Undersize Cylinder Throats?

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WaltWhite

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I just got an 1858 Pietta and have only shot it with a taylor conversion thus far and quite like it. I'm about to head to the store and grab some balls for the BP cylinder and figured I'd measure the throats to see which size ball to grab.

Well they're all really consistent which is good, .445 and change. But isn't that way too small? Shouldn't the throats be slightly bigger than barrel diameter?
 
Perfect would be groove dia up to .002 larger. But undersize balls will bump
up . Just shoot it and enjoy. I would say buy .454 size.
 
This is why most people on here say they need bored out a little.

I found it helps to keep the chambers really clean.
 
If it is better to have revolver cylinders .002 oversized why do they sell the cylinders undersized to begin with? All of my repro revolvers have undersized cylinders.
 
I shoot the .454 size out of mine with good accuracy . Like BowerR64 says , keep the chambers clean it helps a lot. I even polished the chambers on mine so that it would be easier to keep them clean.
 
454 is what you need. I know that Pietta cylinders when new will take 451 but usually after a few cylinders of loading and shooting they fit very loose. Have fun.
 
I'm having my cylinder reamed in my .44 Navy ASM for this reason. 8 to 12 inch groups at 25 yards due to a grossly undersized cylinder! I just have not made it to my cousins machine shop yet.
 
Doesn't matter what size you put in the chamber, you're sizing it to the cyl. chamber. Stuff an elephant in there and it too, will be under sized. I think the under sizing is for liability issues more than anything else. Also, a mismatched chamber/bore wont be as big a deal if the chamber is a little small. Fixing the "built in" cautions is far better than our suppliers being sued out of existence. Thanks to such a litigious society we live in, we get what we get.

45 Dragoon
 
under size cylinders

hi I have found with my pietta.44 that I have to use .457 ball the same as Ruger old army. Mine is quite a few years old, I tried .454 and could push them in with my finger and although they were accurate I was bothered about the recoil nudging them out the cylinder, so guess mine was produced before as has been said the sue culture took over. It seems like all new guns that we purchase in the UK have triggers that require a tractor to pull them for the same reason.
 
This might be wrong but i think i read it on here that they use one die or what ever the tool is to cut both the barrel and the cylinder.

After they do both they then have to cut the rifeling wich then takes more off then making the barrel slightly larger then the chambers.

Then once its all done they have to blue it wich is another coating. Its a thin coating but its still a coating. is it .002"? im not sure but every little bit helps with these IMO.

I was going to buy a reamer and i still might but if you think about it these things are so cheap why not just do it with tools you already have?

If i spent $600. on a ROA and it had this issue i might consider spending the money and doing it right or have a gun smith do it but when your talking $150.-$250. the tool is $90. I may get one just because i have like 6 of these things that all need this done to them.

I used a hopps plastic jag designed to hold a patch and i put a strip of coarse emry paper in it and ground off the blueing on a few of mine with really good results. The plastic threads chuck right up in my dremel. 30 seconds to a minute at medium speed is about all it takes.
 
moses66 said:
hi I have found with my pietta.44 that I have to use .457 ball the same as Ruger old army. Mine is quite a few years old, I tried .454 and could push them in with my finger and although they were accurate I was bothered about the recoil nudging them out the cylinder, so guess mine was produced before as has been said the sue culture took over. It seems like all new guns that we purchase in the UK have triggers that require a tractor to pull them for the same reason.
Click to expand...
Is yours a new gun? Some one may of reamed it for you.

Some of them they have fixed, like the shooter version i think they put extra work in that model making it correct how it should be. They also swagged the chambers so insted of shaving off a little ring to make it fit it just squishes the ball down to size. I think with swagged chambers it also benifits more using filler to get the ball up as high as it can in the chambers this way the ball isnt squished down as much.

Another problem ive noticed on the 1858s when i slug a barrel ive noticed that the breech and the muzzle seems smaller. I understand the muzzle part this helps the blast seal but the breech being smaller then the middle? i think its due to threading the end of the barrel.
 
My Pietta is stainless steel and about 15 years old. It also came with target sights as standard but can tell you little about its previous owners and what they had done to it if anything. It did have a very hard trigger pull till I did some work on the spring so I guess it was as it came from the factory.
 
I measured mine with my dial calipers and came up with .442". I had initially decided I'd open my chambers up to .450" or more, but having it in my hands now I'd be afraid to take anything off of it. Between the chambers is quite thin! And I generally use 30 grns or more with a sporting grade powder.
 
It has been my observation that when a soft lead ball or boolit gets kicked in the butt with a few thousand PSI, it in turn bumps up a few thousandths of an inch in diameter.
 
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