New barrel problem!!

[NorCalMikie]

Just got a new Pac Nor, 6BR, 3 grove, .272 no turn neck chamber for my Savage. Barrel was installed with go/no gauges.
New brass fits fine. The bolt closes real easy.
Resized,full length) brass makes the bolt close hard!,RCBS Full Length Dies) Even went as far as to bump the shoulder back on a few to see if it made a difference. No change!!
Chamber length is 1.580. All brass is under max trim length so it's not a trim problem.
New brass measures .468 at the web. Resized brass is .469.
Remember New Brass fits fine!!
Do you think "tight" brass will loosen up in the chamber after it is fire formed?? Got any ideas or opinions? Thanks. Mike.

 

[ken4570tc]

The neck expander is probably pulling the shoulders back out too far on your brass. I use a 358 die to bump back the shoulders on my 308 brass without the decaping pin/expander then use a neck sizer to get the tension I want.

 

[Forum Boss]

"New brass measures .468 at the web. Resized brass is .469."

I've read this post about 6 times to try to figure out what's going on. First I thought, OK the die's working that brass too much which causes the case to lengthen as it is being squeezed down. Then I thought... no, he's moving the shoulder back.

From above, It seems like the die is too tight at the top and too loose in the bottom, so as you're sizing it's squashing the case and it's getting too fat somewhere. Take a case and mark it with a magic marker and put it in the chamber. Tell us where the contact points are.

If new brass fits fine and sized brass doesn't it sure suggests there's something not Kosher with that RCBS die. Borrow a Forster or Redding die and see what happens.

I'm still puzzled though.

RCBS would certainly not be my first choice for a 6BR sizing die. They sent me a set for review a year ago and I sent it right back. The decapping pin was way too thick and it sized the case way too much.

 

[Aussie_bob]

Might sound silly but is the resized Brass, Brass thats been fired in this chamber or in another.

 

[NorCalMikie]

Paul: Looks like the shoulder to body junction is making contact. Ther's a ring where the shoulder starts to form the straight wall of the case.,on the shoulder side) Looks like it's a problem with the shoulder not being pushed back far enough. I think what was throwing me was the fact that all the brass would chamber in my Shilen barrel and not in the new Pac Nor. Might think about resetting the headspace a little looser.
I just went out and pushed the shoulder back on some cases and the bolt still closes harder than "I" would like. Feels like a loaded round going into a "jam".,I really had to work to get the shoulder back)
I know that two different people can use the same gauges to set headspace and come out with two different measurements so I think it might be more in the "feel". No Go gauge won't go and I think there's still room for adjustment.
My main goal is to be able to use the brass in both rifle chambers without having to "overwork" it and shorten it's life.
I'll think on it and decide which move to make. And thanks Guys for your input.

 

[NorCalMikie]

Bob: All the brass was fired in my Shilen barrel. I just thought I would be able to use it in my new Pac Nor without much work. Looks like it might be a problem between the head space settings of the two different barrels. This barrel I'am working with has never been fired. Just installed it last night and am setting OALs for all my bullets. The problem showed up when I started chambering brass. I'am stepping back a few steps before I move forward.

 

[NorCalMikie]

Did some rechecking on headspace today with the Go/No Go gauges. Both rifles feel almost the same as far as force needed to close the bolt.,on go gauge) Tightenes up on the last 1/4 of closing. Think I'll wait till I get some fire formed brass from the new Pac Nor before I make any changes,if any) to the head space settings.
At that time I'll use my Wilson case length gauges to compare the chamber formed brass. Thanks for all the input.

 

[NorCalMikie]

Lynn: I hear what you're saying but it sure would be nice to be able to use the same brass in both rifles. Might not be possable so the fire formed brass will tell me for sure what I actually have. Still have new, unfired brass to use so I'll fire off a few rounds then sit down and get some real world measurements. Don't want to make any changes till I can see exactily what's happening to the brass. Might be making more out of this than I need to. Range time will tell the truth. And thanks for your input. The more "been there,done that" the better.

 

[NorCalMikie]

Thought I would update this thread. I was trying to compare two different chambers and brass. Fire formed brass was not made to fit two different chambers.:, Like trying to fit a size 12 foot in a size 9 shoe!:nono:
Both barrels were set with a Go/No go gauge. A little on the snug side at that! Even new, unfired brass was a little on the snug side. Backed both barrels off, "just a little",and now the bolts will close with just a little drag. Much mo better!
Got some real good info and input from Rusty Stud. He's a good man to talk too. Thanks Nate!!
And thanks to you folks for "your" input.
Now it's back to the range for more fire forming.,as if I really needed an excuse to do more shooting)
And I might add, the accuracy from both 6BR rifles,even with tight brass sure puts a big smile on your face!