loading old speer 180 rn

[Saxon]

ok have searched and not found results
need to check load data that does not exist for what I can find

old speer 180 grain rn with flat bottom
measures 1.100
closest I can find thanks to delets https://www.jbmballistics.com/ballistic ... gths.shtml
is sierra 180 rn with flat bottom that measures 1.092 and list a COAL of 2.110

did some dummy rounds @ 2.170 and feed ok with two small feed ramp marks but still feeds
this leaves about .206 in the case neck
if I use sierra's coal that should leave .266 in the neck

this should work correct?

[dellet]

In theory that will work, velocity/pressure might be a bit low with less bullet in the case. That might cause cycling issues, but no safety issues. cycling issues are easier to fix when things go wrong than safety.

You can get a good idea of max cartridge length without any special tools.

If you take the expander out of your sizing die and size a case this will have a neck opening around .302". Insert a bullet upside down in the case and measure. Use this as a starting COAL to make a dummy round. If you pull the bolt and insert that into the chamber with finger pressure, it should stick because it will be jamming into the lands. Bump the length down a few thousandths at a time until the round drops out of the chamber under it's own weight. Somewhere between the last length it stuck and fell out is max length.

If what you have already made up will do that, great. But if not you will want to shorten them.

[Saxon]

thanks dellet just wanted to be sure,
not used to seeing (as a few on here) seating depth based on powder charge
for 300 blk.
done oddles of reloading for 30-06 bolt guns and seating just off the land and all but this is just wired
to do it this way, and just wanted to be sure I was not crazy

[dellet]

thanks dellet just wanted to be sure,
not used to seeing (as a few on here) seating depth based on powder charge
for 300 blk.
done oddles of reloading for 30-06 bolt guns and seating just off the land and all but this is just wired
to do it this way, and just wanted to be sure I was not crazy

This all goes back to when the cartridge went mainstream. Right in the middle of the biggest component shortage in the history on firearms. If it was a .308 bullet, it got tried in a Blackout. There was not a lot of published data and people were getting in trouble swapping bullets. Think about the probably 100 plus available 150 grain bullets and trying to load a 30-30 flat nose the same length as a Berger VLD or just to opposite.

Pressure signs and popped primers were pretty common with even starting loads. Keeping the fill ratio the same and the bullet out of the lands is a pretty basic concept, but largely ignored.