Newbie reloading questions

[Ed333]

While waiting for my Browning BPCR 45-70 to arrive, I am itchy to start ordering reloading equipment/components (the old kid in the candy store syndrome). I read a post by Lumpy Grits on using fire-formed brass, and I thought it meant he did not re-size. (Lumpy answered in the negative, he just resizes 'lite'.) Can I get away with not re-sizing? Just go with relatively loose neck tension, or maybe crimp it?
Let me back up, I will have only the one 45-70, so all casings can be matched to that chamber, I am going to start with smokeless powder (any recommendations in addition to 'stick with BP"? I have Varget, IMR 4895, H380 and H322 on hand, none of which do I see mentioned much). Initially I am going to be shooting at 100 yards from bench with front rest and rear bag, and I am not sure if i need the heavy weight bullets at that distance.
When loading for my F-class 6mmBR, I measure base to ogive, and seat the bullet for about a .030 jump, which seems to work well with the Hornady A-Max/Varget/Savage Model 12 combo I use. Any point in measuring base to ogive on the 45-70? Or just COL? I have a Hornady (Stoney Point) tool for measuring chamber/leade length, should i get the modified case for 45-70?
I have also picked up on the idea that I should avoid that factory Hornady flex tip ammo, because of differing case lengths. I figured on shooting some factory ammo and getting my brass that way, am I better off to just buy new brass, and if so, which brands?
And I have a mess of magnum large rifle primers, any reason not to use them on 45-70 cartridges?
My reloading manuals do not mention the Browning 1885 Highwall when they give their three different levels of recommended loads for different specific rifles. Will the Browning BPCR handle loads for the Ruger No. 1 level, or should I stick with the middle ground lever gun loads, or even the trapdoor/rolling block section?
I'll stop there for now. I have the buffalo gun books from TexasMac and Venturino on the way, but I don't know if they are going to be of much help on reloading questions. And I realize I am an outlier in not going with BP right away, but hey...
thanks, Ed

[Semtav]

Not if you are using smokeless. I do with Bh 209, but I''m not sure if anyone calls that smokeless.

[Don McDowell]

Ed shooting blackpowder it likely won't be necessary to resize those cases. The chambers on those rifles are pretty tight.
However shooting smokeless and some of the subs the cases might expand a wee bit much, and resizing will be in order.
Trapdoor section of your loading manuals is plenty for anything a 45-70 needs to do. Of the powders you list varget and 4895 likely the best place to start.
You don't really need magnum primers, but if that's what you have then go right after them.[/i]

[J.B.]

Are you planning on casting.. or at least shooting cast or swaged alloy bullets ? This will factor into everything also. Varget works well... as does RE-7. The lighter your bullet ..the shorter ..and in the case of 45 cal.. makes it hard to seat it out unless the bullet is in the region of 450 grain minimum. You arent going to need huge bullets to get accuracy at 100 yds but as the distances open up..the shortcomings of the 350-450 grain become ( or they did for me anyway ) evident. The 1/18" twist the rifle has is set up for bullets in the 500-550 grain region anyway. As for the strength of the action, having had both a Browning and a Winchester BPCR .. you'll be safe with the warmer loads... but you may not want to shoot them a lot and they may end up being counter productive. My Browning was a tack driver with the Lyman Postell and RE-7 and loads were fairly moderate. Redding would be my pick for dies and once you're shooting then decide on neck sizing vs no sizing / slip fit or neck tension ..etc etc. The hole is as deep as you care to dig it...if you get my drift.