6BR is Siff in Rapid Fire; Resolved.

[alinwa]

Nobody is shooting 6br with a .477 chamber base.
M->
except for you...

And this is relevant HOW??

I'm old..... and I've discussed civilly and uncivilly with a lotta' people...... and I've noticed for 50yrs how it's always the guy with the problem that's doing the arguing!

 

[matorre]

And this is relevant HOW??

I'm old..... and I've discussed civilly and uncivilly with a lotta' people...... and I've noticed for 50yrs how it's always the guy with the problem that's doing the arguing!

...only when somebody uses vague and colloquial terms. how quaint.
go away please.
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[matorre]

Does anybody have any hard-earned real-world experience?

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[bigstick6017555]

most of the suggestions you got were hard earned real-world experience

 

[matorre]

most of the suggestions you got were hard earned real-world experience

...

true enough,kind sir.

I just looked a little bit askance at rubber stamp solutions from folks without asking questions at all.

I took some of the suggestions from thoughtful individuals and put them to work and..... I got some real improvements.

I've run out of time today but by the end of the week I will have conducted full power tests to see how I fare.

I am in a field that requires very critical thinking and no jumping to conclusions... therefor I'm a little bit skeptical about the first five or six answers if I haven't heard any analytical questions.

Anyhow the man who suggested that the neck clearance was much too tight was spot-on.

I didnt want to shout hooray prematurely.

M->

 

[Webster]

Re: 6BR is Siff in Rapid Fire

I've got a 700 in .223 that I had built. Every once in a while, a fired case won't extract without either tapping it out with a bore rod or tapping the handle with a block of wood. I was told by Dan Armstrong (Accutig) to remove the firing pin reinsert the bolt and lift the handle to the 3 o'clock position and place a feeler gauge between the bolt handle and the receiver. I came up with .034" clearance (too much). Dan said I only had 30% of my primary extraction. Dan says he tigs the handle to have .010-.015" clearance for maximum primary extraction. This may not be your problem, but worth a check. Remington doesn't usually give you max primary extraction from the get go and then you have tolerance stacking. Then you have your receiver trued and the internal lugs are cleaned up and then your bolt lugs are cleaned up and you've lost even more. I hope you can make heads or tails of what I'm saying. If this is your problem, you need to have your bolt handle moved closer to the receiver.

Great response. It's called something like bolt timing. Go on YOUTUBE.COM and search for bolt timing Several great viseos

...

true enough,kind sir.

I just looked a little bit askance at rubber stamp solutions from folks without asking questions at all.

I took some of the suggestions from thoughtful individuals and put them to work and..... I got some real improvements.

I've run out of time today but by the end of the week I will have conducted full power tests to see how I fare.

I am in a field that requires very critical thinking and no jumping to conclusions... therefor I'm a little bit skeptical about the first five or six answers if I haven't heard any analytical questions.

Anyhow the man who suggested that the neck clearance was much too tight was spot-on.

I didnt want to shout hooray prematurely.

M->

I used to have a tight neck 6PPC. My first and only tight neck rifle. I turned the necks to what should have given enough clearance. All cases turned the same but only measured a couple. Apparently one case was borderline on the neck being too thick or a bullet was a couple 10 thou bigger? Big assumption that all tight neck chambers are the same exact dimension? Fired many rounds OK. On one case I had to hammer the bolt open. Don't remember if it was tight to chamber, many years ago. The neck was elongated a lot from forcing the bullet out. I most have been well over 70,000 PSI. Lucky I am still alive. Never figured out what happened. The action was not damaged. With a tight neck measure each case neck with a good tube mic. Don't assume they are all the same because you used one setting on the neck turner, It's a critical dimension for safety. Side comment: Everyone should look at a YOUTUBE.COM video about bolt timing.

 

[Alex Wheeler]

You should be .471" .2" up from the base, not at the base.

 

[matorre]

You should be .471" .2" up from the base, not at the base.

You are correct. I misspoke. I apologize for my carelessness.

....went back and fixed it.
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[Patruck825]

Seems i have this same issue, i have the same exact chamber, as you mentioned in my thread matorre. My Redding die was sizing my case at the shoulder and at the .200 line only .0005

I've recently done the small base .308 die thing and have seen a large improvement, but if i have ANY thing at all on my case, sizing lube etc i will get the same issue. In a sport where i often shoot in the rain, this is just a recipe for trouble. I have not yet explored the neck clearance issue, but not sure i should. A loaded round measures .2685 and my neck is .271, id think that that is enough clearance, no?

I have a harrells die on the way to me today

 

[matorre]

Seems i have this same issue, i have the same exact chamber, as you mentioned in my thread matorre. My Redding die was sizing my case at the shoulder and at the .200 line only .0005

I've recently done the small base .308 die thing and have seen a large improvement, but if i have ANY thing at all on my case, sizing lube etc i will get the same issue. In a sport where i often shoot in the rain, this is just a recipe for trouble. I have not yet explored the neck clearance issue, but not sure i should. A loaded round measures .2685 and my neck is .271, id think that that is enough clearance, no?

I have a harrells die on the way to me today

Your report of hard extraction when you get liquid on the case has been historically normal for a firearm, give you trouble in the rain especially when it's loaded right to the wall .
...sounds like a good reason to buy a really wide brimmed Stetson to shoot with
:- )

Sheesh, I should have stuck with 30-06. It was a lot less trouble.
;- )
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[rwj]

You should be .471" .2" up from the base, not at the base.

I’m looking for clarification... I’ve seen multiple citations to the .200” offset distance from the base to the .471” case diameter from very knowledgeable members... yet the CIP standard for 6mm BR Norma specifies .151” Which is correct? Is there a “defacto” standard developing?

 

[BoydAllen]

Reamer prints typically use the .200 dimension. You can accurately describe a given reamer either way, but of course the numbers at the two distances from the bolt head must be slightly different. Working from the calculated body taper (.012/inch) and the difference between measuring locations, the difference in specification of the same reamer would be .0006.

 

[rwj]

Thank you!