Colt Officer's Model Fumblings

HI, 

Same early gun I posted about a few days ago. I am struggling to get good accuracy.  I see no reason it should not group under 1" at 25yards off the bench. I am using 158 grain Commercial cast bullets with Unique and 231.  For testing I use Adam McDonalds fancy powder trickler.  My loads are modest book loads.  I was using up to  4.85 gr Unique and up to 4.55 gr 231 with the 158 grain lead bullets.  These are 800 to 850 ish FPS loads.  

 I did discover a possible significant issue.  I think it has been leaded up since before I got it.  I bore scoped it.  The forcing cone and first inches of the bore were leaded. There was also lead stuck to the frame near the barrel.   I was cleaning between loads during testing.  I have been shooting commercial cast bullets.  I suspect insufficient lube?  

I cleaned the snot out of the bore with lead wipe away cloth.  The forcing cone did not give up easily.  I made a brass cone that matched the forcing cone taper.  I made a rod to drive it from the muzzle, was protected from rubbing with a piece of rubber hose in the bore.  The abrasive was pumice and cosmoline.  That left a crisp polish that removed only some of the original tool marks.  

Should I try dousing my commercial bullets in Lee Liquid allox?   They are 3D and Red Line Brand.  I also found some of the very wimpy loads to show accuracy promise.   

I have never had significant leading with my own cast bullets.  This is new to me.  I am tempted to buy a mold.  IF I were to buy a mold which of the Accurate Moulds selections is a good bet?  

Thanks for any thoughts you may have,

Scot

You can try Lee Liquid, but I’d recommend that you switch to a coated bullet.  Sell, trade or just shoot up the lubed bullets you have.  I switched 5 years ago and no longer recommend lubed bullets.  I shoot them, but won’t be buying many more.

What is our recommended sources of coated bullets?

Mostly for revolver use.
Colt OMM, K38, 1955 model, S&W 57

Brazos, Summers, Missouri, RedLine, and most anyone that sells coated bullets.  Brazos is my favorite, but I’ve had good luck with Missouri and RedLine.  RedLine is local to me so that’s a plus.

dgbullets.com

An undersized bullet or one that doesn't seal in the bore can result in leading. Have you checked the diameter of your bore vs. bullet? A very hard bullet that is driven at lower velocities might not seal.

If you know a PPC shooter you can ask him who built his pistol and if he is still working and get the forcing cone of your pistol opened up to accept lead bullets. You can also find a Lewis lead remover which was made for lead removal from revolvers forcing cones. Leading won't go away using lead bullets till the forcing cone is opened up. Yes coated bullets will help but so does jacketed bullets. The lead found on the frame could be a timing problem also so if it were mine I would be looking for a revolver pistol smith.
Our Old friend Jerry Keifer was very good at this.

Perhaps your cylinder throats are undersize and swaging the bullet prior to entering the barrel.

Shug your bore and then compare to the throat sizes.

Slugging results:

I used pure lead balls.  The barrel and cylinder are perfectly clean.

The cylinder chamber mouths are all very close to 0.3576 +/- 0.0002.  I like that.  

 If I measure across the middle of the grooves I get 0.3540 to 0.3536" depending on the the groove.  To small?  IF I measure across the corners of the grooves I get about 0.3564" +/- a few tenths.  To me that means the rifling cutter profile  was of a larger radius than the correct 0.357" .  

There is also a slight, very slight constriction at the frame threads.  I mean, a slight hitch that a light bump of my hand gets the slug past.   

To me, it seems, the groove diameter is too small, except in the corners.   It is like Harry Pope rifleing done by accident.   It seems like this will promote fins on the base of the bullet.  

I could be over analyzing things too.  This was Colt's flagship target revolver.  They must have known what they were doing?  Hopefully.........


I am tempted to lead lap it.  At least get rid of the pinch a the frame threads.  I will also make a rod to check the cylinder alignment.  

I am equipped and experienced to do my own work.  I tend to avoid sending anything out.  There is nobody in my area to do it.  There are fees to book in and out, for shipping too.   I am not as enamored about this revolver as I was before I got it.  I have my eyes on a Smith 14.  I need to work on the the owner, he will never shoot again, maybe I can make a deal.  My Old SW14 was incredibly accurate with no muss or fuss.  

Scot

There were PPC pistolsmiths making a good living rebarelling S&W revolvers with Colt barrels to get these 354-.356 barrels.  

That said, it also included a rework of the barrel throat.  Sometimes the barrel is offset from the throat axis.  Brownells sold a bunch of “revolver throaters” over the years to pro and amateur gunsmiths to allow for correcting this issue. 

As for the pinch in the frame threads, I’d leave it alone UNTIL all other options are addressed. 

Your primary issue is bullet failure.  I would find some Remington, Winchester or Federal 148 Wadcutter factory ammo.  That will define your revolvers accuracy potential.  Then i’d address the leading problem.  You’re shooting lubed commercial bullets.  I’d approach it from two angles.  Some casters will do custom sizing.  I’d test identical bullets from the same maker at .357 & . 358.  See what your gun likes.  Then I’d test different bullet makers who supply those bullets.  If you want a limiter, limit to 158 RN cast as that profile seems to be a better shooter than SWC.

The forcing cone is generous and centered.  

I made a bore diameter brass spud.  (0.3455")  It is a sliding press fit.  

The chamber mouths are 0.3575 +/- a few tenths

In several cylinders (4) , after cycling it and holding the trigger back, the spud will not enter the cylinder.  

IF I release the trigger the spud sides in easy.  The cylinder is over rotating.   

The timing is off?  My math says more than 0.006"    Did I do the test right? 

That seems like a serious problem?  It sound like I bought a very expensive yet defective revolver.

I’d seek out a revolver gunsmith to ask.  A quick internet search came up with this

https://www.heffronprecision.com/

Shipping handguns to and from California problematical.   It is expensive to do legally.  Crazy people destroy or steal possible gun containing packages.  

I think buying the Colt was a mistake.  I paid too much and did not realize they were so fickle to work on.  I should have searched harder for a Smith and Wesson.

My best luck with my Officers Model Target and Officers Model Match revolvers has involved high-quality factory wadcutters. The only handload of mine that has grouped worth a darn is a 158 grain swaged Hornady SWC driven at a very modest velocity (1.475" OAL, 3.2 grains W231).

I have not noticed significant differences in how quickly my Colts lead versus my Smiths with the same loads.

My cylinder misalignment leaves a ~0.006" gap between the bullet and barrel on one side as it leaves the cylinder and enters the barrel.  It also must shave the tight side.  Gas seal is impossible.  I imagine the transition is beating up the locking bolt too.   Load testing is pointless.  I will check with the local gunsmith tomorrow.  I think the answer is to sell it to a collector, take my loss and get a revolver that is not screwed up.

Added later:

I took it to a local gunsmith.  He reamed the forcing cone.  Hel felt it was too tight and changed it to a modern form 11* taper.  He was not interested in working on the lock work.  

I was wrong on the math of the misalignment.  The gap between the bullet and barrel is more like 0.012".  I do not know much about tuning target revolvers.  TO me it seems that if the bullet slams into the barrel cockeyed accuracy is going to be poor.    The gas will melt the lead on the leaking side and spray it down the barrel and onto the frame.  It will also knock the bullet out of shape.  

I used to think that Colts were the height of revolver quality.  I have come to realize the mechanism is a hold over from the 19th century.  And, most of the guys who work on them are gone.  

I will try it again and see how it shoots.  I expect any target gun I own to hold the X-ring off sandbags or a Ransom rest.  I am not expecting that kind of performance.  

I checked with the gunsmith regarding consignment possibilities.  I would loose $800 if I sold it for a realistic price.  That is not much less than I expect to pay for a SW M14.  Live and learn.

You might give this guy a call, he has a really good reputation on the Colt Forum.  

http://glenncustom.com/

He is in AZ so if you don't want to ship it you could make it a road trip.

I spoke to him last week.  I wish he was closer.  He is the real deal.  He is 700 miles from my home.  Unfortunately travel expenses would buy me two M14s.  Shipping  is not an option to do legally and I will not risk other sketchy arrangements for shipping.   

I will load more ammo today and see how it goes.  It turns out that two thickness of paper between the crane and frame "fixes" the chamber and barrel alignment.  Maybe some idiot flicked the cylinder closed "gangster style" in the past and bent it a bit.   Now that I figure that out I can test it.

Hey Scota one more person you might give a call, he is here in CA  Bill Martin of Bill's Gun Repair.  His number is 510 407 4602  he shoots at the range in San Leandro quite often and several of the good shooters at the range have used him.  

Good luck.

I will call Bill Martin.  

It shot the Colt  again today.  All groups were shot with a muzzle rest off the bench with sandbags under my hands.  I also shot a S/W.  Both guns like the same handload.

The best load was 4 gr 231 and a commercial swaged 158 gr with a lube wash of Lee tumble lube.  I tried two other loads too.  

The range was 25 yards.  The 11* forcing cone did help.  A paster between the crane and frame also helped a bit more. 

I brought a control revolver a S/W  M14 8" single action only.  It shot about 1" consistently for five shots.  To bad the Smith is not a competition  legal gun.    

The Colt ran around 2 1/2 ".  So still not good enough for the intended purpose, but better.  The leading situation was resolved.

Nice to have a control gun to compare loads with, helps remove the "is it the gun or me" factor.

Gauge your cylinder throats.  Get Matt's bullets to cast you some Lyman 170 gr RN in a diameter that matches or is .0005 under your measured throats.  Should take care of it regardless of lube, powder, charge, velocity, crimp, seating depth...  Most accurate mold for many folks and tightest groups out of a RR going through my model 14.