Projek uit Oz : 470 Win Mag

[tripodmvr]

All started around 7 or 8 years ago when I was playing with a 458WM and just happened to have some 458WM, 458 Lott and 470 Capstick dummy cartridges side by side on my “ Shelf of Inspiration “

This got me thinking on why the 458WM had not been necked up to 470 before, or I just haven’t heard of it.

I drew up the 470 Win Mag to scale to get an idea, it looked good, so made a couple dummy cartridges and got excited, contacted Dave at Manson reamers to inquire if it had been done before, nope, not to his knowledge. So I contacted Dave at CH4D to ask same question, with same answer.

Back to chatting with Dave at Manson about making me the reamer, he cautioned me in regards to the cartridge possibly not having enough body taper for reliable extraction. So I shelved the idea and went on to the next crazy idea.

Few years passed and I happen to stumble across the dummy cartridges I made up. Threw caution to the wind and contacted Manson again to request the custom reamer to be made. Then the wait began.

In the mean time I arranged two hand lapped C/Moly barrels from TSE, bloody love their C/Moly barrels, best in Oz and great value.
Next was the reloading die set, quick call to Simplex and the ball was rolling.

Now to find a suitable donor rifle and Winchester being my absolute Favourite. Managed to find a beautiful Winchester M70 Pre G push feed made between 1967 and 1968.
Unfortunately when I received it there were big cracks in the RHS of the butt, where the previous gunsmith had to poured molten reclaimed battery lead into the two drilled holes, to add weight I’m guessing. I could still smell the battery acid, the lead corrosion had expanded the stock and caused the cracks. Just plain silly!

Sent a few pictures off to Brett at BDR Custom Stocks and he assured me it was repairable, that sorted that.

With the action in hand, I had the chance to give it a birthday and tidy it up ready for when everything else arrived.

I started with 458 WM cases from Bertram as dummy cycling cartridges, then decided to go all out and get some custom head stamped cases done.
Joe down at Sydney Gun works waved is magic wand and soon the cases arrived in mail. Bloody awesome

In mean time I machined up a case trim die and custom crimp die to suit.

Next was to create a couple Quick Load predictions with different powders, 2208 and 2206H, to get an idea of what to expect and most importantly a starting load. I guessed at a good mid-range 458WM load with 500grners would be good start, and QL predicted similar, once I put in all the data, case volume, barrel length etc etc
On paper the cartridge looks to have good potential with 2206H as best choice and 2208 as next best.
QL prediction of 74grn with 500grn RN for 2150 fps.

Checking that against a few cartridges in loading manual using 500grn RN and 2206H

458WM – 69 to 74grn
2030 to 2160

458 Lott – 78 to 82grn
2120 to 2230

450 Rigby – 92 to 98
2215 to 2360

Following in the style of my other push feed Win M70s in 458WM and 416 Ruger, I wanted a 23 ½ to 24” barrel, clean with no open sights
Was a shame to cut the TSE barrel back from 26” but 24” is handy and allows good velocity.

With all bits and pieces arrived and assembled, the rifle come in at 9 ½ pounds loaded, topped with a higher magnification scope fitted for load development, I chose a Vari X 3 in 2.5 – 8 for now.
Once the load is settled, I’ll change the scope out for a scope more suited for hunting and have a VX3 in 1.5-5 waiting
The rifle is a bit heavy, but it balances well in hand.

Set up for reloading with starting load of 74grn 06H and loaded up in 1grn increments till case capacity was reached, with 82grn being the top load.
Checking back on the QL prediction, the top load velocity was around 2330 fps with 500grn RN. But only way to find out would be real time range shoot.

Range day arrived and I was excited, I bloody love these ground up builds.
With a few test shots of 79 to 80grn in 08 to make sure it didn’t blow myself up, and everything seemed to function well.
Then went onto the lighter 74grn 06H loads
Using a Magnospeed chrony the 74grn load yielded speeds of
2198
2176
2203
With an average velocity of 2192 and SD of 14.3
Not bad and pretty close to the QL prediction.
With bonus of putting all three inside 50 x 50 at 100 off the bench, good start.

The load development was next and this is the fun part, rough off the bench, but fun.

Top load of 82grn yielded
2308
2351
2346
With average of 2335 and SD of 23.5
Not bad for a little Win Mag case and very close to the QL prediction.

Next will be some field trials, to iron out any flaws in

Functionality
Usability
Longevity

Then final engraving and ceracoating

Absolutely wrapped in how it all turned out

[Johan van Wyk]

Met ander woorde, 'n kort .470 Capstick. Daar moet seker verveelde mense orals wees.

[Wouter Roets]

Johan

Hoekom voel jy die ontwerp is n mors van tyd?

Groetnis
Wouter

[Johan van Wyk]

Wouter,

As dit 'n man se hare terugblaas om moeite op so 'n projek te spandeer is ek bly. Vir my is die betrokke wiel egter alreeds ontwerp. As dit byvoorbeeld 'n .404 dop was wat opgenek was na .474" toe sou dit myns insiens baie meer insiggewend gewees het. Maar dis maar ek. To each his own, maar hierdie een is nie vir my nie.

JvW

[Wouter Roets]

Johan

Persoonlik dink ek die ontwerp is glad nie te versmaai nie. Jy sit met n rondte wat in n standaard aksie pas, goedkoop donor doppe wat min werk vat om gevorm te word en baie goeie balistiek gee met min poeier. Koeels is ook volop. Wat wil n mens meer he? Ek haal my hoed af vir iemand wat iets nuuts probeer en nog groter, dit deurvoer. Lyk my julle Ozzies is ook maar hard opmekaar.

Groetnis
Wouter

[Johan van Wyk]

Wouter,

Dink so daaraan: dit kon 'n gesprek ("eensydige, sinnelose monoloog" is waarskynlik 'n beter beskrywing) oor elektriese voertuie gewees het...

Dis wine o'clock hier en ek sit met 'n erge geval van jetlag na ek gisteroggend net na 5h00 eers in Melbourne aangekom het. Gesondheid!

Johan

[Wouter Roets]

Cheers ou bul!