Undersized mould RCBS 45-300-FN

[WARD O]

I would imagine that this topic as been discussed in detail elsewhere and if someone can lead me to that discussion I would be grateful.....

I have an RCBS two cavity mould 45-300-FN and it is a gas check. I would like to use it for the 45-70 Marlin I am planning on acquiring shortly so I decided to cast up some bullets last Friday and get them ready.... I made up some alloy of about 16/1 and cast up a couple of hundred bullets. When I come to mike them - they are running about .456. Running them through the .457 sizing die will not even secure the Hornady gas checks. This just isn't going to work!

Anyone care to offer suggestions?

THANKS for your help
Ward

[rockrat]

Mines the same way. Thinking of sending it back to RCBS

[Ben]

Send it back !

[44man]

Yes, it is too small. you might need .459" to .460" for the marlin. I would not even mess with a .457" die.
Very few 45-70 guns can use .457" boolits and a .456" boolit is just not right.
My big gripe with factory molds. TOO SMALL!
Rapine has selections of each boolit in different diameters. A very smart man that understands.

[leadeye]

I might be interested in buying them, I size some .458 molds down to .454 or.452 if I like the shape. I have just the opposite problem with my RCBS 452 300 SWCGC, it drops very large, about .457-.458.

[WARD O]

That's what I'm trying - sized some of them down to .452 and loaded them into the 45 Colt for use in the Ruger. Will take them out to the range soon and give them a whirl and see how the accuracy is fairing.

Just wasn't quite what I had planned on......

[WARD O]

Well I sent it back to RCBS three weeks ago and last night I received a brand new replacement. Will try this one in the next week or two and hopefully it will be large enough to work out in my Marlin 45-70.

Ward