And The "Mastering The Whitworth" Project Continues...

The Search For A Better, Easier To Produce     Hexagonal Bullet That's Easier Loading

One factor that very likely topped the list of why the hexagonal bore Whitworth rifles failed to become widely popular with accuracy minded long-range marksmen of the mid to late 1850s had to have been the difficulty of producing the odd-shaped bullets...and loading them.  In his excellent book, "The Muzzle-Loading Cap Lock Rifle", published in 1947, Ned Roberts eludes to the expense of turning out mechaniclly fitted hexagonal bullets, and the difficulty of loading these into the Whitworth bore as the primary reasons why the British War Office chose the .577 Enfield over the .451 hexagonal bore for military use.  And this is in spite of the fact that the Whitworth rifle delivered far superior accuracy at long range than the easy-loading, hollow-based Minie bullet shooting Enfield.  (Records show that at 500 yards [meters?] the rifle presented by Sir Joseph Whitworth produced a group that was under 4 inches across, while the Enfield group was 2.42 feet across.)    

Well, muzzleloading shooters today are even less interested in having to work hard to come up with the fodder for their frontloaders than the shooters of 140 to 150 years ago.  In fact, very likely 90-plus-percent won't even consider going to the trouble and expense of casting pure lead projectiles for the rifle or rifles they shoot.  The majority of today's muzzleloader owners have gotten into the sport purely to hunt the muzzlelaoder seasons, and the most popular projectiles among that group  are the saboted bullets - and generally copper jacketed, copper plated or all-copper bullets at that.

And it has very likely been the need to match a conical bullet to the bore of a rifle for optimum accuracy (plus range and knockdown power) that has kept most traditionally minded shooters and hunters from ever owning a true 1840 to 1860 style bullet rifle.  Simply put, it is just easier to get acceptable accuracy with a patched round ball from a slow twist rifled bore than it is from a fast-twist bullet shooting rifle.  Still, some of the most accurate muzzlelaoders of all time (4 inches at 500 yards!) were the elongatedc bullet rifles of the mid 1800s - and that most deifnimtely includes the Whitworth.

One very major goal in my ongoing "Mastering The Whitworth" project has been to first come up with a precise, easy to produce and load bullet for Dixie's odd-bore reproduction of this historical rifle.  And for these reproductions to ever see much of a following, that is a major hurdle for those who produce and/or market one of these rifles. 

Now, Dixie Gun Works offers a big .448" diameter 580-grain hexagonal soft lead bullet for the Whitworth reproduction they offer.  And, at $25.10 for a box of 50, the price is not that much higher than what modern in-line shooters normally pay for premium saboted hunting bullets.  However, I've found that this bullet is far from being "easy to load".   In fact, by the time I whack a short starter a half-dozen times to force one of the bullets into the hexagonal bore, there's usually four or five grains of shaved lead at the muzzle.  And that is mostly because my calipers reveal that this bullet is actually .451" across.  My measurements of the reproduction Whitworth bore gives me .448" across from hex flat to hex flat...and .471" across from corner to corner.  (I haven't got a clue where the .451 bore designation came from! )

Fortunately, one of my best friends, a master machinist by the name of John Sorbie, also took an interest in this project...and in short order he produced a bullet mold, with the pitch of the hexagonal bore built in, and a sizing/forming die for producing very consistent (and properly sized) bullets for the rifle.  And when forced through this die, the Dixie bullet fits (.447 dia.) precisely and loads easily.  However, John also produced a die that sizes down to .441" - allowing the bullet to be wrapped with lubed paper patching.  And these load extremely easily - and shoot with exceptional accuracy.

And since I determined early on that this was the route to take with this rifle, I began looking at different cast .45-70 bullets that could be reformed by the die into precise hexagonal bullets for the Whitworth.  And fortuante for me, I ran into an extremely good one early on in my search.  And that bullet is the semi-spitzer 500 grain .459" diameter bullet produced by the Lee Precision No. 459-500-3R bullet mould. 

The bullet produced measures 1.37" in length, compared to the 1.34" length of the rounded Dixie bullet.  And once pushed through the sizing die (using a standard drill press to force the bullet through) this bullet transforms into a hexagonal projecitle that can be wrapped with two layers of cotton based paper (available from Buffalo Arms).  The bullet still loads easily into the reproduction Whitworth bore...and the accuracy produced speaks for itself.

My plans are to actually hunt with this rifle, so develping a load with enough moxie to cleanly bring down deer sized game at 150 to 200 yards has been my primary concern. So, when I headed to the range, I didn't even mess around.  I went right to FFFg powder instead of slower burning FFg, and with a 70 grain charge, I got the big swaged Lee Precision bullet across the screens of my chronograph at 1,273 f.p.s.  (I'll bet John Chapman would have given anything to have had a Shooting Chrony when he penned "The Improved American Rifle" back in 1844!)

Now, this may sound awfully slow to those of you who have been shooting only the light patched round balls or modern saboted bullets.  But we're now talking about a 500-grain bullet.  And this particular, very aerodynamic, bullet has a ballistic coefficient of .443!  At the muzzle, this load is good for 1,796 foot-pounds of energy.  And thanks to the long, sleek shape of this swagd .441" bullet, it maintains velocity and energy very well down range.  In fact, this bullet with this powder charge is still moving along at 1,136 f.p.s. at 100 yards, and hits with 1,427 f.p.e.  And out at 200 yards, the load retains 1,022 f.p.s. velocity and 1,161 foot-pounds of energy - which is more than enough to cleanly take any bull elk wandering the Rocky Mountains.  (Compare this with the performance of even a hot .50 or .54 caliber round ball rifle, and you'll see why the conical bullets of the 1840s and 1850s made the round ball obsolete.)

As for accuracy, with the standard Enfield/Volunteer/Whitworth rifle type rear sight, in its lowest setting, my shots imprinted on the target about 2 inches down...but most three-shot groups were right at an inch across.  My best was 3-shots inside of 3/4".  And at 100 yards, with the sight stepped up to the 100-yard setting, groups were about 2 to 3 inches below point of aim, and several stayed under 2 inches across.  The one and only 200-yard target shot with the open-sighted Dixie Whitworth rifle reproduciton still managed to "keep 'em in the kill zone" of a whitetail sized target...and grouped right at 3 1/2 inches.

My next goal is to mount one of the period correct Leatherwood 3/4" diameter scopes on this rifle.  Only then will I truly realize the accuracy potential of this bore and the hexagonal bullets.  Watch for an update on that stage of this project in late December or early January.

If any of you reading this are also playing around with the Whitworth rifles,  I would enjoy hearing from you.  I'm particualrly interested in sourcing some linen based paper for patching these bullets.  I can be reached at NAmlhunt@hpmuzzleloading.com .  -  Toby Bridges, NORTH AMERICAN MUZZLELOADER HUNTING

The author could not determine where the .451 bore designation of the Whitworth came from - none of the measurements taken were of that dimension.

The cast Lee Precision 500-grain .459" diameter bullet is shown at right, with the same bullet after being swaged (laying), and the big 580 grain Dixie Gun Works bullet for the hexagonal Whitworth bore.

Bridges' swaged bullet for the Whitworth rifle, wrapped with several layers of lubed cotton-based paper, proved capable of excellent accuracy.  This 3/4 inch group was shot at 50 yards.

Here is a 1 3/4 inch across three-shot hundred yard group shot with the Dixie Whitworth reproduction and swaged Lee Precision bullet.  The next stage of this project is to mount a period correct scope on this rifle.

Dixie's copy of the 1850s original Whitworth is an excellent long-range bullet rifle capable of 200 yard big game taking performance..

Shooting hefty charges of black powder behind 500+ grain soft lead bullets can produce very noticeable recoil.  The flat butt plate of the Dixie Whitworth makes shooting this rifle very tolerable.

Published 9-1-07

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