Chamber issue causing clickers?

[Dusty Stevens]

You mean base of the brass is too large, not the chamber? I have fixed many a clicker by polishing the base of the chamber to make it larger when I didn't have a small base die.

How bout the chamber is too big from excessive polishing, which in turn makes the brass too large and causes clickers.

 

[Alex Wheeler]

The unfired and the once fired brass both measure .499 at the .200 line, so I don't think that's the problem.
Another landmark on a reamer print I found online is the 1.00 line, new brass measures .486 and the fired is actually smaller at .482.

If your chamber is not allowing your brass to expand then a die cant size it back down. Tight diameters are what cause clickers. A common .2" chamber diameter for Lapua is .501" thats actually minimum spec. .502" wouldnt hurt either. My guess is your reamer was spec'd for Winchester brass which is smaller. Id fire some warm loads with the same case a few times to be sure, but if it really wont grow over .499", thats not going to work. One other thing to check, measure the fired case all the way up. Make sure it keeps getting smaller towards the shoulder and there are no fat spots in the middle.

 

[Albany Mountain]

What is the root cause of a undersized chamber? Worn reamers?

 

[INTJ]

How bout the chamber is too big from excessive polishing, which in turn makes the brass too large and causes clickers.

I suppose that could happen, but how big would it have to be? I over polished my current HG chamber (.006" over) and it still fixed the clicker issue I had. And no, I didn't mean to polish it that much.........

 

[ckaberna]

How bout the chamber is too big from excessive polishing, which in turn makes the brass too large and causes clickers.

I don’t understand this either. I have a 6br (old school rem chamber) that I polished approximately.002-.003 oversized and lapua brass works great now. Had clicks before polish. Of course, that’s after cutting what seems like 1/2 the neck off the brass.
May just be the dies I use with it? Not small base dies.

 

[rijndael]

How are you all polishing .002-3 from your chambers?

 

[ckaberna]

How are you all polishing .002-3 from your chambers?

Wooden dowel split down middle with sandpaper folded into the slot then spun in an electric drill is how I did it. 320 grit if I remember correctly, continue to keep a back and forth motion

 

[rijndael]

That's what I figured, thanks for the confirmation.

 

[LCazador]

I had this same clicker problem with a Cooper in 280 Ackley. I shaved .005" off a shell holder and problem solved. I couldn't save the original brass I started with but it was only ten cases. The reason I always say experiment with a few cases before doing a hundred. That problem with the rough chamber shoulder may be livable. Looks like someone ran the lathe in a bit of a hurry.

 

[Coyotefurharvester]

Have never had "clickers" , if the base is expanding and hindering extraction. Does the brass(before sizing) rechamber with resistance? I always set my die to size brass(hunting ammo) so a bolt without pin/spring will close free fall.

 

[Field_2_Fork]

Wooden dowel split down middle with sandpaper folded into the slot then spun in an electric drill is how I did it. 320 grit if I remember correctly, continue to keep a back and forth motion

Must be difficult to keep even pressure on the entire circumference no? I'm very handy with a cordless drill, but this is something I could see being easy to oblong the chamber by favoring a side too much.

 

[762 ULTRAMAGA]

I had this same clicker problem with a Cooper in 280 Ackley. I shaved .005" off a shell holder and problem solved. I couldn't save the original brass I started with but it was only ten cases. The reason I always say experiment with a few cases before doing a hundred. That problem with the rough chamber shoulder may be livable. Looks like someone ran the lathe in a bit of a hurry.

Wouldn't that cause the shoulder to be bumped way back as well?
Have you measured shoulder bump after taking. 005 of your case holder?

 

[ckaberna]

Must be difficult to keep even pressure on the entire circumference no? I'm very handy with a cordless drill, but this is something I could see being easy to oblong the chamber by favoring a side too much.

Nope, just center it and spin the drill. Don’t apply pressure to one side. The rpm of the drill will keep it centered.

 

[mikecockcroft]

How about a body die used with a shell holder that has been milled down several thou?
I have a shell holder that I milled off couple thou. Use it for a couple rifles I’ve bought over the years that had short chambers that standard die/shell holder would not size down enough

 

[Phys86]

Nope, just center it and spin the drill. Don’t apply pressure to one side. The rpm of the drill will keep it centered. View attachment 1295348

How tight of fit?

 

[ckaberna]

How tight of fit?

Doesn’t have to be tight, you want it loose. The centrifugal force will spin the sandpaper outward “honing” the chamber walls evenly.

This chamber was cut by Clay Spencer and trust me, I would never touched it had I not had a VERY prominent gunsmith explaining how to achieve the results I wanted. (Lapua brass)

 

[pdhntr]

Doesn’t have to be tight, you want it loose. The centrifugal force will spin the sandpaper outward “honing” the chamber walls evenly.

This chamber was cut by Clay Spencer and trust me, I would never touched it had I not had a VERY prominent gunsmith explaining how to achieve the results I wanted. (Lapua brass)

Yes, loose.

Before computers and internet offered simple answers to seemingly complex problems, there were a few of us that were building stuff basically without a clue as to the perfect way to do it. We didn't know how to spec reamers, chambers or had access to custom dies.

We ran into clickers once in a while, and I can't say I remember anyone coming up with the reason why.

But we discovered the fix, or someone found out about it through word of mouth. I don't know. May not seem proper to some when dealing with a custom chamber, but the fix has been around for a long time, and it still works.

Jim

 

[LCazador]

Wouldn't that cause the shoulder to be bumped way back as well?
Have you measured shoulder bump after taking. 005 of your case holder?

In my case the die (Redding Type S) didn't match the chamber and wasn't producing proper bump . Taking .005" off doesn't mean you'll bump .005" you can use a competition shell holder set to control bump. Without proper bump the case head remains unsupported and instead of expanding forward it expands at the rear. At this point you would need a special die to resize the cases.

 

[762 ULTRAMAGA]

In my case the die (Redding Type S) didn't match the chamber and wasn't producing proper bump . Taking .005" off doesn't mean you'll bump .005" you can use a competition shell holder set to control bump. Without proper bump the case head remains unsupported and instead of expanding forward it expands at the rear. At this point you would need a special die to resize the cases.

Makes sense in your scenario, I had a clicker issue and tried turning my die down a little further. It sized the base but gave me .006 shoulder bump, no Bueno.
I recently ordered a custom reamer with the saami max base diameter which will be .002 fatter than my die

 

[Phys86]

Doesn’t have to be tight, you want it loose. The centrifugal force will spin the sandpaper outward “honing” the chamber walls evenly.

This chamber was cut by Clay Spencer and trust me, I would never touched it had I not had a VERY prominent gunsmith explaining how to achieve the results I wanted. (Lapua brass)

I've got a few additional questions if you don't mind answering them:

Does rpm matter?
Do you need to put any different finish on after the 320 grit?
How far into the chamber do you go? Would measuring with standard calipers be sufficient to measure progress?