What would you recommend for single digit SD’s? Is there additional steps I should be doing? I use the same process for my 6.5PRC and repeatedly get single digits. I will say that I do use Lapua brass for those though.
My process starting from post-firing:
1) Deprime
2) Clean in ultrasonic
3) Anneal
4) FL Size
5) Neck lube with moly
6) Mandrel
7) Trim
8) Neck lube again
9) Charge
10) Seat with an arbor press and LE Wilson seaters
As far as cleaning, I run a copper cleaner through the bore, followed by a brass brush and then clean patches until dry. Then another wet patch that sits overnight. Dry patches until they come out clean and then finish with a lubricant.
Thanks
Three things:
1) If you're not using something that attacks carbon, then it is likely you've got some buildup going that could be causing what you're seeing. Get a good carbon cleaner and run patches through using the process I outline below - but let sit longer. Or you could plug the end of the barrel, stand it up with muzzle down, fill it with some carbon solvent, and let sit overnight, then do the process.
2) I only use brass brushes when absolutely necessary. If you scrub a barrel enough with them, it will negatively affect the barrel. Same thing with abrasive cleaners.
3) You might be getting some copper buildup as well. The process you're using will get some copper out, but certainly not all.
My process:
1) Run two wet patches soaked in Boretech Eliminator - I mean SOAKED
2) Let sit for 15 minutes or so
3) Run a couple dry patches through
4) Repeat the above steps until you get only very light blue (or none) and very light/no carbon.
Then:
5) Clean behind the lugs
6) Mop the chamber
If I'm fighting carbon, then putting patches around a used nylon brush (vs. a jag) will put more uniform pressure against the barrel and seems to be more effective in pulling the carbon out.
If I'm fighting a carbon ring in the chamber, then I put in a +1 size nylon brush (e.g. for my 300, I use a 338 brush) into the chamber with a patch around it soaked in carbon cleaner. The bigger brush + patch will be too big to get into the barrel, so stops at the end of the chamber. I let that sit for a long time (overnight usually), then twist it in the chamber. Repeat as necessary. Carbon rings are a bitch to remove, but I've found this to be at least somewhat effective.
Lastly, I just reread your original post. You mention finding a velocity node. I do a lot more ELR than anything else, so I care about SDs more than someone doing PRS, as an example. My definition of a velocity "node" is one that gives me the best SDs, not the best group size. Once you find that SD sweet spot, then tune for group size using seating depth.
On my 300's new barrel, I found a velocity range that's delivering good SDs, then on my last trip to the range I did a seating depth test (then validated at 500 yards with 5 shots - then 850 with a bunch - no grouping pic because it was a frikking bog out there and I couldn't get to the target):
