is it too much head space?

[savagelover]

My 6BR is acting up.

With a starting load from the berger manual using
H322 with the 68 grain bullets,I am getting a stiff
bolt lift..And the cases will not rechamber..
I am full length resizing as well..I seems to do it
with other powders as well..I put the barrel on myself
as I have done with a few others,and never had any
issues..
Will too much head space cause this ??? I suppose it
is possible the nut did not get locked down tight enough.
If it is head space problem..My other barrel was ok..except
I wore it out..I just sent into the place to rent the
go and no go gauges..All brass (lapua) has been trimmer
and like I said..Full length sized.They chamber with
ease..But as mentioned,after fireing,will not rechamber..
Thanks for any advice...

 

[230RN]

Do you mean the lock nut(s) on the loading die(s) or the lock nut on the Savage I assume you replaced the barrel on?

That cartridge has the "look" of a difficult-to-extract case anyhow, with its rather straight walls.

 

[Vern Humphrey]

Generally speaking, if you have a little too much headspace, the fired cases will still go back into the chamber they were fired in, but not into a chamber with standard headspace.

Have you tried chambering an empty, fired case? If it will go, the problem is seating bullets out too far, so the bullet engages the rifling before the bolt closes.

Have you tried reducing the charge?

 

[savagelover]

Let me add a bit more There is NO signs of pressure on the
case. Now flat primers,bolt face marks or anything like that.

I have tried different oal's as well...One fellow told be there was
excessive head space ? Like I said,I get stiff bolt lift with
other loads as well..The case extracts easy but the case will
not rechamber..And,according to the measurement,I am bumping
the shoulder back .oo25 inch,which should be correct....
I rented the go and no go gauges and when they get here I am
going to check it..I suppose there is a possibility,that when I tightened
the barrel nut,the barrel may have backed out a tad ?:banghead:

 

[larryh1108]

This may get more answers in the reloading section. Lots of helpful people over there.

 

[Larry Ashcraft]

This may get more answers in the reloading section. Lots of helpful people over there.

I'm thinking the same thing. I'll move the thread with a one week redirect so it can be seen both places.

 

[rcmodel]

Excess headspace does not cause heavy bolt lift.

All it causes is premature case stretching and incipient case head separation.

You can shoot an old mil-sup rifle with very excess headspace from now on.
And there will be no good indication of it till it starts breaking cases off in the chamber.

Bend an L on the end of a paper-clip or piece of wire and reach down inside the fired cases and feel for a stretch ring in the brass about 1/2" ahead of the case head.

If you can feel a stretch ring?
Then you probably have excess headspace.

If there is no internal stretch ring inside the cases, you don't.

rc

 

[savagelover]

I have no noticed anything like you mention.My M1 garand used to do that once in a while,But I have not seen it here...thanks anyway..

 

[Slamfire]

Do you have a chronograph? What are your velocities? I am of the opinion that you have a pressure problem not a headspace problem. You full length size the case, push the shoulder back, but upon firing you have sticky bolt extraction. Sounds like high pressure to me. Primer signs are unreliable though if you were blowing or piercing primers you would know 100% your loads are over pressure.

Even if you don't have a chronograph, which would give you the clue that with high velocities, you have high pressures, I would cut your loads by a grain and a half and see if you still have sticky extraction.

My Kreiger barrels are so tight that I had to cut my old loads by a grain and a half in a 223, so, loads developed in one barrel type can be overpressure in another.

I just looked at a dimensional drawing of the 6 mm BR. That is one straight sided case! I have always believed in case taper as taper means the sidewalls relax in a diagonal instead of a line.

 

[ironworkerwill]

While installing the nut, you should have had the "go gage" installed in the chamber and the bolt closed. Torquing the nut will cause the barrel to spin with it. Savage uses this "minimum head space'' technique on factory rifles.

If you have a 6mmBR they are often times they are cut to minimum spec.

 

[243winxb]

High pressure signs -

a stiff
bolt lift..And the cases will not rechamber.

Other reasons a fired case will not enter the chamber. 1. Oval chamber. 2. Bolt face not square to the chamber. I think your problem will go away with correct setting of the barrel headspace using go & no go gauges??

 

[rogn]

243 probably has the answer. Bad chamber seems to be the answer, oval or off axis, are most likely. Bolt and receiver were OK prior so are probably still OK. Real rough check, spin a fired case in a v-block and look for any kind of wobble. Mike the case walls at 60* intervals and look for inconsistencies

 

[savagelover]

I already did that with my concentricy gauge..No more that .0035 out is all I found. wheni get the go and no go gages I will recheck everything.:banghead:

 

[gamestalker]

I've never barreled an action before, but I've seen it done a few times and always, always it has been done with a go / no go gauge, or with some means of determining / measuring head space. Head space is a critical element of barreling an action, so much so that the general range of specification is .006" to SAAMI dimensions, though custom rigs are often built to a much tighter spec in this respect. Too much head space can turn into a catastrophic disaster, too little and you'll need custom dies to get the brass to chamber.

GS

 

[ironworkerwill]

On a side note, if you own the "go" gauge you can use it to set up your FL die.

 

[savagelover]

Need to get a small base sizing die.Chan
mber is very tight..Why no one thought of this
I don't know.Called McGowin barrel and he said.

 

[FLIGHT762]

It also may be you not bumping back your shoulders enough in your F/L die. How are you measuring your shoulder bump length from your fired cases?

You might need to turn in your F/L die in a bit more. 1/8th of a turn can move the case bumping / shoulder sizing .009". It's a fine adjustment.

 

[ironworkerwill]

Hello! I told You 6br chambers are minimum spec.