Size RD 44-265 GC for micro groove Marlin?

[smkummer]

I lucked out getting this 6 cavity mold. Just now getting around to using it. Wow, the accuracy of the load with IMR 4227 at over 1500 FPS out of my mid 70’s marlin is spectacular. These unsized bullet do budge my cases a wee bit but chamber. I see that lee is offering a overrun of .432 sizers. Should I get one for more consistent bullets? These bullets are dropping out at about .433.

Also I am about to this load in 2 Ruger super blackhawks. I know mine has a .4305 groove diameter. I am guessing good results as well.

Thanks ahead of time.

[farmbif]

interesting. today I loaded a few 265 grain gas checked boolits, cast in mp 432640 mold, in 44 mag with 4227 and shot them through an older marlin 1894. I lube sized to .431 and had no leading or problems. I'm starting out with 18.5 grains 4227 and tomorrow will work it up to at least 20 grains

[smkummer]

My load is 22 grains IMR 4227 and about 1500 FPS. My bullets are dropping out .433 and more when I rotate in the calipers. My concern, if it’s a concern, is that .431 will loose any surface hardness from water dropping. Maybe I don’t need concern with a gas check.

Just checked my throat diameter on my mid 70’s RSB. .4325. With a groove diameter of .4305. I probably can’t go wrong with either but I am leaning towards .431 so my cases don’t bulge.

[Nobade]

I wouldn't size them at all. As for bulged cases, that's because the sizing die is too small. Carbide I bet? The steel ones don't size down as much and cases last longer.

[EDK]

NOE has a sizing system similar to the LEE PUSH THROUGH, but more diameter options. There is a sizer body and the additional bushings are under $10 each.
I'm using 432 in my 24 inch MARLIN COWBOY RIFLES. I have the RANCHDOG, the NOE clone with conventional lube grooves, and the MIHEC 432640...plus a bunch of others accumulated over the past 50 years of casting.