Bullet Selection (.45 Calibre)
The .45 cal. Gibbs has rifling with an 18:1 twist rate. Long heavy bullets which have performed well in .45 cal. cartridge rifles will usually work equally well in the Gibbs so if you already have such bullet moulds or commercial bullets (swaged or cast) which can make bullets .448″ to .451″ diameter give them a try and see if your Gibbs likes them. Suggested lead/tin alloy is 35:1 up to 60:1.
Pedersoli offers their own Gibbs bullet mould #USA 308-451 which is 535 gr. and has a .451″ cast diameter. Mould handles are available under part #USA316. This grease groove type bullet (and all others of this type) should be sized down to .448″ to .449″ using the Pedersoli bullet sizer #USA 514-450 or by using any brand of bullet sizer which will produce this size bullet diameter.
Paper patched bullets need to be sized according to the paper thickness being used. The English Higginbottom-Rigby style 540 gr. paper patched bullet is specially favored in the Gibbs and has set some long range records.
Many .45 cal. “Postell” shape bullets used in cartridge rifles can be tried as many have proven to be very accurate in the Gibbs. The NEI brand #349C as well as the Lyman #457132 have been reported to be very accurate when sized down properly. However… these commercial moulds normally cast bullets which are .457-.459″ and sizing down to Gibbs size will ruin their accuracy because too much metal has to be moved and this spoils bullet concentricity. If you can order a custom made mould which casts the proper size then these types can work very well when sized slightly down to .448-.449″.
The bullet diameter for your gun will be correct when the lubricated bullet can slide slowly down the “cleaned” barrel when the loading ramrod weight is all that is pushing the bullet. This rule is correct for both paper patched and grease groove bullets. Due to slight manufacturing variations in broach rifling tolerances your rifle may require a slightly different bullet diameter.
A good “black powder” bullet grease must be used on grooved bullets. Pedersoli offers a proven bullet grease called Lubriblack, part #USA 488 which can be applied using a conventional bullet sizer/lubricator or by the pan lubrication method. Other recognized good black powder bullet greases are TC-Bore Butter, SPG, Rooster Labs BP-7, Black Magic, DGL, Lyman Black Powder Gold, and White Lightning greases. There are dozens more which will work well and many shooters make their own grease. Experimentation is a big part of black powder shooting so it is good to try many products.
This instruction sheet will not go into the making of paper patched bullets but those instructions can be obtained on the world-wide-web by searching that subject name. We will mention that paper patched bullets can be fired with dry paper or with oiled paper by dipping or wiping the patched bullet with sperm oil, olive oil or other suggested liquid lubricants.
Over Powder Wad
The Gibbs does not require a card wad over the powder and the bullet rests gently on the powder itself. However, many master class shooters using paper patched bullets have found that using a .45 cal. Ox-Yoke Wonder Wad on top of the powder has given excellent long range accuracy. This felt wad is impregnated with a BP grease and serves to protect the bullet base as well as to help leave the powder fouling softer. It is commonly used with paper patched bullets which have no grease grooves but can be tried even with grease groove bullets. Several expert Gibbs shooters use a conventional .030″ card wad placed over the powder charge when using grooved bullets so these types of wads should also be experimented with.