Sunday, March 20, 2011
Energy! Energy! Energy!
By Toby Bridges
Few of us ever forget taking our first buck. Mine was shot on opening morning of my third deer season back in 1964. I was just 15-years-old, and hunting with a muzzleloader for the first time. I'd run an after school trapline the previous winter, and had worked most of the summer at a local gas station to earn the money to buy one of the long-barreled .45 "Kentucky" rifle reproductions from Dixie Gun Works - and spent the rest of the summer learning to load and shoot that percussion frontloader.
My load ended up being 80-grains of FFFg black powder behind a patched 133-grain .445" diameter soft lead ball - which I cast myself. By the time deer season rolled around, I could hit a tin-can at 60 yards with just about every shot, and felt confident that I could do a far better job with the muzzleloader than the only other gun I could legally hunt deer with in my home state of Illinois - a shotgun with slugs. Back then, I had no idea about the amount of energy the load produced, or what was really needed. I just felt that the rifle was more than adequate for taking whitetails.
Only a few distant shots had sounded that opening morning, and when I looked up to see an eight-pointer crossing the woodlot 65 or 70 yards away, I was soon tracking the buck with the open sights of the 40-inch barreled rifle. This was the first time I'd ever had a horned buck in my sights, and I'd be a liar if I said that I wasn't excited. Still, I held my fire until the deer stepped into a clear shooting lane, then tightened my finger on the trigger. The rifle boomed - and through the thinning smoke cloud I watched as the whitetail raced several hundred yards up the shallow valley, eventually disappearing in the mature hardwoods. I'll admit that I honestly thought the deer would have dropped on the spot, or maybe after a short 20 yard run. To watch it run off kind of diminished my faith in the deer-taking performance of the .45 muzzleloader.
After a long tracking job, an old friend and I finally found the buck - more than a 1/4-mile from where it had been shot. The 133-grain ball had hit its intended target perfectly, about two inches to the rear of the front shoulder - centering both lungs, and coming to rest under the skin of the opposite side. The ball was well flattened, adding even more to my wonderment at how the buck had traveled so far.
After 45 seasons with a muzzleloader, I now know a lot more about muzzleloader ballistics and the energy levels needed to insure a clean kill.
At the muzzle, the rifle and load I used for my first muzzleloader hunt had a muzzle velocity of right at 2,000 f.p.s., but due to the light weight of the ball, it generated a not-so-whopping 1,175 f.p.e. At the 70 or so yards the deer had been shot, that aerodynamically challenged .445" sphere of lead had retained just barely 500 foot-pounds of game-taking energy. And that's about 300 foot-pounds shy of what most deer hunting experts accept as the minimum amount of energy needed to cleanly bring down deer-sized game.
So, what kind of energy does it take to bring down big game? For deer, knowledgeable whitetail hunters agree that it's right at 800 foot-pounds of knockdown power. For bigger game like elk, large bears and Shiras moose, with a well placed shot it still takes around 1,200 f.p.e. for the punch needed for consistently clean harvests. And for game as large as Alaska-Yukon moose or bison, the required energy level jumps to 1,500 foot-pounds. Also, keep in mind that this is the "retained energy" at the distance of the target, not at the muzzle. The rifle and load I used to take my first muzzleloader buck had dropped below the needed 800 f.p.e. at only about 40 yards.
It was the lackluster performance of the old patched round ball rifles that opened the door for the development of new rifles, new projectiles and hotter loads that could produce higher energy levels - and retain such knockdown power well past a hundred yards. That first happened back during the mid 1800s, then again during the late 1980s and on through the 1990s.
The first true long-range muzzle-loaded rifles were developed and refined through the 1840s, built to tap the accuracy, range and knockdown power of the newly developed elongated conical bullets of the same period. While the earlier round ball rifles were built with exceptionally slow 1-turn-in 60 to 70 or so inches rates of twist (to prevent the patched ball from stripping the rifling at high velocity), the new bullet rifles featured rifling as fast as 1-turn-in 18 to 24 inches. The snappier twist was needed to stabilize cylindrical projectiles that could be as much as 3 or more times longer than in diameter. They were also heavier, often 300 to 500 grains for a .45 caliber rifle, and with a stout powder charge these great hunks of lead could retain high levels of energy out to and past 200 yards.
Some of the better made rifles of this period, produced by master rifle makers such as William Billinghurst, Edwin Wesson, Norman Brockway and Morgan James, continued to be used during long-range competition until well after the modern breech-loading target rifles like the Sharps or Remington rolling block were in widespread use. Many shooters found the slower-to-load muzzle-loaded bullet rifles more accurate, and continued to out shoot competitors using metallic cartridge rifles - even in 1,000 yard competition.
A .45 caliber bullet rifle (32" barrel) of the late 1840s, loaded with just 70 grains of FFFg black powder and a bore-sized 500-grain conical bullet was good for just 1,260 f.p.s. at the muzzle, due to the heavy weight of the bullet. However, thanks to that same weight, the load generated 1,759 f.p.e. Out at 200 yards, the aerodynamically superior elongated bullet would retain 950 to 1,000 foot-pounds of energy. In fact, these rifles and loads retained enough energy (800 foot-pounds) to drop a whitetail out to about 225 yards.
One 1840-1850 style bullet rifle I shoot regularly, and still hunt with on occasion is a custom half-stock that I built back in 1983. Back then, I had installed a custom turn-in-24 inches twist .50 caliber barrel on the rifle - and over a 20 year period, I literally shot that barrel out. A couple of years ago, the original barrel was replaced with one of the 32" cut-rifled turn-in-24 inches twist Green Mountain .50 caliber "Sharpshooter" barrels, which I now have scoped with an 1880s style Leatherwood/Hi-Lux short "Wm. Malcolm" 6x scope. With a 100-grain charge of FFFg GOEX Express black powder, the rifle will get a bore-sized 440-grain Parker Productions "Traditional Hunter" lead conical out of the muzzle at 1,506 f.p.s., with 2,213 f.p.e. At 100 yards, the load is still good for 1,048 f.p.s. and 1,078 f.p.e., and at 200 yards velocity is right at 910 f.p.s. with a retained energy of 805 f.p.e.
Note that a heavier but smaller diameter, and longer, 500-grain bullet out of a .45 caliber bore retains more energy at 200 yards, shooting 30 grains less powder, than the 60 grain lighter bore-sized bullet out of the .50 caliber bore. That's the effect of improved aerodynamics, or in other words, of the improved ballistic coefficient of the longer, smaller diameter and heavier bullet. Still, the .50 caliber Green Mountain barrel makes my custom half-stock an honest 200-yard rifle for deer, and a solid 90-yard elk rifle. And with the precision Leatherwood/Hi-Lux scope aboard, I can on occasion keep five-shot 200-yard groups inside of 3 inches. Not bad for a 160-year old rifle design.
What today's in-line rifle designs have done is to make it easier for the average shooter to obtain this kind of muzzleloader performance.
Even the early No. 11 percussion cap in-line models of the late 1980s and early 1990s, like the Knight MK-85 and CVA Apollo, could be loaded to deliver the accuracy and knockdown power needed for deer at 150 yards and elk at 100 yards. One of the hottest loads I shot out of a stainless .50 caliber Knight MK-85 during the early 1990s was 110-grains of Pyrodex "P" behind a saboted 300-grain .452" diameter Hornady 300-grain XTP hollow- point. At the muzzle of the 24" barrel, the load was good for 1,620 f.p.s., and 1,755 f.p.e. At 100 yards, the blunt-faced .181 b.c. bullet slowed to around 1,375 f.p.s. and hit with right at 1,250 f.p.e. Out at 150 yards, the speed of the big jacketed hollow-point bullet was down to 1,150 f.p.s., where it hit deer-sized game with about 875 foot-pounds of punch.
Recently, I pulled that old rifle out of retirement, installed a breech plug and plunger hammer that allowed use of hotter No. 209 primers for ignition, and ran a few loads of FFFg Triple Seven across the chronograph. And instead of shooting a saboted 300-grain hollow-pointed "pistol bullet", I did this shooting with the higher .255 b.c. Harvester Muzzleloading .451" diameter Scorpion PT Gold bullet of the same weight. The difference was amazing.
At the muzzle, a 110-grain charge of FFFg Triple Seven gets the sleek spire-pointed 300-grain bullet on its way at 1,881 f.p.s., which translates into 2,355 foot-pounds of muzzle energy. Because of the noticeably higher ballistic coefficient, the bullet retains 1,610 f.p.s. with 1,725 f.p.e. at 100 yards, and 1,380 f.p.s. with 1,266 f.p.e. at 200 yards. For deer sized game, this load will deliver the energy needed all the way out to about 260 yards, where the bullet is still moving at just over 1,100 f.p.s. with 804 foot-pounds of retained energy.
The energy a bullet generates at the muzzle is simply determined by its weight and the velocity it exits. How well a bullet retains those ballistics down range is determined by its aerodynamics, or its ballistic coefficient. The higher its b.c., the higher the velocity and foot-pounds of energy a bullet retains, and the flatter its trajectory. The point at which the powder and charge allows a bullet to drop below the minimum game-taking energy levels given earlier should be considered the maximum effective range of the rifle and load.
Modern in-line rifle manufacturers, powder suppliers and bullet makers have certainly stretched the ranges at which today's rifles and loads can still deliver the knockdown power and accuracy needed to take big game. Twenty years ago, most rifle makers set "Maximum Recommended Powder Charges" at 100 grains - and that was with black powder and Pyrodex. Today, every manufacturer of hot No. 209 primer ignition in-line rifles promotes the use of magnum 150-grain Triple Seven Pellet or Pyrodex Pellet charges - some of which are now generating internal barrel pressures of 30,000 p.s.i. and greater. Muzzleloading rifles today are now being subjected to the same pressures produced by some milder smokeless powders.
Why? Because the modern muzzleloading hunter is looking for greater range, and for greater knockdown power at the outer limits of these rifles' practical effective range. And that has opened the door to the development of other modern muzzleloader propellants. One that has won over a lot of muzzleloading hunters is Blackhorn 209 - a nitrocellulose based powder formulated to give top end velocities and energy with a lower peak pressures than other more recent black powder substitutes. With just a 110-grain volume measured charge, this powder can match the velocities of the 150-grain compressed pellet charges. And it burns so clean that the shooter can fire 20...30... 40 or more shots without wiping the bore - and still shoot with excellent accuracy.
The latest in-line rifle models, like the Thompson/Center Arms "Encore Endeavor" and "Triumph Bone Collector", have been built around today's newer powders, with No. 209 primer systems for sure-fire ignition of the harder to ignite muzzleloader powders, plus stocks with built-in recoil reducers to help tame down the added recoil that comes hand-in-hand with added velocity and knockdown. Traditions and CVA also offer similar models.
Through the winter and spring of 2010, I was testing a new "Super Magnum" in-line model for Knight Rifles - when word reached me that the company had called it quits and was closing its doors, due to the poor economy. That rifle was to hit the market as their new .50 caliber Extreme Ultimate Slam model. Unlike earlier DISC Extreme models, this new bolt-action muzzleloader did not require the use of plastic primer carriers. A redesigned breech plug and bolt allowed this rifle to be fired with a bare primer, forcing the front edge of the primer tightly against a shoulder at the front of the primer chamber. The fit insured that very little fire escaped rearward, putting more fire into the powder charge. And Blackhorn 209 likes a hot spark.
The Green Mountain barrel, breech plug and receiver had been designed to shoot true magnum powder charges - 130 to 150 grains of Blackhorn 209, or three pellet charges with the 60-grain equivalent pellet Triple Seven Magnums or IMR White Hots. And with the hotter charges in this rifle, saboted 290- and 300-grain bullets were getting out of the muzzle at 2,150 to 2,200 f.p.s. Such hot loads were generating 2,975 to 3,100 foot-pounds of wallop.
The most impressive load I shot out of the prototype rifle had to be 130-grains of Blackhorn 209 behind a prototype 350-grain saboted Scorpion PT Gold that Harvester Muzzleloading has been thinking about introducing. Now, this is the heaviest saboted bullet I've shot from a modern .50 caliber in-line rifle, and because of that weight the velocity is right at 2,030 f.p.s. - with 3,200-plus-f.p.e.! This longer and heavier version of the Scorpion PT Gold would have a b.c. that's getting close to .325, meaning that at 200 yards this load would retain around 1,565 feet-per-second of bullet speed, and drive home with 1,900 foot-pounds of energy. In fact, way out at 300 yards, this load would still be good for 1,425 f.p.s. - and more than 1,500 foot-pounds of energy that will take anything that walks North America.
Now, that's muzzleloader performance! And now that Knight Rifles has new owners, this rifle is scheduled to be in produciton this year - as the "Mountaineer".
Another hard hitting load combination consists of 120-grains of Blackhorn 209 under one of Hornady's 325-grain .458" FTX soft polymer-tipped semi-spitzers, loaded with a Harvester Muzzleloading "Crush Rib" sabot. (This somewhat sharp-fronted bullet was developed for .45-70 lever-action rifles.) Out of the 27-inch barreled "Mountaineer" prototype, the load is good for 2,017 f.p.s. - with 2,938 f.p.e. Hornady has established that this bullet has a .230 b.c., meaning this load would retain right at 1,400 f.p.s. at 200 yards, and hit with more than 1,400 foot-pounds of wallop.
Here's a tremendous elk load, which the .50 caliber Knight "Mountaineer" is fully capable of grouping inside of an inch at a hundred yards.
Today's modern rifles, improved saboted bullets and hot new powders continue to raise the bar on muzzleloader performance - delivering, with superb accuracy, the knockdown power needed to cleanly take large game well past 200 yards.