While the Winchester Big Bore rifle does have a stronger action I would not underestimate the strength of the Winchester Model 94, especially the Model 94AE action.
I have experience loading Winchester Model 94AE and the Marlin 336 rifles reamed for the 30-30AI cartridge. While I have no way of determining the exact pressure I have loaded the 30-30AI to high velocity for several years. I am not alone in this and my rifles exhibit no sign of distress.
Searching the internet will allow you to see pictures of several Marlin 336 rifles with actions which failed in the barrel thread area. The only picture of a Winchester Model 94 I have seen which has failed in the barrel thread area been the rifle pictured in P. O. Ackley�s book Handbook for Shooters and Reloaders, Volume 1.
Several years ago there was a thread on the Leverguns forum discussing a Winchester Model 94 and a Marlin 336 barreled for the 454 cartridge. Both rifles yielded in the locking lug area after a short number 454 cartridges had been fired through them.
My experience with the 30-30AI cartridge indicated the Marlin 336 would not accept as high pressure as the Winchester Model 94AE. I am a fan of the 307 Winchester and after reading many internet reports of remarkable possibilities with the 30-30AI cartridge I decided to compare the two cartridges. While exploring the upper limits of the 30-30AI cartridge I loaded above my stop points looking for a margin of safety � If I was going to share loading information on an open forum I wanted to be confident I was not on the edge of disaster. The Winchester Model 94AE was able to equal and exceed the velocity of the factory loaded 307 Winchester cartridge � but not at a pressure level I felt comfortable with. The Marlin 336 was not able to reach this pressure level, the rifle exhibiting sticky extraction and alarming case growth (stretch) prior to reaching 307 Winchester velocities. If you experience sticky extraction with the 30-30AI cartridge you are well above prudent pressure levels.
When I posted these results on the Leverguns forum Myron Rockett was kind enough to post about his .308/444 wildcat and its standard Model 94 rifle. This rifle has been digesting 307 Winchester loads for many years with no distress.
I suppose my point is both the Marlin and the Winchester lever action rifles have adequate strength for the cartridges they were designed for with a good margin of safety. Christian Helbig wrote several articles of high pressure loading for the 38-55 in years past. While Helbig did not load to 375 pressure levels he did load the 38-55 cartridge to high pressure.
I would not suggest having an old rifle re-bored or re-barreled for a high pressure cartridge but I believe the Modern Model 94AE is as good a candidate for this conversion as Marlin 336.
