Upper node is missing?

[Texas Solo]

I'm can't seem to find the upper node. I started low and hit a load that shot .260. As I went up, the group opened, then began to close. But before I could get back to even 1" I got a sticky bolt. Is it possible that I don't have an upper node with these components?

Rifle is a new Savage #12BVSS .308 with less than 100 rounds fired

Nosler 155CC, LC brass, WLR, IMR4064...CBTO at .006" off

 

[Jay Christopherson]

There's an upper node - there's always another higher node. That doesn't mean you can safely reach it. Or maybe with the load you started with, you just happened to already be at the highest node you can reach. I don't know how you chose your starting load (or even what that is, since you didn't list it) so it's tough to say.

 

[Texas Solo]

Sorry, I should have been more specific. I started at the minimum listed load on Hodgdon's site, minus 1.5gr due to the LC brass. ( I actually measured case capacity of the LC vs. Win and got a 1.5gr difference with IMR4064....twice)
My start load was 41.8, which produced the .260 grp.
42.2 opened up to .456
42.4 was @ .575
42.6 was @ 810
42.8 was @ 1.172
43.0 was @ 1.463
43.3 was @.750
43.6 = slightly sticky bolt, @ .810
43.8 = VERY sticky bolt @ 1.438 (only shot 3 and quit)

So should I assume that my high node is somewhere around 43.3 and that node just doesn't shoot as well as my low node?

 

[Jay Christopherson]

It's possible. I don't have specific expertise with .308, so someone who does might chime in. But with regards to nodes, depending on your setup, it might be possible that you won't be able to reach the next highest node. Maybe your barrel is too short, or too slow, or some other factor. You've also put less than 100 rounds through it. I'd maybe back down to your 41.8 load and do some work there with seating depth and whatever other changes you might want to try. Once you get 150 rounds or so down the barrel, you might try another workup to see if your barrel has "burned in" and picked up some velocity, letting you reach that next node.

I don't really do a lot of powder testing during the first 100-120 rounds of the barrel's life. I shoot the same powder load until my chrono says the velocity has plateau'd and then I start doing powder testing. Until then, I might do some seating depth tests, get my come ups, etc...

 

[JamesnTN]

Try a different primer. Also with just under 100 rounds the barrel isn't broken in yet. What twist barrel?

 

[Texas Solo]

I don't really do a lot of powder testing during the first 100-120 rounds of the barrel's life. I shoot the same powder load until my chrono says the velocity has plateau'd and then I start doing powder testing. Until then, I might do some seating depth tests, get my come ups, etc...

That's makes good sense, thanks. I may be rushing it a bit expecting to get dialed in so quickly.
I just loaded another 30 rounds of the 41.8 at the same depth, so I'll just begin to get my 600yd scope dope with those.
Will also run the chrono beginning on the next trip.

JamesnTN.... barrel twist is 1/10, 26". I will try some 168's and 175's later. I prefer to work with the 155's until I get the best I can, then start over with the other stuff. Then again, if I can .260 groups consistently....I'm done.

 

[JamesnTN]

.260 groups consistently from a factory rifle is doing very well. I don't think I've come close to that with my 308 but I do know its shot well under 1/2" on everything I have shot thru it including LC long range match and also FGMM both using the Sierra 175 Mk

Using the lighter bullets you may want to try some H 4895 that may yield you better results in accuracy.

 

[JamesnTN]

Actually I was wrong here's a image of 6 shots that went just in under 1/2" and I took that same case that I thought was a flyer reloaded it and reshot it and that went back into the group of 4 making the group under .2 I did settle in on a load of 42.3 grns of IMR 4064 using the Sierra 175 Mk and a F 210m primer with a Lapua case.

 

[Shynloco]

I don't really do a lot of powder testing during the first 100-120 rounds of the barrel's life. I shoot the same powder load until my chrono says the velocity has plateau'd and then I start doing powder testing. Until then, I might do some seating depth tests, get my come ups, etc...

That's makes good sense, thanks. I may be rushing it a bit expecting to get dialed in so quickly.
I just loaded another 30 rounds of the 41.8 at the same depth, so I'll just begin to get my 600yd scope dope with those.
Will also run the chrono beginning on the next trip.

JamesnTN.... barrel twist is 1/10, 26". I will try some 168's and 175's later. I prefer to work with the 155's until I get the best I can, then start over with the other stuff. Then again, if I can .260 groups consistently....I'm done.

Texas Solo,
I'd also make a change in the brass you are using. Try the same loads using Lapua Brass. Just last month, I bought up a bunch of LC Match and LC National Match brass for testing my .308 loads. Using the same loads and Federal Match Primers, my rifle printed groups better/tighter with the Lapua than either of the LC brass groups and with that, the LC Match groups were better than the LC Nat'l Match brass that was once fired brass. Just a thought and something to try if you are game.

Alex

PS. What Jay said about having shot such few rounds down the barrel makes me wonder as well. Personally, I like at least 200 rds down any tube (not MG quality) before I rely completely on a load.

 

[TMiller]

There are several of us here shooting the Nosler 155's with good accuracy, after we started jumping them .040. Couldn't get them to group at or near the lands at all. This was in Bartlein, Brux and Krieger barrels with a couple of different Palma chambers. Once we got to .040 off they shot as good as the old Sierra 2155s.

 

[jsthntn247]

Try a different powder if you want more speed with the 155"s. 8208XBR is your friend with the lightweight bullets.

 

[Shynloco]

Try a different powder if you want more speed with the 155"s. 8208XBR is your friend with the lightweight bullets.

Since we're talking different powder, I'm curious how well Benchmark works in those 155's. Have you tried any of that? I haven't but due to the powder shortage mess, I've been told Benchmark is worth giving a try. Just wanna see if anyone has tried Benchmark with those 155's. Thx

Alex

 

[JamesnTN]

Try a different powder if you want more speed with the 155"s. 8208XBR is your friend with the lightweight bullets.

Since we're talking different powder, I'm curious how well Benchmark works in those 155's. Have you tried any of that? I haven't but due to the powder shortage mess, I've been told Benchmark is worth giving a try. Just wanna see if anyone has tried Benchmark with those 155's. Thx

Alex

My guess is benchmark would be too fast.