Fire forming new 45-70 brass with Smokeless

[Stormin.40]

I will be loading up my forst BP 45-70 rounds for an original 1873 Trapdoor rifle, its in great shape. I was wondering if it would be okay to fire form some of the new shells using smokeless powder, H4198 is what I planned to use.

Thoughts?

 

[Chawbaccer]

Why would you need to fire form the cases?

 

[Foto Joe]

My question is what would you be "fire forming" them with? Using smokeless in an original 1873 Trapdoor in my opinion would be a bad idea. If you fire form them in a modern gun then they won't be fire formed to the Trapdoor.

I'd use a starting load of say 40gr of Black Powder plus filler and fire form them that way. Besides, what fun is shooting smokeless out of a 45-70?

 

[scrat]

you dont really need to fire form the cases. Fire forming cases is good for bottle nose type cases. The 45-70 is straight walled. After shooting them you will still need a sizing die as the neck will need to be re shaped. Otherwise you will find you will have loose bullets in some of your cases.

I you have a lee loader or plan on neck sizing only then the term fire forming is done. As when you shoot the shells they will only fit the chamber of your rifle. Thus neck sizing them only will still make them only fit your gun. Now if you full sized the shells after firing then they really are not fire formed any longer as you are putting the case back into sami specs. Also i would not be trying to fire form them with smokeless powder. the powder you are going to use is what you use.

 

[Stormin.40]

Most of the literature I have read regarding BP cartidge reloading recommends only neck sizing and since these cases will only be shot out of this particular gun I thought smokless would be an easy way to do it. I want to work up the a load that this particular rifle likes and thought I should have formed brass before I started checking the accuracy. Seems I was wrong, I will just load up as planned, thanks.

 

[scrat]

Stormin i load and shoot both smokeless and Bp. What i have found is this. 1 they dont mix mix at all. if your going to shoot smokeless then shoot smokeless. if your going to shoot bp shoot bp.

Smokeless loads are a lot higher in pressure than any bp. This high pressure can cause spider cracks in cases. Even though the cases are made to expand and contract that high pressure does a number on the cases. When loaded correctly and keeping your loads on the lighter side within the proper specs brass will last longer. When you pull the trigger on a gun when the primer ignites the powder the case expands and contracts in a high rate of speed. Something that will not happen with the same amount with black powder. Same time not all guns can you just neck size. Some you need to always full size. this includes some tube fed guns. As fire formed cases can sometimes get stuck in tubular magazines as well as some regular magazines.

 

[buttrap]

No smokeless laods are not higher pressure than BP loads at all unless you are a idiot on loading. They may have a longer curve on the pressure but its a lot lower PSI with a proper load.

 

[PapaG]

That trapdoor isn't going to be accurate enough for you to see the difference between "fire formed" and right from the box cases. Load 'em up with black, seat the bullet, crimp lightly and have fun.

 

[dprice3844444]

use the 405 grain lead bullets.sights are calibrated for those loads

 

[Pete D.]

huh?

Fireform? Why?
For a Trapdoor...again why?
Neck size? How do you neck size a case that doesn't have a neck?
The Lee loader partially sizes the case - as does the Lyman 310 die - Ok...that ain't neck sizing.
Why start with 40 grains? Load the case with what amount of FFg it will hold, seat a 405 and go shoot.

For most of my BP 45-70 loads, I don't size the cases at all. Drop the powder (long tube....compress a bit), put in a grease cookie, seat the bullet, crimp lightly.
Pete