Bolt click on sized brass

[Matt_3479]

Trying to help a friend out here and I couldn’t seem to come up with an answer minus possible bad chamber. He’s running a 20 tactical and new unfired Dakota brass chambers beautifully. After firing the brass is annealed, cleaned, bumped 2 thou and it’s got a heavy click on open and hard on close. I’ve measured the brass myself and every dimension is less then what the 20 tactical dimensions are online that I could find? He’s using redding dies

would this be caused by bad die possibly or a tight reamer/incorrect reamer measurements?

 

[BoydAllen]

The important dimensional comparison is between fired and sized cases.

 

[Ccrider]

I would size a shoulder back .008 or so on a fired piece to be absolutely sure that the press ion close is not coming from the shoulder. Then you no that the clock is coming from the base.

Or take a black marker and color the case. Chamber and see where you are making contact.

 

[Coyotefurharvester]

So new brass loaded and shot, no heavy bolt/click, annealed and sized and now a fit problem? Sizing ruined the chamber fit? Sizing changes length and diameter.

 

[Whisky Tahoe Foxtrot]

Bolt click aka "clicky bolt" is more likely caused by brass expansion above the case head.
Resizing the shoulder doesn't improve this.

You can measure the width of unfired brass and fired brass at the base just above the rim.
You will see it has expanded after firing (probably)

Small base dies address this for lots of calibers.
These dies are spec'd at the minimum of the case diameter specs.
Useful for trouble free chambering of semi-auto actions.

223 Rem is the parent case for 20 tactical so in theory a 223 rem small base die might work to resize the case body provided the shoulder area has enough clearance.
Small base body dies address this by only sizing the case diameter and leaving the shoulder alone

Note:
In addition to primer pockets, brass expansion at the case head can be a sign of higher than normal pressure.
In my experience, case expansion shows up before primer signs will flag high pressure.
Worth the time to read up on.

 

[Jtate]

Aex Wheeler has great videos on his web site that will help you understand why clickers happen. https://www.wheeleraccuracy.com/videos