Newbie needs input on RB and Conicals for NMA

[Long Gulch]

I just took the plunge and bought 2 New Model  Armys from Cabelas. I'm not new to shooting or BP but have never shot or loaded for BP revolvers. I have read quite a bit from this forum and others and feel fairley well informed, however like a lot of newcomers I still have questions.

If using conicals such as the Lee Mold, in say .457, do I need to ream the clylinders in order to seat the bullet or is the base of the conical tapered to accomplish loading? If I do ream the cylinders, what size for either .454 or .457  RB or conicals.?

Any response is appreciated. More questions to follow I'm sure!

Thanks
Long Gulch

[Professor Marvel]

Greetings Monsieur Gulch -
Congratulations on your purchase, and that you used the correct nomenclature "New Model Army" :-)

The Cabelas Piettas are very nice, I have some myself.

My Pietta cylinder mouths seem to slug out to approximately .447 to .450, depending :-)  When  shooting RB, the balls seem to upset adequately to fill the bore.

Before you do more than contemplate reaming your cylinders, I would suggest you get a box of balls and a box of conicals and play with them, see what works for you and what doesn't. Further, you should slug your barrel, and slug each chamber so as to determine exactly what you have to work with. Reeming is generally recommended  for chamber mouths that are  dramatically undersized in comparison to the bore size.
You may have read of Angel Eye's experiences with his .36 Pietta NMA : http://www.cascity.com/forumhall/index.php/topic,24204.0.html

if your NMA are like mine, .451 round balls will do most nicely, and not put a strain on your loading lever.  RB sized at .454's may "cut a nice ring of lead" but are larger than required for my chamber mouth . Due to the size of the chamber mouth the Lee Conical Mold that is listed at .450 should do very nicely. The .457 is generally recommended for the Ruger Old Army.

Roundballs are often preferred; according to the several written accounts of Civil War Vets, they preferred the round ball as it "put down" their adversary in a more satisfactory manner than the Conical.

perhaps you should shoot your revolvers "as is" for a bit and see how they group on paper at 20 yards from a sandbagged rest. If you can achieve teacup sized  groups or better, I would be inclined to leave the chambers alone.  If one does decide to ream, one ought to ream only to the groove to groove size or just a tad ( .001) over, and I would actually do it to a spare cylinder first. These cylinders are remarkably thin in the .44 calibre .

Conicals designed for the C&B revolvers (at least those droppped from the Lee molds) generally have a "rebated base" that allows it to start correctly, then the bottom driving band engages.  If you wish to try some Lee conicals and have trouble finding any, give me a pm , I can cast up a few in .450 and stuff them in an envelope for you, as long as they are going to the CONUS. Customs laws of other countries are legion, not to mention confusing....

hope this helps
yhs
Prof Marvel

[Wolfgang]

Welcome to shooing New Model Armys.   I mostly shoot the Hornady .457 round balls that I get from Cabelas.  The Conicals sold by Cabelas shoot great but are pricey.  Ya might get a box and try them as well as round balls before you get molds to cast your own.  Good shootin', . . .  

More of my guns & stuff . . . www.drburkholter.com/cf4.html

[Long Gulch]

Thanks for the information gentlemen. looks as though the correct thing may be to shoot and ask questions later . I did indeed slug the barrels and they are .444 while the cylinders seem to be .447 or .448 by the use of calipers. .451 looks to be the way to go in a round ball and .450 or so in a conical. While I do contemplate using the original gun powder at some point, for now I will use the replica offering since that is what I have a good quanity of on hand now.
I may not get to shoot these for a while but I do enjoy tinkering with them. By reading  the wealth of information on this site I have already planned a couple of small projects. Thanks everyone for the contribution of ideas. Hope i may return the favor at some point.
Since this my first venture into the realm of cap and ball, I have just one last question. Why did I wait so long?

Thanks again,
L G

[Wolfgang]

I'd not heard of any barrels slugging that small a groove.  Maybe new production guns are being made to better tollerances.  A good thing.  Mine are all older production and the chambers tighter than the barrels which I understand has been typical.  With the dimentions for barrel and clinder that you give .451 will work great.

Good shootin', . . . 

[Deadguy]

The grooves on the Piettas are an odd number, so they don't line up straight across.  As a result, when you slug the barrel and measure straight across the slug with a calipers, you will get a measurement much smaller that the true groove diameter.  In reality, the Piettas usually slug anywhere from .450" to .454".  if yours really turned out to be .444", then it is severely out of spec, but if your chambers are .447", that is perfect for a .444" bore.  Shoot it and see!  If it shoots conicals all over the place, then you know for sure that the bore is bigger than the chambers.

[Raider2000]

First off, Congratulations on your new revolvers, they are fine pieces.

I hope you saved your slug from the bore, because to properly measure it you have to place it in the mike & close the jaws to touch the slug & then rotate the slug slightly so that it measures the corner of one grove to a near adjacent grove corner.

I did my Pietta New Model Army w/ 5.5" barrel & found that my grove was .4495 in diameter but my chambers were .4460, since I had intended to shoot conicals out of this lil cannon I bought a .4510 reamer from Manson reamers "after a great conversation with David Manson we found exactly what I needed."

If you intend to shoot just ball out of your new revolvers then .451 ball will work or you can cast your own.
If you don't do anything to your revolvers chambers you can shoot the Lee cast .450 200gr. conicals out of em & it'll load very easily because of the base being slightly smaller than the rest of the projectile.
I shoot a .457 cast ball "have so for more than 25 years" & also a .456 220gr. Lee cast conical in my lil Pietta & some others that I have around here.

I do BTW have both lee molds.

[Long Gulch]

Lordy, Lordy. I thought I was too old ta learn and end up getting schooled again! I sure don't mind cause I do like learning new stuff about my favorite subject, loadin' and shootin'.
I did go back and check the slugs as suggested and the barrels truly are .444. Since last posting I had a chance to slug the cylinders and they are .447 to .4475.
I may not be able to wait to shoot these firearms. The drama is beginning to be much to bare!

LG