Smaller bullets = higher velocity

[DannyinJapan]

If I wanted to get higher velocities from a 45/70, could I simply use a shorter, lighter bullet of the same diameter and the same amount of powder?
Say, instead of 405 grains at 1500 fps, 325 grains at 2100 fps ?
Would something like that work ?

 

[campbell]

I hear reloading manuals publish loads with a variety of bullet weights.

 

[The Bushmaster]

Dannyinjapan...He's right...Do you have a reloading manual like...Oh say...Lyman's 48th Edition? There are too many variables. Not to mention "old" and "new" rifles. Some requiring a lighter pressure loads to prevent KA-BOOMS...

 

[DannyinJapan]

I dont reload, Im just curious about the 45-70 being able to up its velocity with lighter bullets, but none of the bullets weights I could find were under 370 grains. Maybe somebody knows a lighter, faster yet safe round.

 

[rcmodel]

So far, you haven't mentioned what rifle you want ammo for.
So that opens the question of whether or not you have a modern gun like a Marlin or Ruger, or a 140 year old trap-door Springfield?

Anyway, you will run into rifling twist problems with very light bullets in the 45-70.

The guns are designed around the old standard bullet weight which is 405 grains, and anything lighter then about 300 grains is too short for the rifling twist.

This right here is as good as it gets for flat trajectory.
http://www.ableammo.com/catalog/product_info.php?products_id=79375

More info on 45-70 factory loads.
http://findarticles.com/p/articles/mi_m0BQY/is_3_46/ai_59281219


rcmodel

 

[Coltdriver]

Once you figure out which loads your particular rifle is suited for, see if it will put up with the Leverevolution rounds from Hornady.

They are, as you cite above, 325 grains and just over 2000 fps out the muzzle.

The problem you have is that with such a fat bullet the BC goes down the shorter you make it to get to a lighter round. The Hornady rounds compensate by making the round pointy with a polymer tip that is safe to use in a tube magazine.

 

[DannyinJapan]

Well, Id like to get one of those EAA double rifles, but I dont want to risk blowing it up with +P ammo, and yet I have been told that standard 4570 ammo isnt fast enough for the Big 5.
325 at 2000 sounds like it would qualify for even elephant.

 

[iiranger]

Welllllll....

What you suggest is exactly what was done in black powder days. Lighter bullets went faster. .45/120 had a 300 grainer at 1600, I think.
HOWEVER, if you refer to smokeless powder then you might find the lighter bullet not providing the resistance to burn that powder correctly.
.45/70 is a black powder case design and you will find case life is less than more modern/sturdy cases. .308, etc. Please be EXTRA careful.
I think Herc, now Alliant, had a trapdoor pressure [LOW] load with Reloader 7 powder and a 300 grain bullet at 2200 fps. If you are talking dangerous game, that is another consideration. Few are wounded by deer attack. You will want a 300 grain bullet that will hold together. But they are available. Equally important, you want to be sure that the shooter can place the bullet. A miss with any bullet is still a miss. HAPPY HOLIDAYS. Luck.

 

[Coltdriver]

If you can get close enough or you are good enough with the arc of a 45 70 you can take any game on earth with it.

That Hornady 325 grain bullet hits with just over one ton of energy at 100 yards.

That will punch a hole through anything you hit in North America every time.

The problem with 45 70 rounds is that the arc of the bullet is fairly significant. You have to get pretty familiar with a particular load to hit anything past 200 yards.

If you can get within 100 yards the good old black powder buffalo round of 70 graings of FFG under a 405 grain bullet will also down anything on the planet. Millions of Buffalo can not be wrong!!

 

[Brillo]

Here is a suggestion. Join Ammoguide.com. They list many loads for the 45-70 Gov. starting as low as 300 grains that have MVs above 2000fps. It's a great guide for the reloader but, as with all load suggestions, you should use it with great care and work up to the max loads always checking for over pressure signs. Be aware that Ammoguide consists of user supplied data and what works for one reloader may not be safe in all other circumstances. With modern firearms it's hard to run into trouble with the 45-70 using rifle propellants such as Hodgdon 335, especially with the lighter weight rounds.

 

[DannyinJapan]

The Remington website says :
For Use with SAAMI Compliant Loads Only (28,000 PSI / 28,000 CUP Operating Pressure).
Do you think the 300gr/2100 fps load will stay under that ?
If so, then I am good to go.

 

[Coltdriver]

I am not familiar with the capabilities of your rifle.

I would suggest that you call Hornady and ask them.

My Lyman book shows a 350 grain bullet driven at 2025 fps that generates 36,600 C.U.P. I have no idea what C.U.P. the Hornady rounds generate but I am guessing its going to be over 28,000 C.U.P.

So there is a good possibility that your rifle may not be designed for the Hornady ammo. Shooting over what your rifle is designed for can kill you or a bystander if the rifle blows up.

That being said, a 405 grain cast bullet over just black powder will go clean through a buffalo. So don't underestimate the capability of your 45 70 just because someone told you that it does not have the velocity of a 300 mag rifle!

The question is, how close can you hunt from? And, how willing are you to learn the arc of what you can shoot??

 

[DannyinJapan]

I was expecting to be within 50 yards or so..

 

[Brillo]

I forgot to mention another site that may be of interest to you with plenty of 300 and 350 grain loads that will take you over 2000 fps. My buddy shoots these types of loads in his lever action Marlin all the time. He likes the faster rounds for some reason. They are quite accurate in his rifle. Some like slow heavy rounds - others like fast light-weight rounds. It's a personal preference issue. Try them both to see what you like. Some of the comments above can be a bit misleading. There is no right or wrong here but just be safe in your approach.
http://loaddata.com/loads/45-70caliberloads.html