Help! How does this crown look?

[VikingCruze]

Several thoughts here that might help, for you to consider.

Biggest thing is I am a big proponent of using chrony to isolate good vs so-so barrels. Nodes will show up at pretty much known MV ranges for barrel length and have small SD's. So if you have one of those low-SD loads concentrate on that load, and re-check its MV/SD data in a couple of shooting sessions. If the low SD remains, then play with coal by 0.010's to see what length gives the best group. If that will not group then something is loose, either mechanically or with your hold technique on that gun. (Are you shooting w/ bipod on a bench? I've stopped using bipod at the bench and use only benchrest and sandbag now for bench. Maybe you've already covered this but I'm listing things to think about with no assumption on your techniques.) Since you tried several scopes I'm thinking it is not internal to the scope.

The bottom row of shots seems to be about 1" give or take. I think I see some what I would call flyers in some of the other groups... the latest issue I've been working on, and at least some flyers come from "cheek weld" -- never understood what that was until I started fitting stocks with some sort of riser so I could get a solid perch for my fat head (LOL!!), and steady sand bag underneath the stock at the rear. So if the scope rings are torqued, the base is torqued, the barrel is torqued, gas block sealed well/tight and the trigger is consistent with clean break, the rifle should shoot consistently and we're back to the load workups.

Me personally I'm not fond of TAC for heavier pills, find some use for it in the 90-100 ranges. I'd try as mentioned, XBR or H335 with some 100 gr eldm's, maybe even XBR with the 123's but be keenly aware it can spike on 123's at ~28.5 or a bit less. CFE 223 or even AR-comp with the 123's like sst or eldm, ARC not above 28.0 in an AR, CFE is listed for sst up to 31.2


In case I missed it, do you have some chrony data on any load ladders? not just a single load but a range, one bullet, one powder, one case/primer for each of a couple ladders. I'd like to plug it into my spreadsheets and give a look-see.
What MV/SD data did you get on the 123 Black rounds?

Gray fox,

Thanks for the solid advice. Unfortunately I don’t log data into my book until I can repeat and verify a load so I don’t really have much to share except a few index cards on my bench that haven’t made it into the trash. I didn’t have the Crono setup for the factory loads; that’s probably worth doing so I’ll pick up another box. On my last index card I have 27.9G of TAC and 123SST’s yielding the lowest SD of 11.5 with an ES of 30 for a 5 shot grouping. This was with the SST held .010” off the lands. I used CCI450’s and the average velocity was 2450. If I remember correctly the COAL was about 2.2525”.

I have XBR but I get ejector marks at 28 grains. Have you ever noticed less accuracy when reloading brass with pressure signs vs those without? This week I’ll pick up a pound of CFE223 and ARC for the 123 I would prefer to shoot for long distance. We shoot out to 1300 yards on my buddies farm. We’ve got 12 - 16” steel targets spread out with hit indicators on all steel past 800.

I tried flexing my handguard and I can get the screws on the clamp on gas block to touch which was surprising so I’ll get that fixed by Dremeling part of the heads off. I’ll have better data this Sunday. I’ll also try another lower I have to see if it’s a cheek weld problem but I’ve have three friends that all shoot sub 1/2MOA try it as is.

Thanks