New to 45-70 seeking advice on initial loads

[Strtspdlx]

I'm using a mp molds 462gc hammer mold. In deep HP they're about 310gn if memory serves me right and in flat nose they're about 33xgn. These will be target loads as I cannot hunt with this rifle. Which by the way is a marlin Guide gun. I'm using cci #200 primers and lubing with something comparable to nra formula. For powder I have imr4198 and h322. I have load data for both and plan to work up the loads but I was curious if anyone had any tips as this case is pretty big. And with 49gn of imr4198 it looks to have a good bit of room. Thanks

[Digital Dan]

http://www.hodgdonreloading.com/

[Soundguy]

You want a near full case with safe fps for cast lead? I'd go trail boss, and flat nose vs hp.

[RickinTN]

Be careful and don't push it too hard until you get a feel for the recoil. A 45-70 in my experience can become a beast very quickly as the velocity climbs, especially in a light rifle such as the guide gun. For an enjoyable load I would start with between 10 and 12 grains of Unique. Your 322 and 4198 are very similar to each other in burn rate. If I were going to use them I would start with recommended starting loads and not worry about the case being full.
Good Luck,
Rick

[Crusty Deary Ol'Coot]

You have a Marlin, but just know that many Trapdoor loads will do great.

Sorry you can't hunt with your 45/70! My RUGER with a 465gr Wide Flat Nose cast at 1650fps is nothing short of awesome on deer and elk.

Go with cast bullets of 400 or greater grains in weight and make sure you have proper bullet to bore fit.

I have shot lighter bullet when I first started with the 45/70 and while still laboring under the loading practices developed over years loading typical high velocity jacketed bullet loads, so I tested loads to just over 2500fps and hunted the first year with the 355gr WFN at just over 2300fps. HUGE!!!!!!!!!!!!! wound channel. Never want to see that again, EVER!

But no leading issues even at the high velocity point using the gas checked bullets.

If you have leading issue, meaning leading the builds up and is more then just light smears, you have a problem which could very likely be an undersized bullet.

Crusty Deary Ol'Coot

[Strtspdlx]

I wouldn't say I want a full case. I'm just concerned with proper ignition and repeatable shots. I don't know if it's necessary to put something in the case to keep the powder against the primer like you would with black powder.

[Crusty Deary Ol'Coot]

No problem with full cases as long as it is the proper powder and you have done a proper work up.

Then you will find few 45/70 shooter that ever talk about using fillers. There are just too many suitable powders and some like Unique are easy to ignite!

DON'T over think this!!!!!!!!!! Start with one of the many Trapdoor loads and go have fun.

Again, any trapdoor load listed in a reputable publication will be safe in your Marlin. Just follow the load recommendations and as said DON'T over think the situation. ZERO need to do that as way to many folk have walked this ground before you.

AND, just because it is a Trapdoor load doesn't mean that many of them wouldn't be hunting worthy!

Crusty Deary Ol'Coot

[RickinTN]

I wouldn't say I want a full case. I'm just concerned with proper ignition and repeatable shots. I don't know if it's necessary to put something in the case to keep the powder against the primer like you would with black powder.

I concur with Crusty. Unique is easily ignited and in my mind 12 grains with your bullet of choice which fits properly is a classic load. The Marlin 45-70 I've worked with recently likes bullets sized to .460". Keep in mind the trapdoor loads in the 45-70 almost drove the American Bison to extinction.
Take care,
Rick

[Bird]

load up a few cartridges with near max loads to around 40,000psi. Six rounds should be plenty enough to realise they are not pleasant to shoot.
Load the rest of your cartridges to trapdoor loads maybe to 1400 fps. You may not need gas checks, and they will be very comfortable to shoot.
Look at some ballistic charts for various velocity loads, and you will see that you will not gain a whole lot in the trajectory area.

[JimB..]

Many people like to see how accurate their new rifle is, so they shoot it off a bench. I find the guide gun with a stout load to be very uncomfortable from a bench and suggest that if you are new to large bore that you shoot it standing unsupported, at least initially.

[country gent]

A good bullet at around 1150-1200 fps will be more than suitable for paper punching and even hunting. The marlins work well with bullets up to 450 grns or so. I don't recommend the heavy loads to start the flinch they give you is to hard to get over most of the time. The trap door level loads made the 45-70 what it is. I Shoot BP loads at 1150-1200 with a 535 grn bullet out to 500 yds accurately. Knowing the trajectory is the big thing