Designing a 7.62×39 Handload, by Tunnel Rabbit

At this moment I am anticipating the arrival of an antique Mauser rifle that has been fitted with a new barrel chambered in 7.62×39. By the grace of God, I was able to obtain an antique custom rifle in the ubiquitous 7.62×39 from Elk Creek Company. This will be a scoped rifle that might use the same ammunition that I already stock for my semi-automatic rifles that use 7.62×39 ammunition with bullet diameters of .310 inches.

An Expectant Father Waits for the Arrival

As I wait for it to arrive via UPS, I am writing this article and thinking ahead and designing a load for it. And I am already shopping for reloading dies at the lowest price available that come with both .308 and .311 neck expander and bushings. It might have a .308 barrel instead of a .310 barrel so I may need to load for this using .308 bullets from my inventory, or order a more suitable .310 bullet. The load could closely duplicate .30-30 performance and could surpass .30-30 performance past 100 yards because it will use a spitzer bullets with a better ballistic coefficient instead round nosed or flat point .30-30 bullets that have very low ballistic coefficients. Here is my thought process as I design a practical hunting load for this rifle.

Bullets for Lower Velocity Applications

A portion of this information could be applied to other lower in velocity cartridges that use .308 bullets such as 300 Savage, .30-30, and rifles in 7.62 NATO, or rifles that are based on antique actions that should not be loaded to pressures higher than 46,000 CUP, and preferably lower. If the expected rifle has a .311 bore, I can use .308 bullets. If it has a .308 bore, for an 7.62×39 hunting load, then I might use Hornady’s 150-grain bullet (#30303) that was designed specifically for .300 Savage. Hornady’s Reloading 6th Edition manual specifies that this bullet should be used if the muzzle velocity would be between 2,200 to 2,700 feet per second (fps) as it expands reliably and is designed to penetrate well at .300 Savage velocities.

The load that I might develop could generate the minimum recommended muzzle velocity of 2,000 fps that IMR4198 can produces at 46,000 CUP, in antique small ring Mauser actions. Since this is a boat tail spitzer bullet, it would have a flatter trajectory than a heavier .30-30 bullet that is the Hornady’s FTX, a 160 grain bullet (#30395) designed for .30-30 velocities (1600 to 2500 fps). Both the #30303 and the #30395 bullet use a similar design and materials, and have an unusual shape and a soft flexible tip needed for safety in tubular magazines. The 160 grain GTX is a much softer bullet that expands more quickly than the #30303 (the .300 Savage bullet). This fact could be both an advantage and disadvantage. It is frankly a toss up as the 150 grain will have a higher MV (muzzle velocity), yet the 160 grain bullet will expand much more reliably at lower impact velocities and the additional mass will increase penetration and increase the size of the wound channel. It is indeed a very heavy bullet that few would choose for 7.62×39. Unfortunately, there is no load data available for a 160 grain bullet for the 7.62×39 cartridge.

The tougher 160 grain FTX bullet for the .308 Marlin (#30396) would also work yet not as well at the low velocities of 7.62×39, but perfectly well at 300 Savage and 7.62 NATO velocities and would be better for black bear in those cartridges as it would hold up better on heavier bone and thick muscle. The FTX bullets have a lower B.C. (.395), but it does hit harder, yet may require different dies that do not crush the tip, but the tip can be removed. Removing the tip would allow its use in lever action Savage 99 rifles. I have not loaded a bullet like the FTX yet.  I have a large supply of IMR4895 that could be used, yet the velocities in a 7.62×39 would be lower than if IMR4198 powder were used.

If I am stuck using IMR4895 it would be best to use the .30-30 FTX bullet (#30395) as it will expand at impact velocities as low as 1,600 fps, or a lower mass bullet. As a distant second choice, I would consider Hornady’s #3035 that is a 150 grain round nose. It was designed for the .30-30 Winchester.  Heavy round-nosed .308 bullets that are 180 grains or heavier are advantageous in higher powered cartridges for punching through brush or for penetrating deeply though very big and tough game as these bullets a very stable in flight and in tissue, but the lighter in mass round-nosed bullets offer little and are best reserved for use in rifles with tubular magazines.

Less Mass and Higher Velocities

The recommended muzzle velocity for the 150-grain round-nosed bullet #3035, that is designed for use in tubular magazine is between 1800 to 2500 fps. However, past 75 yards a round nose has lost a considerable amount of energy. If the bore of the barrel is .310, then Hornady’s 123 grain spitzer bullet #3140 that is designed for 7.62×39 would be good choice as the minimum muzzle velocity needed for this bullet is 1,900 fps and its retained energy and trajectory would make it adequate for deer out to maximum of 200 yards because its velocity would be adequately high enough when using IMR4198. Another way to go is is the Hornady 125 grain (.308) SST. Because Hornady offers the 123 grain (.310) bullet in a self-defense load it was easy to find a video demonstration that provided ballistic gelatin testing and results from a chronograph. The test barrel is a standard 16-inch barrel of an AKM rifle. The rifle that is arriving has a 21 inch barrel, so the velocity of my load could be significantly higher and certainly no less in velocity, even if my powder selection is limited.

Video Demonstration

Here is a useful video demonstration:  Making Commies Great Again: 7.62x39mm Hornady Black 123gr SST Gel Test. It convinced me that the 125-grain Hornady SST bullet is the best bullet for my rifle and powders that I have to use for this load. Because my best powder choice that produces the highest velocity is limited to IMR 4198 that produces at most only 2,200 fps with a 125-grain Hornady bullet out of a 20-inch barrel, there would be less fragmentation than in this ballistic gelatin test. This would be a good self defense load and that is what Hornady developed it for. It will also take deer inside of 200 yards if I can place the shot off of the shoulder, otherwise this fragible bullet could fail to penetrate into the vitals.

This is ammunition that can be roughly approximated with my hand loads. While not quite as potent, my load will cost just slightly less than the advertised retail price upwards of 65 cents per round. The current cost of inexpensive steel case ammunition is between 50 and 60 cents per round making this high quality ammunition a bargain, in comparison. I might buy this ammunition instead of reloading if the rifle has a .310 bore:  Hornady 123 grain (.310) and 125 grain (.308) SST Bullets

With these bullet choices that will perform similarly, whatever the actual bore diameter the rifle has, be it a .310 or .308 bore, I have found a good choice in useful bullets given the powder I have on the shelf, IMR4198. H4198 could produce a velocity as much as 200 fps higher, yet IMR4198 is good enough and what I currently have available, if I use either the Hornady 123 grain SST, or the 125 grain (.308) SST.

.310 projectile only: Hornady 123 grain SST.

.308 projectile only: Hornady 125 grain SST.

Using Ammoseek.com, I was able to find low-price Hornady 125 grain SST bullets at 33 cents each.

Other Reloading Component Costs

Reloadable brass will cost about 25 cents each and the primers now cost about 9 cents. The powder will cost about 7 cents per round. Less the cost of the reloading dies, the material cost of each custom round will run me about 75 cents per round. It is a good thing that I purchased the powder and primers when the cost was about one-third of their current price. Even so, the cost of reloading is not in this day and age inexpensive, but it is much less expensive than purchasing specialty ammunition.

If the bore of the barrel is .310 in diameter then I can use inexpensive Russian ammunition that can be found at .60 cents per round. Fragmenting and expanding 7.62×39 steel-cased ammunition can be found at around this price. I could also use 154-grain Tula soft point ammunition that I have in stock, but past 100 yards the 154 grain bullet may not adequately expand. It would however be a good bullet for black bear and even elk at close range inside of 100 yards. The advantage of a .308 bore is that I can produce accurate loads using more common bullets that are .308 in diameter.

Conclusion

I am very much looking forward to this rifle. Here is a full review of a modern rifle in 7.62×39 that would be an approximate equivalent. American Arms Channel did an excellent review of the CZ 527 in 7.62×39. The review is not just about the rifle, but also about the ammunition, including subsonic ammunition that I can duplicate using Trailboss or Unique powder. 7.62×39 can duplicate and even outperform .300 Blackout. Given that the Hornady SST bullets have a hard polymer tip, they will reliably feed through a semi-automatic rifle.

Given the competitive price of the 7.62x39mm Hornady Black 123gr SST that can be found at near the same price point as inexpensive steel case ammunition, I would buy it by the case and use it as my defensive load and for deer hunting.