6.5CM Brass to 6CM

weisenbu

Lil-Rokslider
Joined
Aug 24, 2017
Messages
255
This may be a dumb question, but I’m going to ask anyways…

I have a bunch of never fired 6.5 CM Lapua brass. I also have a Hornady 6.5 CM match grade full length bushing die with a .291” bushing for my old 6.5CM rifle. Since I no longer own a 6.5CM rifle but do own a 6CM rifle, could I simply buy a smaller bushing (e.g. .269”) and insert it into my 6.5CM die to resize my Lapua brass to be used in my 6CM?

Would it be smarter to also buy an intermediate bushing (e.g. .280”) and resize the neck in 2 steps?
 
I resized 100 Hornady 6.5cm brass to 6cm over the last 2 nights.

I spray the body of the cases with one shot and then dip the necks in graphite and size them in one pass with "regular" dies, then trim and tumble.

I do the same thing with 22 creedmoor.

I don't use bushing dies but I imagine whatever is the equivalent bushings size will take you straight there in one pass.
 
I believe lapua 6cm has slightly thicker necks than their 65cm. The 65cm neck once sized down will gain a lil thickness, so I think they'll land pretty close.

Using a bushing die, will leave a lil bit of the neck unsized, it's not a big deal as it'll form out upon firing. However it MAY cause interference on the first firing via HEADSPACE, maybe not as well depending on how much bump your using.

I use 271 bushings with my 6cm lapua brass, gives me 0025-003 neck tension. Making a pass from 65 to 6mm with a 271 bushing will likely size it a fair bit under the 271 diameter due to the big step. Either use a slightly larger bushing for correct sized neck, a mandrel to bring them back to desired diameter, or use the expander ball. I personally don't use the expander ball on any my bushing die, I just use the appropriate bushing for my desired sized neck, which is generally 002-003 under a loaded case neck diameter.
 
A 6.5 haas about 8% more brass in the neck than a 6mm so when sized down would be about 8% thicker, or .001”ish thicker, so not much. Should neck down easily in one step.
 
But lapua 65cm VS 6cm is 7% thiner in neck wall thickness, so it's gonna be lost in the noise. Stuff is likely all formed from same cups, hench why the smaller neck has more thickness.
 
Back
Top