burs in throat

[oley55]

Playing with my new Teslong borescope I found these burs or whatever I should call them on three lands in the throat of my Savage 10 in 308. I have always had a problem accurately measuring my length to lands and would get different measurements depending on how I wiggled the case. I just couldn't get that "just kissed" the lands feel. I always felt like there was something at the throat that would grab the bullet.

Ignoring the checkering and carbon fouling, what would cause or how would these be created? Is that excess material left behind when the button was drawn through?

 

[DDRH65PRC]

How does your rifle shoot?

 

[mikecr]

Yeah, that won't be there for long.

 

[jepp2]

I found these burs or whatever I should call them on three lands in the throat of my Savage 10 in 308.

Is what you are calling a burr, in the center of the circle of your pic? I would think that is an indentation, not a high spot.

 

[oley55]

yes that is what I was referring too. here is the same land pic taken from the other direction. If it was a low spot would I not expect to see a black carbon spot as opposed to a shiny?

 

[oley55]

How does your rifle shoot?

actually I have never gotten it to perform to expectations, 5/8"-3/4" is the best I can consistently get at 100 yds.

 

[Fotheringill]

What rifle, please?

I see someone besides me is playing with his new Teslong.

 

[oley55]

Savage 10 FCP-SR, 308WIN.

 

[Webster]

Playing with my new Teslong borescope I found these burs or whatever I should call them on three lands in the throat of my Savage 10 in 308. I have always had a problem accurately measuring my length to lands and would get different measurements depending on how I wiggled the case. I just couldn't get that "just kissed" the lands feel. I always felt like there was something at the throat that would grab the bullet.

Ignoring the checkering and carbon fouling, what would cause or how would these be created? Is that excess material left behind when the button was drawn through?[/QUOTE

]Maching tool marks. Poor quality.

 

[Dusty Stevens]

You need a new barrel to fix that. Chalk another one up for the barrelmakers courtesy of teslong

 

[fyrewall]

My thoughts:

The barrel would be rifled via button before chambering.
Upon chambering the throat problems developed - the defects appear to be galling - torn off surface metal - indentation.
Possibly a reamer with a non-rotating pilot was used to chamber the barrel and the galling occurred then.
I see shadows, not black stuff.

It is a mass produced barrel & .625 - .75 groups might be the norm. This defect should not affect bullet seating feel or inability to "kiss" lands.

 

[Richard Coody]

actually I have never gotten it to perform to expectations, 5/8"-3/4" is the best I can consistently get at 100 yds.

Tool marks from the chamber reamer. They usually polish out after shoot the rifle a while. Nothing unexpected in a stock savage barrel.

Now lots of things could be causing your disapointing groups. Too many to name here. I would say if you have consistent groups less than 1 moa you are doing pretty good. If you want to eliminate the barrel as one.of the variables then buy you a shilen select match barrel.

 

[Dgd6mm]

Tool marks from the chamber reamer. They usually polish out after shoot the rifle a while. Nothing unexpected in a stock savage barrel.

Now lots of things could be causing your disapointing groups. Too many to name here. I would say if you have consistent groups less than 1 moa you are doing pretty good. If you want to eliminate the barrel as one.of the variables then buy you a shilen select match barrel.

Richard is right.

 

[Texas10]

Not the worst railroad tracks I've seen in a Savage, but the worst I've seen also shot very small groups. Just coppered up quickly.

Shooting some Federal Gold Medal Match 168 gr loads will tell you a lot about the potential accuracy of your Savage. I don't see anything in your pics that would cause me to say you need a new barrel.

One problem I do see over and over again in the Savage brand is action screw torque. Quite frequently at the range, I encounter a Savage shooter who just can't get their gun to shoot as expected. At that point I break out my torque wrench and find actions screws loose, or not tighten properly. Once torqued, the gun suddenly shoots great.

Have you read this article?:https://www.accurateshooter.com/technical-articles/savage-action-screw-torque-tuning/

I'll pm you with the method I use to find lands very accurately.

 

[Texas10]

Pm sent, but you may have to upgrade your membership to see it. It'll be the best money you've ever spent.

 

[jepp2]

If it was a low spot would I not expect to see a black carbon spot as opposed to a shiny?

If it was a burr (high spot) I would expect to see a fiber from a cotton patch hanging up on it. And as mentioned by someone else, a burr will shoot off quickly. And from the look of the barrel, there have been some rounds through it.

But I will be the first to admit, that looking through my Hawkeye, I have to look for a while at some things before I decide what they are. The magnification and fact you are looking at a reverse image due to the mirror, and be deceptive.

 

[oley55]

Texas 10, Good article, thanks for the link. I will experiment with my action torque settings.

When new I discovered the front screw was too short and was only grabbing 1.5 turns/threads. I had a similar hex key screw (slightly larger hex size) on hand and cut it's length so that I was engaging all of the threads. I'm fairly certain with my new found confidence of not striping out that front screw, I happily over torqued by hand.

edit: got your PM gonna go read it now.

 

[oley55]

If it was a burr (high spot) I would expect to see a fiber from a cotton patch hanging up on it. And as mentioned by someone else, a burr will shoot off quickly. And from the look of the barrel, there have been some rounds through it.

But I will be the first to admit, that looking through my Hawkeye, I have to look for a while at some things before I decide what they are. The magnification and fact you are looking at a reverse image due to the mirror, and be deceptive.

Thanks Jepp, understood completely. With 400 rounds down the pipe it certainly seems improbable a burr could still be sticking up, but the borescope made it seem otherwise.

 

[dogdude]

I clicked on the pic's before I read the post...my first thought...Savage.

 

[luckyshot52]

Suggest u make sure new screw is not touching barrel threads. A little sharpie will tell u