More on Bolt Click

[2dogs]

I bought a Dan Dowling 6BR barrel 1/14 twist from the classifieds. I headspaced it up on a Remington action, had the bolt face bushed by Gre-Tan and carefully worked up a load. I settled on 35.5 of AA2230 on a 55 grain NBT and lit it off with a CCI 450 primer. Velocity runs 3920 fps. While loading, I dissassembled my bolt and used my chamber and dead bolt as a case gauge to get a perfect fit. While shooting, I could open my bolt with one finger and close it the same way. My primers looked great. I had 200 cases and decided to order 200 more in case I got the chance to go on a volume varmint hunt. I put my ammunition up in 50 round Frankford boxes. When I switched to a fresh box of 50 rounds I got a bit of a surprise. The bolt was hard to lift and I got a healthy "click" that I didn't like not even a little bit.

Needless to say this threw me a bit. I knew my case fit was right. I had individually weighed all my charges so I knew that was right. What on earth?? I did my research on here and one by one checked all the known maladies. I tried using a small base 30-06 die to size my loaded rounds and got another surprise. The web of the fired sticky cases measured .470" and when I checked my small base resized sticky cases they measured .470". This Dowling chamber is very tight. I have tried to call Dowling but just get a busy signal so I am unable to get the reamer specs from him. Looking at some other reamer prints they show .471" at the web. Hmmm

Next I got out all 400 of my brass cases, some loaded and some fired. I started checking the web of the cases and yet another surprise. 200 cases are .470" at the web and I have 200 that are .469" at the web. On a hunch, I took a box of the .469" base cases and I was right back to a one finger bolt lift and no other signs of an overloaded round. Now you would expect the base of the fired cases to be .470" like the others but they measured .469" instead.

So I know I have a tight chamber that prefers the size of the web of my cases to be .469". So I wanted to ask some of you guys to measure the web of your fired and loaded cases and share what you are getting. I need to add that I am using a Starrett 1" micrometer to measure my brass as a micrometer is so much more accurate than dial calipers. What resizing die are you using? What do the bases of your resized cases mike out at? Thanks in advance, I am weighing my options so I can move forward. I see were Harrells offers a number of differently dimensioned resize dies. Any thoughts there?

 

[Murray Brook]

I have a 6mm br Norma built on a Rem short action. My fired cases measured at the .200 line measure .4709 on average. My sized cases sized with my Redding body die measure .4700 on average at the same point and I also have a honed out Forster sizing die that when used sizes the cases to .4692 at the .200 line. So far no clickers with either die.

 

[Bill Norris]

My 6BRX Peterson brass measures .470@200/L on a fired case and .4695@200/L on a F/L sized case. I am using a Wilson F/L bushing die.

 

[JFrank]

Using my calipers that only show/resolve 5/10 th the below numbers may vary from yours however I find no downside to an extra .001 of sizing provided by the Wilson.
Reamer print .4714
Fired 3x .4705
HARRELS D 2.5 sizes .4695 - occasional clickers
Honed Wilson sizes .4685 - no clickers reported

 

[KMart]

Pick out 3 cases that is giving you clickers. Resize the necks just enough to hold a bullet. Shoot them 2 more times just sizing the necks., then send them unsized to Harrell's. Put a note with the cases telling Harrell's that these are giving you clickers.

He should be able to send you a die that will take care of your sizing problems

 

[LHSmith]

AA-2230 is very temp sensitive. Beware. BR level accuracy in my 14 tw. 6 BR also, but not so much when the temp.swings.

 

[ckaberna]

I have Krieger 14T on a panda action and also using the 55 nosler ballistic tip at 3830 with A2200 and fed 205 primers my lapua brass is measuring.4693 fired and .4692 sized with a hornady match FL bushing sizer. As mentioned above I highly recommend the harrels die but this hornady seems to work fine in this rifle.
I have been as high as 3960 fps with no ill effects but accuracy is at 3830

 

[LHSmith]

FWIW- my Redding FL bushing die gives me 0.4690." on 2x Fired cases. That is with my mic and my finesse? reading a mic. If you have the $, Harrels will make life easier, and you can always sell your existing die.

 

[KMart]

@2dogs Just curious. What brass are you shooting? I think that most of us are assuming that it is Lapua, but it shouldn't matter.

 

[Danley]

Ditto on the Harrell’s

 

[ckaberna]

Surely you don’t have the older Remington 6br chamber? What’s the oal of your cases?

 

[2dogs]

I have a 6mm br Norma built on a Rem short action. My fired cases measured at the .200 line measure .4709 on average. My sized cases sized with my Redding body die measure .4700 on average at the same point and I also have a honed out Forster sizing die that when used sizes the cases to .4692 at the .200 line. So far no clickers with either die.

Thanks for that information.

@2dogs Just curious. What brass are you shooting? I think that most of us are assuming that it is Lapua, but it shouldn't matter.

Lapua. But 2 different lots.

 

[2dogs]

Surely you don’t have the older Remington 6br chamber? What’s the oal of your cases?

Nope. The chamber is right. It’s just very tight.

 

[2dogs]

AA-2230 is very temp sensitive. Beware. BR level accuracy in my 14 tw. 6 BR also, but not so much when the temp.swings.

I’m well aware and did my load development during the S Texas summer. Thanks for your thoughts.

 

[JFrank]

Thanks for that information.

Lapua. But 2 different lots.

Are your clickers coming from the older brass with the most firings ? If so that may be a bit of memory developing as do mine when I run a high node load.
As i mentioned earlier that I really see no difference when having a touch more radial sizing except the noticeable free chambering rounds and lack of clickers while running a string.

 

[2dogs]

Are your clickers coming from the older brass with the most firings ? If so that may be a bit of memory developing as do mine when I run a high node load.
As i mentioned earlier that I really see no difference when having a touch more radial sizing except the noticeable free chambering rounds and lack of clickers while running a string.

No Sir. This is new Lapua brass. But you are right. After awhile brass will work harden and the die may need to adjusted for the change.

 

[AckleymanII]

SPJ hit the nail on the head! .4714 for me also....life is easier. I tried the .470 at the .200 line, clickers abound at the .200 mark, and both the 6 BR and 6 brx's loves loads at the red line. I Full length size with a Redding Body die, 6 BRX.

I shoot AA2230 and H335 with the 70g as well. love the lack of throat wear with this powder. I do have a hot weather load and a normal weather load. 55g Nosler is at 4000+ shooting a bug holes, 28" barrel, 10T, X caliber barrel with .020 freebore. 87g V max also shoot bug holes with H4895 with this short freebore reamer. No doubt that the 6 BRX is a varmint hunters dream come true.

If you have the patience to learn the powders, H335 and AA2230 in how they react to heat, your barrel life will be 6000+ rounds shooting in the 2's and lower, this number is conservative.