size or not ?

[Franklin7x57]

I've got a RCBS sizer and size my pistol bullets. Right now I only cast for pistols. I've got a 45-70 carbine barrel That want to cast for, Times are tight, and I'd like to just cast, use a liquid lube and shoot. I'll be shooting light trapdoor loads.
How big a diameter can I shoot on average, I haven't slug it yet, can I get away without pressure rising? Which lube with WW?
I'm trying to piece it together, mold, then sizer and top punch as needed.

[geargnasher]

Size or not? Depends. One should always strive for good fit to the gun, and since there are so many variables as to groove diameter, mould diameter, alloy shrinkage, you should probably count on having to size your boolits.

But we really need more info than that, Franklin. The .45-70 isn't known for having consistent groove size, the first thing you need to do is buy some large lead "barrel" sinkers and slug your bore. Once you know what you have, then decide on boolit weight and style based upon distance you plan to shoot and what you are shooting, whether paper, silhouettes, or meat. Once you get that straight, decide if you're going to shoot BP or a substitute, or Smokeless. THEN you can buy your mould, sizer die, top punch, and worry about lube.

I'm sure plenty of folks use liquid Alox with good success in their .45-70s and you will probably hear from them shortly.

Gear

[dromia]

As Gear says more info would be good. When dealing with cast boolits its always better to deal in specifics rather than averages.

You need to find what works for your equipment and components, average in equals average or less out unless you are lucky.

Why trust to luck when you can control your outcomes by being specific.

[Franklin7x57]

do you think there would be any danger in shooting a oversize bullet? If your bore mic out at .458 and your bullet runs .461. With light trapdoor loads would there be pressure signs? How much oversize can your bullets be? .003+-

[Casting Timmy]

I shot a 405gr flat nose from Lyman, mine casts at about .458-.459". I run it through a .458" sizer and it does more lubing than sizing. Lubing I use white lithium/beeswax/ little parafin....whatever you pick, have fun! There might be a group buy going on here for a 45-70 mold. Honestly you might consider that, it definitely goes faster if you have a couple of holes in the mold as opposed to just one.

[EDK]

Why not get the LEE hollow base mould? If it will chamber UNSIZED in a dummy round, give it a couple coats of LLA and load them up.

It would help to know what type of rifle you're using. I size to .460 for my MARLINS and am going to lap the die out to .461 before I use it again. FWIW, I go to .431 for ALL my 44 rifles and revolvers.

[largom]

Buy a mold for the boolit weight you want. The 405gr. RCBS shoots great in all of my 45-70's. After you cast some boolits and let them age a couple of weeks see if an unsized boolit will fit into a FIRED unsized case [fired in your gun]. If they fit load one up and see if it will chamber easily, if not you will need to slug your throat and bore. I have several rifles that take unsized boolits. Being a few thousands over bore diameter is usually a good thing.

Larry

[Franklin7x57]

I've got a T/C 16" carbine barrel. I'll get the sizer and top punch sometimes in the future if needed, just trying to save some money and just piece it together. The sizer and top punch are more than a Lee mold. I was thinking about the 340 grain mold first.

[geargnasher]

I've got a T/C 16" carbine barrel. I'll get the sizer and top punch sometimes in the future if needed, just trying to save some money and just piece it together. The sizer and top punch are more than a Lee mold. I was thinking about the 340 grain mold first.

Franklin, as much as you want to you can't cut corners on boolit fit.

Do yourself a favor, slug the barrel FIRST and get an accurate measurement of the slug. If you need tips on how to do this either search here or pm me, I'll be glad to walk you through it.

Then decide which mould. The Lee 340 grainer is rated at .457" and the one I have casts exactly that with WW alloy. If your bore slugs .458" you will most likely have major leading issues and poor accuracy with the .457" boolit and you will need to buy a mould that casts .459"+, like numerous 400+ grain moulds do, including the heavier Lee moulds.

Once you get that sorted out, you might consider buying a $15 Lee push-through sizer kit which will save you the cost of lube and top punch. the Lee Alox should be fine for shooting in a new, modern barrel like yours that's not too long.

Gear