"Bolt Click"

J

John Scheets

Guest
I need to find the cause and solution for "bolt click" I seem to remember it has something to
do with case sizing, but can't remember the details. Can you point me the the right direction.
THANKS!
 
Well, I can't agree withy that.

The SOLUTION is to make your chamber fatter, and then to fit a die to it.

A Carstensen will do.

al
 
If the action bolt is clicking or popping at the top of the bolt lift, it indicates that the brass is too big near the base. Once you start getting this, you might as well throw the brass in the garbage, as it will be impossible to stop when using full power loads. I think this is the most common complaint with 6mm BR or 6 PPC chamberings. If the bolt closes and opens hard throughout the whole stroke without the pop at the top, this indicates the shoulder needs to be pushed back.

There is nothing wrong with what he said here.
Lynn aka Waterboy
 
Lynn said:
If the action bolt is clicking or popping at the top of the bolt lift, it indicates that the brass is too big near the base. Once you start getting this, you might as well throw the brass in the garbage, as it will be impossible to stop when using full power loads.
Lynn aka Waterboy
Click to expand...

NOT impossible to stop, make the chamber fatter. The brass is now no longer "too big." .007 over will allow you to reach full potential, the brass can grow (or not) until the primer falls out and no click. Anybody who claims you can "contain" the brass casehead from growing is out to lunch.

al

al
 
John ...

If you shoot a 6PPC, 22PPC, 6mmBR, 30BR, 6X47, 6.5X47, or 30X47 built on the Lapua case, the easiest, inexpensive, and Best Solution is to buy some new brass, fire form it twice, send two pieces to Lynwood Harrell and then enjoy the experience of a no click world with one of his $70 full length bushing dies. Here's the link: http://harrellsprec.com/index.php?crn=207&rn=384&action=show_detail. :)
 
In the past, there have been some misadventures in reamer design, by the over application of the "a closer fit is better" principle, that resulted in chambers that were too close to the diameter of the solid portion of the case head. It is this area, trapped between the supporting bolt face and the pressure of burning propellant, cases will, if loads are hot enough, actually grow in diameter, to the point that they contribute to an interference fit with the back edge of the chamber. Adding to the problem is the fact that standard dies are ill equipped to reach down this far on the case, and reduce the diameter of a solid portion of the case. By specifying a chamber dimension that allows some room for growth in this area, and using a die that is small enough to adequately size the area immediately adjacent to it, the problem of bolt click is largely eliminated. Having a good amount of primary extraction, that is adequately distributed in the bolt lift also helps.
 
I have done several projects where we sized a few fired, well work hardened cases, and sized them with a factory die, and then ordered a reamer to fit the sized cases, with the clearances that we wanted. Because these were one piece dies, the chambers were tight neck, because that was needed with the die neck IDs. Dave Kiff gave us just what we needed, and the resulting ammunition, its fit with the chamber, and the rifles' accuracy are excellent.
 
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Hal
If you buy Redding Dies Dave Kiff at Pacific Precision makes the reamers for them so the fit is very good.

Alinwa
If you look at Boyds post he has it correct.

This is just an example: If your reamer cuts a 0.500 base and your brass measures 0.498 after it comes out of the full length die you'll never get rid of the click.If your reamer cuts a 0.503 base and and your brass comes out of the full length die at 0.500 you won't have a problem.
What Jim was saying in his article was if your web area measures 0.500 your reamer needs to be 0.003 larger because no die will shrink the web area.If your reamer measures 0.551 or 0.552 he won't even build you a die as you'll never get rid of the click with a reamer that is that close to the webs diameter.

Art
I have several Harrels dies and none of them worked right until I bought a second die.I don't usually send stuff back.

Lynn aka Waterboy
 
Lynn, That's a shame, my Harrell's die has been an absolute "tool of perfection" from day one. My cases go in and come out as smooth as a hot knife cutting through softened butter.
 
You know, I have read so many posts about unobtainium components, I just have to tell you about my Harrell Vari-Base die (no longer available). It has several base inserts that screw into the bottom of the die. They go from too small to too big in steps of .001. it sizes the neck with your bushing of choice, bumps the shoulder, and sizes the base. Another thing, i think that case heads can be hardened by being shot and FL sized a few times at medium but shootable pressures. After that they have less tendency to grow into a click. Comments?
 
Boyd
In the old days you could take Lapua 6BR brass out of the box and shoot maximum loads in it without a problem.The new brass requires 2 fireformings before it will take the same loads.
With the longrange guns and Norma brass it takes two mild loads as well.If you hit it with a heavier load the primer pockets are toast in 3-4 firings.
Its so soft that if you have a crush fit on chambering you will get an ejector mark without ever putting any powder or a bullet in the case.Unfired brass with an ejector mark.
Lynn aka Waterboy
 
Lynn said:
Hal
If you buy Redding Dies Dave Kiff at Pacific Precision makes the reamers for them so the fit is very good.

Alinwa
If you look at Boyds post he has it correct.

This is just an example: If your reamer cuts a 0.500 base and your brass measures 0.498 after it comes out of the full length die you'll never get rid of the click.If your reamer cuts a 0.503 base and and your brass comes out of the full length die at 0.500 you won't have a problem.
What Jim was saying in his article was if your web area measures 0.500 your reamer needs to be 0.003 larger because no die will shrink the web area.If your reamer measures 0.551 or 0.552 he won't even build you a die as you'll never get rid of the click with a reamer that is that close to the webs diameter.

Art
I have several Harrels dies and none of them worked right until I bought a second die.I don't usually send stuff back.

Lynn aka Waterboy
Click to expand...


Lynn,

I'm also in agreement here, with one small difference, .003 is not enough for me .... that's it. I'd say that FOR ME, .004 over would be my absolute minimum, I prefer .005 over for total click elimination.

And I've been "agreeing with Boyd" on this for lo these many years (6yrs?-8? I dunno) This is the rationale behind my "fat butt" stuff.

My old lot of 6BR brass AND my current lot of 6.5X47L brass end up seasoning in at about .003 over. Primers seat softer but still seal well and I can fire these cases as many times as I wish. BUT, some of them keep growing to .004 over before they stabilize. I've got a batch of 75 or so match cases for one of my barrels that all run .004+ because I tried to shoot a match at 3250 with 108's..... pressured out to at least 3300 maybe 3350fps due to weather or something, stressed the cases perty good. Primers still holding but I set the barrel aside to work with a Krieger.


I've got reamers for these cases (and for the .308 case) that run from .002 over to .009 over at the butt in .002 increments. I use the .007 measurement for reasons that I've outlined many times in prior posts.

MANY times.

al
 
Al, I'm trying to get a handle on this "seasoning" brass concept. Now, don't get me wrong. I'll take your testing as a good answer. But it is a whole lot better if it fits into a model, a predictive model, because we've learned time and time again that one man's test includes a bunch of things unmentioned. Sometimes those turn out to be important. The conclusions of the test weren't wrong, but repeating them by someone else may not work quite right.

OK a true story.

Back in the late 1990s, a 1,000 yard shooter named Joe Cain wanted to honor Newton, so he chambered up a barrel in .30 Newton. His original cases were made from the 8x68 brass. At the time, RWS was the only good manufacturer of the 8x68, and RWS components were available in the States only through The Old Western Scrounger. Availability was variable, and price was high.

So Joe got some .300 Win Mag brass and fireformed it in his .30 Newton chamber. He not only lived, but the rifle shot quite well.

OK, dimensions (All dimensions from Howell's Designing and Forming Custom Cartridges):

The 8x68 case is beltless, and has a diameter at the head of .5236.

.300 Win Mag has a belt of .5320, and the case measures .5130 just ahead of the belt.

I don't know if Joe turned the belt .008 to fit his chamber or not. But the brass at the head, just after the belt, had to expand .019 -.020 to fill the chamber. It did, and it worked.

After the mandatory Don't try this at home statement, what do you think?

Not as important, but aside from the theory, I got two notions. (1) If absolutely safe this would be a nice way to get rid of the belt. After buying the appropriate reamer, I know guys who turn the belts off in a lathe. Much less work to start with a different reamer and just blow out the case. IF SAFE, of course

And (2)? Oh. I shoot a .30 S.O.B., also on a 8x68 case. RWS brass is still expensive and hard to get. .300 Win Mag isn't.

And maybe (3), I'm about to order a reamer. The case has a head diameter of .498, a bit bigger than your usual toys. Would you recommend a reamer of .004 over the virgin diameter at .020 up from the boltface? Or do you predict that the larger the diameter, the more clearance desired? Again, this will be that hard RWS brass. (Yes, I know, I'm being inconsistent. But I already got over 200 pieces for this new toy, which should see me through to the end of my days. I'm already out of 8x68 brass.)
 
Lynn said:
If the action bolt is clicking or popping at the top of the bolt lift, it indicates that the brass is too big near the base. Lynn aka Waterboy
Click to expand...

The 'click' does not always indicate a problem at the back end. -Al
 
I would believe there would be an issue anywhere the brass yields(beyond springback) to leave an interference fit on chamber springback.
I haven't tested extreme loose tolerances, but have tested extreme tight tolerances. And as long as pressures allow the chamber to contain brass from yielding(<1.5thou/side), there is never a popping extraction or later sizing issue.
I understand there are advantages to very high pressure loads. But wouldn't anyone also expect costs for it?

What's to keep brass from continually growing, if allowed to yield with every shot?
Wouldn't loose tolerances only delay the inevitable?
I mean, I ask because I don't know(haven't tested it).
 
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