|L - R .500 NE, stopper par-excellence; .470 NE, the standard double rifle cartridge by which all other dangerous game rounds are judged; .450 Ackley, its good ballistics are compromised by pressure problems; .458 Lott, duplicates the knock down power of the .470 - its what the .458 Win was meant to be; .458 Winchester.|
On re-chambering, there seems to be quite a bit of confusion over the minute variation between Watts and Lott. All the modern chambering reamers make the chamber long enough to accommodate a case 2.85" long, and any difference is simply in the throat dimensions. It wasnt always like that, and I have frequently seen rifles converted to .458 Lott in South Africa that were only made to accommodate a case 2.80" long. This is a real problem when trying to use modern A-Square Factory ammo, or even most reloads. The front of the chamber pinches the round in the area of the crimp. Chambering of the longer rounds is frequently possible but the pressures are through the roof as the crimp cannot unfold to release the bullet (a bit like firing 2 ¾" shot gun shells in an old shotgun with 2½" chambers, something has to let go sooner or later). Make sure when you order the conversion you specify that you will be using the longer cases:- I cannot emphasise this enough, just be sure, very sure. On throat dimensions, Jack Lott got it right. The longer throat lowers pressure and that is definitely required in a dangerous game rifle. Consequently, I dont know why anyone will order a rifle chambered for the short throated Watts anymore.
Apart from the obvious improvement in terminal performance, what else does the Lott have going for it? Firstly one can still fire standard .458 Win ammo in the longer chamber without any danger and very little loss in performance. This means one can practice with cheaper ammo, and if push really comes to shove out in the middle of nowhere, you can probably scrape together a few .458 Win rounds from the local game warden or a neighbouring hunter. Also anything the .458 Win can do the Lott can achieve and more. Its easy to download to standard .458 Win ballistics for practice (especially if you dont like recoil) and yet have full throttle rounds for the real thing. Most .458 Lotts also shoot cast bullets remarkably well for even cheaper practice. The .458 Lott also has a tapered case, just like the .458 Win (and unlike the .450 Watts) which improves extraction, which is particularly important in a dangerous game rifle. And finally, many rifles with magnum length actions (like the Bruno) feed the longer Lott round much, much more reliably than the short .458 Win. The disadvantages? Well the Lott has significantly more recoil than the standard .458 in full house loadings. If your rifle stock isnt properly bedded, its going to crack in short order. Zeroing your Lott with full power loads from the bench or even sitting constitutes a significant emotional event as far as I am concerned. Its a long way from my idea of fun, and something I will go a long way to avoid in future. In practice though this isnt really a problem. From the bench you shoot standard .458 Win loads, which whilst hardly a pleasant way to spend an afternoon, is at least within my recoil tolerance level. You then do the final check with full power loads from the standing position. ( Note: if you are working up your own reloads and have to shoot from the bench, unless you are one of that rare breed who have a very high tolerance level to recoil, find a few friends who want to shoot a real rifle and con them into doing it). From the standing position (which is how one will almost invariably shoot in the bush) the recoil is not noticeably different from a .458 Win or .416. I doubt that you could actually tell the difference.
Is the conversion to .458 Lott worth while? Very definitely! Its everything the .458 Win wanted to be and more. Any rifle with a long enough action to take the Lott should be converted. It is the bolt guns answer to the .500 Nitro and the most readily obtainable stopping cartridge on the market today.
Finally, and with much caution I publish a few reloads that have worked well, in the test rifle. Case head expansion was well within limits and there were no other pressure signs. This does not mean that they are safe in your rifle. Back right off and work up slowly.
Please Note. The charges listed below are, in my opinion MAXIMUM. Increasing the charge gave either measurable case head expansion and occasionally sticky extraction, or simply resulted in no worthwhile increase in velocity (eg 84grains of S321 behind the Speer bullet gave an average of 20fps less than 83 grains). Neither the author, nor the publisher can be held responsible for the use of this data. Having said this though, the .458 Lott is a very forgiving cartridge to load for, no sudden pressure peaks, no erratic burns, just like the .458 Win but with more case capacity to play with.
|.458 Lott (2.85" chamber)|
|500 grain Hornady|
Steel jacketed solid
|475 grain PMP|
|S321||78 grains||2293 fps|
|400 grain Speer|
standard soft point
|S321||83 grains||2396 fps|