heavy loads for 45 LC in Marlin 1894 Cowboy

[swifty]

I have been shooting the Lyman 454190 cast lead to tin 20-1 sized .454 with a OL of 1.6 inches in my Marlin 1894 cowboy.
My powder has been Winchester 231 at 8 grains with a velocity of 1060 feet per second. I have a couple of LBT moulds a 265 grain FN and a 300 grain FN.
My question is what powder would work well with the 300 grain bullet realizing that I may have to seat it a bit deeper. The bullet length for the 250 grain is about .70 the length of the 300 grain is .830. My concern is if I seat the heaver bullet deeper the powder pressure spike would be a problem

[O.S.O.K.]

Depends on what velocity you want. If you want thumpers (like "Ruger" loads in the books) then H110/W296 is hard to beat. If you want 1000 fps then there are plenty of options with the faster burning powders...

[swifty]

I am looking for about 1100 feet per second with the 300 grain bullet.
My concern is the powder pressure spike with a fast burning powder.

[meanc]

When you said "heavy loads", I thought you meant the Ruger type loads.

For a levergun, a 300gr at 1100fps is more of a light/medium load and can be accomplished with several powders. You'll just have to work the loads up and keep an eye out for signs of excessive pressure.

Still, I'd make sure not to use them in anything other than a strong actioned Levergun or strong Ruger Blackhawk type single action revolver.

[JReed]

H110 and 2400 are good powders.

[1886]

H-110/296 need load density, ie. DO NOT REDUCE recommended starting load. In all likely hood 1000fps will be below the recommended starting load velocity but 18.5grs might get you there but the load density will not be correct. H-110 likes about 10% compression for optimum performance and 18.5grs will not be enough for proper compression. Do you have any Unique? If so about 9.5grs will get you where you want to be give or take a little. Remember jacketed projectiles will require a little less powder than cast to achieve your objective. These loads should not be used in a single action army or any single action army clone. This load will serve you well. 1886.

[swifty]

I like unique and use it frequently. I will try the 9.5 grain load and check it for velocity. I have used a good bit of 2400 but have found it a bit dirty with a lot of unburned granules. It may be it likes more of a magnum load and a heavy crimp.

[bj94]

I usually don't think in terms of fast powders with heavy bullets. For what you are trying I would think Unique would be the fastest powder to try, and personally I would want to use something slower like Herco. Not sure why you want to use heavy bullets since a 250 grain bullet will do a lot in that gun.

Now if you really want to have fun, load those 300's with a stout charge of 296. The rifle will really like that, and you will definitely know when you fire one of them.

[DJWright]

I used to use 2400, but with my LBT 300 gr. WFNs, I found that 20 gr. 'Lil gun powder is a tack driver. As long as the bullets are sized correctly for your bore. More velocity, less pressure.

[Guncase]

I load LBT 300 grain WFN over 23 grains of H110. I have never tried it in a rifle, only my 5" Bisley/Vaquero. It gets your attention.

[adirondakjack]

Try about 9 of Unique or Power Pistol. With heavy bullets at what amount to slightly over SAAMI, (but still middle of the road for a Marlin or Ruger), these are good powders. If ya want MORE snot, go to H110, 4227 or 2400

[swifty]

I will try your suggestion of 9 grains of Unique and run it past my chronograph.