will have to look into this further, but it is the one thing that really worries me. Since ACP cylinders appear to be available, it isn't going to keep me up at night.

Overall, I am very pleased with my new toy I have always had issues with chopping up survivors, so this one is perfect for a project. I am fortunate to live close to Andy Horvath and he has already worked on a few of my single actions (a OMSS and a Seville). Maybe I'll drive over and drop off my new toy so he can give it the once-over... twice!

 

[contender]

Congrats on getting it. The pic makes it look a bit better than you describe it. However, you did mention that the pic didn't show the finish issues.
You've checked the throats, but have you slugged the bore? It might need a bit of tweaking. MOST (but not all) of us have found that a throating of .4525 is optimum. Of course, that's after you slug the bore to see what it measures.
I'd install a sight blade, & just test it out BEFORE doing any mods. You might get surprised, or you may say, wow, it does need work.
The frosting in the bore shouldn't be due to the front sight being soldered on. More likely, just neglect. I'd scrub it good to see how it turns out. And as for the ACP cylinder flaking & possible plating. Install the cylinder, & measure the endshake, and cylinder gap. If no problems there, just clean it good & shoot it to see how it does. No sense in spending extra money if not needed.

 

[cellar701]

Looks like a good deal, and a good plan for that revolver. Those OM 45s are great guns!

 

[Tommy Kelly]

Nice looking gun. Looks like a prime candidate for a 4 5/8" cut off. I have 3 45 colts all new models only 1 convertable and 2 came with 4 5/8" and I am seriously concidering bobbing the 7.5" to 4 5/8". The only reason I haven't already done it is I have the 2 others already that length. The 4 5/8" is my favorite length and I have every 4 5/8" ruger offers now and a couple that I have cut that ruger doesn't offer in my length.