.338 Imperial Magnum Chassis fun project

[Gert Odendaal]

Maybe worth mentioning, my good friend did point out the RSA action is a great action for the correct purpose...as well as that I have to keep in mind it is manufactured twenty odd years ago..and can not compete with a new rifle technology and steel used by rifle manufacturers like HOWA, Tikka , Winchester ect...
I am not saying the RSA Action is inferior , it is just old technology...It is difficult to get hold of , for the same price I can buy a brand new HOWA .338 Win Mag barreled action A-R..R9000 as a private buyer and even a better price when bought from suppliers to Gun-shops.

[Gert Odendaal]

Maybe it is prudent to point out this project will be a fun shooting /long range shooting rifle for my personal use and available to fellow club member`s use as well.

My aim being the following:
It will be build on a scares caliber , the .338 Imperial Magnum based directly on a 404 Jeffery case, without any changes made to the 404 Jeffery case.

I really like the 404 Jeffery hunting caliber rifle , I have my own 1931 Westley Richards hunting rifle that I am using a lot at the shooting range and do about every hunt with it , from Duiker to Eland , a one man hunting rifle .

I am not a rifle collector , instead I find building scarce rifle calibers based on the 404 Jeffery case more suitable for me and much , much rewarding.

There are only three calibers I currently know of that derives directly from the 404 Jeffery case.

The Imperial Magnum caliber range designed by Aubrey White in Canada. ( discontinued )

The Canadian Magnum , currently developed by Aubrey White and currently sold by Aubrey White in Canada and Alaska for long range heavy game like Grizzly Bears /Moose and probably Humpback whales if you have a boat to hunt in Alaska

The 9.3 x70 DWM directly based on the 404 Jeffery case .

Only three rifles exist that I know of :
German Gunsmith Oscar Schewey of Berlin build a hunting rifle for Herman Goering ( one of Adolf Hitler`s most famous generals) the rifle is in a museum in Germany.

Gunsmith in Belgium build his rifle from a blue print of a reamer he received from Harold Wolff . He told me the 9.3 x 70 DWM maybe seen as the equal of the .375 H&H Magnum( Germans designed this caliber to be the opposition for the popular .375H&H Magnum,
He pointed out that the 9.3 x 70 DWM has by far more recoil than the .375 H&H Magnum hunting rifle .

Then there is a member on the African Hunting .com forum that build this scarce caliber already and made his own re-loading dies from the reamer he got.

When my 9.3 x 70 DWM is completed it might just be the fourth rifle in the world build on this caliber..keep in mind I do not see the German Drilling rifles as a dedicated hunting rifle in this caliber since this caliber is found as a rimmed version in their Drilling rifles.

This is why I will accept the use of the HOWA .338 Win Mag barreled action to build the .338 Imperial Magnum on a chassis . This rifle is not going to be use in long distance shooting or hunting competitions at all, but a long range fun shooting rifle and maybe to learn what long distance shooting at paper or steel is all about.

The main focus being the chassis milling work ..the practical skill thereof and the challenges to be as accurate as possible when milling the three parts of the chassis form a solid block of high grade aircraft aluminum..

So there is the story and rationale of this rifle build..

[Gert Odendaal]

Doing some planning on the parts that can be made before hand on the milling machine..
I will be making changes to the butt stock to fit a recoil damping tube , weights into the butt stock.
acc-mdt-chassis-09_1024x1024_1 (1).jpg

The front end design I will mill from a piece of high grade aluminum hexagon extrusion.
AX_QD_Sling_Mount_03.jpg
hex.jpghexagonal.jpg
It will be nice to mill out this component from these aluminum hexagon tubes ..
and if I really want to go fancy, it will be made from this piece of material
perforated-tube-open-shape.jpg

[Gert Odendaal]

Bullet choice:
I will be shooting the Perigrine VLR 4 , BC .0681 in a heavy straight taper barrel with a rifling twist of 1:9.5 the bullet weight 270 grain

The practice bullet:
Perigrine VLR5 , BC .0681 , 276 gn bullet

Barrel: Bartlein barrel blank" 30" inch 1:9.5 rifling , straight taper , .338 diameter $300 +shipping $30 = R4673.00

[Gert Odendaal]

Good, I spoke to a fellow rifle club member who shoots a .338 Lapua , he suggested I rather shoot the Perigrine Range Masters.
290 GN Perigrine Range Master bullets
BC = 0. 952

[Gert Odendaal]

I did get conformation in regards to the suitability of using a HOWA .338 Win Mag barreled action from a gunsmith that works regularly on the Howa rifles and barreled actions to convert to long range shooting rifles. I will use the HOWA .338 Win Mag barreled action, ream the chamber to the .338 Imperial Magnum and use is as is with the Howa barrel in tact...after shooting out the barrel in the next four years time ( maybe) I can re-barrel to the Bartlein or Brux barrel..I need to keep in mind the HOWA barrel is only 26"inches long ..but this will really give me a lot of insight into shorter barrels vs long barrels on a long range shooting platform over the next four to five years..

I spend some time on the internet today to source a hexagon extrusion aluminum pipe..nowhere in South Africa is this item available at all. So I need to do some creative thinking to sort out this challenge. I think maybe going the round pipe route and mill out a long picatinny steel rail to bolt onto the top of the aluminum pipe cover for the barrel..I think it is more about esthetics and looks than having a place to fit items to the chassis.
AX_QD_Sling_Mount_03.jpga89208491563cba740c1fa8755ab8d0c.jpg

[Messor]

Where did you get the info that it is 26" long?

[Gert Odendaal]

Where did you get the info that it is 26" long?

No, correction Messor it is 24" inch

It will be quite a big difference between the 24" inch Howa barrel that I will be using in the barreled action and the later 30" barrel it will be replaced with.

[Gert Odendaal]

I had time to review my old aluminum casting methods , it seems there are a lot of progress in regards to aluminum casting methods..I will be looking at two different methods to make the butt stock , the first method will be milling a piece of solid aluminum 40mm sheet into a final product . The second method will be casting the butt stock...will see how that goes..all the adjusting knobs will be cast in aluminum...

[Gert Odendaal]

Messor, what is your opinion in regards to the Perigrine Range Masters.
290 GN Perigrine Range Master bullets
BC = 0. 952