Bulging case necks with 107, 108, 112 grainers in 6BRA

[mikecr]

You really shouldn't change anything until you understand what's going on.
Why else would you get into this endeavor, and cycle forums with an issue, if not for the learning?

 

[Old Navy]

Are you sure you have the right die?

 

[titus123]

You really shouldn't change anything until you understand what's going on.
Why else would you get into this endeavor, and cycle forums with an issue, if not for the learning?

Mine don't look like that before or after, that's why I asked.
Color your case and check for rub marks after chambering a couple times.

Are you sure you have the right die?

Yes Sir, the die is correct. The chamber on the other hand might be out of spec, which will be confirmed soon( once I send the barrel out, or deliver it to a fellow who offered to borescope it, and if need be, recut the chamber. He and I are guessing it is most likely a bad chambering job. The previous owner of the barrel neck turned his brass( even though the chamber is supposed to be a .272 no turn). So that fellow might have never run into an issue, I however haven't turned the necks.

 

[Mulligan]

Does a fired case extract easily?
CW

 

[titus123]

Does a fired case extract easily?
CW

Yes Sir.... Being as I've only been able to successfully load and shoot the 95gr. Bergers ( they have a shorter bearing surface, and aren't seated deep enough to bulge the case neck).

 

[titus123]

It is rapidly becoming apparent that the chamber for whatever reason is not a .272 neck. Perhaps a worn reamer is to blame.... So at this point I am going to either
A. Have the barrel reamed with a known good reamer
B. Start turning my case necks(, after the chamber issue is either proven or disproven
C. Have a new barrel made.

 

[Mulligan]

Yes Sir.... Being as I've only been able to successfully load and shoot the 95gr. Bergers ( they have a shorter bearing surface, and aren't seated deep enough to bulge the case neck).

The reason I asked about extraction is the ring or line around the case neck.

I had a chamber that once a case was fired, it too had a similar line or ring around the neck. After several cases were fired, it was harder to extract the cases.

The ring was caused by a ridge left in the chamber by the reamer. It is suspected that a chip got under the reamer and left the small ridge.
A small portion of the barrel was cut off and the new chamber fixed the issue. The smith did try to “clean up” the ridge, that really didn’t work, so he took a half inch or so off and recut the chamber.
Worked great.

CW

 

[titus123]

The reason I asked about extraction is the ring or line around the case neck.

I had a chamber that once a case was fired, it too had a similar line or ring around the neck. After several cases were fired, it was harder to extract the cases.

The ring was caused by a ridge left in the chamber by the reamer. It is suspected that a chip got under the reamer and left the small ridge.
A small portion of the barrel was cut off and the new chamber fixed the issue. The smith did try to “clean up” the ridge, that really didn’t work, so he took a half inch or so off and recut the chamber.
Worked great.

CW

As of now no issues, but it has only been fired once.( Brass)

 

[titus123]

The reason I asked about extraction is the ring or line around the case neck.

I had a chamber that once a case was fired, it too had a similar line or ring around the neck. After several cases were fired, it was harder to extract the cases.

The ring was caused by a ridge left in the chamber by the reamer. It is suspected that a chip got under the reamer and left the small ridge.
A small portion of the barrel was cut off and the new chamber fixed the issue. The smith did try to “clean up” the ridge, that really didn’t work, so he took a half inch or so off and recut the chamber.
Worked great.

CW

But at present that is the plan( the rechambering of the barrel)

 

[dellet]

If fired case neck diameter is the same as loaded neck diameter, then it would seem likely to be a chamber/neck problem. But the question of not chambering the longer bullet remains.
I’m sure you have checked bullet diameter, if not it would be a good idea.

I would also check bullet fit in the fired brass with both long and short Bullets. You might be able to feel what you can’t measure. They both should slip down past the neck to shoulder junction and feel about the same resistance.

It may only take about .0005” difference in bullet diameter at a single point to make a difference in how it chambers given how tight the fit is in the chamber. I would expect to see a rub mark on the neck if that’s where it is sticking.

 

[titus123]

If fired case neck diameter is the same as loaded neck diameter, then it would seem likely to be a chamber/neck problem. But the question of not chambering the longer bullet remains.
I’m sure you have checked bullet diameter, if not it would be a good idea.

I would also check bullet fit in the fired brass with both long and short Bullets. You might be able to feel what you can’t measure. They both should slip down past the neck to shoulder junction and feel about the same resistance.

It may only take about .0005” difference in bullet diameter at a single point to make a difference in how it chambers given how tight the fit is in the chamber. I would expect to see a rub mark on the neck if that’s where it is sticking.

Bullets have been measured ( long tedice process), and all bullets measure correctly. As for the neck, I have sharpied the neck on a number of dumby rounds and all of them swipe the neck to a point at the shiny ring( could be a bushing ring, might be a bad spot in the neck of the barrel.

 

[LRPV]

I think you’re gonna save yourself A LOT of headache by at least getting it re chambered. If it doesn’t shoot right off the bat when you get it back, sell it to the guy that’s gonna quote my post to tell me I’m wrong. Lol

otherwise chuck it

 

[titus123]

I think you’re gonna save yourself A LOT of headache by at least getting it re chambered. If it doesn’t shoot right off the bat when you get it back, sell it to the guy that’s gonna quote my post to tell me I’m wrong. Lol

otherwise chuck it

It's going to be rechambered for certain.... As signs point to a .270neck. Which explains why the previous owner who turned his necks didn't have a problem.... As of right now, the barrel is a shooter, and I believe that with a rechamber( and a bit of luck finding a decent supply of 105 grain Bergers, it will serve me well for my intended purpose( varmint hunting)

 

[bfiles]

Why don’t you neck turn 10 pieces of brass so that the seated outside neck diameter is .267 or so. Shoot them and see how it goes. Hell, just turn one and see if it will chamber with a long bullet. That seems way easier than re-chambering or worse yet chucking the barrel…especially if “it shoots”. If it works and you just don’t want to hassle with neck turning, send the brass to somebody who will do it for you. Still cheaper than a chamber job.

 

[titus123]

Why don’t you neck turn 10 pieces of brass so that the seated outside neck diameter is .267 or so. Shoot them and see how it goes. Hell, just turn one and see if it will chamber with a long bullet. That seems way easier than re-chambering or worse yet chucking the barrel…especially if “it shoots”. If it works and you just don’t want to hassle with neck turning, send the brass to somebody who will do it for you. Still cheaper than a chamber job.

I'm not set up to neck turn and honestly the cost of the set up is about the same as having the barrel rechambered.

 

[titus123]

I'm not set up to neck turn and honestly the cost of the set up is about the same as having the barrel rechambered.

 

[titus123]

I'm not set up to neck turn and honestly the cost of the set up is about the same as having the barrel rechambered.

Though I do have two metal lathes

 

[bfiles]

Gotcha. In that case, absolutely get it whittled on. Neck turning is easily the worst brass prep job.

 

[titus123]

Gotcha. In that case, absolutely get it whittled on. Neck turning is easily the worst brass prep job.

Yes Sir.... It believe it is

 

[WIB3]

Typically all of my Dasher brass comes out of the chamber .001 smaller than the reamer dia. My neck dia. Is .2660 and I shoot a custom bullet that measures .2432 on the pressure ring. I turn my necks @ .0102. What I am trying to get at is measure your fired cases. It is crucial to calibrate your micrometer with gauge pins.