12FV: copper shavings, tight bolt, marks on brass

Not trying to be a whiner, but I’m seeing some issues with my 12FV.
Using Lapua brass and handloads, I’m getting a fair amount of copper shavings, tight bolt, and marks on brass. Keep in mind, these are second fire brass FL resized and all trimmed to spec. COAL is 0.020” from th lands.
Do I:
a) try and run some flitz in the chamber to polish the bore
b) take it a smith
c) call Savage?

keep in mind, I’ve had some rounds that won’t even close the bolt and these are fully resized, unfired reloads.

Thoughts?

I think maybe it’s a sizing issue. Try turning your die in a quarter turn more and give that a shot. I’ve had this happen with several short fat cartridges. WSM are the worst of them all.


Sent from my iPhone using Tapatalk

Have you tried any factory ammo? Also, what caliber? Might be your sizing die isn't set right, maybe bump the shoulder back a bit more. If it is a tight chamber, maybe a small base die if it's .223/5.56 or .308. Another thought, maybe you're off measuring the lands, try starting with recommended book COAL, then increase from there. Good luck.

Dave

It is your Creedmoor right?


Sent from my iPhone using Tapatalk

I’m using RCBS dies. I know my lands measurement is spot on.
It’s a 6.5 CM.


Sent from my iPhone using Tapatalk

https://uploads.tapatalk-cdn.com/201...df26c26996.jpg


I’ll try bumping the neck a little more. I’m new to reloading a 6.5.
I do have an interesting and consistent J scratch on all my once fired brass. Something is obviously not perfect in my chamber, but that’s not the real culprit.
Is there a good technique to polish the neck of the chamber without taking the barrel off and affecting the lands?


Sent from my iPhone using Tapatalk

Can you see a burr in the chamber? Every single one has that? Did you shoot any factory loads that came out with scratches?


Sent from my iPhone using Tapatalk

Every single one, including factory rounds has the J scratch. I can’t see a burr, but there has to be one.


Sent from my iPhone using Tapatalk

Take a q-tip and rub it around in the area(s) of concern, see if you can get it to pull any cotton. Then see if it’s something that can be removed without a reamer.

Do you get the scratches if you just feed and then eject without firing? Hard to tell in the pictures but they look like pretty substantial scratches. Does factory ammo feed smooth and the bolt closes easy?



Sent from my iPhone using Tapatalk

Quote:

---

Originally Posted by lowerriver

Do you get the scratches if you just feed and then eject without firing? Hard to tell in the pictures but they look like pretty substantial scratches. Does factory ammo feed smooth and the bolt closes easy?



Sent from my iPhone using Tapatalk

---

Yup, pretty substantial J pattern scratch just feeding a new, unfired, factory round in and out.

The factory ammo does feed smooth and easy though. My reloads are the ones that tend to be tighter. I had the sizing die set as usual, raise the arm, lower the die until it touches the die. I’ll screw it down another 1/4-1/3 turn to get the neck down more and see if that helps, but the big scratch is a concern. That will require a polish of the neck chamber area.


Sent from my iPhone using Tapatalk

https://uploads.tapatalk-cdn.com/201...fc34bba640.jpg


Sent from my iPhone using Tapatalk

Try feeding one out of the magazine but don’t chamber it fully. Just get it past the feed ramp then pull it out and see if the scratch is there. May be a sharp edge there in the ramp or magazine area.


Sent from my iPhone using Tapatalk

Looks like there is a problem at the transition of the shoulder into the neck area of the chamber. Chamber hone to fix?

i have a few 12 fv's, and two of them have burrs in the chamber. one leaves an impression on the shoulder of a fired cartridge, the other a scratch on the neck. i single feed. i have a borescope and can clearly see the imperfection that puts the imprint on the shoulder. the other rifle is more subtle. the latest model 12 has a chip (slight gouge) on the bolt face right at the firig pin hole that embosses the primer cup.

such is the way with mass produced $300 rifles i guess. we tolerate 'things' to get 0.5 moa accuracy right out of the box, eh?

So I turned my FL size die another 1/4 turn and made a dummy round. Bolt is closing normally and seems great now.
Strange thing is that I used a brass that wasn’t scratched and fed it 3-4 times in and out and no scratch????
I’m confused. I did give it a good cleaning last night, but I’ve already cleaned it on several occasions so that shouldn’t have mattered?
I do have a factory round that I was testing weeks ago and it has the neck scratch and has never been fired.

A gunsmith said he’d look at it, but it’s a 2hr drive. I might head over to see him next week, or see if the scratch miraculously solved itself.


Sent from my iPhone using Tapatalk

You might try removing the ejector and then chamber a few cases and see if the scratch returns. Looking at your photo, I see what looks like a gouge in the shoulder with the scratch starting there. This might be made upon withdrawal from the chamber, and the case slamming against a sharp corner of the bolt abutment as the ejector applies a sideways force on the case. Blending and polishing this corner is something I do to each new action before installing a new barrel.

On the other hand, I did have to send a new 12FV back for chamber work because it was tearing up every piece of brass I put into it. Not just one scratch, multiple deep gouges on the case walls that were so deep, I would not reload it.

I've never seen a "burr" like that but I guess it is possible. There is a desperation method (usually for corrosion from surplus primers or machining "chatter" in surplus rifles). Put a bit of 0000 steel wool on a .22 LR cleaning brush and work it back and forth in the neck of the chamber. It is aggressive. A bit of 3M Scrunge pad on a .22 jag may do to remove a burr as well. But I would certainly make sure one was there before I went that route.

As shiny as that scratch is wouldn't you say that it's happening on the way out? Someone earlier mentioned swabbing around with some dry q-tips. I think that's very good advice.

I'm still baffled by it, but I couldn't reproduce it the other night. I took a case that had no scratch and cycled it through 10 times. No scratch. Weird. Unless its happening when it's hot/expanded after a shot...but I have a factory unfired round I have never fired and it has the scratches from cycling.

I realize now that the tight bolt was from not sizing the cases down a little more. I'm new to reloading 6.5, and it's obvious a little extra turn on the sizing die was needed.

I did clean the chamber really well Sunday night. I used a .38 nylon brush with some never dull in a drill bit. Maybe that was the cure? Again, it's a weird one. Guess it's nothing to worry about for the moment since I can't reproduce it. I'll keep an eye on it next time I hit the range.

Just a guess, but I think that scratch is happening during extraction/ ejection. My 110E 243 gets scratches when the case mouth clears the chamber and angles up in the bolt raceway in the right receiver ring. Check there for a burr.

Quote:

---

Originally Posted by freediver111

I'm still baffled by it, but I couldn't reproduce it the other night. I took a case that had no scratch and cycled it through 10 times. No scratch. Weird. Unless its happening when it's hot/expanded after a shot...but I have a factory unfired round I have never fired and it has the scratches from cycling.

I realize now that the tight bolt was from not sizing the cases down a little more. I'm new to reloading 6.5, and it's obvious a little extra turn on the sizing die was needed.

I did clean the chamber really well Sunday night. I used a .38 nylon brush with some never dull in a drill bit. Maybe that was the cure? Again, it's a weird one. Guess it's nothing to worry about for the moment since I can't reproduce it. I'll keep an eye on it next time I hit the range.

---

Concerning the case that you used for the last "test", is it one with a bullet seated in it or just a new case? Keep in mind that a new, unloaded case will have a neck diameter that is several thousandths smaller than a loaded round. You may not replicate the scratch on the neck without a bullet seated in the neck to expand the case to its full diameter. The scratch on the neck certainly looks like a burr on the shoulder/neck transition area to me. You could get a definitive answer to this by first chambering a new, empty case, then seat a bullet into it and rechamber it and see if the scratch appears. If you know someone with a finish reamer they could easily just touch the chamber up by hand if there is a burr in it. Good luck!

A fired empty case will have an even larger neck.

But your .38 brush & pad may have removed the burr. :thumb: