Savage LRPV 6BR Sweet Spot Velocities??

[RonAKA]

It seems to me that guns with barrels of the same design and length should have velocity sweet spots that are repeatable from one gun to another. Testing in my LRPV 6BR which has a 26" fluted barrel seems to indicate a sweet spot from just under 3100 to just over 3200. See graph of vertical POI plotted against velocity below. There may be another flat spot from 2900-3000 which coincides with some testing I have done with an 80 grain. There is also a hint there may be another above starting around 3300.

Do you agree with the theory that in a given barrel design and length that velocity ranges of the sweet spots should be reasonably consistent?

At what velocities have you identified sweet spots in your LRPV 6BR?

Seems to me one could significantly shorten load development if these ranges were shared. For example I suspect with Varget I could get 80 grain velocity up to the 3150 range. Would be much easier to just ladder test from 3100 to 3200 fps, instead of a whole load range. Have just used H322 to date and it falls a little short.

 

[camac]

OK Ron,
I have a lot of data on this as well. Digging back through, I have a node between 3080 and 3150 fps (assuming my chrono reads same as yours for 80 gr. 70 gr I found 3320-3390.
Fits in pretty well with your data I would suggest.

 

[6BRinNZ]

Hi Ron,

Sorry, slight tangent to your post -

to create the chart - are you simply measuring POA vs vertical POI? I am curious as currently I am plotting FPS vs powder which shows plateaus, but I also wanted to overlay the fps with vertical, I am hoping the two approaches will show a node/s that is the most consistent.

 

[RonAKA]

to create the chart - are you simply measuring POA vs vertical POI? I am curious as currently I am plotting FPS vs powder which shows plateaus, but I also wanted to overlay the fps with vertical, I am hoping the two approaches will show a node/s that is the most consistent.

My plot is simply vertical point of impact (ignoring any horizontal) in inches, all with the same aim point. Horizontal axis is just velocity. Actually grains of powder vs vertical gives a nicer plot, and suggests there probably is some additional error in the velocity measurement (Alpha Master).

I did also plot velocity vs grains of powder, but not for the purpose of trying to find sweet spots. I just wanted to predict how much powder I needed for a specific velocity. Here is what I got. I really don't see any flat spots, and I'm not sure there should be any.