Does anyone have experience with handloading heavy bullets in the .450 Marlin. Whats the heaviest bullet I can use and which powder and charge I can load with consideration of the max. pressure.

Thanks, Martin

400 grains and Reloader-7 powder.

If you go with a heavier bullet designed for a 458 Win., then you'll runn into seating issues due to the short throat of your chamber. If you ream the throat longer and seat them out longer, then they won't feed. If you seat them deep, then you will run out of powder capacity and the velocities will be too low.

350 grains is the ideal weight for this cartrige. It gives a nice ballance of velocity and penetration.

As far as a big game load goes for the 45/70/.450 I like woodleighs 405 gr flat point over 46 gr of AR2207.

550 grain Jae Bok Crater.
http://www.competitor-pistol.com/jb%20home.html

In my .450 Guide Gun (18.5") I've been using the following and have been very pleased with accuracy and velocity...

405gr Rem JFP/51.0gr H322/CCI200/Hornady case = 1910fps

Accuracy is 1" to 1.5" at 100 yards with XS ghost ring sights

Remember that the heavier the bullet, the slower it will fly. At some point, you will gain nothing in terms of penetration and your trajectory will look like a rainbow.

A 550 grain wide meplat hard cast bullet driven 1550 fps will have a 6" diameter point blank range of 150 yards and will probably out penetrate any other 45-70 load you can come up with.