Brad's 325 WSM Feeding Project Follow-up

[roscoedoh]

What Didn't Work:

 

 

Upper row:

 

Left - ejector cut on the recurve to enable lead point to strike farther into center of the case head.

 

Center - standard original ejector blade.

 

Right - ejector lead edge notched to move the point of impact for ejection out towards the outer edge of the case head.

 

Lower row:

 

Left - ejector box/bolt stop with the bolt stop ground back to cause the ejector to protrude farther past the bolt face.

 

Right - stadard unmodified ejector box for comparison.

 

Two more to come.

 

[roscoedoh]

What Worked:

 

 

Left - orignal unmodified ejector blade.

 

right - extended ejector blade with notch to allow folding into the ejector box.

[roscoedoh]

The Rifle:

 

 

This is the empty WSM case peeking out of the bridge tunnel with the bolt fully retracted. Not much there to initiate inertia and not much wiggle room.

 

 

 

Brad

[Doble Troble]

Nice study.

 

Excellent experimentation and result!

 

This is definitely one for the archives. Damn I love it when problems are solved...especially via patient tenacity. That's what made this country great!

[roscoedoh]

Here's the solution explained:

 

IT WORKS! IT WORKS!

 

The longer ejector blade solved the problem.

 

But it wasn't quite all that simple, I spent most of the day getting it going. Mostly because I wanted to go slow and to revisit all the things we discussed here, just to be sure.

 

This is going to be a long story, so if you're interested, get comfortable. If you're not thinking about something like this you may want to pass.

 

I want to share this with you is because the reason - not the CAUSE, but the REASON - that this wasn't ejecting is something that escaped all of us.

 

The CAUSE, a short fat case in an action never designed for it and the action longer than it needs to be for a WSM. "Reason" to be discussed shortly (well, longly).

 

First, what I did:

 

1. Extractor - I put a std mag extractor on again and tried it - tons of tension. Nothing. I hand fed a 7mm Mag case that way and ejected it, and it sent it to the moon. Extractor not the problem.

 

2. Ejector not hitting far enough in toward the center - Normally the depth of the slot in the bolt through which the ejector slides controls the depth at which the ejector protrudes across the case head. Don't know why we didn't have that conversation before - we all know it.

 

However I decided to sacrifice a couple of ejectors in quest of truth and knowledge. First one, I ground away the recurve behind the lead edge until I got the ejector blade to protrude farther into the receiver, thus hitting close to the center of the case head. Nothing once again.

 

3. Ejector hitting too far in toward the center of the head - Next I took another new ejector blade and cut an even bigger notch than before on the lead point of the lead edge, effectively moving the striking point out to about 3/32" from the outer edge of the rim. Nothing.

 

4. I liked the idea that sonic 1 made of grinding the bolt stop back to make the bolt stop farther back and thus making the ejector protrude farther and striking harder. Kind of like what I was thinking of doing anyway. So I sacrificed an ejector box/bolt stop and ground and tried and ground and tried, etc. Guess what?...Nothing. Hmmmm, why didn't that work??? It really did protrude a lot farther.

 

Therein lies the secret. Have you ever looked down the canyon, I mean tunnel, under the bridge when the bolt is fully retracted against the bolt stop? It must be an inch or more deep!!!

 

Now the REASON. A standard length cartridge or, for that matter a WSM with a bullet in the end has enough forward weight to cause inertia and begin the case to fly NECK FIRST when it hits the ejector. And, for a standard case, enough lateral clearance within the tunnel to get moving and keep moving.

 

A little short fat WSM has very little clearance to allow lateral movement down in the tunnel even when there is sufficient weight up front to intitiate inertia. But the real problem is that when that chubby little sucker is back down in the depths of the receiver bridge tunnel, by the time it hits the ejector, it's not going anywhere!

 

After ejecting several dozen times in several dozen configurations I started watching what happened. The case did indeed jump mightily, hit the other side of the tunnel and then just rattled around in it's too-deep cavern, but it wasn't going anywhere.

 

So, why does a longer ejector blade work? When we ground the bolt stop back, the bolt - well - stopped farther back, making Tubby even farther down in the tunnel when he was trying to get out. Remember the chubby kid in school trying to get over the wall? My apologies if you were him, no offense intended.

 

However, a longer blade hits much sooner, thus booting the case out harder AND sooner thus avoiding going deeper into tunnel AND having more get up and go.

 

How'd I do it. Well my barrelsmith welded (hard weld) enough material on the lead edge to make it impossible to fit the blade into the slot so that I could hand fit it as tight as possible - lengthwise. I did not have to lengthen the slot, but could have if needed.

 

I carefully ground the lead edge, consistent with the original angle, until it would just clear the forward end of the slot. I could always take more out later, but I don't weld anymore and I didn't want to send it back for more metal. Maybe .002" front clearance.

 

With the additional length the blade no longer folds into the ejector box enough to allow bolt passage through the receiver tunnel. Easy enough, I carefully filed a square notch in the outside edge of the blade so that it would fold into the box the same depth as a normal ejector blade.

 

Now when I eject an empty case - bingo! It's out of there every time. Not to the moon, but a good two feet, anyway. No jams!

 

Data: An original blade measures 1.340" absolute length, but that isn't real meaningful. Flushing the lead edge to one side of the caliper and measuring to the other end gives a reading of 1.206" functional length for the standard. My new one measures 1.421" absolute length and 1.374" functional length. In other words I added .168" to the functional length of the ejector blade (1.374 - 1.206 = .168").

[Clemson]

Brad, that is an impressive bit of persistence and intuition coupled with a massive dose of ingenuity!

 

Congrats! I would have taken a bet against getting that fat case to operate through a model 98.

 

Clemson

[BradD]

Thanks guys. And especially thanks to Jason (roscoedoh) for his hard work posting these pics.

 

If you like a challenge this is an interesting one. If you just want a WSM to shoot, go buy a Model 70 and tell everybody it's a Mauser.

 

Now to see if I can get them to hit the target....

 

Brad

[manureman]

I'm with DT this is archive material .THANKS guys!! Jim