Hunting with .224 for antelope.

[wywindsor]

A few years ago I purchased a set of corbin dies here. I built about 2k the first time with no core die. All cores were made with a blank lee mold. These shot about 1.5 moa at 100 yards. Any and all spent cases were used. 55 grains there about total weight.

Last year I decided to clean up the bullet making process. All cci 22mag cases were used. They were shot from one of my 22mags. I started with 200 spent cases. Cases were tumbled in SS media. Next they were cut down to .7XX with a modified lee trimmer. weighed on an AD FX120 scale and only the 12gr kept. Cases were annealed at 650 F. for 10 minutes. I drilled out 3 hole on my core mold deeper to make 52 grain cores. The core die set to make 50gr cores. All components cleaned with brake clean. Then the usual seat the core and point form the bullet. Off to the range. These bullets were loaded with 23gr of cfe. FPS 2800 and change out of a savage axis. They did shoot better but not much. 1.2 moa. This gun shoots factory loads no better. However it does shot 77gr, SMK bullets at .75. All 3 shot groups.

I shot doe last October at 153 yards behind the front shoulder. She dropped where she stood. The bullet did not exit. My son shot a small buck later that morning at 265 yards. His buck traveled 10 to 12 yards and piled up. That bullet did exit. Just a jagged hole unlike other bullets I have seen. More like a ballistic tip.

[rolltide999]

Great work increasing accuracy on your swaged bullets. The rimfire jackets are thinner than standard jackets. That makes them expand better, but can have a negative effect on accuracy for several reasons.

When a bullet is fired, an explosion pushes against the base of the bullet. First the pressure has to overcome inertia of the bullet and crimp. Then, as the bullet moves forward and hits the rifling, this is a sudden start, then a sudden twisting resistance. The base of the bullet can slightly expand and the base of the bullet can even slightly yaw as it is being twisted at the front by the rifling, and pushed by 40,000 to 60,000 psi at the base. I understand they have actually researched this through micro measurements of different types of bullets. This can induce a slight eccentricity that hopefully gets ironed out as the bullet eventually presses entirely through the barrel. Especially if it is a long slender bullet and the base of the bullet has not yet entered the neck of the case before the bearing surface encounters the rifling, this can be more likely to happen. (The case neck seems to hold the bullet straighter during these stressors as long as the base is inside the case neck when the bearing surface encounters the rifling.) Also if the jacket is thin, or if it is a slender, solid lead bullet, this can be more likely to happen. Of course we are talking about .001" or less deflection, but the smaller the caliber, the longer the bullet, the higher the velocity, and the thinner the jacket, the more this could effect accuracy. Another issue is that these sudden, twisting forces as the bullet encounters the rifling can cause the lead core to slip and spin inside the jacket, effecting accuracy. A good cannelure, and/or chemically bonding the core and the jacket, will resolve this. The cannelure might cause those 224 bullets to yaw and fragment on target at high velocity at close range. This must be kept in mind from a terminal ballistics standpoint.

Of course your bullets are still plenty accurate for distances out to 300 yards on deer size game (as you and your son have adequately demonstrated), but probably not up to BR (bench rest) competition. A drawn 25acp case will probably make a more accurate jacket for 224 bullet. The thicker walls and the solid brass case head at the base of the bullet will tend to lessen the likelihood of the phenomena described above. A BR jacket, like the ones used in the SMK would be most accurate, and most expensive, but a lot less time and effort. Bullet expansion also is a challenge with the thicker jackets, so your terminal ballistics on game may suffer.

Frankly though, you achieved your desired result at about the maximum range for the cartridge and the prey, so I am not sure if you need to change a thing. Minute of antelope at 265 yards is pretty impressive accuracy for a homemade 224 bullet using a rimfire case, and pretty impressive terminal ballistics as well on antelope size game. If you were shooting prairie dogs at 700 yards, you might need to tighten the groups a bit.

Thanks for you in-depth report on you bullet making process, and the fine field report as well. Both were excellent and appreciated.

[Manwe]

Any medium sized caliber weapon will work well. 25-06, 243, 270, 280, 30-06. I personally like a hot loaded 30-06 with a 120g hand load.