The 8mm JDJ & 20 years

[Lee Martin]

Interesting story with this one. It took 20 years to finally get closure. Back in 1999, I called JD Jones and ordered a .416 JDJ barrel. We had a nice talk which ended with me saying, "I'll be ordering another barrel after this one. I really like the looks of your 8mm JDJ". He said fine, we can make one up no problem. The .416 arrived and I was impressed with its performance over both the chronograph and on paper. But other projects kept sucking up my gun money. Then in 2002, I found the website of a guy who dealt in Contender barrels. He had a never fired 8mm JDJ by SSK. It was hard chromed, ported, and even had the TSOB base with rings. The best part? He wanted $185 (to this day I still can't believe the price). The barrel came in and I immediately called JD only to find RCBS wouldn't make the dies anymore. I guess there wasn't much interest in the cartridge. Jones recommended I buy a 309 JDJ shell, load it with pistol powder, cap the mouth, and fire-form using pistol powder. CH4D could make the dies from a fired round. I did just that and mailed one off to CH4D. A few days later, they called and said all they received was an empty mail pouch. Somehow the brass tore through an edge and fell out. For 20 years I meant to send another, but never got around to it. This year, on a whim I called SSK Industries since they're under new ownership. I also knew they switched to Hornady for their custom dies. The lady said, "You're in luck. Hornady can make you a set of 8mm JDJ". Problem solved.

To form the brass, I started with .444 Marlin by Hornady. I've heard their brass is hard and can split upon neck forming and shoulder setting. Jones always told folks to use Remington, but I'm not a fan of their brass. The pockets seem to loosen quick. Instead, I annealed virgin Hornady .444 in my AMP and proceeded as follows:

1) Case sized in my .416 JDJ die
2) Case necked to .358 in a .358 Winchester die
3) Case necked to 8mm in my new 8mm JDJ die
4) Annealed again in the AMP
5) Fire-formed using a 170 gr cast bullet and 40.0 grs of 4350.

I shot them today and they formed beautifully.

Right to left - .444 Marlin, .416 JDJ formed, stepped to .358, stepped to 8mm, and final 8mm JDJ:



The gun minus the 3 scope rings. After 20 years, they found their way onto another Contender barrel. I also use this frame for my .416 JDJ barrel:



I plan to get three rings and a Leupold 4x scope soon. After 20 years, I'm really looking forward to playing with this one.

-Lee
www.singleactions.com
"Chasing perfection five shots at a time"

[leadhound]

Well looks good Lee!

Had my 10mm dies a decade before I laid hands on my first 10mm pistol. I knew I wanted one one day.

[bula]

Pretty neat stuff Lee. While I am having troubles getting used to a scope on a handgun, and still find the Contender kinda alien, I am enjoying the 430JDJ as a cartridge. Shot some at camp last weekend. I got to enjoy a talk with JDJ . It will remain a good memory. 
He was patient and polite. 

[contender]

It's often funny how a project can take time,, and not always seem as important as other things. Then, suddenly,, we realize we should have gotten to work on things a lot quicker.

I've never shot one of the 8mm JDJ's,, but if given the opportunity,, I'd try it for sure.

[Lee Martin]

After 20 years, this 8mm JDJ is finally done. I added a Leupold FX-II 4x28mm scope, set in three SSK rings. I can't remember the last time I was this excited about working with a cartridge. I guess 20 years of waiting will do that to a guy.



The load I'm going to start with is 50.0 of AA4350 and Sierra's 220 gr GameKing.



Here's the second barrel I use in this frame. It's a .416 JDJ....quite a thumper.



I should also mention the scope on the .416. When JD did the barrel for me back in 1999, I had the Simmons on the shelf. I gave it a 50/50 chance of holding up to that type of recoil. 23 years later and it's still rock solid. Not bad for an $80 handgun scope.

-Lee
www.singleactions.com
"Chasing perfection five shots at a time"

[Encore64]

Hal Swiggett told me many moons ago that the Simmons 2.5x7 was the only handgun scope that would hold up on his TC 45-70. I've used them plenty with complete satisfaction.

I don't have an 8mm JDJ, but do have a 338 JDJ #2. It's the 444 Marlin case necked down with a 25° Shoulder. The original 338 JDJ was the 303 British necked up and fireformed.

[squigz]

Those are some handsome contenders.

I have several of the "older" handgun scopes across my contenders, albeit that they're not all on heavy recoiling rounds, they've always held up and shot as good as I could with them. I generally always try to look for them if I'm in need of a EER scope just because they've always worked well.

[Lee Martin]

Oct 28, 2022 11:26:18 GMT -5 Encore64 said:

Hal Swiggett told me many moons ago that the Simmons 2.5x7 was the only handgun scope that would hold up on his TC 45-70. I've used them plenty with complete satisfaction.

I don't have an 8mm JDJ, but do have a 338 JDJ #2. It's the 444 Marlin case necked down with a 25° Shoulder. The original 338 JDJ was the 303 British necked up and fireformed.

Like Hal, I've always had good luck with Simmons. And your .338 #2 is a fantastic round. Better than the 8mm JDJ when it comes to bullet selection. I never knew why JD did the first one on the .303 case. And the #2 has a 25 degree shoulder whereas the 8mm has a 40. I chose the 8mm though because I like oddballs and always stock 8mm bullets (I have two 8mm Rem Mags).

-Lee
www.singleactions.com
"Chasing perfection five shots at a time"

[Encore64]

It was in SSK's Brochure years ago that they "switched to 444 Marlin Case after they learned how to form cases." I never got around to asking exactly what that entailed.

I anneal cases, size down in a 358 Win Die, then one pass thru the 338 JDJ Die. Works just fine...

[magman]

For my 338HDJ#2, I sized with my 375JDJ sizer then straight to 338.

[Ken O'Neill]

I understood that initially the forming of a .338 JDJ No. 2 was a sometimes troublesome 2 step process. By 2002, though, my new Hornady dies were a simple 1 step process. The round is indeed fantastic. Years ago when buying, I went straight from the .309 to the .338 No.2, skipping the 8mm, as I suspect most people did. The 8mm should perform on game about as well as the .338 though, depending upon bullet selection, although that 8mm bullet selection is more limited.

[bigbrowndog]

Lee the shoulder on that 8mm looks more like the Weatherby radius than normal, is it just not fireformed or is it supposed t9 be that way??

Trapr

[Lee Martin]

You have a good eye. That brass has only been fired once. The next firing will sharpen the angle. And I agree, it looks like a radius as-is.

-Lee
www.singleactions.com
"Chasing perfection five shots at a time"