https://thegreatmodel8.net/

I had heard some where that the 35rem chambers and therefore the sizing dies had a change. I'm trying to figure out when that change happened as I'm reloading for both my 1930 Model 8 and my 1956 Marlin 336. Any information will help as I'm planning on Black Bear hunting with my Remington?

If you're handloading then I'd suggest that you just neck-size the 35 Remington. It's low enough pressure that, once fired, it should still chamber easily and headspace should not require a Full Length sizing operation to be accurate and reliable. Just work up whatever load you want to use for your bear hunt.

Otherwise I have never heard of the "chambers changing" with 35 Remington. At some point the cartridge was adopted by the SAAMI organization and Remington's ammo/reamer specs for their 100+ year old .35 Remington may not be 100% the same as the current US industry standard. There's also the possibility of production tolerances. A new, different or worn reamer may cut a chamber that is different than your set of dies.

I went back and found the post I had read about this.

"Unseated fired primers on reloaded .35 Rem ammo? - thegreatmodel8.remingtonsociety.com"

I also use that same round in my Marlin 336, which makes it hrd to determine which one is from which. Thank you for your advice on neck sizing as that is what I'm leaning towards.

You can try to separate cases by brand so that "Remington" headstamp stays with the M81 and "Winchester" headstamp stays with the Marlin, etc.

Also, at least in my case, the M81 firing pin is huge compared to my other rifles, so fired primers are obvious what came from what.

Some help for headspace measurements:
http://thegreatmodel8.remingtonsociety. ... b8f#p19378

Hoernady finally came out with an affordable headspace tool.

Thank You I just ordered the head space adapters I already use the OGIVE gauge. I just got the Model 8 back from the smith he went right through it replaced the leather washer with neoprean and added the proper sling mount. I'm ready for bear season this fall.