More question on big bore 307 conversion

[handirifle]

Ok I got all the parts I ordered. I installed the cartridge guide and just to see it function I stuck a 307 case in the magazine and tried to cycle the bolt. Tried!
The case only comes about halfway out until I half cycle the lever a few times then it pops out and seems to want to cycle completely. Can't tell for sure as I haven't swapped the barrel yet. Am doing this in stages to learn. When I pull the brass out it has a bunch of little dents just behind the shoulder, right about where the lifting gate makes contact. Was I supposed to swap that as well?
Also, the bottom piece (name unknown) that serves as the cartridge stop for the magazine and lifts what I THINK is the lifting gate, has a little tab that catches the rim of the case as it tries to exit the magazine. Does that need to be changed too? It look like the tab that catches the rim is what's denting the cases.
when I remover the screw that holds that piece in place, the case pops right out of the magazine, like it's supposed to.

HELP!

[Marc]

IIRC you are converting a 375 to 307? I don't know what the lifting gate is. Do you mean the carrier? The carrier is the same for both calibers.

The little tab on the lower link is the cartridge stop. You will have to file it down a little because the case body of the 307 is bigger than the 375. The stop needs to be tall enough to catch the rim but not so tall that it hits the case body when the link is lowered. There isn't much wiggle room there so take off just a little at a time and try it. If you take off to much the round will slide under the carrier and jam the rifle.

[handirifle]

I wasn't sure of the name of it, but here are some pics.

This is the bottom view of the part in question.



This is this inside view showing the tab. I believe the carrier you are referring to is the silver colored piece that actually lifts the cartridge up (hence my incorrectly calling it the lift gate) to be chambered, correct?



I assumed the cartridge stop (the tab as I called it) could be filed down, BUT, would it still work, if i decided to ever swap back to a 375? And yes, I am converting from 375 to 307.

Would there be a different model for the 307?

[flatnose]

Handirifle,
I think marc has the answer to your problem. The cartridge stop may well be your problem. The cartridge diameter for both the 30/30 and 375 is close to the same diameter, measured to the 30/30 shoulder length. The 375 a little less maybe. The 307 at the shoulder is around 0.050'' larger in diameter, so in theory you would have to reduce the height of the cartridge stop by less than half that amount, start with 0.010?
If the cartridge is pinching at the stop, take the forend and magazine tube off, and try feeding a cartridge by hand through the front of the receiver. You may have gained a little more wiggle room(thickness of the magazine tube wall), and the cartridge may feed. At least you may see if the stop is binding on the case.
There are different part numbers for the lower link, but these are for the side eject. I don't think they made the 307 in top eject.
94120481...link complete sn above 5,550,001
94070290...link complete big bore 5,550,001 ...no info as to what big bore, but I think it for 307 and 356.

[handirifle]

OK I found them on the schematic, I was looking at the wrong picture, duh! No wonder the pieces didn't look the same.

Well will work on making an action wrench and barrel vice to pull them apart and will carefully file the stop. By the way, just for kicks and grins I tested the 375 cartridge with the 307 guides installed. Cycled slickern snot.

I also still need to locate a front band screw. I will see if I have the tap and dies for that size screw, but am doubting it. It's itty bitty in diameter and very fine thread.

I will test the 375 cases again, once I get the stop working with the 307 cases. Hopefully it works still.

[flatnose]

Just tried 307 cartridge in my custom 94 22-250R. Same problem you have. The 307 is jamming against the stop. Dimples the cartridge in the same place, and I use a standard 30-30 lower link.

[Marc]

I think you have it now. The lower links are different between 30-30's and the 307, 356 and 444. The cartridge stop is taller on 30-30's and I expect the 375 uses the same link as the 30-30.

I did an experiment. I loaded five 30-30 rounds in my 356 Winchester. They cycled through the action without a hitch. My 356 was abused when I got it and the cartridge stop was worn to the point it jammed. I welded the tip up and carefully filed it down just enough to let the 356 cartridge feed. The repaired cartridge stop on my 356 is now taller than the cartridge stop on my 444 Big Bore. The 444 is apart right now so I can't test it to see if it feeds 30-30's but based on my experience with the 356 I doubt that it will reliably. The cartridge stop is a critical part so don't take any more off than you have to and it should still work fine for the 375 if you choose to go back.

[handirifle]

Thanks Marc, I will go at it carefully.