1899B rotary mag stuck

[Slinky Pickle]

Forestar, I'm glad to hear that what I posted helped a bit. As you suspect, that carrier should rotate in the bore it sits in. Are you able to get a set of calipers into the bore and check the diameter in a few spots? If it's egg shaped then it may be possible to gently bump it back into shape. It doesn't need to be a perfect fit because once the lock pin 99-437 is in place it's not going to turn. However, it should turn freely until the pin is inserted.

As for disassembling the carrier, remember that all the threads are all left hand. You should start by holding part 99-436 and unscrew part 99-438 by rotating it clockwise. Once it's off, grip 99-436 again and now turn the end of 99-435, again clockwise. It should unthread from 99-436. Once it's out, the whole assembly should then come apart. I've been meaning to make a video of the disassembly process but I haven't managed to do it. I'll see if I can put something together this week.

[Forestar]

Slinky

Thank you for the quick reply.

I did not try to measure the receiver bore hole with a caliper, but I can see that it is somewhat deformed. (I’ll check with calipers as soon as I get a chance.) I think it got “squoze” by someone who overtightened it in a vise - perhaps when they changed out the barrel?? What I did do is try to feed the carrier in backwards - just to check for “roundness.” It’ll go in with a bit of wiggling, but it’s a tight fit - tighter in some spots than others, I’m sure. And it - sure as shooting’ - won’t rotate freely. Matter of fact, it (99-436) won’t turn at all. I did manage to reinstall the carrier assembly (not backwards) but I cannot adjust the timing since the carrier spindle head (99-436) does not rotate freely and I could not reinstall the carrier spindle head screw (99-437). Not much sense trying to put it all back together in its current condition.

I read elsewhere some additional info on the carrier assembly dis-assembly. There were a bunch of pics at one time, but it was an old post and the pics were no longer available (photobucket). But the description was very similar to what you just posted above, including noting LH threads. Since the carrier assembly seems to be in working order, I’ll probably just leave it alone for now, although I’m sure a good cleaning wouldn’t hurt.

If you or anyone else has any thoughts about the bolt not closing on a dummy round (full length sized, trimmed to length to spec, and loaded with a 150g round nose with no crimp) I like to hear them.

Thanks again for your time and help.

Forestar

[Slinky Pickle]

Forestar, when you mention that the receiver may have been pinched in a vice that seems very similar to how one of mine was when I got it. There were obvious vice marks on mine and it had certainly been squeezed at some point. I could not close the bolt even without a round in it. I ended up GENTLY spreading the receiver. I've got 3 1899Bs here and I'll measure the inside of the receiver on each and see what they measure. If yours is too narrow, spreading it ever so slightly may solve both of your issues.

Update: I was able to reach down into the top of the receiver and measure across the opening. It's lower on the right hand side so you have to get the calipers in far enough that they contact both sides. I only measured two of my rifles but I'll assume the other is similar. The measurements I got along the length of the receiver varied between .595" and .605". Let me know what you find on yours.

[Forestar]

It’ll have to wait until Wednesday; tied up tomorrow.

Thank you.

[Forestar]

SP

I took some measurements and here’s what I found:

1. Inside the receiver bore hole:
1.229” from the 1 o’clock to 7 o’clock position
1.218” from 2 o’clock to 8 o’clock
1.209” from 3 to 9
1.223” from 4 to 10
1.220” from 5 to 11
I cannot measure the 6 to 12 o’clock diameter
NOTE: my other 99, a 1936 takedown chambered in 300 Sav, measures 1.215 +/- a few thousandths all the way around

2. The receiver inside width measurements from front to back measured:
~.589” just back of the rounded corner in the forward right hand corner
~.605” immediately ahead of the automatic cutoff
~.633” at the forward cartridge guide pin (99-415)
~.635” at the rear cartridge guide pin.
NOTE: the 1936 model measures .592, .635, .635 and .635 in the same locations, as best as I can measure it.

To be continued...?

Regards.