Seating 40 cal from 9mm into a 10mm problem

[lukewmtdew]

I have such bad luck! Lol was trying to seat some bullets I made and it seems as if I'm forming the bullet as I'm seating it! The bullets start out looking like hollow points but end up looking like round nose hollow points! And the over all length was going up as I was working the charge up I started at 12 grains of Aa no 9 and was working my way up to 13.5 got to 13 grains and stopped will these be compressed loads? Maybe I should work up from 11 grains I'm using modern reloading as a source

Using Aa no nine and a 200 gr jacketed my data says starting is 12.2 max is 13.5

Whereas 200 gr xtP says start 11.3 max 12.5

[ReloaderFred]

You've got to remember that bullets swaged from cartridge cases are longer for the weight than bullets swaged from regular jackets. The only way around this is to trim the base rims off the brass prior to annealing, which is something I prefer not to do.

The longer bullet reduces the volume of the case, and this has to be taken into account when working up a load. I normally use data for a factory bullet that is quite a bit heavier than the bullets I swage from cartridge brass. In my .44 Magnum bullets, which come out at 230 grains using a .40 S&W case and a 158 gr. cast bullet for a core, I started with data for a 240 gr. bullet, but ran into extraction problems before I even got to mid-range loads in the manual. I them started using data for 265 gr. factory .44 bullets and got much better results.

If you're running into a tightly compressed load, then it's time to stop and reconsider your data. Accurate Arms #9 isn't going to compress a whole lot.

You can form a seating stem to the bullet nose shape by various methods. Hot glue works, as well as epoxy. You can also reform the seating stem in a lathe or on a drill press.

Hope this helps.

Fred

[DukeInFlorida]

Before you seat a bullet, put a proper powder charge in the 10mm case. Using a wooden dowel, put the dowel into the 10 mm case, and measure/mark the dowel, to indicate how far in the case the top of the powder is. Transfer that mark to the outside of the case, using the same mark on the dowel.

Now, hold a swaged bullet against the outside of the 10mm case, and adjust it to the proper overall length. Now, you can easily see if the assembled round is compressed one.

[lukewmtdew]

You guys are good! Thanks guys!