Lyman sizing die ?

[sac]

I have a Lyman 450 sizer with different dies. I just got a rcbs 45-270saa mould and cast them and went to size them to .452 in the .452 die and after sizing they are .453. was wondering if anyone has run into this before. The die is probably 10 to 15 years old. Should I get a .451 or another .452?

Thanks Scott

[Beagle333]

A different .452
Not all dies are equal and you certainly can't count on them being .001" oversized as a rule. If you find a deal on a .451, it is a snap to hone it to .452 though. And you know you would be exact, for certain!

[upnorthwis]

If they fit in the gun, I would shoot them to see if they work. Could also be what you are measuring them with. If you're using a calipers, you can easily be off by a thou.

[sac]

If they fit in the gun, I would shoot them to see if they work. Could also be what you are measuring them with. If you're using a calipers, you can easily be off by a thou.
I am using a micrometer, and I had my throats opened to .4525 in my ruger, and they don't slip in.

[Calamity Jake]

Hard alloy will spring back a little after sizing.
If .453 won't work for you then buy or trade for a .452 size die.

[JonB_in_Glencoe]

Have you used this 452 Die before?
if not, maybe someone lapped it out?

Also, the 270 is a long boolit (I have a GB clone mold), if you aren't pushing the boolit all the way down into the sizing portion of the die, the drive band will not be sized all the way down. I've run into that, when trying to use the top row of lube ports of the die with a boolit with only one lube groove. Have you measured the boolit base and compare it to the drive band?

[sac]

Hard alloy will spring back a little after sizing.
If .453 won't work for you then buy or trade for a .452 size die.
It is a .452 die

[sac]

Have you used this 452 Die before?
if not, maybe someone lapped it out?

Also, the 270 is a long boolit (I have a GB clone mold), if you aren't pushing the boolit all the way down into the sizing portion of the die, the drive band will not be sized all the way down. I've run into that, when trying to use the top row of lube ports of the die with a boolit with only one lube groove. Have you measured the boolit base and compare it to the drive band?

Jonb, I bought the die new and have used it before but never measured them because they where just for SASS shooting. Now I have this black hawk for hunting I want the most out of it and measured it. The base and driving band are all .453. I will check tonight how deep it goes down and maybe try sizing them again.

[Shuz]

What size is the boolit dropping from the mould? If it is .454 or larger, with a hard alloy, you may be experiencing "spring back" as another poster has mentioned. If they drop .453, I'd try them and see how they work. I routinely shoot .431 diameter cast boolits outta my .4285 Smith throats and get good accuracy and no leading. Alloy is Bhn 11.

[runfiverun]

umm.
453 would be correct for your 4525 throats.
I'd try about 5,000 cylinders full before I got all worked up.

[sac]

umm.
453 would be correct for your 4525 throats.
I'd try about 5,000 cylinders full before I got all worked up.

I will try them, I thought you where suppose to go under the throat size. My bad