Oversized Revolver Chambers

[sussexmuzllodr]

I have a remington Uberti about 2012 date of Manufacture. Used .451 they go down easy but need a cork wad in the front. Went back to .454 and they load with a little effort but shave the lead. tap out the ball and it got a flat band around it.....so imagine the cylinders are .452-.453 Its a good shooter it does what it has to.

 

[arcticap]

I have not (don’t own them). I’ve wondered the same thing about that crown, and hadn’t even realized just how rough the bore does look until I took that pic. It made me consider running some sort of compound through it a little to see if I can smooth it up a bit after I empty it.

I don’t recall now, but someone had tried to convince me the crown wasn’t so important on a pistol. I don’t see the logic, but I’m not knowledgeable on things like this.

IMHO your crown doesn't look like it needs attention nor does the bore show obvious signs that it needs lapping.
I'm more concerned about the difference in the rifling between the 6 groove and 7 groove, which your post indicates that the 6 groove is later since it was made in 2013.

Because your lands are much narrower and there is 1 land less, that's more reason to not lap the bore.
Why cause more pre-mature wear on the lands by lapping if the barrel doesn't need it due to pitting?
If there's scratches near the muzzle from using a bore brush or an aluminum rod or such, then stop using them, or use a muzzle protector.
But since you can't lap only the top of the barrel, you shouldn't lap at all, especially if you don't need it.
Photos can sometimes magnify minute details that aren't important and not even visible to the naked eye.
I wouldn't base a decision to lap or chamfer a crown on a photo because photo artifacts can make things look weird...weirder than reality.

 

[rodwha]

In other words continue to lap with lead?

 

[M. De Land]

IMHO your crown doesn't look like it needs attention nor does the bore show obvious signs that it needs lapping.
I'm more concerned about the difference in the rifling between the 6 groove and 7 groove, which your post indicates that the 6 groove is later since it was made in 2013.

Because your lands are much narrower and there is 1 land less, that's more reason to not lap the bore.
Why cause more pre-mature wear on the lands by lapping if the barrel doesn't need it due to pitting?
If there's scratches near the muzzle from using a bore brush or an aluminum rod or such, then stop using them, or use a muzzle protector.
But since you can't lap only the top of the barrel, you shouldn't lap at all, especially if you don't need it.
Photos can sometimes magnify minute details that aren't important and not even visible to the naked eye.
I wouldn't base a decision to lap or chamfer a crown on a photo because photo artifacts can make things look weird...weirder than reality.

I have been personally hand lapping rifle and pistol barrels for over 30 years and so have quite a bit of actual experience in what it does and doesn't do.
No pits that can be felt will ever be removed by lead slug barrel lapping. Lapping removes metal in the ten thousands range. You can lap until your arms fall off and never remove any where near .001 from a bores interior. Pits are not the primary cause of leading, bore constricting changes in diameter and rough finish do. What lapping does is remove these inconsistencies in diameters and bore roughness.
A better crown chamfer protects the land ends from damage and the way they come from the factory is bearly adequate in my view. Good barrel lapping will never ruin rifling if executed in a professional manor. What it does do is remove ragged reaming and rifling imperfections from the land corners , while maintaining the rifling profile. These machining imperfections will be present to one degree or another regardless of wither the rifling is buttoned, single point cut, broached or hammer forged. Shooting does indeed smooth land corners and to a lessor degree groove bottoms but will never change bore diameter inconsistency which is a major cause of leading. Most revolvers will be bore tight right under the barrel threads where it comes through the frame and looser in the muzzle. Best accuracy is accomplished from a level or tapered bore getting evenly tighter toward the muzzle. A level bore into some choke at the muzzle if probably one of the best configurations of bore profile for accuracy.
Land count has almost nothing to do with either accuracy or leading. Even or odd land count if balanced with groove depth ,width and bore consistency will be equally accurate.
Decrying the virtues of quality hand lapping is simply ignorance manifestation plain and simple by those who have not learned how to execute it properly or even attempted to actually learn how.

 

[arcticap]

Mine has thin grooves.

Have you ever run a plug gauge down bore to see how consistent your bore diameter is? Looking at your muzzle bore it looks like it might could benifit from a good lap job and deeper chamfer at the crown.

I think that a lot of light is being reflected in the photo due to over-exposure and the white background.
Because of the angle of the photo, there's no indication that he needs a new and deeper crown because it can't even be fully seen.
I don't see anything wrong with the bore either, especially since the view of it is being cut off as well.
What looks like scratches could very well be mere reflections in the bluing due to excessive camera flash.
That's nothing being shown there that would lead me to a conclusion that it needs lapping.
I agree with some of the things that you said about lapping and disagree with others.
You said yourself that gauges would help determine if his bore needed lapping, but you've already recommended the lapping without measurements to determine if the bore is not uniform.
And you also stated that a machine rest could be needed to determine if lapping would be beneficial or not.
Conversely, that also means that lapping could cause harm.
I simply disagree with the recommendations because there's virtually no evidence that they're necessary.
Lapping simply for the sake of lapping is too much like being lap happy.
There's something to lose and very little to gain.
If the bore and crown are already relatively perfect then there's no way to determine with certainty whether the recommendation is a good or bad one from a single obscured photo.
It's just a matter of perspective about looking before leaping....and lapping.

 

[rodwha]

Here’s what I figure is a better pic of the crown. I’ve never seen such a minuscule crown before in a handgun. Figured it might give a little perspective by putting my ROA in there as well.

It looks rather like the chamfer on my chambers.

 

[M. De Land]

I think that a lot of light is being reflected in the photo due to over-exposure and the white background.
Because of the angle of the photo, there's no indication that he needs a new and deeper crown because it can't even be fully seen.
I don't see anything wrong with the bore either, especially since the view of it is being cut off as well.
What looks like scratches could very well be mere reflections in the bluing due to excessive camera flash.
That's nothing being shown there that would lead me to a conclusion that it needs lapping.
I agree with some of the things that you said about lapping and disagree with others.
You said yourself that gauges would help determine if his bore needed lapping, but you've already recommended the lapping without measurements to determine if the bore is not uniform.
And you also stated that a machine rest could be needed to determine if lapping would be beneficial or not.
Conversely, that also means that lapping could cause harm.
I simply disagree with the recommendations because there's virtually no evidence that they're necessary.
Lapping simply for the sake of lapping is too much like being lap happy.
There's something to lose and very little to gain.
If the bore and crown are already relatively perfect then there's no way to determine with certainty whether the recommendation is a good or bad one from a single obscured photo.
It's just a matter of perspective about looking before leaping....and lapping.

What I notice is what looks like some roughness and slight leading on the land corners and a very shallow chamfer. Lapping will clean that up very nicely. I can almost guarante a plug gauge will reveal bore diameter inconsistency with a looser muzzle diameter than the rest of the bore. The other thing on some of these spaghetti revolvers that I like and own is on occasion in some of the older models the muzzle will not even be square and level with the bore.
Crown chamfers should include the groove as well as the land in a single angle of run out into the bore interior. This insures maximum protection from crown distortion and allows gas vector at bullet or ball exit to be circumferential-ly uniform.

 

[M. De Land]

Here’s what I figure is a better pic of the crown. I’ve never seen such a minuscule crown before in a handgun. Figured it might give a little perspective by putting my ROA in there as well.

View attachment 50777

It looks rather like the chamfer on my chambers.

Yes, a very good and strong crown! I wouldn't expect any less from Ruger. Notice the single angle taper run out into the bore including groove and land in the same taper.

 

[M. De Land]

What I notice is what looks like some roughness and slight leading on the land corners and a very shallow chamfer. Lapping will clean that up very nicely. I can almost guarante a plug gauge will reveal bore diameter inconsistency with a looser muzzle diameter than the rest of the bore. The other thing on some of these spaghetti revolvers that I like and own is on occasion in some of the older models the muzzle will not even be square and level with the bore.
Crown chamfers should include the groove as well as the land in a single angle of run out into the bore interior. This insures maximum protection from crown distortion and allows gas vector at bullet or ball exit to be circumferential-ly uniform.

Krieger, one of the best barrel makers in the country routinely laps after reaming and again after rifling. It is presently and historically quite routine in single point cut or broached rifling for custom best quality barrel making. It is a false notion that properly executed lapping of a barrel causes any harm. It will either improve a barrel or leave it the same accuracy wise and it will without fail improve a barrels leading tendency if present.
I have yet to plug gauge any revolver made from Pietta that did not show inconsistency that could be removed with judicious lapping. I have also tested fire lapping with lap charged slugs in rifle and pistol. It works quite well in cartridge revolvers but is not nearly as control-able as to final outcome as is hand lapping.
My point about using a machine rest or sand bags is simply that either removes much of the human error factor when determining accuracy gain.
I have and routinely use a Hawkeye bore scope which is helpful along with a complete set of hardened plug gauges , micrometers , calipers etc to assess barrel uniformity and smoothness. I'm not guessing about what I've posted, it's based on years of actual experience about the subject.

 

[nkbj]

The first percussion revolver that I bought was a Navy Arms 1861. The best shooting load was a full charge of FFFg compressed under a bullet from a Lee 9mm mold that I drilled out to 3/8". The bullets were swaged into conformity within the chambers by really getting down on the loading lever. Colt designed the 1860 and 1861 loading lever for that and the .36 caliber offers so much less resistance than does a .44 that it was easy to accomplish.

Thinking back to how I loaded that piece in the 1970's... there's no reason that such wouldn't work with a dragoon and .45ACP and .45 Colt molds. It might even work in a .44 1858 but I really don't trust the strength of the lever linkage.

 

[M. De Land]

The first percussion revolver that I bought was a Navy Arms 1861. The best shooting load was a full charge of FFFg compressed under a bullet from a Lee 9mm mold that I drilled out to 3/8". The bullets were swaged into conformity within the chambers by really getting down on the loading lever. Colt designed the 1860 and 1861 loading lever for that and the .36 caliber offers so much less resistance than does a .44 that it was easy to accomplish.

Thinking back to how I loaded that piece in the 1970's... there's no reason that such wouldn't work with a dragoon and .45ACP and .45 Colt molds. It might even work in a .44 1858 but I really don't trust the strength of the lever linkage.

I made a cylinder loading press for just this kind of thing so the revolver loading lever doesn't take such a beating. It's made from a valve spring and some spare steel I had laying around. I found you don't need an adjustable base plate pin to go through the cylinder base pin hole for alignment. The ball and circular brass punch head will self align perfectly every time and protect the mouths of the cylinder chambers.
Click on the photo for enlargement.
The removable block held in by the tab limits the seating depth for the ball to be flush with the chamber mouth.

 

[rodwha]

Hmmm... My understanding is that even a little bit of leading will show itself quickly on the targets. I’ve never seen it. Consistent to would be boring if I didn’t love boom, recoil, smoke, and a grin. Same with my Ruger with a longer barrel. Granted this is always offhand (Weaver-ish stance) so that’s not exactly consistent compared to a rest, and always at 15 yds because they didn’t have a 25 yd pistol range. Absolutely not saying you’re wrong, and never worked with lead bullets until I found I enjoyed BP. I feel I understand a fair bit about the multitudes of angles BP shooting brings but sometimes wish I was a little closer to VA where I might just see if Hanshi was willing to take on a not quite so young guy who would love to learn a thing or two. Fortunately I was one who learned quick enough that mom (and others who’ve been there and done that) and as all too often right, and that it’s best to learn from your mistake than mine

 

[M. De Land]

Hmmm... My understanding is that even a little bit of leading will show itself quickly on the targets. I’ve never seen it. Consistent to would be boring if I didn’t love boom, recoil, smoke, and a grin. Same with my Ruger with a longer barrel. Granted this is always offhand (Weaver-ish stance) so that’s not exactly consistent compared to a rest, and always at 15 yds because they didn’t have a 25 yd pistol range. Absolutely not saying you’re wrong, and never worked with lead bullets until I found I enjoyed BP. I feel I understand a fair bit about the multitudes of angles BP shooting brings but sometimes wish I was a little closer to VA where I might just see if Hanshi was willing to take on a not quite so young guy who would love to learn a thing or two. Fortunately I was one who learned quick enough that mom (and others who’ve been there and done that) and as all too often right, and that it’s best to learn from your mistake than mine

I have not noticed that personally in rifle or revolver. Actually I'm quite amazed at how accuracy holds up with quite a bit of lead build up in the bore but the tipping point when inaccuracy begins to result in fliers happens quite rapidly.
I can shoot one ten shot relay with some sighters with good accuracy and when I clean at the end of that relay I will get some large flakes of bore lead out of the barrel. I don't mean little specks, I mean a tight gunzilla patch smeared with large flakes of lead and it takes about three such patches for the bore to be cleaned out. This is in my lead bullet shooting match rifle with plain base bullets at about 1600 fps. As long as I clean between relays accuracy will remain even with the large lead flake deposits still in the bore.
When I see a bit of lead on the land corners as in your muzzle pictures this indicates a rough edge which lead will accrue on along with diameter changes that is one of the main reasons revolver barrels lead just ahead of the cone and especially so if it is tighter there than up bore. This occurs from friction and gas escapement around the edges of the seal against the bore.The same thing happen in tight spots up bore and is why barrels need to be at least level and smooth to reduce lead build up.
Actually pits get major blame for leading but I have found that pits are not the major reason for a bore leading up. They fill with lube before they do with lead and the bullet slides right on over usually without leaving much lead behind. Machining marks and tights spots in a bore are a different matter in my opinion. The bore scope usually shows leading right after a tight spot when the bore opens up again in my opinion.

 

[rodwha]

You have me rethinking my small lube groove as well. Were you to add lube would you feel it more beneficial to deepen or widen the groove?

 

[M. De Land]

In a pistol bullet that has no need to be as ballistic-ally clean as does a long range rifle bullet I would go with both deeper and wider in the lube groove. Say perhaps .050 deep and .100 long. If you have an example of a .44 Kieth bullet it would be a good design to copy with some mods.
This .44 Kieth bullets groove is .090 wide and .075 deep (.0375 per side). It's width at base measures .430 , weight is about 250 grains , length is .800 and meplat is .300. I've also thought a slight redesign of some .45 ACP lead bullets would work really well in our .44 percussion guns.
Shortened design mods on this bullet which is probably one of the very best ever developed for penetration and long range work would be good. The upper angled groove is for seating in the case mouth which could be deleted for percussion use.

 

[YJake]

Here’s what I figure is a better pic of the crown. I’ve never seen such a minuscule crown before in a handgun. Figured it might give a little perspective by putting my ROA in there as well.

View attachment 50777

It looks rather like the chamfer on my chambers.

I used a chamfering tool to machine my 1858 barrel crown. It’s nothing like that Ruger but it’s slightly recessed now.

-Jake

 

[rodwha]

I used a chamfering tool to machine my 1858 barrel crown. It’s nothing like that Ruger but it’s slightly recessed now.

-Jake

Does it self-align? I’d not fear doing more mods if I knew they were idiot proof.

 

[rodwha]

In a pistol bullet that has no need to be as ballistic-ally clean as does a long range rifle bullet I would go with both deeper and wider in the lube groove. Say perhaps .050 deep and .100 long. If you have an example of a .44 Kieth bullet it would be a good design to copy with some mods.
This .44 Kieth bullets groove is .090 wide and .075 deep (.0375 per side). It's width at base measures .430 , weight is about 250 grains , length is .800 and meplat is .300. I've also thought a slight redesign of some .45 ACP lead bullets would work really well in our .44 percussion guns.
Shortened design mods on this bullet which is probably one of the very best ever developed for penetration and long range work would be good. The upper angled groove is for seating in the case mouth which could be deleted for percussion use.

Well, I wouldn’t want to give up that much mass to allow for that much more lube. I’m not truly certain I really need anymore, which brings me to the suspected leading. This you believe has to do with a tight squeeze through the barrel threaded area, right? If I’ve done well with the amount it has had, then the only reason I’d need more is for extended range days. I’m thinking that reducing some of the lead in the back half would potentially give it a better weight ratio fore-aft so that it should be less prone to deviating in an animal, and this would lead me to thinking deeper grooves, but will the barrel get to eat it all?

 

[nkbj]

In a percussion revolver bullet there's no need for lube grooves.

 

[YJake]

Does it self-align? I’d not fear doing more mods if I knew they were idiot proof.

Some do, some don’t. Mine had brass inserts and I found one that fit the bore of the revolver to assist me. A few turns is all it took to shave the edge off and create a light bevel. Lapping the crown smoothed things out. I used it on the chambers too to allow the balls to swag into them. .457 balls still shave a ring of lead but it’s not as pronounced as before.

-Jake