Originally Posted by Sheister
I've always seen brass uniforming as an incremental process. Each step of the process gets a small amount of improvement in consistent ignition which may or may not be noticeable by itself, but if you take each step and add them together once you get to your desired goal, you can notice the difference if you are paying attention and keep a few loads available without the improvements as a 'control" group...

Quite a few years ago I bought a flash hole deburring tool and started using it on any new brass or once fired brass I was reloading for the first time. The one I got has an adjustable tapered head to keep it centered in the case mouth and a tapered cutter for the internal flash hole with a tube around the exterior that acts as a stop when it hits the bottom of the case. Memory is the second thing to go, so I can't remember where I bought it... In any case, I found some brass would take a quick twist of the wrist to clean and deburr the flash holes and would remove very little brass. Others would take a couple turns and I would dump out several pieces of brass burrs that were removed. It was a pain doing 300-400 pcs of brass in a go, but you only have to do it once for each piece of brass so I keep it as one of my reloading rituals... wink I did notice once done the flash holes seemed more round and concentric once deburred...

What I found was that many of my more fussy cartridges became a lot more consistent with their groups and for the most part a bit more accurate. It wasn't a lot of difference, but enough to notice. Once I started getting a little more anal about measuring my loads, brass prep, seating bullets as straight as possible, and other things I'm sure most of us do, I did notice a real difference in how several of my rifles would group. But I believe that deburring the flash holes was a big impact on how my reloading improved my groups. Even if I did drill my flash hole, I would still deburr the interior as even the best drill bit will probably leave a bit of burr and i always thought that was the most inconsistent step in the whole ignition process... interrupting the primer flame shape with a burr IMO can cause inconsistent powder burn... I'm pretty sure I read that somewhere from somebody a lot smarter than me, but it makes sense IMO...

Bob

I have not gone from the case mouth side and deburred the inside of the case. It does sound logical. I'm going to rethink my load and bullet and maybe give it another go next spring. I'll have the winter to collect and sort brass then drill the primer holes. The biggest issue I did not think of was how the powder explosion affects the case itself. I was looking at primers and I probably should of been looking at the insides of the case looking for stress cracks.

kwg

For liberals and anarchists, power and control is opium, selling envy is the fastest and easiest way to get it. TRR. American conservative. Never trust a white liberal. Malcom X Current NRA member.