Multiple accuracy nodes?

[mroels]

Reloaded first .308 for my 700. Using RAM TAC CCI BR2, and 168gr A-max. Went in .5gr steps from 41gr to 43.5gr. Sweet spot was between 41.5 and 42, solid 1/4moa. Then it opened up really badly, but the 43.5 started to close up again. Max is listed at 44.2gr so is this something wirth pursuing to hit another accuracy node with better velocity? There were no pressure signs at 43.5.


Another thing, I'm getting a new stock this week. Will that affect loads?

[joelogic]

You shot a 1/4 MOA with a 700 while working up a load? Thats pretty awesome.

[mroels]

I am pretty awesome It was more like .35" doing a round robin. The worst group was 1.5". I'm probably going to redo these loads with a bit more neck tension. Plus I didn't like this method of testing loads due to crease fires making barrel temp very inconsistent.

ETA: I'm not taking credit for that group btw, I've just been blessed with a rifle that shoot honeycomb clusters all day of given decent ammo. Guess I caught the 700 factory on a good day.

[rsrocket1]

The stock will theoretically affect the load, but in reality it probably won't make a measurable difference unless one or both are already affecting the accuracy. If the barrel was and will be properly bedded or floating, then no difference.

Take a look here. It's a pretty interesting read and for spreadsheet nerds, there's even an excel spreadsheet to predict the accuracy nodes if you have QuickLoad. Does it work? It was pretty close for me with a 20" .223 and a 22" .308, but 1/2 to 1 MOA is close enough for me and once I found loads for it, I didn't go any further.

Note: Hit the "UP" button to find the link to the spreadsheet and you have to enable Macros and ActiveX to make the spreadsheet work.

[Bill Steele]

1/4 moa with a statistically meaningful number and you are done...

On investigating the hotter loads, I have found some of my favorite powders work best loaded closer to max in my 308 Win. On the other hand, so far, my AR-Comp testing shows low to mid-range working best (which is not saying much). If you do chase up higher, keep an eye on pressure signs. Max published loads with rifles are not like speed limits on Bay Area freeways.

A stock change can change everything, depending on how the action and barrel fit. Heck, just free floating the barrel can make a meaningful difference. I am going to start a pillar bedding job on my new Boyd's stock as soon as the pilot counter bore shows up.

[mroels]

My AR is the same, doesn't respond well to hot loads. But I was .8gr under listed max so I'm going to retry these charges with a bit more neck tension and just add a 44gr load. I won't go over max ever, isn't worth it to me no matter how promising it may seem.

Once I find what looks like a sweet spot I will try to get the sample size up for determining luck vs load success.

Hopefully my new stock won't mess everything up. I know my stock now isn't truly free floating as when I load into the bipod it's noticeable on the groups.