If you bump .006 repeatedly it will lead to case failure. With that much bump you are changing seating depth which is the most likely reason for the difference in accuracy.

Another great episode! Very interesting technical information.

Nice video.

Each cartridge will behave differently particularly as you go up in size. Great example of how there are misconceptions and myth surrounding best practice. The rule is, what applies to one caliber in one barrel won't necessarily apply to another caliber in a different barrel. 6mm by it's nature and particularly the 109 LRHT loves jump distance. Seems the greater the jump, the more the bullet likes it. I find this to be the case in my 6mm rifles from 105gn up to 115gn. I would've chosen the group with the flatter waterline though, which I believe was the fireform brass. Jack Neary has said on multiple occasions that new brass shoots best. Unfortunately for us, it's also outrageously expensive to shoot new brass every time. I would like to see what the cartridge does with 1.5 thou bump and 3/4/5 thou. That way you could map the different harmonic nodes. Great video!

A good example of how shoulder bump affects your jump- distance to the lands. Seating depth should be measured from your shoulder to the ogive as that’s the bit that matters. All you are doing is a seating depth test by changing your bump instead of the bullet depth. Stick with.002” bump and do a proper seating depth test.

Awesome video! Would love to see a photo of your waterline shots at 950yds after you made the .1 mil adjustment? Was the shot on the line? That 6BRA is the real deal! Thanks

Good shit man, I just ordered a Lone Peak Fuzion and decided to go BRA.

Good stuff

0.006" shoulder bump is ALOT of work on your brass.. i only bump my shoulders in my bolt guns between 0.000⁵-0.001⁵", for my gas guns i bump them all 0.001-0.002". If you want brass life you should only shoulder bump the absolute minimum possible, play with powder charge/seat depth/neck tension

Who is doing your barrel work? I have the same MPA but in 6.5 creedmoor. Looking to go to 6 br very very soon

Any chance I could shoot you an email and ask you a few questions about the 6mm BRAI?

.0015 to .003 bump is all you need, .006 is not gonna gain, your cases r swelling because of pr at the .200 line try some n135

Almost thought I saw a monkey fall out of the tree at 1:59