Any other size

[No Powder]

Are there any other size round balls available for a 38 cal. besides .375?  If so, where could you buy them?

[Bigsmoke]

I have had great success with Tanner Bullet Moulds.  He makes them in any diameter you want.
This was especially helpful when I was playing with the big bore rifles, as when was the last time you saw an .820 or a .980 round ball mould on the shelf of your local gun shop?  Me neither.
Here is a review of his products from a few years ago:
https://www.thereloadersnetwork.com/2018/10/09/jt-bullet-moulds-670-round-ball-mold/
IIRC, I think Jeff Tanner passed away a few years back, but the business is being continued.
I was right:  https://www.ballmoulds.com/history-articles/
Hope all this helps.
John

[No Powder]

Thanks John. I sure hope you have access to a lot of lead flashing. You're sure going to need it for those big round balls.

[Bigsmoke]

As a matter of fact, when I was playing around with them, I did have access to a lot of lead sheeting.  A fellow had torn down an x-ray room at a clinic and stopped by the shop wondering if I would be interested in buying any.  Oh yeah   And I sure did buy it.  Nasty stuff though, it had a pretty thick coating of glue on one side.  Yuk!!
John

[The Miner '49er]

Tom, our friend,  Mr. Google says that Hunters Supply has .358, and DGW has .376 and .380.

[No Powder]

Popular calibers normally have sizes of .005 to .010" smaller than bore size. Apparently not so with the 38.  Apparently these sizes are popular for the 36 cal. revolvers. Also had a similar experience with lead sheeting, out of a dentists office. Had some type of purple adhesive on it, along with paper off of the drywall. Left it sit outside for several winters thinking that would surely remove it. Wrong answer. Just cut it into small pieces and threw it in the pot. Just made a little extra stuff to skim off the top.

[The Miner '49er]

Ard you looking for larger or smaller than .375?

[No Powder]

I personally would think .370 or .375 would be fine so that .015 to .018 patching would work well.

[Butler Ford 40]

http://www.bagmolds.com/UNZIPPED/htdocs/1.shtml 

[No Powder]

Thanks to all you guys for responding. I would personally go with the mold ideas. But in my last phone conversation with my friend, he stated that life is now getting in the way. I think our first shoot is on April 7, so at that time I'll inquire how he is making out with his nephews rifle. I looked in my Blue Book of Blackpowder values, to see if I could find this rifle. He said it is a Pedersoli, and I can only find one Pedersoli listed in 38cal. I think it is called the Plainsman Rifle. Poor guy should be out making smoke with that thing instead of it sitting in the corner collecting dust.

[Winter Hawk]

Track has .360 round balls: https://www.trackofthewolf.com/List/Item.aspx/127/1

I'm striking out on .370

A quick call to Bagmolds.com and see if they can get a mold out quickly?

[No Powder]

Thanks for your input Kees. I guess if he wants .370's, he'll have to cast them. So I guess it's up to him now.