****Despite the title, some of you are coming in from searches for entirely other firearms. These are specialized firearms and this data is completely dangerous in other firearms****
Hot rodding loads is a very iffy proposition taken from the pressure capabilities of a firearm and the published load data pressures. Due to liability concerns both numbers are safe and reliable along with a built in safety margin. A good condition firearm loaded to the published maximum load table for that firearm is safe, well within a margin of minor loading errors and temperature effects. Exceeding load table data is something to be done with great care, if at all. I do not recommend doing it and anyone who does so should be aware of the risks, starting with a damaged firearm and going to serious injury and death. If that does not scare you...
I have a Ruger Bisley Vaquero in .45 Colt with 5.5 inch barrel, a new and very nicely put together revolver. A local company, Oregon Trail Bullet Co makes Lazer Cast bullets, these particular cast bullets are .452 diameter 360 grain gas checked with copper base semi-wad cutters. Gas checking is accomplished with o-rings and the lead is silver alloyed to increase hardness without brittleness. The load tables call for a max load of 22.5 grains H110 with a velocity of 1221 fps. Brass was once fired PMC +P and CCI Magnum Pistol Primers. This round is a handful and I have very strong and tough hands. I have a hammer bite mark on the back of my hand just off the side of my thumb, I shoot single handed. These are very intense rounds, at twenty five yards the round went through the tread face of a steel belted semi tire (10-22) and out the tread on the opposing side at the max diameter (approx 40 inches), tearing a half-dollar sized hole. That might be enough.
I moved the loads up by 0.5 grains to a total of 24 grains. I built each of those 0.5 grain increases and fired them by one round loads each firing from the first increase and checked each round carefully for case condition, bulged primer or case or any signs of cracking and during extraction whether there was any sticking. The cases showed no sign of damage although the extractor rod was required for removal on the 23.5 & 24 grain loads, the push required was minimal. Let me be very clear, this revolver is in known new condition and was checked with each firing and temperatures were just below 40F. These rounds are a very intense shooting experience, the Bisley design makes ordinary heavy load recoil much more manageable than other designs, at the max table load barrel climb is extreme, note the hammer bite. The two upper over loads result in not only that extreme muzzle climb but also in the revolver winding up turned on its side from barrel twist rate. This makes a second shot time consuming and difficult. Note that I shoot single handed, though I am doubtful a two handed grip would make any appreciable difference. I don't think the overloads are needed, the penetration demonstrated by the max loads is sufficient for anything short of grizzly or Alaskan Browns, unless as a last measure. The bullet manufacturer tested this round at its max load and achieved 26 inches penetration in a ballistic gel block. ****Please note this is a new model Ruger Bisley Vaquero**** the only other make strong enough is a Thompson Contender. If you own another .45 Colt it is important to plainly mark each individual round, I used black permanent magic marker on the primer base, these rounds will damage or destroy most models with very serious injury probable.
The Ruger No1 in 45-70 is a light rifle for its caliber and though short achieves that through the absence of a bolt mechanism, it is a breech loader falling block. This rifle is capable of high pressures, 50K CUP is the published data. The bullet is .458 diameter and the bullets I used are 500 grain Speer jacketed soft round nose. Per Lyman reloaders handbook for Ruger No 1 & 3 -ONLY - using IMR 4895 the max load is 57 grains generating 39K CUP and 1897 fps. I moved the load up to 58 grains, fired one and checked for case damage. The case ejected easily and showed no sign of any damage. The damage was all mine, scuffs on the back of my fingers from the lever and a nice sized knot on my right cheek from the stock, my shoulder only mildly tender. My reaction - Holy Mackerel. I was shooting from a bench so my position was not optimal for this heavy round's recoil. I was shooting at a 100yd target on a 200 yd range position, the backstop for 200yds is approx 240 yds, the bullets threw fist sized dirt clods and left holes in the ground plainly visible to the naked eye. These are not target shooting rounds beyond what is needed to zero them. I set windage and approximate elevation with standard 400 grain "any rifle" factory rounds, these are soft slow rounds, going about 1000 fps, they are quite capable of taking a deer. The hot rod 500 grains will kill anything in North America, the draw back is that this is a single shot rifle, requiring a breech reload after having the snot knocked out of you. Because even at a pushed velocity the rounds will not exceed 2000 fps the drop at 200 yards is considerable which puts dangerous game into fairly close proximity. An enraged Alaskan Brown bear can cover 100 yds very quickly, lacking a second shot would be bad. This is a beautiful powerful rifle but it has limits. The 45-70 is the oldest commonly used cartridge, a straight tapered rimmed cartridge which means that for resizing the cases should be lubricated, even with carbide dies, or crushing is possible. The penetration capability of a 500 grain round nose bullet is extraordinary and bullet carry after target strike is a real consideration, what is on the other side of the biggest bull elk is at risk with this sort of round.
If you will insist on trying these hot rods, be aware that they were tested in known new firearms of high quality manufacture and with CUP ratings vastly superior to other more common ones. Use of this loading in any other firearm or one of these in poor condition is a recipe for disaster. Best practice is to follow loading data from reputable loading books.