Target Sports

AMMUNITION DEVELOPMENT: HIGH VELOCITY

Created on 14th May 2009

ROGER BAKER continues his journey through the evolution of interesting guns and calibres, this month concentrating on ammunition development

IN PART one last month we concluded by briefly exploring the requirements for 300yd loads. However, this performance involves generating 2,938ft/lb of energy - a tad more than that of a .308 rifle. It is impossible to cope with these kinetics for more than a very few rounds when you're using a hand-held firearm. The 454 Casull revolver has, in any event, performed best in high-velocity mode with lighter projectiles. Clive Stevens'stests, reported in the January 1991 Target Gun, showed Freedom Arms' own 240gn bullets to deliver the best performance, albeit at eye-watering velocities. One of my Speer reloading manuals offers data for 33gn of Hercules 2400 powder - Elmer Keith's favourite Magnum propellant - driving a 260gn jacketed bullet at 1,925fps, which still involves coping with 2,139ft/lb at the muzzle.

The bullet will still be travelling at 1,144fps at 200m but falls to 960fps through the final 100m, so for British Long Range matches, supersonic is still not the way to go.

I made the Casull 454 handloads back in the mid-1990s used 20gn of Hercules Blue Dot under an RCBS 300gn gas check which I still cast today; it was a fantastic performer at 100m but went off the boil at 200m and 300m for the above reasons.

In theory one could use lighter projectiles and ever-higher velocities but the ballistics always frustrate improvement as the coefficientnumbers keep falling. Most 300gn bullets are in the .2 to .23 bracket and are very efficient at maintaining energy, but the BC of the 260g falls to .183, that of a 225g falls to .158 and a 200g offers just .140. We can push the velocities higher and higher but to no effect - the decays in retained energy always nullify progress.

Thus the combination of heaviest possible bullet but subsonic velocity is hard to beat, except for its Achilles heel: the severe falling parabola between 200m and 300m, which can be 12ft plus change in trajectory. The rear sight needs to be cranked up very high.

If a Freedom Arms revolver does become available to you it will hopefully come with Iron Sight Gun Works (ISGW) Silhouette sights, which give plenty of elevation leeway to cope with this drop. The front sight is easily adjustable and detachable in a Silhouette model. It can be raised, lowered, shortened or replaced with a smaller one in moments.

Of course this recipe of limiting velocity and maximising bullet weight tends to hold one back with the best of the .44s, such as those Rugers; indeed, there are a small number of FA revolvers around in .44 calibre already, but this rather misses the point.

Firstly, the .454 has the potential to propel bullets that are even heavier than my 300, 330 and 340gn .44 models at the same velocities. I'm trying to locate a mould at the moment for a 495gn monster casting at .452" which I recently saw listed.

Secondly, the option of using maximum velocity, should the gentler method fail you, is always there with the .454, and it will be completely safe.

Thirdly, if you're intending to shell out a lot of money for a Freedom Arms revolver you might as well treat yourself to the most highly-reputed calibre you can use in the UK rather than get by with a .44 Magnum - unless, that is, your Chief Constable favours your ownership of a 500 Wyoming Express (see below).

Fourthly, a lot of your requirements can be met by using .45 Colt brass cases and standard bullets available everywhere - even the traditional Single Action Army load of 8gn of Unique and 255gn flat-nose should give you a just-subsonic velocity with the usual bullet... but it's the fifth part that really matters, namely, how these revolvers are made. For one example, take the cylinder. Most revolver-makers drill out a blank cylinder with six drill-bits at once, then marry it to the barrel - not necessarily the most precise way.

Such multi-drilling methods, fast and efficient though they may be, require large margins for error such as steep angles in the forcing cone to give the bullet a chance of emerging from the chamber-throat and meeting the rifling. The bullet can ‘rattle' and sustain damage before it obturates and takes the rifling to rotate.

Alone among revolver manufacturers as far as I am aware, Freedom Arms fits blank cylinders into its revolvers, locks them up tight and drills each chamber through the barrel, so alignment is absolutely perfect. This permits a very tight angle of entry in the forcing cone. The bullet is guided perfectly into the barrel, sustains no deformation or loss of metal and has much more chance of attaining consistent grouping at distance.

While the writer has almost without exception used heavy gas-check bullets cast at home for Long Range duty, Elmer Keith disapproved of their use in revolvers; he stated that while they were fine in rifles and automatic pistols, the cylinder-gap in revolvers could result in an escape of propellant gas during the bullet's transfer from chamber to barrel.

I hate to dispute the words of a revolver giant, but his logic was based on the fact that gas checks prevent base expansion which bullets use in blocking off the escape of energy from burning powder. It is easy to understand the theory in light- and medium-weight bullets, but in my experience not with the heaviest.

The diameter of a bullet cannot change with weight, so heavier means longer. The completion of transfer from chamber to barrel therefore takes more time and appears to prevent gas leakage between cylinder and forcing-cone.

Interestingly, Freedom Arms has recently introduced a .50" calibre round of its own, Fifty Wyoming Express, so as to remain at the top of the competitive pecking order in Silhouette shooting, the longest of Long Range events, needing very heavy bullets to knock steel targets over. The firm sells four weights of bullet for handloading; its 370, 400 and 440gn beasts are cast gas-checks. Perhaps this time Elmer would change his mind...

Handloading

Think of everything sized at or around .452" designed for revolvers, M1911 pistols and lever-action rifles: the choice is vast, and the 454 Casull round can house them all. I recommend having some 454 and .45 Colt brass cases on the shelf. Begin with the latter to get used to the larger frame of the Freedom Arms revolver and try some of the standard bullets available everywhere.

Handloading data needs to be read with the wisdom that none of the powders on the charts have been used in very long barrels. It's comforting to know that there is no such thing as a dangerous charge in these immensely strong revolvers, but proceed cautiously anyway. Irrespective of manufacturer, .45 Colt brass cases are fragile - stronger, certainly, than their black-powder predecessors but not to be over-pressured. If you decide upon heavy handloads, 454 cases are the ones to use.

For the bullet-caster, a short walk down memory lane doesn't come amiss. There have been three short periods in which Magnum calibres have supplanted standards: 1935, when .357 replaced .38 Special; 1955 with the two .44s and 1984 featuring our current subject. Mould-makers have provided a tremendous help in making the transition in the form of the double cannelure, or crimping-groove.

The original idea was to enable owners of older firearms with shorter cylinders to rival newcomers owning Magnum calibres, by using the same bullets in smaller brass. In a Freedom Arms revolver, though, you can do the opposite and lengthen a shorter round. Why? Because making a .45 Colt round as long as a 454 Casull round, especially with a gas check on the bullet's base, offers you three benefits. Firstly, the bullet has less distance to travel before meeting the chamber throat; secondly, the gas check on a long bullet won't bulge the case and finally more burning-room abides, lowering pressure and/or permitting larger charges of a slower powder to be used.

Lyman, one of the great shooting corporations of the world, publishers of fine books and makers of every kind of handloading equipment, sells a mould numbered 2660651 bestowed with two cannelures: in my estimation it's just the one for 454 Casull. It's very heavy, it's a flat-nose and it's a gas check. The label says ‘325gn' but that's in Lyman #2 alloy; if you're staying subsonic there's no need to go quite that hard. With a tad more lead in the mixture think 345gn and base your loading data on that - you won't go far wrong.

Handload tables

Over the page are two tables of handloads, created using an Excel spreadsheet which makes life easy by automatically calculating muzzle energy. Please bear in mind that these figures are maxima - always start your powder charges 20% lower and increase them by no more than ¼ of a grain each time.

AMMUNITION DEVELOPMENT: HIGH VELOCITY

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AMMUNITION DEVELOPMENT: HIGH VELOCITY

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