New rifle!

[obssd1958]

Just finished with the November "Ray and Don's Gun Show", and in the items that I just couldn't resist, is a custom rifle that I purchased!
In very fine print, stamped on the barrel, is "6mm Rocket". I got 20 loaded rounds with the purchase, and it looks very much like the 240 Weatherby (neck and shoulder), in a 30-06 case.
Anyone here ever hear of this wildcat, or have any experience with it?

 

[Wiresguy]

I suspect this was the 220 Weatherby Rocket - a modified Swift - that has been necked up to 6mm.

P.O. Ackley's books likely have info on it.

Sounds like an interesting rifle/cartridge.

 

[RBHarter]

I have the Ackley book if I remember tonight I'll get a picture for you .

 

[Bret4207]

Roy Weatherby, father of the "overbore" cartridge line that bear his name!

 

[RBHarter]

The 1967 4th printing doesn't name one but I have to say the the 264 WM necked down to 6mm turning out almost 3900 fps with a 90 gr bullet wasn't the most outlandish ........ There were 2-3 based on 300 H&H ......

 

[obssd1958]

Fired case is a mil-surp 30-06. The loaded cartridge is one of 20 that I got with the rifle. Looking at them side by side, the wildcat looks to me to be a standard 6mm-06. The barrel also had, just below the cartridge designation, E. Nanson. Some Google searching found a E. Nanson, gunsmith, in California, who passed away in 1979.
This looks like I'll be able to make ammunition by just necking down a 25-06, loading, and fire-forming. The shoulder on the wildcat is .452", as opposed to the shoulder on the -06's .441".
If I ever get my 'round tuit, and get to the range, I'll report back with velocities.
Oh, the rifle is a 1917 Enfield with a new barrel, and a Leupold Pioneer 4x scope with the post reticle, on top!

 

[harm]

Interesting! Is the body blown out like an Ackley Improved round, too?

 

[Wiresguy]

Well, no Swift progeny
It should be more efficient than the 240 Gibbs I used to have.

 

[Bret4207]

Huh, I thought when you said Weatherby neck and shoulder you meant the Weatherby style double radius thing. That sure looks like a standard shoulder. Load it hot and it'll be a barrel burner for sure.

 

[obssd1958]

Bret,
I'm going to blame it on poor eyesight. I knew what the double radius looked like, and when I was at the show, that was kinda what my old eyes said it was. It wasn't until I was taking the pictures that it became apparent that it wasn't a Weatherby style shoulder.
I read an article yesterday, on the 6mm-06, and they also said that it would be a barrel burner. They said accuracy would drop off after 1500 rounds or so... At the rate I have been going to the range, I would have to live to 100 to even come close to that!
It does look like it will be fun to wring it out, and find out what it's capable of. I'm going to try to figure out what twist rate the barrel is, so I have an idea of what length projectile it should be happy with.

 

[RBHarter]

From the Ackley book . A necked 270 that keeps that shoulder .
The Gibbs is and AI type with about .1 less neck , the 300 Gibbs is an 06' with 308 neck and shoulder more or less , it's the same length so that lets out the Mashburn .

 

[obssd1958]

Rich, thanks for taking the time to find all of that and post it!
A couple more measurements from the pre-loaded ammo that came with the gun:
Base diameter: .467
Shoulder diameter: .453
Neck diameter - loaded: .272
Distance from base to shoulder: 1.940 ish (hard to measure exactly with a set of calipers!)
Distance from base to neck: 2.090 ish
Case length: 2.487
I don't have anything to measure the angle of the shoulder, but it looks steeper than that of the -06.

 

[Joshua]

I don’t think it’s the 6mm-06 AI, your example sure looks like it has an extra long neck on it. The body taper is however similar to the measurements on this reamer drawing.

Instead of a fire formed cartridge, it would seem that your cartridge was designed to have the shoulder pushed back a bit to create it’s more accute shoulder angle.

 

[fiver]

he ain't got an Ackley.
having said that, i have seen at least 5 different versions of the 7X57 Ackley cartridge.
anyway that ain't one.

personally i'd just go with using 6mm-06 data and follow the usual reloader's mantra.
i'd also be tempted to use 25-06 cases, but since i already have a couple of 25's i'd not hesitate to use the 270 brass i got in the box downstairs and trim the necks back to fit the chamber.
the worst that could happen is i'd have to cut case necks, and use a bushing die in a wssm die.

 

[StrawHat]

The 240 Weatherby used the 06 head size case. The belted head was 06 and the rest was smaller. Looks to me like what you have is an unbelted 240 or some other flavor of the 24/06.

Kevin

 

[obssd1958]

Update:
I decided to make a few cartridges, and take them to the range, along with some of the cartridges that came with the rifle. I used a .243 Winchester sizing die to neck down 3 25-06 cases that were originally made from Military 30-06 brass. I ran them into the sizing die a little at a time, until they would chamber snugly in the rifle. After priming, I belled the case mouth just enough to get the bullets started, and dropped 10gr. of Unique into each one. Then I seated a Saeco #243, 85gr gas checked, CR lubed and sized to .244, cast bullet in each of the 3 cases. Smoothed out the case mouth, and headed for the range.
I wasn't really looking for any accuracy, just wanted to see if my case forming method worked. I shot the 3 rounds with the cast bullets at a target that was set up at 25 yards. On the first shot, I was aimed at the target, but just settling in behind the rifle, and brought my finger into the trigger guard to locate the trigger - and the rifle fired. I knew from dry firing it, that the trigger was very light, but got reminded of the care that must be taken with a trigger that light (1lb 4oz. according to my Lyman guage)... The bullet strike was about half an inch left of center, and perfect for elevation. The next two rounds went 1 inch to the right of the first hole, same elevation, and looked like one hole.
I then shot 3 of the rounds that I got with the rifle. They made 1 ragged hole, about 1/2 inch above the 10 ring - still at 25 yards.
Once at home, I found that 2 of the 3 cases that I formed, had split in the neck and shoulder area. So that part of the experiment didn't fare so well! I think it was partly because using the .243 Winchester sizing die moves the shoulder back too far, in order to have the neck long enough to chamber. I am going to anneal the cases before sizing the next round, and see if that resolves the splitting issue.
Today I was getting a bunch of cases ready to go in the wet tumbler, and then go through the process of reforming the neck and shoulder. I deprime all of the cases first, and when I tried to deprime the three cases that I shot from the ammo I got with the rifle - I couldn't! A flashlight showed a tube attached to the base of the cases, at the flash hole, and rising about 2/3 of the way to the shoulder!
I've never run into this, and never read of it anywhere, so I Googled it. Seems there were a few of the old wildcatter's that thought that by putting a tube in the case, to direct the flame from the primer to the top portion of the case, and get the powder to light from the top of the case down, that it would burn more efficiently and maybe just as importantly, not scour the throat with unburnt or still burning powder.
There were a couple of different ways that they put these in the cases, but for now, I'm just not even going to deal with that. I'm going to just reform some more standard brass, and start working up loads.
Oh, and I bought a 6mm Creedmoor sizing die to come a little closer to the correct angle for the shoulder. Haven't used it yet, but it's on the docket.

More to come...

(but knowing how quickly I get to things, it may not be too soon?)

 

[Michael]

A number of years ago I had 219 Zipper Imp. The real adventure was finding a way to form cases without loosing too many in the process. Initially I went with 25-35 Win cases, then worked out a forming sequence using 30-30 cases, while a bit more time consuming actually gave better results.
During this process and I do not recall exactly where I read it, but too little pressure in the fire forming load can result in higher case loss with split shoulders.... hmm, that was one of my issues. It was recommended to use a normal powder charge, as in starting loads when fire forming for better results and less case loss. Figured the lighter loads certainly aren't working well so what is there to loose. So I loaded up some and gave it a try, it worked. Loaded up a few more, still good. I did loose a few more cases in long run, talking maybe 5% vs. every other one.

I won't tell you that this is the best answer for your rifle/cartridge combination, but it the one that worked for my Imp Zipper. One other thing before I forget, was to form an auxiliary shoulder that provided a bit of crush fit when closing the bolt. Annealing was also part of the process, I just don,t recall if it before or after case forming, but it was before the final step of fire forming.
Hope this helps, best wishes in this journey.

 

[CWLONGSHOT]

When I make my 6.5/06 from 06 cases I have to anneal size and anneal again. Otherwise I loose more than 75%. Even one annealing before causes 25-30% loss. With two annealing I generally only loose 1-3 in a few firings.

BUT, I also see hard bolt lift when I KNOW its not hot loading. So Im beleiving the shoulders necks are soft enough to "bite" into chamber walls better. (To much)

CW

 

[RBHarter]

To the flash tube .
Not just old skool catters , 2 guys at Springfield Armory did a bunch of work with the forward/top of the case flash tube . I did a split 15 shift yesterday day on 6 hours sleep in the 39 hr to bed 7 hr ago so my cognitive skills are not cogging really well . Hatcher and Whelen I think ....... But maybe it was the guys that blew the barrel out of the type 38 Arisaka with an 06' round ......
Anyway they did a lot of work in the 06' case and got impressive returns but not enough to justify the extra cost in production for millions of rounds . Circa 1938 ?

Anneal , form , anneal , neck size , load has worked for me from 06' to 7x57 and back with Dad making 22-250 from 308 . I haven't settled on a final for 308 to 6.5 Jap but the more I tinker I think it's going to end up scrounge a bunch of 6.5 CM and just size the base .......

I'm babbling now so that's enough of that .

 

[obssd1958]

I had some Berdan primed -06 cases, so I thought I would use them as sacrificial practice cases to figure out the process
for forming brass for this rifle. Annealed 5 of them and ran them through a 270 Winchester full length sizing die, as a preliminary
step. No problems. I then used the 6mm Creedmoor FL sizing die, because the shoulder needs to be closer to 30-35 degrees on
the finished product. Cranked the die down a little at a time, trying the case in the rifle chamber for fit in between. Finally got the
bolt to close on the first one, but it was pretty stiff. Left the die set where it was, and sized another case (I had already run it through
the 270 sizer), and the bolt would not close on that case. Moved the die down a touch, and it still wouldn't close. Then I noticed that
the shoulder looked bulged, so I took the decapper out of the 270 sizer, and ran the brass back in it, Took most of the bulge out, but
I still couldn't get the bolt to close. Closer examination, and a little bit of thought, and I figured out that the case had grown too much
in length, and needed trimmed. Trimmed it to the proper length, and the bolt easily closed.
Took 50 boxer primed, military headstamped brass, deprimed them and ran them through the stainless steel pin cleaning process.
Sized a couple down using a 270 Win FL sizing die. Then tried sizing them down with the 6mm Creedmoor FL Sizing die -
collapsed/accordianed the shoulder on both. These had not been annealed - but at the moment, I don't know if that had anything
to do with it or not.
I give up for tonight........................