Starting load for a 50 cal. Johnathan Browning mountain rifle, shooting .490 patches balls.

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The data shown in the owner's manual, posted by @Dale Allen Raby in post #8, are very informative. Browning suggested a range of ball sizes, while many manufacturers suggest only one specific size. I noted that the ball sizes suggested by Browning for the .45 and .54 caliber rifles were .005"-.012" under the nominal bore size, while the balls recommended for the .50 were .004" to .010" under the nominal bore diameter. This makes me wonder if the .50 caliber JBMRs might have had slightly oversized bores. Not that it would matter much.

To augment the information Dale provided, I photographed a page from my old 1982 edition of The Gun Digest Black Powder Loading Manual, by Sam Fadala. I apologize for the lousy image... I could not get the book to lie flat. I hope it's legible:

50 JBMR 1.jpg

Note that Mr. Fadala gave us some of the bore specs for the JBMR which I haven't seen elsewhere, namely a 1:62" twist and groove depth of .012"-.014", which is pretty deep for a production made rifle.

Here is a slightly better image of the load data chart:

50 JBMR 2.jpg

Mr. Fadala only tested one ball size (.490") and one type of patch (.015" ticking), but the data collected from the various powder charges were interesting. Note that he provided the volumetric powder measures as well as the actual grain weights. @Keeffer asked specifically about Pyrodex, and it appears Mr. Fadala only tested the maximum recommended Pyrodex load, but at least we have that. Some accuracy comparisons from those different loads would have been interesting, but Mr. Fadala was primarily interested in hunting, and he put a massive amount of work into compiling all of the data shown in this book.

Best regards,

Notchy Bob
 
OK, here are the files for the Jonathan Browning Mountain Rifle Manual. I am going to attempt to attach a .pdf and an .epub file here. If you need another format, I MAY be able to accommodate you. The file sizes proved to be too large for the website's server to process, so I am going to try to post a link to a server in Switzerland where I maintain an account. If it doesn't work, we will have to find annudder way...

EPUB: Proton Drive
ODT: Proton Drive
PDF: Proton Drive

 
OK, tested the links in the above post and they seem to be working. As in all things, your mileage may vary. I'll keep the files active for a while, but as some of you know, I have stage four cancer, so won't be around much longer,,, maybe a few years. After that my Proton account will be closed and these files will no longer be available, so grab 'em while you can!
 
OK, tested the links in the above post and they seem to be working. As in all things, your mileage may vary. I'll keep the files active for a while, but as some of you know, I have stage four cancer, so won't be around much longer,,, maybe a few years. After that my Proton account will be closed and these files will no longer be available, so grab 'em while you can!
Very much appreciated!! I downloaded the .pdf file easily.
 
That’s a new one for me. There appears to be a patent breech behind the flash hole. Not sure why they would do that. Shouldn’t be an issue for shooting, mostly cleaning. Here’s my routine at a shoot with a cleaned gun, that I have stored muzzle down. First, run an alcohol patch thru the barrel to remove protective oil. Two, snap a cap or 2 with muzzle near a grass blade to assure you’re seeing flash into and down the barrel. Load, powder, prb, seat and shoot. Repeat powder, but seat prb with a moist patch. This clears fouling in the barrel and assures the barrel condition is uniform for every shoot. For my 50 cal. Hatfield , I shoot 40 gr at 25 and 50 yds, and 70 at 100 yds. 3F, .490 ball, .018 pillow ticking. Good luck!
 
Dale, thanks for all your efforts to make this contribution. That manual is a terrific asset for the many folks who are just getting started with muzzle loaders.

........though I gather that I can go higher if I feel the need to punish myself for some reason.

I'm sure you occasionally have reason enough to do so. 😀
 
Dale, thanks for all your efforts to make this contribution. That manual is a terrific asset for the many folks who are just getting started with muzzle loaders.



I'm sure you occasionally have reason enough to do so. 😀
Not that often these days as I am too old and decrepit. Though if I actually get that Pedersoli flintlock double rifle that I have been drooling over, I just might grow a pair...
 
That’s a new one for me. There appears to be a patent breech behind the flash hole. Not sure why they would do that. Shouldn’t be an issue for shooting, mostly cleaning. Here’s my routine at a shoot with a cleaned gun, that I have stored muzzle down. First, run an alcohol patch thru the barrel to remove protective oil. Two, snap a cap or 2 with muzzle near a grass blade to assure you’re seeing flash into and down the barrel. Load, powder, prb, seat and shoot. Repeat powder, but seat prb with a moist patch. This clears fouling in the barrel and assures the barrel condition is uniform for every shoot. For my 50 cal. Hatfield , I shoot 40 gr at 25 and 50 yds, and 70 at 100 yds. 3F, .490 ball, .018 pillow ticking. Good luck!
Browning was making a snailed breech (okay, ram's horn design) for their Mountain Rifle. The snail is far sturdier than a drum and nipple and is cast as one piece. Since the breech plug included the snail for the percussion cap, the breech plug is designed with a chamber to connect the nipple seat to the powder chamber. The chambered breech design makes manufacturing easier and more robust. The design is also quite compatible with making a hooked breech. Makes cleaning after shooting easier as the chamber gets forcibly cleaned by removing the barrel and cleaning in a bucket of water.

My Browning Mountain Rifle always seemed to like a 0.500" ball with a 0.015" linen patch or a 0.495" ball with a 0.018" pocket drill patch. I use 1 part of water-soluble oil and 7 parts of water to lubricate my patches.

Thanks to @Dale Allen Raby and @Meggadeath for posting the PDF versions of the JBMR manuals.

Sorry for running off from the answering the original question, which has been answered quite well in the Browning Manuals and the page from Sam Fadala's work in the "Black Powder Loading Manual" from 1982 posted by @Notchy Bob.
 
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When I started BP shooting both cartridges (45/70) and a TC 50 cal kit the late Doug Knoel told me “John you have to experiment”!
His notes on the 3 Hawkens I bought from him had the same load : 80 gratings FFG, .490 pure lead ball, pillow ticking patch lubed with SPIT, seated with 3 good taps. Be able to push PRB fully with ONE firm push! Wipe between shots with wet then dry patch.
So this works well out to 100 yards! To go to 40rods I go up to 100 grains.
EXPERIMENT!!!!!
John
 
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