Rock Island Auction Company

November 3, 2017

Shooting Fat Mac – The .950 JDJ Collector Firearm

By Joel R Kolander

Share this post:

Our videos on the SSK Industries rifle chambered in 950 JDJ, a.k.a. “Fat Mac” has been up less than a week and is already the most popular video we’ve ever made. If you haven’t seen it yet, this was its introduction.

Subscribe to our YouTube Channel for more great gun videos!

Features of the 950 JDJ Rifle

This behemoth was developed by the cartridge’s namesake and president of SSK Industries, J.D. Jones. It is 20x110mm Vulcan Cannon cartridge shortened and then necked down to .950 caliber. It’s so large it had to receive an ATF “Sporting Use Exception” from the ATF to avoid be classified as a Destructive Device. Only three rifles were made by SSK to fire this mammoth round.

Fat Mac is one such rifle. Absolutely pushing the boundaries of small arms, this massive single shot collector firearm is host to a collection of features designed to mitigate its powerful recoil. First, it is bedded in a bench rest stock, so shooters can more easily utilize a shooting platform of sorts. Second, it is fitted with a gargantuan muzzle break, nearly as large in diameter as a 2-liter soda bottle. Lastly, this leviathan long gun tips the Toledos at a whopping 61 pounds! No wonder it needed a bench rest stock.

big bore rounds
L to R: .30-06, .700 Nitro Express, .950 JDJ, and 4-Bore rounds

Shooting the 950 JDJ

With a gun this rare and powerful in-house, it was only a matter of time before the desire to shoot it became insurmountable. One beautiful fall afternoon I was fortunate enough to take Fat Mac out to a private range along with the other two monster rounds shown in the photo above.  The .700 NE was fired from an immense Searcy & Co. double rifle (also appearing in our December 2017 Premiere Firearms Auction) and the 4-bore was thrown from a beautiful crafted Ken Owen double rifle (ditto). To say it was an amazing morning is an understatement. Check out our video where we shoot some of the world’s most powerful collector firearms.

Takeaways from Shooting Some of the World’s Largest Collector Firearms

So how was it? Not as “shoulder wrecking” as one might think. Obviously, and as one can clearly see in the slow motion footage, these rifles pack a wallop! Their booming report is more akin to artillery than to a rifle. But what about their recoil? Let’s  describe them one-by-one:

700 Nitro Express

B. Searcy & Co double rifle
Massive Engraved B. Searcy & Co. Double Rifle in .700 Nitro Express. Sold in December 2017 for $23,000.

This is a power rifle to be sure! Literally, people have used smaller rifles to kill elephants. Think about that for a second. All things considered, the recoil is quite manageable. No bruising, no marks made by clothing, and no tingling or ache in the shoulder area. If you are someone who bruises easily, your mileage may vary. While enough to elicit your favorite expletives upon firing, for me there were no negative effects on the body after firing. Five seconds after the fact, as far as my body knew, I might as well have fired a .30-06. Excepting of course for my ridiculous grin and the tangible excitement coursing my veins. No doubt the rifle’s 17 pounds and generous recoil pad helped to dull the vigorous kick.

700 Nitro Express size comparison


Ken Owens Rewa 4-Bore double rifle
A 4-bore worthy of a maharaja. Watch the video to find our why.

Here was the bad boy of the bunch. Modeled after a rifle made for the Maharaja of Rewa, India, this rifle was made by gunsmith Ken Owen of Memphis, Tennessee in the early 1990s. He produced only six such rifles and is quoted as stating each massive double rifle took approximately 1,000 man hours to produce. A quick glance gives an immediate impression: it’s short, stocky, beautiful, and my-god-how-big-are-those-barrels? After much prepping and adjusting, and a quick farewell to my rotator cuff, a light squeeze of the trigger unleashes an absolute lightning strike. It throws the shooter back about as far as the .700 Nitro Express, but the sensation is markedly different and more powerful. In fact, this was the only rifle fired that day where the sensation of the recoil didn’t end after the shot. The shoulder tingled for some time after.

Ken Owens 4-bore double rifle

Think of it this way. After you fire a hunting rifle or a military surplus collector firearm, you fire and then the sensation is finished. You walk away no different. Now imagine you have asked a good friend to haul back and slug you where you normally position the butt of a rifle or shotgun. That sensation doesn’t end as soon as the punch does, it lingers. The same can be said for the 4-bore and its cordite-powered punch.

4-bore size comparison

950 JDJ

950 JDJ rifle

Finally, we got to the 950 JDJ. It was the fattest round of the day fired by the largest rifle of the day. Dealing with this much power, we were absolutely treating this rifle with the utmost respect. After constructing a make-shift “sled” out of sandbags and bags filled with lead shot, we securely positioned the rifle. The bolt was removed, the round placed gently in its claw, and both were then slowly inserted into the rifle. After giving the bolt a gentle turn, everything was locked into place and we were ready for whatever this rifle had in store.

It was rather surprising when Fat Mac produced the most manageable recoil of the day. Then again, when you consider all the recoil-dampening features listed earlier, perhaps it isn’t so surprising after all. Despite requiring all the brass to be custom made and the rounds to be handloaded, this is a gun that you want to shoot until the ammo is gone. If only we had more time with Fat Mac to test its power on a wide variety of unsuspecting and unusual targets.

What Does it Take to Own Fat Mac?

Only money and an account with Rock Island Auction Company. Since the ATF granted a “sporting use exception” for it to be created, no NFA paperwork is required to own it. Typically, any firearm that fires a projectile over .50 caliber would necessitate being registered as a “destructive device,” but whoever takes home Fat Mac can keep the $200 required to do that and spend it on reloading tools instead. This powerhouse rifle requires no special licenses, no registration, no training courses, no permits, and no tax stamps. Hooray for America!

Oh, and for those who don’t have an account yet to bid with Rock Island Auction Company, what are you waiting for? There are tens of thousands of collector firearms sold each year no matter what your budget. Click here to watch a quick video on how to sign up and start winning the guns you want in your collection.

Subscribe to our YouTube Channel for more great gun videos!

Recent News

Historic Powder Horns

Historic Powder Horns

If you watch a frontier or military movie set in the mid-19th century or earlier, look at historical paintings, visit a fur trade rendezvous or reenac

Read more


Please login to post a comment.