Is there more then 1 sweet spot

[Wjesswheel]

savage ftr with 30 inch barrel iam shooting Sierra 168 with 42.3 grains of varget around 2650fps. did testing which when I began reloading I considered safe this seemed to be my sweet spot where it shot best. Tried up to 1 grain higher and 1 lower. Shot with a guy the other day with same gun same barrel same bullet shot a little better then mine. He was talking about a gun having different sweet spots. He was shooting up around 2850fps he said, and his load was louder so iam assuming it was faster. Thinking with like 45 grains of varget I could get close to that does that sound safe and is there possibly different sweet spots?

 

[22BRGUY]

As long as you know for sure how to look for signs of high pressure as you gradually increase your load, there might be a higher node, but safety comes first. Would suggest going up in powder charge in 3/10's grain increments while doing a ladder test and looking for 2 loads that are 3/10's grain apart that hold the same vertical.
Be careful
Good luck

 

[Joe R]

savage ftr with 30 inch barrel iam shooting Sierra 168 with 42.3 grains of varget around 2650fps. did testing which when I began reloading I considered safe this seemed to be my sweet spot where it shot best. Tried up to 1 grain higher and 1 lower. Shot with a guy the other day with same gun same barrel same bullet shot a little better then mine. He was talking about a gun having different sweet spots. He was shooting up around 2850fps he said, and his load was louder so iam assuming it was faster. Thinking with like 45 grains of varget I could get close to that does that sound safe and is there possibly different sweet spots?

What the other guy was calling sweet spots many of us here refer to as accuracy "nodes". Yes, there are generally two attainable accuracy nodes and then the velocity is too low or too high. The concept of nodes AFAIK was first implied by Audette's ladder test, he found there are points when one adds powder to a bullet but the point of impact does not change much, that plateau is referred to as a node. More recently Chris Long ( http://www.the-long-family.com/optimal%20barrel%20time.htm ) quantified the concept with his OBT (Optimal Barrel Time) Theory.

To put Chris's theory to work you need a chronograph and QuickLoad, a software program, and by using the two together you get to your OBT. OBT is dependent on barrel length. So it is different velocity for someone with a 28" barrel than someone with a 30" or 32" barrel.

The bottom line is that you are trying to time your velocity so that the bullet exits the barrel at the point where the vibrations make the crown of the barrel the most accurate. Of course this is an oversimplification because there are several other key factor that have a direct impact on precision. Nonethless, OBT is a key indicator that many people use to refine their loads.

Regarding your question of going up to 2850 fps with a 168 grain bullet it is very doable, but it may or may not be very precise. I've pushed a 180 grain at 2920 fps, but I got two rounds that leaked gas around the primer and the third round blew the primer right out. That's what I call getting to the edge of the abyss, I wouldn't advise it. At the time I was a newbie and I was just trying to find the upper limit. I haven't gone back to that neighborhood since.

Like 22BRGUY said, go up slowly and watch for the usual signs.

Kindest regards,

Joe

 

[Lapua40X]

1. Shot with a guy the other day with same gun same barrel same bullet shot a little better then mine. ... He was shooting up around 2850fps he said, and his load was louder so i am assuming it was faster.

Louder doesn't necessarily = faster

2. Thinking with like 45 grains of varget I could get close to that does that sound safe

Use your reloading manual to determine margins for safety

3. ... is there possibly different sweet spots?

There can be more than one; some are sweeter than others. But load what's safe and sweet, not what's sweet.

 

[Pappy5]

I can only state what my findings were:
I shoot a Bartlein .308 Heavy Varmint 28" 5R 1-11.25 twist and my finding were very close to what you have stated. Shooting 168 Berger hybrids over Varget CCI-BR2 primers in a Lapua case trimming to 2.010, I found a node at 43.0 Varget, chronograph @ 2710 FPS muzzle and it was a very accurate load. I shot this load at many Mid-range 600 yrd matches. I then started increasing the charge by 0.3 until I found an even more accurate load at 45.0 Varget on the chronograph 2840. I needed the extra velocity to stay super sonic at 1000 yrd. matches.
The manual and Hodgdon shows 46.0C as max load (C) designating it as a crushed load!! I am in no why telling you to load these without properly working up to find YOUR accuracy nodes.
Be safe, shoot often and hit the X.