The "click" ????

measurements

Ok. Define the "web area" on the brass in a way that I can accurately compare measurements. I am FL sizing with a Redding S-type sizer. I don't have a reamer print for this barrel so I am not sure of the match between reamer and sizer. It is a 0.332 neck. I did switch to a new lot of H4198 recently and loaded several rounds up a "hot" without realizing it. I refilled the 1 lb bottle and didn't make proper notes and forgot. The load accuractely was terrible and heavy bolt.

I have a new Shilen 30BR barrel coming that was reamed using a std Robinett 30BR .330 neck according to Wade. How good of a match is this reamer to the Redding dies? Do I need to go ahead and go with a custom sizer?

Starting to see why you guys own your own reamer....

tiny
 
A custom die from Harrells is not expensive. As suggested earlier after firing a couple cases in your new chamber a couple times, send it to Harrells and get them to make you a die. Sometimes in spite of how you chamber or what type of reamer you use, sometimes the base is a little larger. It is pretty hard to match a commercial die to a custom reamer.
Butch
 
Butch, the issue there is that there are several chambers that those dies ultimately won't work in. Unless they've changed there is a variety of sizes but it's still somewhat of a missmatch with some chambers, which I found out myself. While I know smith's really do not like to made them, if you can get it made for your chamber or reamer, it just works so much better IMHO.
 
they can't make one from your reamer. it wouldn't do nothin. if you send harrel 3 fired cases he makes em the right size in the right spot. it ain't an off the shelf crapshoot. now they can make a seater die from your reamer
 
Tim,
They are making it from your fired brass and it is for that chamber and reamer, not other chambers and reamers. I don't think you will get one size die to fit all of your chambers.
Butch
 
hey butch

DSCF0023.jpg


:p
 
Polishing a die

Jerry, I know you're well equipped, but how did you polish your die? I had one of my FL dies Hard Chromed and now it's not smooth enough inside to suit me. The cases come out of it looking kind of "frosty" for lack of a better word. I don't know if I should try tumbling it like they do for gem stones or ??? :confused:
 
zippy06 said:
DuanePA. I use Flitz on a chamber mop and attached to a drill. For 30 sec.
Did this to all my dies and a couple chambers. Makes things real shiny.
Got it from Varmint AL.
http://www.varmintal.com/arelo.htm#Polish_Chamber
Click to expand...

Well Hey....... I'm all about polishing chambers, dies, knobs, whatever else needs polishing BUT......... I don't agree with Varmint Al's assessments and assertions as provided in this section A'tall.

Al provides ZERO data showing that a polished chamber is in fact "slipperier" than unpolished, in fact his own anecdotal info indicates otherwise. And his stories about how "with a polished chamber the case is allowed to slide back....etc etc" is purest speculation, speculation which my experiments and most others DO NOT agree with.


al-notvarmint-inwa
 
My Experineces with "the click"

here are some things that I have run across that significantly contribute to the click:

Brass that as parent brass is too large for the chamber (less than .0015 inch clearance at rear and shoulder) This does not allow the brass to go far enough beyond its elastic limit to have some snapback so that end brass dimensions are smaller than chamber dimensions when the elastic chamber walls have snapped back.

die that does not size case enough at base


action that does not have the closing, extraction and cocking cams along with extractor lip timed correctly and/or do not havae true helical closing and extraction cams that match each other


chambers that are highly polished so that bolt thrust is increased
 
Last edited:
Jim Borden said:
here are some things that I have run across that significantly contribute to the click:

chambers that are highly polished so that bolt thrust is increased
Click to expand...

Jim, a bunch of us here on the board had this discussion about chamber polishing back in about '96-'97. Frank L Murphy was involved. As I remember, some experimenting was done and the "slipperiest" chambers were those that'd been cross-hatched with 320 grit.

Are there any data which indicate that polishing a chamber increases bolt thrust? Does polishing actually make a chamber more slippery or is this just one of those "stands to reason" things?

I've never had a chamber, polished or rough, which allowed brass to slip back under working pressure. My contribution to the discussion back then, my only experiment, was to polish a "long" .243AI chamber which had a tendency to "pop" primers up like the old Palma .308's with a mild FF load. After firing the round you could stand the case up on the table and it'd wobble on the primer, the protrusion was right at .006, analogous to the excess headspace. Polishing it up didn't change the action of the cartridge in any way that I could see. Protrusion did not change after polishing. IMO the cases with popped up primers were showing essentially zero bolt thrust.

Of course loading it hotter "solved" the problem by driving the casehead back, stretching it at the web and flattening the primer. As can be expected, the brass ended up crooked. Once the cases were stretching I'd guess that the bolt thrust was only what was left over after stretching the brass, coupled with a slight hammering effect.

wondering


al
 
Chamber Finish

Granted, 99 percent of what I deal with are shorter chambers used in 100-200 yard Benchrest, but I have always found that the finish that exist in a properly reamed and sized chamber, (with nothing else done), is the best all around for avoiding a tight bolt at the beginning ofthe stoke, (case slamming back against action face or too much action stretch), or the click, (brass either shot, or ill fitting components)...........jackie
 
I'm not about to argue with Jim but I have always polished chambers on both br length and hunting rounds.. I have never had that contribute to bolt clicking.. However, I have found that all else that Jim mentioned to be the areas that would cause problems..
 
zippy06 said:
DuanePA. I use Flitz on a chamber mop and attached to a drill. For 30 sec.
Did this to all my dies and a couple chambers. Makes things real shiny.
Got it from Varmint AL.
http://www.varmintal.com/arelo.htm#Polish_Chamber
Click to expand...

Thanks for the reference. But let me point the reader to this page:

http://www.varmintal.com/a243z.htm

Some might think that there is no data here, but I differ. I recently revisited the chamber finish calculations and used a scaled chamber pressure curve instead of a ramp function for loading. Admittedly the 6 mil clearance between the bolt face and case head might be a tad too much, but it does show the effect of the case grabbing the chamber walls to a more or less degree depending on the friction coefficient.

Good Hunting... from Varmint Al
coyotel.gif
 
Varmint Al said:
Thanks for the reference. But let me point the reader to this page:

http://www.varmintal.com/a243z.htm

Some might think that there is no data here, but I differ. I recently revisited the chamber finish calculations and used a scaled chamber pressure curve instead of a ramp function for loading. Admittedly the 6 mil clearance between the bolt face and case head might be a tad too much, but it does show the effect of the case grabbing the chamber walls to a more or less degree depending on the friction coefficient.

Good Hunting... from Varmint Al
coyotel.gif
Click to expand...

I guess that if you find the data presented to be "meaningful" then yes, you've presented it well.

These same tests were run in the early 80's as I recall and I discounted them then as well as now. The premise was the same, drag a control weight over various surfaces and extrapolate.

If one is to believe that the baseline established by dragging a couple pounds of brass over a plate is accurate when applied to a 50,000-80,000psi load......... then one can be convinced that the experiment was meaningful.

Actually SHOOTING rifles with unpolished and then polished chambers yields completely different data IME.

al
 
experineces

experiences with a ppc barrel and a 300 wsm barrel continue to make me believe in the polished chamber resulting in more bolt thrust scenario--I do not use excess headspace when I do this--I use cases that are at most bumped .001.

a highly polished chamber has shown me harder bolt lift--than the same chamber "roughened" and shot with same loads--in both cases, the chamber is dried with mop and alcohol before cases are fired after rifle is cleaned.

guess I need to make the time to instrument the rail gun adn do the experiment again


Jim
 
Jim Borden said:
experiences with a ppc barrel and a 300 wsm barrel continue to make me believe in the polished chamber resulting in more bolt thrust scenario--I do not use excess headspace when I do this--I use cases that are at most bumped .001.

a highly polished chamber has shown me harder bolt lift--than the same chamber "roughened" and shot with same loads--in both cases, the chamber is dried with mop and alcohol before cases are fired after rifle is cleaned.

guess I need to make the time to instrument the rail gun adn do the experiment again


Jim
Click to expand...

Thank you Jim :)
 
You must log in or register to reply here.
Back
Top