The Hunt for 10mm - Why is REAL 10mm so hard to find? It actually isn't.

10mm Automatic is a wonderful little cartridge with an interesting past. I finally found my way into 10mm but sadly, 10mm's history can make it difficult to find what I would have called proper ammunition. By proper, I mean the ammunition has the bullet weight and velocity to match it's legend and philosophy; a powerful round in excess of 500 ft-lbs of muzzle energy.

Generally speaking, 10mm Automatic is believed to come in two flavors; FBI (or watered down) and Norma (or full power) levels. This comes from 10mm's lovely past where Norma developed the cartridge from Jeff Cooper and friend's idea and the FBI adopting the cartridge but eventually watering it down leading to what ultimately became the 40 S&W.

In my search for ammo, I've found really three different levels but both are broken down into those two categories. Here's the breakdown. Please note that this applies to FMJ/ball only. You can find plenty of 650 to 700 ft lbs in HP/defensive rounds. We're looking for affordable "range ammo."

You have loads from companies like American Eagle, Winchester, PMC, CCI's Blazer and Atlanta Arms who have offerings that reportedly run in the 1000+ fps range with a 180 to 200 grain projectile. This tends to be considered on the weaker end but may actually be closer to what Jeff Cooper was originally looking for (speculation). Then you have the middle ground of 180 grains moving around 1100+ fps. Personally, I would have thought that these offerings are closer to true 10mm but they still seem to be on the lower end of the 10mm hype train. You'll find MagTech, Remington and S&B operate around this level. Typically, I go with the S&B for cost and availability reasons. Interestingly, I have found only one big name company making ammo that I would consider operating close to the Norma levels of 200 gr at 1200 fps or 170 gr at 1300 fps. SIG's Elite Performance FMJs are reportedly running at around 1250 fps with a 180 gr FMJs (this is over 600 ft lbs of energy if true).  I have yet to find any other factory ammo readily available at or above this level that isn't self defense/boutique ammo.

Update: Underwood makes a line they call 'Range Supply' that is very similar to SIG's offering with a 180 gr @ 1250 fps and at a very similar price.

With all these offerings I wondered what Jeff Cooper's original idea of what 10mm was supposed to be. I went looking.

The problem here is finding the right information. I have seen some places say a 200 grain bullet moving at 1000 fps which is fairly slow. I've seen some claim 1200 fps which feels more like what it should be for 10mm's legendary status. Ultimately, I will need to find statements from Jeff Cooper and friends on this.

Personally, I'm currently at the opinion that the SIG Elite Performance is the closest we'll get to what Norma was producing back in the 1980's. Despite this, for cost reasons, I am running the S&B SB10A load when I find it for under $0.33 per round.

The interesting thing is that the lower end loads are nothing to scoff at. Even at 1050 fps, a 180 gr round is still in the 400 ft-lbs ME range. This is still more powerful than your average 9mm or 45 ACP loads from a 5 inch barrel. I would be willing to use this for personal defense from a two-legged critter any day if I had to.

That last idea plus the fact that you can run self defense rounds that push into the 700 ft-lbs range makes the 10mm Auto a versatile cartridge. Suitable for personal defense in the city or woods, more than capable of being used for hunting game, 10mm Automatic can run choice ammunition in the same gun for different missions. I have so much more to learn from this cartridge but ultimately, if you define "real 10mm" as Norma level ammo, then you're going to have a hard time. If you look for Col. Cooper's OG idea then you'll be just fine.