Maxium Cartridge Overall Length COL in SA centerfeed???

Well, I am sure this has been discussed, but couldn't seem to find a good hit.

I have Model 12 SA with magnum boltface bolt. Was a 270 WSM if that matters, but going to become a 7mm SAUM

I am planning to make some dummy cartriges with 168 Berger VLD hunting bullets to test feeding and ejection of loaded rounds from the port.

Anyone care to give real world COL experience from the short action centerfeed magazine?

Judging from my rough estimates using a caliper, it looks like about 3.2" max to get a loaded cartrige to eject. To get loaded cartriges in the magazine, looks around 2.9" max.

Do those numbers jive with anyone elses experience?

The current plan is to throat the new barrel to magazine depth and see what I get, in terms of accuracy. If I like what I get, it stays that way. If its not great, it gets throated further out and becomes a single shot.

Make Sense?