Forcing cone cutter

PJ Hardtack · September 24, 2013, 02:55:25 PM

Just acquired a Brownell's 11* .38/.44/.45 forcing cone cutter kit. Any advice or tips based on experience?

Am I going to be able to do a good job as a person with reasonable mechanical skills? Or do I need to seek out the services of a professional? I do read and follow instructions - well, most of the time .....

The first gun I'm going to work on is a late model Pietta Remington .44 cap gun (the model with the improved grip frame) that has the rifling coming right into the factory cut forcing cone.

Pettifogger · September 24, 2013, 07:03:23 PM

Quote from: PJ Hardtack on September 24, 2013, 02:55:25 PM
Just acquired a Brownell's 11* .38/.44/.45 forcing cone cutter kit. Any advice or tips based on experience?

Am I going to be able to do a good job as a person with reasonable mechanical skills? Or do I need to seek out the services of a professional? I do read and follow instructions - well, most of the time .....

The first gun I'm going to work on is a late model Pietta Remington .44 cap gun (the model with the improved grip frame) that has the rifling coming right into the factory cut forcing cone.

Did you get the whole kit, i.e., the rod, bore guides and cutters? If so, it is pretty straight forward. If you are shooting only round balls out of your Remington, I would not get to ambitious with the 11 degree cutter. In fact, unless you are having some problem shooting round balls I wouldn't mess with it.

PJ Hardtack · September 25, 2013, 11:28:29 AM

No, I didn't get the full kit, just the .38/.44/.45 11* cutter. Wish now I'd gotten the barrel guides and the forcing cone gauges they suggest in the destructions.

Looking at the forcing cones in my .44 cap guns, none of them has what I would consider a good job - tool marks, non-concentricity, etc.
I want to gain experience on them before I tackle my Uberti .44 Russian which has NO forcing cone, just a barely broken edge. It's a lead spitter, dangerous to both the shooter and an RO standing nearby.

Pettifogger · September 25, 2013, 12:14:43 PM

With just the cutter you really can't do anything. You need a brass bore guide for your caliber. On a .44 C&B that would be the .45 guide, the rod, the tapered bore funnel and a handle. Otherwise, you are going to have to take it to someone that has these parts.

PJ Hardtack · September 25, 2013, 01:39:03 PM

What you've shown is the facing cutter. I've got all the other parts 'cept the bore guide.

How long a leade does that cutter make when done to the proper depth?

Blair · September 25, 2013, 02:01:21 PM

PJ,

Just an observation on my part with the original # 3 S&W's I own... there in not much of a chamfer in the forcing cone area on these original hand guns.
Just a thought you may want to check out for yourself if you can.
My best,
Blair

PJ Hardtack · September 25, 2013, 02:26:34 PM

That may well be the case, however are any of your guns 'spitting' lead to the point where people who shoot it are saying they're glad to be wearing glasses?

I've only put 100 rds through my .44 Russian and haven't so much as had the cylinder off, but examining it with a strong light through a cylinder chamber, it appears that there is little to no forcing cone. The timing of the gun seems to be right, so I attribute this spitting to the lack of a forcing cone.

I won't be desecrating an original gun by so altering it, and I'll be a lot more popular on the firing line.

A friend once owned a nice Colt Official Police .38 Spl. revolver that had NO forcing cone! It was a 'spitter' and he did cut a cone, but not knowing any better, cut one that would have admitted a .44 bullet. The gun shot well afterwards, according to him, but he was not an accomplished handgunner.

Blair · September 25, 2013, 03:19:21 PM

PJ,

No, none of these are "spitting". Not the shooting originals nor the two reproductions I also own.

Please understand, I offer this only as an observation on my part.
Blair

PJ Hardtack · September 25, 2013, 05:53:30 PM

Re: your avatar ....

A US friend has just completed his 2nd 1862 pattern Gatling Gun. Like the first, it uses steel 'chambers' that accept a .58 calibre Enfield musket blank. This one uses shotgun primers whereas the first uses standard musket caps.
This one is going to be built on a Naval tripod carriage, unlike the first which has the period correct two wheeled gun carriage and limber.

So, if you've got several thousands lying idle in your chequing account, you too could emulate Clint Eastwood in "The Outlaw Josie Wales".

Pettifogger · September 25, 2013, 07:17:10 PM

Quote from: PJ Hardtack on September 25, 2013, 01:39:03 PM
What you've shown is the facing cutter. I've got all the other parts 'cept the bore guide.

How long a leade does that cutter make when done to the proper depth?

Yes, that photo shows a facing cutter. Forcing cone cutter works the same way. I had those photos in my file. Didn't feel like dragging everything out for another photo.

Blair · September 26, 2013, 08:29:50 AM

PJ,

Re: My avatar...

Yes, this is an 1862 pattern Gatling Gun, with 6 rifled .50 cal. barrels.
It uses CCI pistol caps with 35 grains of BP and a .495 dia. round ball, in the steel sleeve cartridge type chambers.
It has both the tripod stand and the light field carriage.

I would like to see photos of the Naval "tricycle" carriage with the Gatling Gun mounted to it.
The Naval carriage uses a single mounting lug on the bottom of the barrel (instead of two trunions, one on the each side)... so it would be interesting to see how this would be set up.
My best,
Blair

Coffinmaker · September 26, 2013, 07:09:27 PM

PJ,
If your going to get it "right" you'll need the "T" handle, rod, bore guide and the cutter. I also suggest you snap up a can of "cutting" oil. And, Pettifogger's suggestions/directions are spot on. Cutting an 11 degree forcing cone is a very good thing as long as you don't overdue it. Back to the Brownells catalogue.

Coffinmaker

PJ Hardtack · September 26, 2013, 08:56:44 PM

Blair - my Gatling making buddie's email is: marshall@rockisland.com I'm sure he'd like to correspond with you re: your common interest. He is a wealth of historically correct info, a master machinist and caster of bronze for restoring antique marine steam engines.

Coffinmaker - got all of the above 'cept cutting oil. For the amount of metal being removed and the low speed of hand turning the cutter, is it strictly necessary or will some other form of lube be OK?

PJ Hardtack · September 27, 2013, 07:24:07 PM

Today I used my new forcing cone cutter on my lead spitting Uberti .44 Russian.

Took all of ten minutes, and that because I removed the cutter once to check progress. Dead simple operation, the metal cutting like cheese. I used a machine oil to lubricate and the muzzle bore guide provided in the kit. Like Brownells says, it would be VERY easy to overdo it.

I used my S&W M29 as a guide, since they both shoot nominal .429/.430 bullets. The S&W has a forcing cone that measures a whopping .460. A .430 bullet goes into the throat quite a way, more than it does in my recut .44 Russian now. Brownells recommends no more than .020 over nominal bullet diameter, so I stopped at .450.

I measured the forcing cones of three cap & ball revolvers (DGW, Uberti, Pietta) and they miked at .451, .464 and .470, not in that order, all with very abrupt angles. Haven't yet decided if I'm going to recut any of them, being of the "if ain't broke ....' school of thought. None of them spit lead, shave lead and I'm not unhappy with their accuracy.

For those that have never done this operation, you can tell by 'feel' when you have cut through the original factory forcing cone. After that, it's merely a matter of not over doing it by going too deep. It would be reassuring to have the depth gauge offered by Brownells and the next time I place an order, I'm going to order one.

Now I gotta prove the work by shooting the gun .....

PJ Hardtack · September 28, 2013, 01:52:31 PM

Based on my success in cutting the 11* forcing cone of my .44 #3 Russian repro, I got bold and just did the same thing on my S&W M29-2 .44 magnum. After doing my Russian, I watched a video on doing it on a S&W revolver and Lo! - I had done it good. Now I was getting bold ....

I was cleaning the M29 which had accumulated a lot of leading ahead of the factory forcing cone. I got into it with a brass bore brush and Lead-Away cloth on a tight fitting bore jag. That got rid of the lead and now I could really examine the abrupt factory 8* forcing cone. It looked rough, and there was a decided 'gouge' on one side of it, the side where there was the most lead build up.

I made the cut in four stages, not wanting to overdo it as per the 'destructions' that came with the kit. There is still a trace of the 'gouge' left, but I'm not willing to remove any more metal to get rid of it. Perhaps polishing will suffice. But first, I'm going to shoot the gun and see if things have improved.

From what I read on several sites, the forcing cone is an area not given enough attention by manufacturers and one of the first things addressed by gunsmiths when working on problem guns.

Bibbyman · November 04, 2013, 12:46:56 AM

I have two new Uberti Cattleman 45s. The forcing cones look to be correctly done. But they are a little rough and look like they would benefit from polishing. Would the same kind of tool with a brass or bronze button and valve grinding compound work to polish out tool marks.

Coffinmaker · November 04, 2013, 09:37:13 PM

The chances of your Ubertis having a correct 11 degree forcing cone are essentially nill. Can they be polished, yes, if you can figure out what degree they were cut at. You must use a centered cone with a bore guide. Polishing the cone area to a concave shape will give you leading problems big time.

Coffinmaker

Bibbyman · November 05, 2013, 03:12:42 AM

Quote from: Coffinmaker on November 04, 2013, 09:37:13 PM
The chances of your Ubertis having a correct 11 degree forcing cone are essentially nill. Can they be polished, yes, if you can figure out what degree they were cut at. You must use a centered cone with a bore guide. Polishing the cone area to a concave shape will give you leading problems big time.

Coffinmaker

Yes, I can see the problem. Not knowing the angle or being able to measure it would only leave a person with a WAG as to what the angle is.

I see 11º a lot when talking about forcing cones. What's magic about 11º? Looking at MidwayUSA, they only list a 5 and 18º cutters.

Pettifogger · November 05, 2013, 10:14:14 AM

Quote from: Bibbyman on November 05, 2013, 03:12:42 AM
Yes, I can see the problem. Not knowing the angle or being able to measure it would only leave a person with a WAG as to what the angle is.

I see 11º a lot when talking about forcing cones. What's magic about 11º? Looking at MidwayUSA, they only list a 5 and 18º cutters.

Absolutely nothing. If 11 degrees was a magic number don't you think all the factories would be using it?

Coffinmaker · November 05, 2013, 10:55:55 PM

Well, 11 degrees is a nice middle of the road angle that is widely reputed to reduce leading and improve accuracy. I personally recommended and cut bunches of 11 degree forcing cones before I retired. I didn't see any real change in accuracy, but an 11 degree bevel did reduce leading and ease the bullet transition into the rifling. Not magic but works quite well.

Coffinmaker