Bolt click and brass memory

R

RAG2

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I've been told bolt click is caused by not sizing the base enough. yes?

Anyways, bolt-click crept into my lot of Lapua 6BR brass after 5 or 6 firings...I have 800 pieces so it took a while (I think it took time for the base to stretch enough to start causing a problem, even though my loads are stiff for sure!). Eventually, I could not measure a difference in the diameter of the base (at the datum line) between fired and sized brass (but the shoulder was getting squeezed by about .001) so I sent some fired brass and Harrels die back to Harrels...the die they returned to me appears to sqeeze the body (and base) by about .0005" (1/2 thousands) more than the last one. Haven't tested newly sized brass yet, but I've heard that the brass has memory and even if the current die properly sizes the brass for that chamber, it is likely I will continue to get bolt click because of the brass memory. Anyone experience this?

The reason I ask is because I plan to take about 400 pieces this brass and size down to 20BR (next slated chambering for me). However, when I design the reamer, rather than mimic the body specs of my 6BR reamer, I'm thinking I should build in an extra .0005 or even .001 at the base datum line so I can continue using all this beautiful brass and not get bolt click...yet I should be able to keep using the same die (only with a different bushing for the 20 cal)...I hope.

THANKS!
 
Your logic seems good to me, but you could just use the reamer you have and polish the chamber out about .001" and get the same end result.
 
Bolt click comes from the brass not being sized enough in the web area of the brass. 0.0005 more sizing may stop the problem but I doubt it, most people get a 2.5 or 3 die from harrels and that will cure the problem. Try the die you have and see what it does for you, if it doesn't cure the problem get a 2.5 or 3 br die from harrels and it will cure the problem for both guns.
 
Good idea, from both of you.

Steve, so your feeling is you can size the brass enough to elimate the click? The die (just arrived) I now have is the 2.5. Based on the dimensions of my reamer/chamber, the web is only getting sized about .0005 now, so I may have to step down to the 3.

I'm sure I'll figure it out. Thanks!
 
I have got to think that if my rifle was doing this..."6700 rounds on my 6BR and still punching 1's, 2's, the occasional 3's and screamers, I...probably wouldn't mess with it...JMHO :)
 
Yeah, the bolt click is annoying though. I figure I'm going to get 8000+ rounds easy out of this Hart, as I'll keep shooting as long as she can hold 3s with regularity. This gun was always a shooter...1 NBRSA match, 1 win (with PPC chambered barrel, but the BR is right there). Only match I ever shot actually, then I moved away. The really crazy thing...I'm getting that accuracy with ballistic tip varmint bullets - last trip to the range I shot a few different groups of 58 V-max and 55 Sierra BKings, and all groups were 1st and 2s. Barrel has been recrowned a a few times, but that's it...never rechambered. Though I sometimes use bronze brushes, mostly, after a day of high-volume varminting, I plug the chamber and fill the barrel with BBS and let it soak for 10-24hrs, cleaning out all the carbon and copper with minimal wear...so I really feel this has extended my barrel life.

MarkR said:
I have got to think that if my rifle was doing this..."6700 rounds on my 6BR and still punching 1's, 2's, the occasional 3's and screamers, I...probably wouldn't mess with it...JMHO :)
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I just went and re-measured. the 2.5 is giving me a hair over .001 squese at the shoulder and exactly .0005 at the base/web...so I'm thinking I should go down to the 3. Also, my past PPC and BR Harrels dies never through more than .001 run-outon the neck, but this one is throwing a tad over .002. If I take the bushing out, perfect, so the bushing is offcentered a bit. I then unscrewed the top 1.5 rotations so it would only size 1/2 the neck and runout was only .001. So I kinda want to send it back for this reason too, but I don't know if I'm being too picky...I kinda like everything perfect even if it is just a varmint gun now.

steve stanley said:
Bolt click comes from the brass not being sized enough in the web area of the brass. 0.0005 more sizing may stop the problem but I doubt it, most people get a 2.5 or 3 die from harrels and that will cure the problem. Try the die you have and see what it does for you, if it doesn't cure the problem get a 2.5 or 3 br die from harrels and it will cure the problem for both guns.
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If you are concerned about runout, there should be a carbide bushing in your future. I have spent some time working on concentricity. If carbide cost the same as steel, no one would use steel.
 
Boyd Allen said:
If you are concerned about runout, there should be a carbide bushing in your future. I have spent some time working on concentricity. If carbide cost the same as steel, no one would use steel.
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That's great to know. I am sold...from here on out, Carbide it is! However, in my case, that bushing is used on a 6PPC and my previous 6BR Harrels and less than .001 was/is the norm.
 
aka Hunter said:
Would someone tell me what is "bolt click"? It looks like I've stumbled upon something new (to me, that is) :
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It is resisistance encountered when opening the bolt at the very top of the throw...you can feel it snag and then when enough force is applied, it "clicks" to the top and the bolt opens. Not to be confused with heavy bold pressure from hot firings (or not setting head-space back enough) whereby you feel steady bolt pressure when opening the bolt throughout the throw.
 
RAG2,

If these fixes don't work please keep us posted. Often it takes more than just replacing a die.
al
 
One thing that can make this challenging is when the engaging surface of the back of the chamber (the part just in front of the chamfer or radius at the back of the chamber) covers brass that the die cannot reach when it is set for a proper amount of shoulder bump. If this is the case, a tight enough die can pull the unsized band to a smaller diameter by over sizing right next to it, which will make the round chamber OK, but once it is fired the click will be back.
 
I had to read a couple times, but I get it. And it makes complet sense. If this occured with a batch of PPC brass, I'd simply toss the brass and move on...but since I'm talking about a batch of 800 pieces of Lapua brass, it's a different story. Since this particular barrel/chambering is quite long in the tooth at this point, I think the solution is to simply chamber up new 6BR (and a 20BR I'm planning) using a slightly larger reamer/chamber dimensions at the base. Do you guys speculate this would remedy the problem...since my brass now has a "memory" of dimensions too wide for my current reamer?

Boyd Allen said:
One thing that can make this challenging is when the engaging surface of the back of the chamber (the part just in front of the chamfer or radius at the back of the chamber) covers brass that the die cannot reach when it is set for a proper amount of shoulder bump. If this is the case, a tight enough die can pull the unsized band to a smaller diameter by over sizing right next to it, which will make the round chamber OK, but once it is fired the click will be back.
Click to expand...
 
RAG2 said:
I had to read a couple times, but I get it. And it makes complet sense. If this occured with a batch of PPC brass, I'd simply toss the brass and move on...but since I'm talking about a batch of 800 pieces of Lapua brass, it's a different story. Since this particular barrel/chambering is quite long in the tooth at this point, I think the solution is to simply chamber up new 6BR (and a 20BR I'm planning) using a slightly larger reamer/chamber dimensions at the base. Do you guys speculate this would remedy the problem...since my brass now has a "memory" of dimensions too wide for my current reamer?
Click to expand...

It'll work as long as the relationship between the chamber and sizer is proper and you don't/haven't hammered the brass terribly. It's also somewhat contingent on the brass only haing 5-6 firings on it now. You should be good. I'd spec the new reamer .001 bigger at the web area than your fired brass is now. Fwiw...Mike
 
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If you have used the 800 pieces of brass equally that is just over 8 firings per piece of brass, I have 30 br cases that have been shot way more than that and they still size fine and shoot without a click. Most people just go straight to the 3 and forget it, I'm using a 2.5. I really think the proper die will cure your problem and it's such a simple inexspensive fix.
 
steve stanley said:
If you have used the 800 pieces of brass equally that is just over 8 firings per piece of brass, I have 30 br cases that have been shot way more than that and they still size fine and shoot without a click. Most people just go straight to the 3 and forget it, I'm using a 2.5. I really think the proper die will cure your problem and it's such a simple inexspensive fix.
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I agree, Steve. Even cheaper and just as good, would be to polish the back of the chamber about a thou, but what he proposes will do the same thing. Like I said, it's all to do with the relationship between chamber and die. Some might argue his reamer was a tad small to begin with, making either opening the chamber a bit or buying an unnecessary die to correct the relationship ...necessary.
 
You should not have a problem when using a FL die properly. However, it's a real advantage to adjust your die height accurately, and the average shooter has no idea how to do this. Another cause for bolt click is when "custom" chambers are cut too tight at the body. Remember that cases are tapered, and mearly bumping the shoulder isn't always enough.
 
mwezell said:
I agree, Steve. Even cheaper and just as good, would be to polish the back of the chamber about a thou, but what he proposes will do the same thing. Like I said, it's all to do with the relationship between chamber and die. Some might argue his reamer was a tad small to begin with, making either opening the chamber a bit or buying an unnecessary die to correct the relationship ...necessary.
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Yes, agreed and understood. The reamer was actually Dan Dowling's dimension, so I think the dimensions were just fine. I think I simply ended up with a FL die that was a little too large, allowing the web to expand too much over multiple firings untilt he click developed. I will try this 2.5 (if work will ever slow down and I can get to the darn range) AND if necessary polish out the chamber at the base a tad. Thanks yall!
 
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