Help and advice needed

[Panama Evans]

I have a savage 12f in 6br. I bought it a little over a year ago, and was happy as could be with it, but now I'm having issues.
See At about 1000 rounds things started going south. What is happening is my groups started opening up at 600 yard shoots. My groups are usually 2.5"-3.5", but now after shooting about 8 shoots at my last competition, my groups open up to as much as 14".
This only happens at shot competitions when I have to do my sight in and then 10 rounds. Up to a total 30 on two targets.
When I let the rifle cool down at target practice my groups have been around 4" with 5 shoot groups. I've tried checking the scope and base for problems but everything checks out to spec. I retested my loads with new brass, and double testing powder to 100th grain accuracy, as well as bullet jump or no jump.
I bought a borescope and made sure I was removing all copper and carbon from the barrel. Rechecked everything on my front rest. Checked all torque settings on stock to action.
Now with a barrel that should last 2500-3500 rounds I'm at a total lost. Is there anything else I'm missing to test.
i know anything is possible but a burnt out barrel at this low of round count? I understood it on my 110 ba in 300 win mag at 1000 rounds. It was doing the same thing, so I had the barrel replaced and all was good.

 

[msinc]

Barrel wear, or more specifically throat erosion, is more a matter of how hot the barrel was allowed to get coupled with continuous shooting. It's also a matter of good barrel steel to begin with, but you say you have that covered. I have shot the throat right out of a 243 in a couple shooting sessions {300 +/- rounds or so} in the middle of the hot summer with continued shooting past the point that it got too hot. Did the same thing with a 204 Ruger, I even slowed down a little with that one...both of these rifles had top end barrels so I believe the steel was not the issue. If the 1000 rounds you put thru this thing were done in a reasonable way heat wise then that should not be the issue. A quick look with a good borescope will confirm easy enough.
Did you by any chance change bullets or lot numbers when this started??? I have had more trouble getting good bullets these days than any other single issue. Over the past six months I have also had two triggers get out of adjustment.

 

[Panama Evans]

Barrel wear, or more specifically throat erosion, is more a matter of how hot the barrel was allowed to get coupled with continuous shooting. It's also a matter of good barrel steel to begin with, but you say you have that covered. I have shot the throat right out of a 243 in a couple shooting sessions {300 +/- rounds or so} in the middle of the hot summer with continued shooting past the point that it got too hot. Did the same thing with a 204 Ruger, I even slowed down a little with that one...both of these rifles had top end barrels so I believe the steel was not the issue. If the 1000 rounds you put thru this thing were done in a reasonable way heat wise then that should not be the issue. A quick look with a good borescope will confirm easy enough.
Did you by any chance change bullets or lot numbers when this started??? I have had more trouble getting good bullets these days than any other single issue. Over the past six months I have also had two triggers get out of adjustment.

I shoot the same bullets (Berger 105 bthp target, but have also tried a new batch of 105's and 108's. I use cci 450 primers, and lapua brass.
Now I have to say I was told to 30.8 grains of varget from a former savage consultant as a load.
I know this is a supper hot load and did give me great results, but yes it did get my barrel hot.
Now on what you said about looking for throat erosion, or other problems. I tried looking up what to look for but am at a loss exactly what I need to look for. I do have a Lyman borescope, and can take pick or video if that helps.

 

[msinc]

You are looking for a burned or scorched appearance in the area of the bore immediately ahead of the chamber. Where the mouth of the brass case would sit in the chamber is where you need to start looking. There and just forward in the area where the case mouth ends but the rifling has not begin yet...that is the throat area and that is what burns out first. If it is real bad there will be obvious checkering of the surface, but if it is just getting started it will appear as like a bad carbon stain that wont scrub or brush out. Any burned looking surface in this area would be an indicator that there is some erosion going on.
I have a Hawkeye borescope and wish I could just send you a good photo...but the attachment to allow the Hawkeye to take photos is like $3000.00.
In an extreme case you will see blurred, rough or blasted looking lines at the end of the throat where the rifling starts, as opposed to good sharp lands and grooves. Post some photos of this area of the bore if you can. The old saying..."a picture is worth a thousand words"

 

[Forum Boss]

How are you cleaning your barrel? Have you checked tightness of barrel nut? What scope brand?

 

[Panama Evans]

Wow that helps a ton. What I see from where the lands start looks schorched and lots of checkering the lands don't have square edges, rather there all round and smooth. This all looks the same for almost 12". I can send picks if you like, but with what you say and what I see not to mention how bad my groups have become it all makes sense right now. Also I compared pics of a new barrel to mine and mine isn't even close. I thought it was just a bad barrel since I had bought I and my sweetie matching rifles from savage. Hers still shoots wonderfully. Now to learn from my mistakes. Ugh. I probably was having a great day and got happy seeing my groups and kept shooting. It usually isn't that hot here in Washington but this year has been supper hot so yup I did it. Thanks tons for the help.

 

[Zero333]

#1 swap the scope with a known good one.

After that you can blame the barrel.

My current 243win target rifle has well over 1,500 rounds and still shoots 1/2 moa. And I get it SUPER STINKING HOT all the time. Some powders will eat your barrel faster than others. I don't clean it often either. Every 200-250 rounds.

 

[Intheshop]

Not sayin this is the issue,so more as a data point.I've had a cpl Savages that had the bedding go away,right now.Meaning,although properly bedded,at around the same round count(1000),the bedding just gave up?One other SA was dang picky from the get go bedding wise,more than ANY rifle I've ever seen.Never happened with 700's,and no this isn't about brand bashing....data,that is all.