Unless you know the actual bore diameter of your rifle, you are just guessing on what might work well, both as to ball diameter, and patch thickness, as well as powder charges.
Please, NOTE that everyone here speaks about ball diameter to a thousandth of an inch- NOT a hundredth as your post here does. A ".49" diameter ball tells us nothing. Do you mean and actual .490" diameter ball, or any .49 caliber ball? I have tried both commercial .490" and .490" swaged balls in my barrel, as well as several different sized CAST balls between .490" and .500". My Actual Bore diameter is .501"
Same problem with patches. We measure them to the Thousandth of an inch, not a hundredth, because the coarser measurement doesn't tell you much.
I have tried, .010", .012", .015", .017", .018", and .020" thick cotton ticking patches in my rifle over the years. Technically, the first 4 would all be .01" thick patching. Please trust me when I assure you that those thousandths of an inch MAKE A DIFFERENT in PERFORMANCE. And, once you find a fabric that seems to seal well, then you have to find a lubricant for that patch that works in your rifle. I have seen groups- good groups--- shrink to half the size when I changed lubes. It scares the heck out of when it happens, because you just thought that you had gotten a patch lube combination that works and gives 'hunting size groups". When you see that group shrink in half, and then shoot another group, and another, and they all are much smaller than what you were getting before changing the lube, You start to rethink everything you have done with that gun from the day you bought, or built it, until this date of discovery.
Anytime you change loading components and either see better groups, or worse, you begin checking everything again.
For instance, I bought some new pre-cut patches, marked the correct size, but then I began using them, they went down the barrel noticeably easier. After a 3-shot group was very disappointing, I stopped, and measure the new patch fabric. It was Not the thickness marked on the package- but was several thousandths of an inch thinner! :cursing:
Years ago, I switched brands of commercial swaged balls I was using, and found out they were not as well sorted or sized as the ones I had been using. The only way I could know that was by measuring the diameters of the remaining balls, with my micrometer, measuring the diameter in several different locations of the ball. I was shocked to find out how out-of-round the new box of lead balls were, when compared to my old "brand."
Most recently, at the insistence of my brother, I tried shooting my rifle using an OP wad made of vegetable fiber. Several changes were immediately noted. The groups were smaller, but higher on the target from my POA.
The most significant change was how much cleaner my barrel was, shooting 2Fg powder. The residue "grit" was smaller- on par with that left when shooting 3Fg powder---- and there was so much less powder residue in my barrel- noted by looking at my cleaning patches. Its apparent that the OP wad is providing a much better gas seal, and was allowing a more complete burning of the coarser 2Fg powder than when I used the same powder with just a PRB.
This is why you will find us telling you to change ONLY ONE THING in your loading procedure at a time. You question asks us to speculate on your bore diameter- which you don't know and don't give to us. Then you want opinions on ball diameter and Patch thickness, and choice of Powder! YIPES!
If we know the exact bore diameter, and groove diameter, and Groove Depth of your gun, the barrel length, how thick the barrel is ( across the flats), we can give you a recommendation on WHERE TO BEGIN in testing loads. IN fast ROT barrels, the GENERAL rule( always exceptions) is that you need a very tight fitting Ball/Patch,Bore combination. The Grooves tend to be more shallow in the fast ROT barrels, as they are designed to shoot bullets, NOT PRBS. Using an OP wad between the powder charge and the PRB will often help improve accuracy dramatically, shooting the PRB, and also allow you to shoot heavy powder charges without fear of burning your patch. The OP wad acts like a Firewall, allowing you to use a larger diameter ball, but a thinner patch in those shallow grooves.
With any barrel under 28" I would normally recommend working with 3Fg powder, so that you can get that PRB up to velocity faster in the shorter barrel. But, 3Fg burns hotter, and that is where using an OP wad seems to be prudent, too.
The hotter powder is more likely to burn that thin patch, which simply cannot hold enough lube to keep from burning. Use the "Firewall" of a OP wad, fillers, or even folded cleaning patches pushed down the barrel in front of the PRB, to prevent the burning of the patch.
As to how much powder to use, you need to do penetration tests at various distances, with different powder charges to learn how effective a PRB IS as a deer rifle projectile. Then let recoil, and accuracy, tell you when enough is enough. :shocked2: :hmm: :thumbsup: :v
