Wildcatting During a Reloading Component Shortage: Using .30-30 Cases to form 6.5 JDJ Brass

Jay D. Hunt, III, PhD

Many years ago, LSA President Dan Zelenka introduced me to perhaps the best all-around wildcat cartridge for the Thompson/Center Contender pistol: the 6.5 JDJ. With a 120 gr. bullet, mid-sized game don’t stand a chance. Even African plains game fall to its punch. The cartridge was developed by famed gunsmith and founder of SSK Industries, J.D. Jones. The 6.5 JDJ is based on the rimmed .225 Winchester, which is necked up to 6.5 mm (.264”) and fire formed to produce the finished case that has about 7% more powder capacity than the parent .225 Winchester. This increased capacity results from the 25º shoulder, which is located 1.530” forward of the base in the .225 Winchester, being pushed forward to 1.630” in the 6.5 JDJ at an increased 40º angle.

When working with .225 Winchester cases, a single pass through the 6.5 JDJ die expands the case mouth to accept a bullet of .264” diameter.  After priming the case with a large rifle primer, a medium burn rate rifle powder like IMR-4320, IMR-4350, H-4831, or IMR-4831 can be used with a 10% reduction from the maximum charge. Typically, I use 140 gr bullets to fire form the cases, but any .264 bullet can be used. Fire forming cases is fun, and you’ll likely find that the reduced charged cases are very accurate, although perhaps not a great choice for hunting given the reduced powder charge.

But what does one do when there is a nationwide shortage of reloading components, there are no .225 Winchester cases to be found, and there is no production of obsolete cases on the horizon? Well, short of paying $5.25 per case to a boutique custom brass producer, one searches the amazingly useful The Handloader’s Manual of Cartridge Conversions by John J. Donnelly. According to Donnelly, .225 Winchester cases can be produced from .30-30 Winchester brass. I just happen to have a pile of once fired .30-30 brass laying around, so I headed out to the reloading shop.

The process of converting a .30-30 Winchester case to 6.5 JDJ involves (left to right) an annealed .30-30 case, a .30-30 case that has been trimmed and the rim reduced in diameter and thickness, necked down to .263″, loaded with a reduced powder charge over a large rifle primer topped with a 140 gr. bullet, and finally the fire-formed finished product.

The first step in the process is to anneal the .30-30 cases. As a case is loaded and reloaded, the process causes the brass to become work hardened. Work hardened brass with eventually result in split necks, split cases, or separated cases. During the process of converting .30-30 cases to accept the .264 bullet, the neck will need to be reduced from .308” to less than .264”. Work hardened brass will be brittle and bad things are likely to happen.

There are many good but expensive annealers on the market. If you anneal a lot of brass, you already own one. But if you don’t, you can anneal brass with nothing more than a propane torch. A simple and effective method is to hold the base of the case with your bare fingers (this is important) and then hold the neck/shoulder area of the case in the flame. Once the case becomes uncomfortable to hold, the neck/shoulder area is hot enough to anneal the brass. Simply drop it on a heat resistant surface and let it air cool. There are many other methods to anneal brass, and you may have your favorite one. If you like the way you do it, then by all means do it that way.

After annealing and cleaning the cases, the next step was to trim the .30-30 cases to a length that approximates the maximum overall length of the 6.5 JDJ case. The once fired .30-30 cases that I used for this project averaged 2.32” in overall length. The maximum length of the 6.5 JDJ is 1.900”, so .30-30 cases were trimmed to 1.93” using a manual RCBS case trimmer. The extra 0.03” of length ensured that cases would not be too short after the final fire forming step and would allow me to trim them to the final 1.900” after the final step.

A 1934 South Bend 9″ lathe was used to reduce the rim diameter and thickness.

The .30-30 Winchester has a rim diameter of 0.50”, whereas the .225 Winchester parent case has a rim diameter of 0.473”. Although 0.027” doesn’t sound like a lot, the rims of the .30-30 cases needed to be turned down prior to use. The .30-30 case rims would not load properly into the Contender barrel. To accomplish this, I used the collet chuck in my 1934 South Bend 9” lathe to hold the .30-30 cases with the rims exposed, and then used a carbide cutting tool to quickly reduce the diameter of the rims. If you don’t own a lathe, there are other ways of accomplishing this task including the use of a power drill and a file.

Donnelly noted that it is not necessary to reduce the rim thickness of the .30-30 case; however, since I had the cases chucked up and thinning the case rims was a quick and easy task on the lathe, I reduced the rim thickness from 0.06” to 0.045”.

Rims were reduced to a final diameter of 0.473″

To allow the highly modified .30-30 case to accept a .264” bullet, the neck internal diameter needed to be reduced from 0.308” to something below .264”. I set the Hornandy 6.5 JDJ die in the press so that the neck was reduced to an internal diameter of 0.263”. This would allow the case to firmly hold the bullet but would also require the least amount of stress on the newly sized brass. This step is the reason that the brass was annealed in the first place.  Incidentally, the outside diameter of the .30-30 brass started at 0.332” and was reduced to .288” (brass thickness of 0.012”). Be certain that you lube the neck and shoulder of the .30-30 case before inserting into the 6.5 JDJ die, or you will have a big mess on your hands.

Ugly ducklings! Highly modified .30-30 cases are loaded a charge of H-4831 prior to fire forming.

A Winchester large rifle primer was inserted and then a reduced charge of H-4831 was used. Layne Simpson recommended a charge of 34.0 – 37.0 gr. of H-4831 under a 140 gr. Speer bullet as a standard hunting load. I had a stockpile of old Sierra 140 gr. SPBT bullets that I was happy to use as fire forming fodder. I measured 30.6 gr. of H-4831 into the cases, which was a 10% reduction in the starting load recommended by Simpson (10% of 34.0 is 3.4 gr. 34.0 – 3.4 = 30.6). Simpson wrote that he uses a flat 5.0 gr. reduction from the maximum load for fire forming, which would be 32.0 gr. of H-4831. Whatever you decide to use as a fire forming load, keep in mind that there is about 7% less case capacity in a .225 case than in a 6.5 JDJ case, and there is likely even less capacity in the long necked .30-30 case before fire forming. It is prudent to be cautious when fire forming brass!

From left to right, a 6.5 JDJ case created from .30-30 Winchester brass, a 6.5 JDJ case produced from .225 Winchester brass, and a loaded 6.5 JDJ case ready for whitetail season.

Of course, the most fun step in the process is the actual firing of the ugly duckling loads to produce the beautiful swan, a useable 6.5 JDJ case. I gave that honor to my 17-year-old nephew who gladly leapt at the opportunity to fire 140 gr. 6.5 mm bullets into improvised targets at the shooting range at our hunting camp. He reported that after a couple of rounds to figure out where the bullets were impacting, he hit 100% of the targets.

If you are interested in the 6.5 JDJ, 14-inch barrels can be obtained from SSK Industries.  I’ve been working with the cartridge for about 12 years and have developed some good data for hunting loads. Here are a few of my favorite loads.

Bullet Charge and Powder

Velocity (FPS)

120 gr. Nosler Ballistic Tip 37.0 gr. VV N550

2431 ± 9

120 gr. Nosler Ballistic Tip 38.0 gr. VV N160

2300 ± 9

120 gr. Nosler Ballistic Tip 33.5 gr. AA2520*

2463 ± 14

120 gr. Nosler Ballistic Tip 38.5 gr. IMR-4350

2347 ± 17

120 gr. Barnes TTSX 33.5 gr. Reloader 15†


120 gr. Barnes TTSX 33.8 gr. Varget

2376 ± 21

125 gr. Nosler Partition 36.5 gr. VV N550

2375 ± 12

129 gr. Nosler ABLR 32.0 gr. Reloader 15

2107 ± 5

129 gr. Nosler ABLR 32.1 gr. AA2520

2311 ± 8

129 gr. Nosler ABLR 32.5 gr. VV N550

2046 ± 35

129 gr. Nosler ABLR 35.5 gr. VV N550

2277 ± 15

129 gr. Nosler ABLR 30.0 gr. IMR-4320

2176 ± 81

129 gr. Nosler ABLR 32.0 gr. IMR-4320

2309 ± 36

130 gr. Berger VLD Hunting 36.0 gr. VV N550

2340 ± 22

*Outstanding 5-shot accuracy = 0.63” @ 100 yards. This is my go-to hunting load
†5-shot accuracy = 0.91” @ 100 yards
All loads developed in Winchester .225 Winchester cases fire formed to 6.5 JDJ using CCI-200 or Winchester large rifle primers. The 6.5 JDJ is not a SAAMI cartridge, but maximum peak chamber pressure should not exceed 50,000 PSI. The reader should reduce powder charges by 5% and work up to these loads in his/her pistol to ensure these loads are safe.

For my go-to hunting load: 120 gr. Nosler BT over 33.5 gr AA2520, CCI-200 primer, COAL = 2.905”

Distance (Yards)

Velocity (FPS)

Measured Group Size (Inches)













Abbreviations: FPS, feet per second; VV, Vihta Vuori; AA, Accurate Powder; TTSX, tipped triple shock expanding; ABLR, Accubond Long Range; VLD, very low drag; COAL, cartridge overall length


Wildcat Cartridges: Volume II, Chapter 129: The 6.5 JDJ by Layne Simpson. Pages 831-8835; Wolfe Publishing Company, Prescott, AZ. 1992

The Handloader’s Manual of Cartridge Conversions by John J. Donnelly. Page 160; Stoeger Publishing Company, South Hackensack, NJ. 1987