High force pressure on virgin brass

[stilllearnin']

Hey everyone
I have some new starline brass for 6.5 cm.
I cut to length,chambered, full length size(habit) used an expander mandrel and bronze brushed the interior necks. K&m press is giving me multiple things at different times including high high pressure, an initial bullet catch with a drag and or multiple catches. I can't for the life of me understand why.....example no burs, consistent reloading process(though I didn't anneal prior), etc...here is the reloading data

.264 nosler cc 140
Neck bushing to .289
Expander mandrel at .263(bolt gun)
Case necks checked between .013 and .014

Here is my math

.264+.028= .292(no tension)
.289 neck diameter bushing the + .001 for spring back getting me to .290 for 2 thousand neck tension

Use the .263 expander then gets me to 1 thousand for my precision rifle

No idea why I have so much drag/tension/force

Any ideas or advice would be appreciated.

Happy shooting

 

[918v]

It’s because the brass needs dry lube. I like imperial graphite for this.

 

[BobinNC]

This ^^^

 

[ShtrRdy]

Squeaky clean brass and squeaky clean bullets like to stick together.

 

[LA260]

Throw it in the tumbler for few hours (corn or walnut) and you'll be good to go.

 

[RegionRat]

...and bronze brushed the interior necks...

Sometimes, this is too aggressive and it opens the door for what the others are warning you about - galling.
Using a less aggressive brush to avoid taking the necks to bare nascent metal is the goal.

Many soft metals, especially ones like copper and it's alloys, are very easy to gall if they are nascent (meaning a surface that has been freshly cleaned and contamination and oxide layers have been removed to expose reactive copper).

We encourage reloading rookies to brush the necks after a firing cycle or after annealing, but that is just to remove the excess crust that creates a higher friction coefficient. However, taken too far in the clean direction can often be worse since that adhesive friction and galling is very erratic. There is a Goldilocks workmanship to brushing the necks where too little or too much is bad.

Dry or wax lube treatments, residues from tumblers, residues and oxides from previous firing cycles, etc., all serve to "passivate" the neck so the bullet doesn't gall. Try not to go to bare metal, or consider a nylon brush with some graphite and see if your seating forces smooth out. Good Luck and in for the follow up reports.