The scratches on the bullets before I marked them with a sharpie must have been coming from something else because the ones I marked with a sharpie did not show evidence rifling but I believe the added pressure it takes to chamber the loaded cartridge is due to extractor pushing the shoulder into the chamberLooks like the scratches are from loading from the magazine.
I've never worked on a howa, but I doubt is too difficult. It's probably not necessary either.
Just measure a fired case from the head to the datum line using a headspace comparator, then like GreggC said, slowly start turing you FL sizing die down.
You'll feel when you "bump" the shoulder.
now measure that case. Zero your caliper with the comparator in it before you do any of this.
You'll get a little spring back so you'll probably have to go just a little bit more,
measure until you move the shoulder .002.
check a fresh piece of fired brass and make sure you get the same results with one movement.
Nothing in this world is 100% reliable.
They will be just as reliable as any other round you can build for it.
I should've specified... is bumping the should back as reliable as as standard FL sizing when using the cartridges I the field?
I think you're over stressing it a bit. In my experience in hunting and with hunters I have seen one failure to chamber issue. The hunter was a new reloader and had not bump sized his cartridge properly. This is one instance in many days at the range and out hunting. The biggest thing with reloading is be meticulous, pay attention, dont be distracted, and check all your specs as you go. If you'll do all this you'll be fine. Like L.Sherman said: If you wanna know for sure chamber the brass after you resize them. Then there really isn't any question if they will function properly. I wouldnt stress it either way, bump size or FL size. The hunting rifles I FL size shoot well under .5 MOA and my long range rifles I neck size shoot under .5 MOA. You'll be fine man with either method especially if you'll be meticulous while making the rounds. Good luck.
I have picked up range brass that has only made it 5 firings, but brass I purchased off the shelf I have never ruined one yet. I have some 6.5 creedmoor with 8 and some 270 with 10. I anneal after every other firing and trim when needed. I would suggest quality brass like lapua, they will pay for themselves with the additional times you can load them. I don't shoot near as much as some of the people on here, most of my shooting is coyote hunting, prairie dogging, the occasional rifle hunt and long range shooting.
How much shooting will you be doing a year? If you're shooting a lot, I would make the transition to bump sizing down the road. For now getting the basics down solid and learning how to do load development would be a great start. If you have any questions as you're reloading you can PM me and I'll do my best to help you. Good luck.
PS, I no longer pick up range brass to reload, I pick it up to trade with people for new brass.
If you run quality brass and anneal after every 2-3 firings and don't run loads hot enough to kill your primer pockets 10+ is not out of question