.35 Ackley Magnum Improved

[Marlin Junky]

I wasn't sure where to post this and it's probably pretty off-the-wall, but I've been wanting to build a SS rifle chambered for a .35 caliber cartridge based on the .375H&H for a while now. Today I found an area on Midway's website where you can order RCBS dies for the .35 Ackley Magnum Improved. At this point I'm wondering which of the two is easier to form: the .35 Ackley Magnum Improved or the .35 Ackley Magnum. I don't have detailed spec's for either but think .338WM cases will be too short for the .35 Ackley Magnum while .375H&H cases will be more than ample for the Improved version. I don't want a short-necked wonder because I want to shoot boolits weighing up to 300 grains.

MJ

[wiljen]

For all practical purposes the 35 Ackley Magnum is the same round (ballistically) as the 358 Norma Magnum and the Improved is the same as or slightly behind the 358 STA or 358/300 Ultra Mag (or the 358/404 Improved). I think with all the more common brass (338 Winchester for the Norma and 300 UltraMag for the 358/300) that I'd shy away from case forming full length 375s. I think you'll find that load data for bullets in the 225-250gr range is far more common than for the 300gr in the 35s. If you are more interested in 300gr than 35 cal, you might look at the 9.3s or the 376 Steyr too.

[Marlin Junky]

I think you'll find that load data for bullets in the 225-250gr range is far more common than for the 300gr in the 35s. If you are more interested in 300gr than 35 cal, you might look at the 9.3s or the 376 Steyr too.

Lack of load data never stopped me. I want a .35 bore and need commonly available (not high dollar) brass... and need some neck length for the 275 to 300 grain boolits.

MJ

[wiljen]

I think I'd go with the 375 Remington Ultra Necked down to 35. That would provide you with a 1 caliber neck length and should provide you with plenty of powder space. Granted it aint 30-06 brass prices, but the next bet would be the 378 weatherby necked to 35. A quick check of wideners shows 375 RUM brass at $51/100 = better than I thought it would be.

[Marlin Junky]

Hmmm... I really don't need a 114+ grain (in water) cartridge case. I would like to be able to do 2500 fps with a 300 grain boolit from a SS w/ a 26" barrel.

MJ

[HollandNut]

Marlin , me and will was speaking of this one , its one I am looking at too ..

On Load from a Disk , I necked the 375 Ruger down to 358 with no other changes .

He asked me to run some numbers for ya and post them ..

310 grain Woodleigh , I got the following loads over 2400 fps with no pressure problems ..

H414 69.6 2426 fps

N165 77.8 2459 fps

IMR 4350 73.7 2429 fps

24" barrel

[wiljen]

to reach those #s you are gonna need at least the 358 STA or 375 H&H case, and the 35/375 Rum will give you a lot more powder choices that will do 2500 with a 300gr bullet.

the 358 Norma wont make it, nor will the Ackley magnums unless loaded way too hot.

[Marlin Junky]

OK then, how do I get all that and a .4" neck on my cartridge case?

MJ

[HollandNut]

I'll go create you a .4 neck and see what it says

[HollandNut]

375 Ruger to 358 with a .400 neck in a 24" barrel

310 Woodleigh

N165 76.2 2445

I4350 72.1 2414

W760 72.1 2432

H414 68.1 2410

[wiljen]

You start with a 375 Remington ultra mag - set the shoulder back .25 and neck it down to 35 then cut the neck back to .4

That should remove some of the extra space and give you the neck you want.

[Marlin Junky]

375 Ruger to 358 with a .400 neck in a 24" barrel

310 Woodleigh

N165 76.2 2445

I4350 72.1 2414

W760 72.1 2432

H414 68.1 2410

HollandNut,

Do you have pressure values corresponding to those velocities?

MJ

[Marlin Junky]

Now comes the $64 question: How much will it cost to have a reamer and dies made... that's why I got interested in the Ackley Magnum.

BTW HollandNut, what angle shoulder did you out on it? I was thinking about a 20 degree angle.

MJ

[HollandNut]

All those are under 50000 , thats the cutoff point for "safe " loads in the program for all cases regardless of operating pressure .. I dont know the shoulder angle , all I did was make the neck .400" ..

If I knew the operating max of the case then it'd be a higher number velocitywise ,
Reamers are around $200 for a custom set like this one .. 450 Ackley wud be a bit less as it is " More common " ..

Dies , probably $200 or so ..

[wiljen]

I still think you'd be well served by the 358 Norma Mag. It probably won't get quite 2500 fps out of a 300gr bullet. I'd bet between 23 and 2400 would be more likely. But dies are $60 and brass can be easily formed. I'd recommend you have your smith cut the neck for using 300 Winchester Mag instead of 338. If you use 338s you have to blow the shoulder forward a bit. If you use 300 Mags, you can get a little longer neck, and one pass through the sizing die and your in business - you wind up with a 358 Norma case with a 35 Whelen Neck. I'd recommend this as the most economical cartridge you are going to find that comes close to your specs. Now, what twist were you planning on to stabilize a 300gr bullet?

[Marlin Junky]

I still think you'd be well served by the 358 Norma Mag. It probably won't get quite 2500 fps out of a 300gr bullet. I'd bet between 23 and 2400 would be more likely. But dies are $60 and brass can be easily formed. I'd recommend you have your smith cut the neck for using 300 Winchester Mag instead of 338. If you use 338s you have to blow the shoulder forward a bit. If you use 300 Mags, you can get a little longer neck, and one pass through the sizing die and your in business - you wind up with a 358 Norma case with a 35 Whelen Neck. I'd recommend this as the most economical cartridge you are going to find that comes close to your specs. Now, what twist were you planning on to stabilize a 300gr bullet?

Wiljen,

Sounds like pretty good advice but one will need a custom reamer to get a Whelen neck on a .358 Norma body, right? At least I know we're dealing with 25 degree shoulders now. There's about 10 grains of water difference between the .375 Ruger and the .358 Norma but adding .14" or so of neck may close the difference by about 4 grains. On the down side, it may not be all that easy to move the .300WM's shoulder back .11" in order to chamber it in the new and improved .358 Norma. Unfortunately, my wildcatting experience is limited to the .30 Herrett and that was so long ago I can only remember how big a PITA trimming and annealing was.

Twist rate would more than likely be 1 in 14" since I'm having some success so far with 260 grain SWC's in the Whelen at under 1800 fps.

MJ

P.S. Wait a second, I don't think you're going to add that much neck to the .358 Norma by using .300WM brass. There's only .11" difference in SAAMI max. length and once you stretch out the .300WM brass, you'll need to square it off; i.e., trim it back somewhat. I still think one is better of using the H&H brass. Or maybe just going with the Norma Mag to begin with 'cause I understand it's freebored somewhat. Maybe a one groove bore-rider would work in the Norma? I dunno, it's too confusing right now, I'll just keep playing with my 16" twist Whelen until I get tired of it. Who needs a 300 grain boolit in the lower 48 anyway?

[wiljen]

using the 300WM cases wont get you a .4 neck, but it will get a little longer neck than will 338 winchester brass. The reamer shouldn't be a problem. On the one I have it had a standard 358 Norma cut, then a different reamer was used to lengthen the neck.

[Marlin Junky]

The reamer shouldn't be a problem. On the one I have it had a standard 358 Norma cut, then a different reamer was used to lengthen the neck.

What reamer did you use to lengthen the neck? What brass are you using? Any ammo pics?

MJ

[wiljen]

What reamer did you use to lengthen the neck? What brass are you using? Any ammo pics?

MJ

Not sure on the reamer - you'd have to ask the smith who did it and that was long years ago. I'll try to get a pic or two put together.

[waverace]

Sorry to bring up an old thread , but I've been tinkering with the 35 Ackley magnum improved for a while and just wanted to share some thoughts ,
I make my brass from 340 Weatherby and neck up to 35 this has been the easiest because the cases and shoulder position are almost identical .
I was lucky to find a set of used dies as before I was chamber fire forming and neck sizing in a 9mm die then using a generic 35 caliber seater die to seat the bullets , now I have the complete set up and I also just had the good fortune to find a chamber reamer on sale so there will be another one at least in my future.
Before I found the dies I was still at a loss as to what this round was and I asked the folks over at the high road for their input see that thread here ;

http://www.thehighroad.org/showthread.php?t=633741

106004106005106006

This is the line up , dies , chamber casts , loaded round and reamer , the last picture is one of my cases next to a 358 STA you can see that it is identical except that the shoulder is about 1/8 of an inch shorter.
All in all it was a journey of discovery and an enjoyable one at that , the 35 Ackley mag is indeed a thumper and delivers a huge amount of energy down range compared to a 308 or 30-06

[NVScouter]

Looks good, I just dont see the point(over just wanting a custom something) over a 375H&H. 300g at 2400 is easy as pie, so is 340g at 2400fps.