Chasing the lands, need your help. NEW UPDATE

[thump_rrr]

I have a Savage 10BA I purchased 4 years ago.
It is my most used rifle. It has been to 3 precision rifle clinics put on by Barney AKA Tactical Teacher and is the rifle that goes to the range every time I go shoot rifle.

Over the years it has had 3,000 rounds go down the pipe.
For the first 2 years I was shooting 180gr SMK's with 42.3gr of Varget in Lapua brass and FGMM or BR-2 primers and my brass is annealed every 3 firings.
OAL was 2.800 and I was 0.020" off the lands.
Accuracy was usually in the 0.5-0.75 MOA. with some really good groups down to 0.25MOA.


Early last year I moved to the 175SMK and have found the best load to be at 44.1gr of Varget.
I didn't chase the lands at all I simply kept loading at 2.800.
A few weeks ago at the last Petawawa Precision rifle clinic I scored 50/50 with 9 Vbulls at the 600M deliberate fire stage (Shot at 500M due to range limitations) so the rifle can still shoot 1MOA or better but it seems to be closer to a 0.5-1.0MOA rifle lately
Today I decided to check the throat erosion and I found that the rifling has moved 0.040" since the rifle was new.

Should I move the bullets forward to go back to 0.020" off the lands and readjust my powder charge to maintain velocity or is there another way to go about chasing the lands?

 

[ultimate_monkey]

long story short, the SMK is VERY tolerable to jump/ jam in terms of distance to lands.. if your happy with the accuracy youre getting now, then i dont see a problem. you could try playing with the seating depth with the same powder charge, say load up 5 at .020 off and 5 at .010 off and take them for your next range trip and shoot them to see what happens. i suspect you will see very little if any difference with the SMK. some bullets, like the berger vld on the other hand are very sensitive

 

[308BAR]

I chase my lands because I know outside of a 5 thou jump for my bullet and rifle combination the groups open up and the SD/ES is higher this was done during testing.

Talking with a very well established TR shooter who shoots 2K+ rounds a year he chases his lands until the barrel shows signs in accuracy.

 

[Ganderite]

Is there enough straight shank on that barrel to set it back an inch or two? That would give you a fresh throat.

if not, load some 2.80" and some at 2.80++ and see which shoots best.

A quality barrel and chamber will shoot better, although your results are excellent.

 

[sunray]

"I scored 50/50 with 9 Vbulls". How very sad for you. snicker. Rule Number One. It works. Don't fix it!
Group size means nothing to anybody but the bench rest guys.
No need to anneal on a schedule. Only needs do when you get one cracked case mouth/neck.

 

[crazy_davey]

Group size means nothing to anybody but the bench rest guys.

I can think of lots of shooters that accuracy matters to, none of them are bench rest guys, myself included.

 

[Mystic Precision]

I would definitely recommend you give OAL adjustment and powder adjustment a test. Why not? You have questions... shooting will give you answers.

But I wouldn't spend a lot of time and components testing. It will return to decent shooting quickly or it will not. With that much bore wear, I would look at a replacement barrel which will offer far superior performance.

Experimenting is a huge part of the sport for me and the costs to do so are part of my shooting budget. BUT if you are hoping to get back to where the barrel was 2500rds ago, save your money and put towards that barrel. At $1 per bang, will not take much testing to just buy a new barrel AND you are testing an object that is well on its way to the boneyard.

Don't bother trying to set back... there is not enough shank to make any difference.

Jerry

 

[thump_rrr]

I went to the range today trying different distances to the lands compared to my original rounds.
I wasn't getting anywhere with tons of vertical stringing when I noticed something with 5 rounds left.

The scope cap was hitting the rail on the 10BA.
I removed the cap and the last 5 rounds came together in a nice little 1/2" group.
I will go back out next week for more testing.

 

[thump_rrr]

I went back to the range since finding the scope cap issue to see how the rifle would shoot.
Without the scope cap installed the rifle is now shooting 1.5" higher than with the cap.
The cold bore shot is the one on the left in the upper left target.
It shoots 1/2" left as the rifle always has.
The second shot along with the second group on the upper right were accurate as far as windage is concerned.
After adjusting elevation I shot the lower left group followed by the lower right group.
I guess the barrel has a little life left in it.