First Workup For 16x10.15x61R Jarmann Cape Gun

Started by gitano, March 10, 2015, 05:27:23 PM

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gitano

One of the reasons I was fairly quick to jump on this firearm is that the 10.15x61R Jarmann cartridge is 1) easy to form from .348 Win cases, and, (another reason why I let it get in my head that it was a Husqvarna) 2) a Swedish military cartridge.

So I have fireformed a case and stuck a 200-grain, (originally .425"), jacketed bullet 'squoze' down to 0.410" in the case to make a 'dummy' cartridge.


I slugged the bore, and it has 7 lands and 7 grooves, which makes measuring the bore dimension, (land-to-land), or the groove dimension, (groove-to-groove), tough. Land-to-groove dimension is 0.406". As I thought about it, that dimension should be about right for a jacketed bullet's diameter. Add a thousandth or two for a cast lead bullet.

The case has a measured capacity of 87.0 grains of water. You will all be surprised to hear that I paper-whipped those numbers in QuickLOAD (QL). ;) Here are the result of that paper-whipping.

200 grain bullet
26" barrel
Max allowed pressure - 25,000 PSI (Fairly conservative, but y'all know I don't like to beat up old guns. That said, this is not that old a gun. I think between 1915 and 1925. Non-damascus shotgun barrel.)
60.2 grains of Accurate 2495 yields a muzzle velocity of 2450 f/s which in turn produces 2675 ft-lbs of muzzle energy. Not bad.

With the sights 0.75" above the mid-line of the bore, sighted in at 125 yd, the rifle is 1" high at 75 yd and 6" low at 200 yd retaining 1280 ft-lbs of energy. Not bad for a bullet with a G1 BC of 0.205.

I'm kinda liking that load - 200-grain bullet, 2450 f/s MV. Easy on the gun. Easy on my shoulder. .40 caliber hole. Moose-lethal out to 200 yd. Tough to beat for what it is.

I have to get a bullet resizing die in about 0.406". I might be willing to shoot 0.410" CAST bullets with a gas check from this rifle. Gotta come up with some reloading dies too. I hate to part with $135+S&H for factory-new dies, but may have to. I don't know if I could find a reamer for cutting resizing die.

Gotta come up with a bullet I am OK shooting through this bore before I shoot it, but it shouldn't take me too long.

Paul
Be nicer than necessary.

drinksgin (deceased)

I doubt you shall load a bunch of these ,why not just turn out a die on your lathe?
Not a really complicated case,it appears.
NRA life, TSRA life, SAF life, GOA, CCRKBA, DEF -CON

gitano

That thought occurred to me, Don. It just appears a bit daunting. The taper of the body. The taper of the shoulder. And there is a small taper in the neck. I have learned about the difficulty of "deep" boring. Boring bars are tough to control if one doesn't have a GOOD lathe, a GOOD boring bar, and SHARP cutters in the boring bar. By the time I part with the cash to ensure I have GOOD tooling, I could have bought the factory dies.

That option remains in my head. RCBS wants $300 for their dies, and Hornady wants at least $160 plus 6 months, so CH4Ds $135 is looking better and better.

Paul
Be nicer than necessary.

j0e_bl0ggs (deceased)

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gitano

Well, you know my success with other attempts at producing D reamers.

Paul
Be nicer than necessary.

j0e_bl0ggs (deceased)

Maybe should just make one for you?
or you make it and I'll heat treat it...
Turvey Stalking
Learn from the Limeys or the Canucks, or the Aussies, or the Kiwis, or the...
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gitano

As you know, I can make (form/shape), them, but the "work" cuts the reamer, not vice versa. I'll probably try one more time. I do have half-inch carbide rod and a tool-post-mounted grinder. Shouldn't take me more than a year or two to grind one. Oops. half-inch rod won't work. Head is 0.545". Bottom of shoulder is even 0.516".

Paul
Be nicer than necessary.

drinksgin (deceased)

Joe and I are on the same page, I would just rough a die, make a quick and dirty reamer, ream a bit and be done.
No real reason the reamer has to be a "D"reamer, I really prefer a 3 flute or more and use oh hss, a quick heat , quench and temper in an electric oven and country boy rides again!

:D:cool:
NRA life, TSRA life, SAF life, GOA, CCRKBA, DEF -CON

gitano

QuoteI really prefer a 3 flute or more and use oh hss, a quick heat , quench and temper in an electric oven
Problem is... that simply has not worked the last three times I did it. (I admit that the first time I did it is used the wrong steel - 12L15.) The last time I even took some serious time and made a 5-flute reamer. It actually made some chips, but not enough to matter. Not even close. Dulled to the point that it wouldn't cut hot butter in about 1 minute. And it was made from "tool steel" rod.

Paul
Be nicer than necessary.

drinksgin (deceased)

I must ask, what are you trying to cut?
I just use a piece of cold rolled carbon steel 7/8 -14 all thread for the die body, I have even reamed it with a reamer of grade 8 bolt material. that I did not anneal or harden.
NRA life, TSRA life, SAF life, GOA, CCRKBA, DEF -CON

gitano

Believe me, Don, it has been far more frustrating to me than you. EVERYONE has told me how "easy" this is to do, and yet, I have broken my sword no less than three times. I am going to do it one more time just because I have a hard head, but... What I like least is the wasted time.

The first one was 'operator error'. I used the wrong steel. No magic there. The next two times I used cold-rolled 1018 steel rod.

Mauser barrels are not particularly 'hard'. One of the reamers - I use the term loosely - didn't cut AT ALL, and the other didn't cut more than a couple of revolutions BY HAND before the edges were round. Like I said, ONE MORE TIME.

Using a bolt is an interesting idea. I'll have to look into that IF I can't find some O-1 tool steel in 9/16ths or 5/8ths locally.

Still, my work 'plate' is VERY full right now. I'm pretty seriously inclined to the $135 THREE DIE SET from CH4D. Tough to beat that for a set of custom dies. especially when 'time is of the essence' AND, I haven't had much success with making reamers so far.

Paul
Be nicer than necessary.

j0e_bl0ggs (deceased)

Quote from: drinksgin;137948Joe and I are on the same page, I would just rough a die, make a quick and dirty reamer, ream a bit and be done.
No real reason the reamer has to be a "D"reamer, I really prefer a 3 flute or more and use oh hss, a quick heat , quench and temper in an electric oven and country boy rides again!

:D:cool:

D only for expediency, I like odd flute numbers too!
Turvey Stalking
Learn from the Limeys or the Canucks, or the Aussies, or the Kiwis, or the...
                   "The ONLY reason to register a firearm is for future confiscation - How can it serve ANY other purpose?"

gitano

Ahh... http://www.buffaloarms.com/Detail.aspx?PROD=158376

http://hunters-supply.com/shop/406-cal-315-p-235.html

And of course there's always Hawk Bullets http://www.hawkbullets.com/Pricelist.htm

So... I should be able to find something I like for this firearm. I like Hawk bullets, I just don't like their prices. That said, their bullets are the kind I REALLY like: "electrical grade" (dead soft) copper, THICK jackets, PURE lead cores. I just end up paying more than $1 a piece once the shipping is included. Takes ALL the fun out of shooting at paper.

Paul
Be nicer than necessary.

gitano

I received the Accurate Molds (http://accuratemolds.com/index.php) mold today for casting 290-grain (nominal), gas-checked bullets for this rifle. Here are some preliminary pictures.








When I first looked at the inside surfaces of the mold and saw the "machine markes" I thought, "Hmm, kinda poor QC on that mill cutter." Then I realized it was actually a pretty cool 'efficiency' of operations. Having one tooth of a facing mill cutter just 'that much' longer cuts the "vents" for the mold at the same time the halves are being precision faced. Reduces operations which reduce costs.





I'll post more pictures and actual weights and dimensions after I cast a few bullets.

Paul
Be nicer than necessary.

gitano

Here are the 'results' after casting a few:

Took a LONG time to heat that large mold up to a temperature where it would throw unwrinkled bullets. Probably approaching 50 cycles. I never got it to produce 'frosted' bullets in spite of having furnace up to its maximum temperature.

I spec'd 0.4065 as final diameter; final weight at 290 grains using wheel weight alloy; and the gas check stub diameter at 0.380". The average weight of the "good" ones was 289.64 grains. The diameter is 0.4065 opposite the 'joint' and 0.407" at the joint. The gas check stub is 0.3795" in diameter.

So... I'd say I learned something. When spec'ing dimensions of thrown bullet, tell Accurate Molds EXACTLY what you want, not "close", or "about". If you want it to finish at a certain diameter with a certain weight with a specific alloy - spec what you want.

I ordered a custom push-through sizing die from Rick Tunnel. (See this thread, http://www.thehunterslife.com/forums/showthread.php?t=15192&highlight=Tunell&page=8, post #73.) I spec'd it at 0.4065". It just barely sizes these bullets. Which is fine. I don't have any .40 caliber gas checks at the moment, so I can't show a picture of a bullet with a GC installed. Most gas checks for bullets in this caliber range weigh about 3 grains. On that assumption, the final weight with GC will be ~293 grains.

Here are the pics.

The 'good' ones:


The 'bad' ones:




And out of the sizing die:


Overall, I am pleased with the die. Next time I might order a steel one. If the aluminum blocks are this big, it takes quite a bit of heat to get them up to temperature and it's tough to keep them there. OR I might just order a single cavity.

Now I've got to find some .41 caliber gas checks without having to mortgage my house.

Paul
Be nicer than necessary.

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