What to do with another Siamese Mauser

Run Away, Run Away.

I have bought a few different 338 projectiles.

Left is 225gr PPSN Woodleigh
Middle is 250gr RNSN Bertram
Right is 300gr RNSN Woodleigh
It is going to be interesting if 1:10 twist can stablise the 300gr Woodleigh. That is one very long projectile, no wonder the 300gr in the 333Jeffery was renowned for penetration.
I am going to use the Bertram 250gr RNSN to fireform the cases as they only cost AU$1.00 each.

I bought some of those 300gr for my 338/06 but haven’t loaded any up, was for a self guided African hunt but ended up using my 9.3x62.

We were using Winchester 338Win factory loaded 300gr cartridges on the Buffalo for the meat works in the old days, we had to head/brain shoot them but it worked well on chest shots to if it came to that.

Yes those Bertram slugs are cheap, I bought a heap of .416 & 480gr .458 bullets for load development & shooting practice, I’d not trust them on DG !!

Its official now! In Vic when you change calibre it needs to be documented and submitted by a registered gunsmith ( I am not). Bob De Vries has been very helpfull registering my weird arse cartridges (as he describes them). As part of the process he also laser etches the calibre onto the barrel.

The metal is now 95% in the wood.

That's looking great

Siamese Mauser 2 position safety arrived last week. Very easy to fit up.
The bolt locking plunger (silver part between the spring and the lever) needed to be shortened by 0.5mm to allow the shroud to fully screw into the bolt body.

The final mod was to grind a bevel on the cocking piece to allow the lever to engage the cocking piece and lift the sear off the trigger. (before grinding the cocking piece)

Bevel ground.

Finally assembled - the safety functions very smoothly, much smoother than the 3 position I made up for my 416WSM. But it might be a bit too smooth, as it would be very easy for it to inadvertently disengage in the scrub, although it is tucked in under the scope so it might be perfectly OK, time will tell.



Very happy with the final result, and the transaction to get the 2 position safety.

This rifle is being made to be able to take animals like this one across gullies. This bloke was camped across a deep steep gully about 400m away on Friday morning. I was up there working on another project and only had a 308 with me and did not have time to pursue him.

I have ordered a Dressel English style grip cap for the Martini project, so while I wait for that to arrive time to get back on this projecct.
I have never liked the bolt knob that came with this action and I had made a couple so it was time to replace the knob.
Set up is important to get it all lined up.


First TIG weld without using filler rod to get good weld penetration into the root.

Small welds to minimise heat as the weld is built up.


Finished ready to blue.


New bolt handle and knob have plenty of clearance to the scope. I hate it when the knob is too close to the scope and you skin your knuckles every time you cycle the bolt.


The scope is in low rings which gives me great cheek weld to the comb. I took 20mm off the breach end of the barrel when I chambered it to get the barrel taper in the right spot relative to the scope. I am happy with the safety and bolt function with this setup.

Next is to finish inletting the action into the stock as well as the recess for the bolt handle.

Very nice

Yes, nice work. I discovered something interesting a few nights ago. For whatever reason (seems there were a couple of possible explanations), cartridges were all of a sudden sometimes jamming in the magazine of my 404 on Czech 98 Mauser. I pulled the gun apart to make sure nothing shifted (I had fixed two internal cracks inside the used stock bought online). All okay. Next, I beveled the top of corners on left side of NECG magnum follower. It appeared the follower was occasionally catching on the lip of receiver where it meets the magazine box. That fix helped but not a cure entirely. Then I noticed the follower spring was slipping sideways against follower. This is because NECG made their retaining slot in follower too wide for the tapered end of standard action spring. I fixed it by squeezing in the sides of follower in vice at the point where the spring is gripped in the follower slot. But it's not a tight fit, just enough to hold the spring. Consequently, the opposite end of spring was allowed to wander. If the spring slipped to one side, pressure would be uneven on the follower allowing it to tip, get jammed against the side of the box, and caught on the bottom edge of receiver. I fixed that by using a carbide carving bit in my Dremel tool to carve a retaining slot in the back of follower for the shifting end of spring to fit into. Now it's locked tight onto follower and spring tension is always vertical. But still some bullets were getting hung up. Finally determined it was because I used RWS brass to make the dummy rounds I used to modify the 8mm rails and ramp to accept 404 cartridges. Unknown to me RWS brass was short and consequently when bullets were seated to cannalure, the cartridge OAL was short. RWS also has inconsistent rim thickness which caused problems modifying the extractor claw. So I switched to proper made Hornady brass. Reset my dies for those cases and cartridges are now proper OAL ... but just a tiny bit longer made a big difference. Some bullets were getting caught on the underside of loading ramp. Dremel to the rescue again. A cylinder carbide tip cleaned up the problem, mostly at left corner of loading ramp. Now the gun is back to cycling flawlessly. With 400 gr Barnes bullets anyway. I guess someone makes 450 gr solids for 404 and I doubt those would feed without further modification of the ramp. But then I'd run the risk of ragged cycling for lighter loads. I absolutely see no reason why I (or anyone else) would need to shoot 450 gr 404 at anything so I'm not concerned.

Good work Ontario - cartridge feed can be fickle, especially when modifying a system that was not originally intended to work with it.

Getting there with the stock - I am starting to get excited about this rifle.

What trigger did you install?

Ontario Hunter said:

What trigger did you install?

Click to expand...

It still has the military 2 stage. Apparently you can use a K98 trigger but you need to modify the trigger lever so the bow is in the correct position.
Triggers are a restricted import item as apparently if I import a Timney this rifle will become a mass murder device.

I guess declaring one sent to you as a bike part would be a tough sell?

I had to modify the trigger lever on my Timney to get the vz.24 action and bottom metal pulled together in the fancy second hand stock I bought online. Also had to shorten the rear action screw. The wrist on this stock was thinner than standard action. Trigger lever was easily reshaped with torch and needle-nose pliers. The entire unit is metal so no worries about melting anything plastic. The trigger now nicely cradles my finger. Probably not so nice if I had to shoot the rifle wearing heavy gloves. But I don't anticipate hunting Alaska brown bears with it. Only African animals in temperate conditions. I bedded a 3/16" rod down through the thin wrist from end of tang, "just in case."

BlueFlyer said:

It still has the military 2 stage. Apparently you can use a K98 trigger but you need to modify the trigger lever so the bow is in the correct position.
Triggers are a restricted import item as apparently if I import a Timney this rifle will become a mass murder device.

Click to expand...

@BlueFlyer
I'm sure one ofe the boys in the USA would send you one without an issue. It's only when you try and buy direct you have issues.
Dang I couldn't even get a set of open sights out of the USA.
Bob