I am very happy to announce that I have began to make 6.5 x 41mm Kurz Cases and Cartridges as the resizing dies have arrived from Hornady Custom Dies. Ben Syring at Hornady was outstanding in understanding the concept behind the 6.5 x 41mm Kurz ECAPTC, (Extreme Conditions All-Purpose Tactical Cartridge) and making the dies in record time! Just under 8 weeks from the initial phone call to receiving the dies at my home! Pacific Tool and Gauge has provided Reamers and Gauges so an Ar-15 to begin testing the new round will be available soon as well as an AK-47 variant and an H&K 93 variant will also be made shortly to begin testing those platforms as well.
The 6.5 Kurz is the result of extensive research with the goal of developing a new Assault Rifle Round that provides reliability of function in extreme environments as well as accuracy and greater terminal ballistics at greater distances than Assault Rifles, Squad Designated Marksman Rifles and Squad Automatic Weapons are designed for allowing targets to be engaged at greater distances which increases the lethality of all individuals armed with 6.5 Kurz Weapons Systems.
Initial research began with determining why the AK-47/74 series of rifles has proved throughout history to be more reliable than the M-16/AR-15 series of rifles and the conclusion was the cartridge. In looking at the cartridge it is simply a matter of the 7.62×39 M43 Cartridge for the AK-47 having a taper to the main body of the case that allows it to function in a dirty environment. The 5.56mm Cartridge for the M-16/AR-15 has almost no taper to the body of the case so even the smallest piece of dirt is in contact with the cartridge and chamber during loading and extraction of the cartridge, jamming the weapon! This is why M-16’s jam and AK’s don’t! It’s the CARTRIDGE!
5.56mm/.223 Remington are based on 222 Magnum Cartridge which is a bolt action ridge cartridge that is NOT designed for a semi or full automatic rifle. ANY straight wall cartridge of small diameter is going to suffer from this “straight wall case dirt” issue until the case diameter reaches .473 inches which would be 7.62 NATO, 30-06 or 8mm Mauser. Cartridges that have too small of cartridge diameter and little or no case taper that do suffer loading and extraction problems in Semi and Full Automatic Weapons are 5.56mm NATO, .223 Remington and 6.5 Grendel. I am sure that other straight wall cartridges suffer this problem as well when fired from semi and full automatic weapons but I personally only tested those mentioned.
Research next went into what type of bullet provides the best balance of flight characteristics, is heavy enough to maintain effective terminal ballistics at distance and does not weigh too much so that Soldiers or individuals can carry enough ammunition to safely see them through a tactical or self-defense situation without being overburdened by the weight of rounds.
From personal experience I knew that 6.5mm bullets have outstanding Ballistic Coefficiency, meaning they fly very well. The weight of bullets available in 6.5mm or .264 inches are heavy enough to provide outstanding Terminal Ballistics but at the same time not so heavy that a large number of rounds can be carried without being burdensome. So I decided that 6.5mm / .264 inches would be the bullet diameter.
Case size was determined by existing platforms available. This cartridge had to be able to fit in an AR-15 Platform because that is what EVERYONE is shooting. So from a practical standpoint the cartridge could not be more than 2.26 inches in length. I also wanted to have the parent case be readily available because I had struggled to get cases when the 6.5 Grendel became available as the parent case was 7.62×39 technically and brass cases in this caliber were expensive and not that easy to come by at the time. By far the most available case in the world is the 7/8mm Mauser and 30-06/7.62 NATO or .308 Winchester and the numerous other cases derived from these cases. This readily available brass parent cases would immediately allow any reloader with the proper reforming and resizing dies to create their own cartridge cases to make ammunition for their new rifle.
With the idea that a taper for the new round was required, the 6.5mm/.264 inch caliber established, 2.260 inches overall case length set and the parent case selected based on durability and availability, all that was left was to determine the dimensions of the cartridge itself. This was done with a lot of drawing paper and discussion with friends. I was stuck for a time trying to determine if I should attempt a few different angles of the case wall to find the ideal angle to maximize case capacity but a friend was kind enough to inform me that the volume I would gain by these minute changes was so small that it was not worth the effort and it as best to determine the ideal angle through comparison with the latest designed Assault Weapon Cartridge, the 5.45×39.
I also put a 30 Degree taper in the Shoulder of the Cartridge because this angle creates the most accurate results in target shooting in long range rifle matches. So 6.5 Kurz has a 30 degree shoulder for accuracy.
When I was done the round was 6.5x41mm and ironically resembled the original Assault Rifle Cartridge the 7.92x33mm Kurz developed by the Germans during WWII, so as an homage to this cartridge I added the monicker Kurz, meaning short, to my own cartridge and it became the 6.5 Kurz.
I used QuickDesign to create the cartridge in autocad and then moved the design into QuickLoad which is a ballistic program that allows the user to test a cartridge design using different propellant powders, bullets and barrel lengths showing pressures attained, powder burn efficiency and muzzle velocity.
The figures I saw from QuickLoad were amazing as the cartridge created muzzle velocities well beyond what I expected. As I refined the data I was even more impressed with the cartridge I designed because it was preforming well beyond what I had expected.
I sent the autocad drawings that I had created in QuickDesign to Pacific Tool and Gauge to make Reamers and head space gauges to make Rifles and to Hornady to create cartridge cases.
Hornady Dies to include 2 reshaping dies.
AK-74 30 round magazine becomes a 17 round 6.5 Kurz magazine with the larger 6.5 Kurz Cartridges
Left to Right – 6.5 Kurz 100 grain Full Metal Jacket, 107 grain Sierra Match King, 105 grain Solid Brass
Left to Right – 7.92 x 33mm Kurz, 7.62x39mm Russian, 5.56mm NATO, 5.45x39mm Russian, 6.5x41mm Kurz
Here is some of the ballistic data created by QuickLoad. 2909 fps!
6.5x41mm Kurz Extreme Conditions All Purpose Tactical Cartridge, ECAPTE, is designed to be a reliable Assault Rifle Cartridge that is capable of effectively engaging targets at long range. It is the result of extensive research that is applied here but can also be used in your decision making procession for your next firearms purchase. 6.5 Kurz has been developed with the intent to make it easy for reloader to create their own cartridge cases from available brass. 6.5 Kurz has been designed to used existing firearms platforms like the AR-15, AK-47 and H&K 93 and available magazines like the AK-74 magazines, the 6.5 Grendel Magazine for the AR-15.
Research will continue once rifles become available and the durability of the modifications to the firearms can be tested.
I will continue to report those test results here.
6.5 Kurz will make its public debut at the Small Arms Review Show, 30 Nov – 2 Dec 2018 at the Phoenix State Fair Grounds in Phoenix, Arizona.