Fire Forming 100+ 45/70 for Two Rifles, Your thoughts?

[Themoose]

Like the title says, I need some experienced help on fireforming 45-70 brass for two different single shots... I plan on sorting out the brass by headstamp and see if there is a logical separation for each rifle... I know that I could use some of my cast bullets that I have, but I was given a few hundred 300 grain cast .459 lubed with SPG that I would think would be perfect for the project(save my lead and heavier cast bullets for load development). Being frugal(2 syllable word for "cheap") I was thinking about using up a lot of Triple7 or BH209 that I used for inlines before I switched back to black... I've read pros and cons about using "substitute" powders... also have read of using small doses of pistol or shotgun powder with fillers(scares me... one of the rifles is my nephew's Shiloh Sharps and I don't want to take any chances at all with it.

Any and all suggestions are welcomed...I'm not adverse to using real black, I would prefer to save it for load development and shooting after the cases have been fire formed. Any recommended loads for the 300gr. bullet, either black or substitute?

Thanks in advance to all for helping me out... it is greatly appreciated.

Kindest regards,

TheMoose

[NSB]

I'm confused. How do you "fire form" 45-70 brass. I have hundreds of 45-70 cases here and I've shot them out of seven or eight different 45-70 rifles I've owned/own. To me, fire forming a case is where you take something like a .223 rem case and shoot it in a 7tcu chamber to make it into a 7tcu case. All my 45-70 cases were purchased at 45-70 cases. What am I missing here?

[Conditor22]

Fire-forming a chase is firing a case in a certain gun (usually with a lighter charge and boolit) so the case forms to the chamber of that gun.

After Fire-forming (which you do every time you shoot), if you don't re-size the case the case will work great in that gun, work OK in guns with the same size or larger chamber but not in guns with smaller chambers.

the 300 grainers should work fine. I would go with a light charge and save on powder.

[Themoose]

Conditor22 is correct in what I am wanting to do.. I want the cases formed the the chambers of each rifle to try to maximize accuracy... I doubt that there is a significant size difference, but I am trying to gain what I can to develop consistent loads for each rifle.

[5Shot]

Personally, I would do some load work up with the brass as is, and then reload the promising recipes in the fire formed brass. An accurate load will still be accurate, just more so, in the fired brass. I wouldn't waste my time with the forming loads. If the bullet is sized for the rifle, there wouldn't be much to gain from the fire formed brass. JMO...

[country gent]

Work up a good load with your normal bullets and powder choice. Black powder is fine and does a great job of blowing out the cases. Fire them in practice or the shorter silhouette ranges 200 and 300 yds. They will do fine as is and may gain a couple grains capacity when formed. One thing on the straight walled cases when fire forming them is to have the bullet butting into or engaged in the rifling to help position the case correctly since there is no shoulder for this. I would also anneal the brass before loading this helps it to expand evenly. Last with these rifles and bullets loaded into rifling a loading assit tool is handy to seat stubborn rounds.

[Rattlesnake Charlie]

10 gr Red Dot, no filler.

[Gunlaker]

I'd just load and shoot them. You are going to see very little if any difference in the loads you develop with new brass vs fireformed brass. The only real difference is if you are shooting slip fit bullets with zero neck tension. In that case you'll need to fire them once.

I'd use real BP and start shooting!

Chris.

[NSB]

I own 45-70 rifles that none of which have used "fire formed" cases (no shoulder on the 45-70). I have several that will shoot five shots sub 1moa without fire forming them. I already knew what fire forming was, but it's a total waste of time in this cartridge being used in a single shot rifle. As mentioned by others, load a lot of different bullets and powders and see what your gun prefers. FWIW, I have two full pages on a spread sheet of loading data acquired over the last ten years or so trying different loads in several (seven?) different rifles. Put your efforts elsewhere for now and save the "fire forming" for when you're no longer able to try different powders, etc.

[rfd]

exactly what chris posted - bp load and shoot, no big deal. then you won't hafta mess with the white devil dust cr@p. :mrgreen:

an option that i do is use a BACO straight .460 plug in a lyman "M" die to expand the brand to *simulate* fire forming on new or brass that was used in other guns and has been sized. i also use a modified lyman taper die to slightly squeeze (not crimp) the case mouth if the bullet or PPB is loose. the bullet is still somewhat loose but won't fall out.

[Lead pot]

I'm with NSB with this.

I hear from a lot of shooters saying they firearm straight wall cases. What is there to form??? run the new cases through a full length sizing die load and shoot. You will fit the chamber with the cases expanding but your not forming anything.
A lot of shooters full length size their brass load and shoot a match with very good results.
Now before Jamison started making brass for the .44-90 BN and the .44-77 that is a bottle necked case I had to buy Bell .44 3.25" basic cases. They were straight wall cases .517"-.519" at the base and I ran them through a case form die putting a shouldered and necked to .468" and also through a base swage die I had to make so the case would fully chamber. This leaves a rounded shoulder like a Weatherby cartridge and this needs to be formed "fire formed" with the proper shoulder. When the case finally has the proper shoulder I can full length size or shoot them as last fried. Even if I full length size the case I'm not forming anything when I shoot.
Forming a round before the factory came out with the .35 Wheeling I took .30-06 cases and expanded the necks and that left the shoulder short of where it should be. Fire the case with the short shoulder and that fire forms the case.
You can take a .303 bn case and shoot it in a .40 cal chamber to blow out the case neck to a .40 and this would be fire forming a .30 cal. BN to a .40 straight wall case.
But saying your fire forming a new .45-70 case in a .45-70 chamber people will know what your talking about anyway :)

[Themoose]

No mas, no mas... I give up....thank all of you for your input............ I perhaps mis stated what I was trying to accomplish and it very well may be needless.. I do no that the fired cases I have been given do mic out with some differences in the base near the rim and also the case neck... I see the point of just going ahead and firing them... I will still sort them by headstamp and use different headstamps for different rifles.

thanks again,
TheMoose

[country gent]

Check them as is in the rifles if they chamber your good to go. If not full length resize them as close to the rim as you can get. There is a portion lost to the top of the shell holder and radius on the die mouth that cant be sized easily. If needed you can push the cases into the die with out the shell holder and out with a pin in a small arbor press to get that last little bit. You could even remove the radius from the die to get it all the way to the rim.

[NSB]

Moose, if you want to try something with the cases that might (theoretical) do something to make a difference, try this: Size the case about 1/3 down, not doing the entire case. Then anneal that part of the case. Some shooters do this to allow (again, theoretically) to allow the case to seal better upon firing. This may allow the case to seal better which may protect the base of the bullet as it enters the rifling. I don't personally think it's something that you're going to be able to measure, but what the heck. It can't hurt either. Half the fun is playing around with this stuff. Good luck.

[EDG]

If both rifles are modern rifles and of decent quality the chambers
may be nearly identical.
I have read of BPCR single shot shooters that do not resize brass to make it last longer. Their bullets are just finger seated.
I have a number of 45-70 rifles and I prefer to have my brass sized to grip the bullets securely.
I would just load and shoot your rifles and not worry about fireforming.
For light plinking loads I use 13 grains of Unique. Do not use Unique if you cannot guarantee you will not double or triple charge a case.
For heavier loads use your trapdoor loading data for 2400, 4227 or 4198. You only need 1100 to 1200 fps for lots of fun.

[rfd]

a new case or die sized case will never be the same as a just fired case. the fired case (call it 'fire formed' if ya like) will get blown out to fit the chamber, will have somewhat more internal volume, will have a larger mouth, will be ready to be cleaned, primed, drop fill compacted, wadded, compressed, and a bullet pushed in .. maybe the case mouth might need a tad of squeezing so the bullet will be concentric and not fall out, but there is still literally no neck tension. orient the brass in the chamber, fire the cartridge, then clean and rebuild without case sizing or expanding, over and over and over and .....

[EDG]

If your ammo is put together with unsized brass it takes almost nothing to make a mess out of it. Drop, turn over or just bump a box of finger seated bullets and you will have spilled powder and bullets to clean up.
What appears to work perfect in theory does not work so hot in practice.

[rfd]

using a taper or sizing die will almost always be required to retain the greaser or PPB. this is more of an issue with a bore rider PPB and usually requires removing about 3/8" from the bottom of a taper crimp die in order to squeeze the case mouth slightly.


https://www.youtube.com/watch?v=oaWbpStoEvA

[sharps4590]

Wasted effort and components.

[Lead pot]

EDG

If you shot black powder you wouldn't have the problem you mentioned :)

[country gent]

With the right sized wads and compression of the black powder bullets can be hand seated the bullet cant seat deeper its supported by the powder wad column, Powder cant spill since the snug fitting wad and compression are holding it in place. My bpcr ammo is hand seated bullets and only the lightest of tension after seated. Bullet still spins in case and can be pulled by hand. I have had them come out handling and with the compression and wads no spilled powder.

As RFD stated with PP bore riding bullets most dies don't size the neck down enough even for this type of fit. Most bore riding PP are wrapped to a dia of .448-.450 and most dies are set up to size down to around .455-.456 inside dia of the mouth. Here is where a bushing die is handy.

[MostlyLeverGuns]

I usually take these steps with a batch of new cases. Uniform primer pockets, deburr flashholes, partially size to insure necks are round, neck expand with step/M die and load, load and shoot at shorter ranges, 200 yards or less. After the first firing, 'neck size', measure case lengths, trim all cases to the length of the shortest, anneal case necks, chamfer and deburr case mouth. Weigh the cases and separate into case weight ranges, weight range is your call. Expand necks and load. Keep cases separated for the different rifles.