I reamed my cylinders to match the bores...

Status
Not open for further replies.
C

Cincinnati Slim

Member
Joined
Jul 2, 2006
Messages
150
Location
Censornasti
Howdy All,

I got my little Franklin Arsenal digital caliper from Midway and some soft lead balls and did some measuring. I have two Remmies and two Colt clones, all from Pietta. I "slugged" the bores and measured the resulting deformed balls. All four guns were very close in measurement; bore groove diameter was 0.448. I then measured the chambers of the cylinders. Again all were very close in size so I guess it is true about Pietta's machine tools being precise new computer controlled stuff. Chamber bores measured 0.444-0.445...too small for optimum accuracy. I keep reading that chambers should be bore groove size or up to 0.002 LARGER for best results. These were 0.004 TOO SMALL !:scrutiny:

So I ordered a size 2/A adjustable hand reamer from www.HermansCentral.com

Size range is from 7/16 (0.4375) to 15/32 (0.46875) so my "ideal" size of 0.448-0.450 was covered. The reamer was about twenty bucks. I took a grinder and shortened the threaded end of the reamer about a 1/4 inch so it could go far enough into the chambers. I used plenty of tap cutting oil and reamed out the cylinder's chambers to just over 0.448

My "slugged" balls now fit neatly into the chambers. I'll be heading to the range in the next few days to see if my groups are any better now !;)

Happy Trails

Slim
 
Hey Cincinnati Slim,

How did those work out?? I have been patiently waiting your report!! :D

Have you been to the range yet?
 
Last edited:
Strange, my Pietta 1858 Remington repro has a bore grove diameter of .453 and chamber diameters of .447. Mine is about three years old. Is yours a more recent manufacture?
 
you might have some issues if you actualy do that, also for measuring something that small, you might want to find yourself a 0-1 micromiter. easy to use and FAR more accurate than a caliper.
 
The best way for measuring the inside of a bore or chamber is not to use a micrometer on it directly, as it's impossible to get a totally accurate reading. It's best to drive a soft lead slug in, carefully remove it, then measure the outside of the slug. Those cone shaped fishing weights work great for that. Just tap them in and using pliers, carefully pull it back out.
 
C.S. may have gotten a small reading for the groove diameter if the lead wasn't "bumped up" in the barrel with a dowel at each side and wacked with a hammer. It's tricky measuring the grooves of a seven groove barrel. Ther's a very small spot that shows the biggest diameter. Keeping the swag of the barrel at a perpendicular to the calipers is tricky too. I'd be willing to bet the groove diameter of those Piettas C.S. measured were closer to .451. I wouldn't bet much though since his could be .448. I just measured the chambers and the grooves in a Belgian Colt and both were .445. The Belgian Colts made from 1960 on were made on the same machines as the original Colts the Belgians made under license from Colt.
 
of course not the inside of the bore. i meant measuring the balls.

the best way to measure the inside of something is useing a bore guage and a micromiter. but as he said he made a slub for the barrel and measured that, so i stand by what i said to useing a mic.
 
I think it would be difficult to measure a lead slug of the inside of a barrel with mics. The lead is so soft it takes some "feel" to not compress it. The edges of the lands(on the bullet from the barrel grooves) are where the widest diameter reading comes from and they can be soft. Mics are more accurate but the caliper has more "feel" to it. You can get readings from a caliper less than .001 inch. It doesn't read it but you see the indicator between the lines. Within less than a .001 in. is good enough for slugging barrels of cap&ballers. You want to get on the high side and even .001-.003 over for the chamber compared to the barrels groove diameter. Depends on the person doing it and their opinions of it. I should mention that "Cerrosafe" is an alloy made for slugging barrels and it's harder than lead and easier to measure even with the more accurate mics. It's sold at Brownells and other places. You put a plug in the barrel and melt the Cerrosafe and pour it in and knock it out when it hardens. Looks like lead but it's an alloy that is harder and doesn't shink when it sets back up. It's not needed for cap&ballers but it's the best.
 
I'll see Monday...

Howdy Folks,

Big annual BP shoot had the range at Friendship tied up this past week and work has prevented any range testing. I'll be off Monday and will try out my new improved chamfered and reamed cylinders then. Got a Stainless Pietta 1858 NMA and a 1851 "Navy" and a blue 5 1/2 inch 1860, all will be getting .457 Hornady ball, 30Gr. Goex FFF, Remington #11 caps. "Wonder Wads" loaded via "Dick Dastardly" cylinder loader.

I'll let y'all know how it turns out !;)

Cincinnati Slim

p.s. I know, 1851 "Navy" ain't suposed to be .44 but mine is ! Blame Pietta..:rolleyes:
 
Bore and chamber measurements

I got the newest Dixie Gun Works catalog from their booth at Friendship last Monday. The chamber size, bore groove diameters and other dimentions are listed for a number of common BP revolvers from ASM, EuroArms, Uberti and Pietta. The specs for the Piettas are in line with my measurements.

Of course the point is; the factory chambers are too small !

.444-.446 chambers opening into a .448-.450 bore can't help accuracy.
Most of the stuff I've read recomends chamber bores equal to or .002 larger than the bore groove diameter for soft lead ball/bullets. True .45 caliber spec chambers of .452 would probably be ideal but since removing metal with a hand reamer is pretty slow process I stopped at .448-.450. I did seven cylinders and it took most of a day working slowly and carefully, taking frequent measurements and then finishing up with a little light "Dremel-work"

Slim
 
Sorta got the hang of it...

Ya, I am pretty confident since I'm right at bore groove diameter now.

I started going and got the hang of it, kept on until the blades on the reamer broke. Had six blades. On the last cylinder I was down to three but it still worked, just more slowly.

I've shot .452 slugs through all these revolvers before via conversion cylinders so I know they'll work OK w/lead ball about the same size.

Slim
 
Cincinatti Slim,

I reamed my Pietta chambers to .4535 (7/16"). Accuracy improvement was considerable using .457 round balls. Whereas 5-6" 6-shot groups at 25 yards were normal before, now I can keep 6 shots inside 2" most of the time.
 
Range Report from Friendship...

Howdy Folks,

Spent a beautiful Monday afternoon at the pistol line on the range at Friendship. Shot my stainless Pietta Remmie using three of the cylinders whose chambers I had reamed .448-.450 to match the bore diameter; Goex fff, Remington #11 caps, wonder wads, Speer .457 balls. Chamfered the mouths of the chambers and used a "Dick Dastardly" cylinder loader. Worked very well, almost no lead shaved; balls swaged into the chambers smoothy. Other than one cap falling off from recoil, no problems or mis-fires.

Shooting at 25 yards at NMLRA muzzle loading pistol bullseye target handheld from a sandbag rest produced several five shot groups each measuring two inches across. Point of impact was also very consistent; six inches low and two inches to the right from point of aim.

I can work with that !

My next step is to file a little off the too-tall front sight to bring up the POI. I'd like to be able to use a six-o-clock hold on the bullseye so that front sight needs to get shortened some. I'll probably square up the rear sight notch some as well. A square cornered "U" shape is easier to use than the factory "V" shape. I tend to string my shots up and down when I try to use a "V" notch rear sight.

Here's the link to the reamer I used...

http://www.hermanscentral.com/site/product.cfm?id=316BC35F-123F-24EC-3E0ECCCABEC5CD71

The adjusting nut moves toward the shaft end as the reamer expands. I set it at the minimum size to fit into the existing chambers and then ground off the rest of the threaded end so it could go down far enough into the chambers to do the job...

This was an easy, worthwhile project to do to improve the accuracy of cap and ball sixguns with undersize chambers. Highly recommended !

Cheers,

Slim
 

Attachments

  • adjreamer6.gif
    adjreamer6.gif
    5.4 KB · Views: 41
Would this compromise the integredy of the cylinder at all using maximum loads? or is .004 of an inch make no difference at all?

New to this btw.
 
Bigger Chambers safe ?

I don't think this is anything to worry about if your using black powder.
My flask spout throws 30 Gr. of fff regardless of chamber diameter so the charge is the same. Also, if you're removing .004 of metal that's only .002 from one side and .002 from the other, really nothing to worry about.

Now if you pack the chambers with smokeless all bets are off...:uhoh:

Slim
 
Status
Not open for further replies.

Similar threads

R
  • Locked
? Ream Oval Chambers on C&B Revolver ?
Replies
11
Views
1K
skeeterfogger
S
T
  • Locked
Cylinder Reaming?
Replies
16
Views
2K
arcticap
arcticap
M
  • Locked
To ream or not to ream
Replies
5
Views
893
Misfire99
M
C
  • Locked
Slugged bores of a variety of six-guns...
Replies
1
Views
666
K.A.T.
K
G
  • Locked
Uberti (current production) .44 New Model Army Cylinder Ream Failure.
Replies
13
Views
853
paul harm
P
Back
Top