I have not gathered that much pressure data with 400gr bullets. I CAN say that, with the lot# of IMR4198 I have, 50grs will give pressures equivalent to the top Hodgdon lever loads, WITH 350GR BULLETS. Again, this is what happens in my gun. No one can say for sure what it does in yours.

With the lots that I have, IMR4198 is 2 grs faster than H4198 (i.e. use two grains less IMR for pressures equivalent to H4198) That could easily be reversed with different lot #s, but with what I have on hand, it is very consistent. Also, given equal pressures, IMR fell, on average, about 40fps short of velocities attainable with H4198. This is with 350gr bullets.

All the assumptions made as to loading the newer generation of lever guns, to be quite honest, scares the poop out of me. Companies that do pressure testing, even by the same method, have wide disparities with the results. Compare Lyman data with Hodgdon data some time. Some of the differences are quite striking. If two, supposedly SAAMI compliant, companies come up with widely different pressures, what's the average Joe to believe?

My background is petro-chemical and all vessels are tested at 1.5 times operating pressure. I believe bolt guns could survive that test (bent but not broken); I'm not so sure that the levers could. Sure like to see someone do that test.

You's may have seen my post on pushing 350 grs over 2000 fps,and with 49 grs of H4198 I was able to realize 2050 fps from the marlin 22".To go more weight/more powder/more recoil kinda does away with the whole idea of using a repeater doesnt it?Before I worked up that load I was piping 400's out just shy of two.Got a nice buck,but I thank God I got him first shot,or that there wasnt more than one,cause I think you could log the amount of time it took me to bring that barrel back down to target with a calender.

I had just put a pachmayer slip on recoil pad on my rifle.

worked like a charm.

The rifle has some push but really is a creampuff.

"As to RMillers load, the top load would be just a little hotter than the BB load, using my components, in my rifle. Whatever that's worth."

Are you refering to the 53 grain load. My guess is that these were done in a ruger # 1.

I plan on sticking with 50 grains myself.

I have found with my Browning 1886 SRC repro that it will gobble up the hottest loads in the Hodgdon manual, although the recoil with them and the carbine butt was ferocious. Since this is a Grizzly protection rifle, I cut the stock, installed a good pad and lowered the loads as I prefer to be able to get a quick one-two at about 1800 into an aggressive bruin than to hit only once with a load at 1950-2000. The difference in recoil is definitely noticeable and the power I want is certainly there.

My Marlin would not handle anywhere close to the loads that the 1886 will, so, I simply popped on an old Redfield 2.75x with a huge post and it is now a rifle for hunting at close range in the late season's rain and snow. I figure that even 1700-1750 is plenty for anything with the 400 gr. Kodiaks and I am reserving the Swifts, which are hard to get and very pricey here, for the Grizzly gun.

A friend of mine shot a Moose with his Guide Gun with the Speer 400 gr. two yrs. ago at about 50 yds. and the bullet went through the entire chest cavity and was in the hide on the offside, so, while not my first choice for bear defense, it certainly works with proper placement.