(Continued from Part 2.)
Sizing the Brass to the Chamber
Assuming we have had a gunsmith evaluate the rifle, we should also fit the case to the chamber by backing out the die a full turn so that the shoulder of the case might be more than 1 to 2 thousandths of an inch longer. This process will compensate for the generous head spacing that exists in military actions coupled with the original military barrel, and remove any remaining and unneeded head space variance out of a re-barreled action. Accuracy might also be improved.
The bolt should not close without force applied or it may not close at all. Incrementally tighten the die so the shoulder is incrementally pushed back in tiny increments, and again test fit the case in the chamber each time the shoulder is pushed back. Repeat this process until there is only a slight crush fit feeling as the bolt is slowly closed.
At this point for a perfect fit, resize the case again without adjusting the die, but by placing a piece of clear adhesive tape that is not packing tape to the bottom of the case and then resize it one last time. This will push the shoulder back .002″ and provide an excellent fit. This method will reduce the chance of case failure due to excessive headspace. Only rely on this method if the bolt lugs do not have micro-cracks or indications of lug setback. This can be confirmed by your local gunsmith. Only shoot these custom-sized case cartridges in that particular rifle.
Antique Sporterized Rifles Chambered in .308 Bullet Cartridges
The .30-30 has over the last century been exhaustively time tested and not only proven itself, but set the minimum standard of performance for a traditional hunting rifle and therefore was the featured rifle in one of my previous articles: Hunting in Desperate Times – Part 1. Any cartridge that approximates or exceeds the performance level of the .30-30 and uses projectiles that are designed for .30-30 velocities are in my estimation good hunting cartridges for most parts of the contiguous 48 States where deer and black bear will be most likely hunted inside of 150 yards. We can apply this minimum as a baseline standard to other antique rifles in our stables.
There was a surprise package delivered by Santa as well: Another 1891 Argentine Mauser, but chambered in .308 Winchester. While the .308 Winchester cartridge is related to .300 Savage, it has more potential. We shall see how I would go about developing load data that can be used to find accurate loads for both rifles, one in 300 Savage and one chambered in .308 Winchester cartridge, but that do not exceed 49,000 PSI (44,500 CUP).
.300 Savage is more than adequately suited and plenty powerful enough for most but the big bears or dangerous game in North America within normal hunting ranges. Yes, it can kill a charging Grizzly, eventually and maybe right away, but I’d rather shoot an enraged Grizzly with a more powerful rifle that may compensate for hasty and poor shot placement and to ensure faster bullet expansion and more power to shatter bones and to thoroughly eviscerate vital organs.
With modern projectiles and modern powders such as Reloader 15 or LEVERevolution that produce higher velocities, or traditional IMR or best, temperature-stable Hodgdon powders, it is certainly good enough and performs well while recoiling with modest aplomb. The .30-30 establishes what I accept as the minimum standard for the purposes of hunting. Any .30 caliber rifle that exceeds .30-30 velocities is bonus, yet an improvement is not required if its load has the correct bullet for the velocity and the intended range to a target.
When developing a load for these newly acquired and sporterized 1891 Argentine Mauser, one with a .300 Savage barrel, and the other with a .308 Winchester barrel, I will use one of several approaches, the safest will use the starting load data from cast bullets that are a notch lower than the starting loads for either listed most modern manuals. The greater range of charge weights will gently approach what is the maximum load for this particular rifle and provide an opportunity to identify several possible accuracy nodes during the process at lower pressures that can be utilized in a future reduced loading that conserves precious gunpowder. I have but only a limited supply of gunpowder and primers, but now more rifles to feed.
The .300 Savage uses .308 diameter projectiles designed for velocities that range in between the performance of .30-30 and up to .308 Winchester. It would be perfectly acceptable and technically easy to reduce the load to .30-30 levels and use pointed projectiles in bolt actions to yet out-perform .30-30 trajectories to hit well beyond 150 yards as the trajectory and resistance to crosswinds is vastly improved. For the purposes of hunting, the maximum point-blank range of a .30-30 shooting 150 grain round nosed bullet at a velocity of 2,350fps is 213 yards when zeroed at 175 yards and the energy at 200 yards is 788 foot-pounds, too low for cleanly taking deer. At the same velocity, a 150-grain .SST .308 bullet, Hornady part number #30303, the MPBR is 283 yards and the energy is 1,277 Ft pounds at 200 yards, well over the 900 foot pounds of energy required for deer. Elk require at least 1,200 foot pounds and a heavier bullet. The Hornady SST spire point bullet is not only flatter but carries appreciably more energy to the target. To see more of this kind of analysis my previous articles on the topic:
Regardless, the same flat-nosed, or round-nosed bullet that .30-30 uses, or the much improved Hornady FTX pointed bullets designed specifically for the tubular magazines of lever guns, .30-30 performance levels would work at .30-30 muzzle velocities of 2,350 fps, and certainly better at 2,550 fps out of the 300 Savage barrel attached to a Mauser action. In the case of the 1891 Mauser with a shorter 300 Savage 20 inch barrel that produces 100 fps less velocity than stated in manual that used a 22-inch test barrel, the rifle would produce an approximate 2,450fps as the expected maximum possible velocity, and that is certainly good enough. Some manuals use a 24-inch test barrel for .300 Savage.
If the maximum pressure is decreased well below 44,500 CUP in deference to the 1891 Mauser action, the reloaded cartridge would perform closer to 30-30 levels, yet I could use a 180-grain Speer BTSP a soft bullet with a ballistic coefficient of 0.540 launched at 2,350fps or as low as 2,150 fps to flatten the trajectory and impart sufficient energy on elk out to 200 yards to create a larger exit wound and have much more performance relative to the .30-30. This load at 2,350fps would deliver about 1,660 foot pounds on the target and like create a large exit wound on the far side. This exceeds the 1,200 ft pound requirement for elk and makes a bigger hole needed for bigger critters
Even if the starting charge for .300 Savage is used for this bullet weight and the muzzle velocity (MV) was reduced for an antique action to 2,150fps, the amount of energy at 200 yards would yet exceed the minimum and would be about 1,374 ft pounds. The MPBR of this down-loaded 300 Savage load to 30-30 levels for its 170-grain flat-nosed bullet, would still be 227 yards. Hopefully, the figures here prove that a very mild load would be effective even on elk, even a starting charge for the 180-grain bullet that would not exceed 35,000 CUP. There is nothing wrong with using a mild charge, the antique rifle performing at .300 Savage levels is more than adequate for North American big game animals.
I am disappointed that Hodgdon’s reloading website only provides incomplete data for .300 Savage, so I will use the data found on page 213 in Lyman’s 44th edition.
So that I might use data that uses CUP instead of PSI, I will roughly estimate that 44,500CUP (49,000psi) is the limit as the data from Hodgdon’s site for the original cartridge, 7.65x53mm that documents that this is a safe working pressure limit. Again, there are no SAAMI specs for this cartridge. The lowest velocity that I accept as useful in this rifle will produce a minimum acceptable MV of 2,150fps out of a 20 inch barrel when 170 or 180 grain projectiles are used to duplicate or exceed .30-30 performance. Heavier bullets should produce an exit hole and two holes total that causes the lungs to collapse perhaps twice as fast. With elk you’ll need all you can get to put them down quickly. But deer are easy.
At a muzzle velocity of 2,350 fps, the best bullet choice for this rifle that I have in stock is the very soft Hornady 150 grain round nosed bullet. This load exceeds the performance of 154 grain 30 caliber projectile in a 7.62×39 cartridge that is at lower velocity. It would duplicate the 154-grain soft point Tuula 7.62×39 ammunition that is well known to be effective on deer and hogs inside of 100 yards when the MV (muzzle velocity) is only 2,100fps from a 16-inch barrel. With a reduced loading, my 1891 Argentine rifle in 300 Savage is more than adequate as a platform for big game hunting at woods ranges.
The 170-grain RN/FP bullet shot out of a .30-30 has a similar MV. Taking a clue from .30-30 data, the best .308 bullet would be the Hornady 160 grain FTX loaded on top of a charge of LEVERevoltion powder that produces the top velocity and the flattest trajectory, but I do not have that powder, but a powder that is more appropriate for use in a rifle with an antique action. The temperature-stable powder Varget produces an acceptable amount of MV at relatively moderate pressures and the Hornady 150-grain RN and is the safer choice when working near the maximum pressure limits of an antique. I would consider that to be the safest combination for the 1891 Mauser actions.
(To be continued in Part 4.)