Sizing question

[Midohhntr]

Ok I read thru several older threads on how bullets increase in size over time, I just acquired a Lee 457-340 F for my 45/70 and cast a few the other day. Surprising they are dropping just slightly less than .460, I run them thru my sizing die @ .459 and they are getting sized to that diameter. My question is, if they increase in size over time could I size them now and say after a month or so they would increase to the proper diameter ?

[Hickok]

I don't think they will increase to any degree that you want. What type of rifle do you have?

Try .459" in your rifle before you get anxious about needing .460". It may be a tack driver.

If you need .001" more inch from your mold, you can "beagle" the mold, or simply powder coat your boolits. Powder coating will put you @ .460" easily.

[Winger Ed.]

If they go through the sizing dies with noticeable resistance, they're being properly sized.

I never worried much about them 'growing' and have got stuff I sized and lubed several years ago and finally loaded.
It shoots just fine.

[RickinTN]

The mold you have is a bore ride bullet. The major diameter of the bullet can be taken care of now, or later with your izing die. If the bullet grows very much the nose may not fit inside your bore? or it may fit better? Only you would know by measuring. Some bullets grow, some don't. It is dependant on your alloy. The only way to tell is to cast some now measure, and measure at a later date. I have 3 Marlin 1895 rifles chambered in 45-70 and I have the Lee 340 grain mold you mention.
The nose will only fir in my older 1895, the one from about 2005. The nose is too big for my later 1895's, the two manufactured in either 2019 or 2020.
Good Luck to you!
Rick

[Rcmaveric]

Honestly.... i cast the bullets and wait 2 weeks for the BHN and everything to stabalize then size. Before in figured out high and low stock I never worried about them growing too much. I never had a problem sizing and loading and then shooting the ammo over a few months.

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[Midohhntr]

Thanks all, the rifle is a Marlin (Remlin) 1895 bought 3 years ago. I had some 350 grain Missouri bullets supposed to be sized at .459 but I found that running a few thru my .459 die would barely make a mark on them, undersize a bit. I have a NOE 396 grain mold WFP, these shot well from the Marlin. I shot some Winchester balistic silvertip 300 gr. these are 1 1/4" @ 50 yds. I loaded a few from the Lee mold this morning with 26 gr of sr4759, accuracy not good at 4" @ 50 yds, about the same with the Missouri bullet. I'm trying some different powders next.

[Winger Ed.]

. I'm trying some different powders next.

My 2002 issue, Marlin long barreled CB seems to like IMR 3031, 4198, and even holy black FF behind a RCBS 405..
Keep tinkering with it, it'll make ya proud.

[RickinTN]

I have found the easiest way for happiness in both 444 and 45-70 Marlins is a mold from Tom at Accuratemolds in the weight of your choice with his Marlin nose. They are not a bore ride design and work very well for me. With the Lee bullet you are working with you have two critical diameters....the body diameter, and the nose diameter. Many Lee molds won't cast large enough in the body for a Marlin rifle not to mention the nose should have a snug fit in the bore also. With one of Tom's bullets with the Marlin nose you only need be concerned with the body diameter of the bullet, I suggest .460" for the 45-70, and success is usually not far away.

[robg]

if they fit in the case and chamber in your rifle dont size them at all