6BR Tight at top of bolt lift

[6BRinNZ]

Lapua gold box cases are on their 6th firing and bolt lift at the top is slowly getting more difficult.
Load is (~2980 fps)
30.5 (2208) Varget
95 Berger VLD (jumped)
CCI450

I use a Redding Instant Indicator to measure shoulder bump and that is ~.001 - ~.0015
I use a Full length Redding sizing die everytime.
Primer pockets are tight - I use a lee primer seater.
Case growth (OAL) after firing is pretty much nil - after FLS it is ~.001
Cases are trimmed to 1.555 every firing
Action is a Howa

Reading previous posts - my load doesn't appear hot - temps over here are relatively cool.
Is it simply that my sizing die is not a good fit for the chamber and should I look at either a small base die or a custom die?
Any other thoughts -suggestions?

 

[Steve Blair]

Custom die is the best path. It solved my 6BR "click of death" problem.

 

[6BRinNZ]

Thanks Steve - who did you use?

 

[Steve Blair]

Mark Spencer at Spencer Tool & Grind. They are simple, reasonably priced and do the job. Mark's dies do not have a decapping stem and it must be done separately. [br]
http://spencertoolandgrind.com/ [br]
If you are feeling flush, I also have the Cadillac of sizing dies for my Shehane, the Warner Tool sizing die. It is beautifully done but expensive. [br]
http://www.warner-tool.com/

 

[BoydAllen]

Friends, who ran into the same problem, sent a couple of , tight, fired cases off to Harrell's Precision. Lynwood prefers that you give him a call before sending anything. His dies see wide use in benchrest competition, and are an excellent value. http://www.harrellsprec.com/

 

[6BRinNZ]

Thanks Guys - if I go down this track is it advisable to get my own reamer as well? - you guys have listed some very nice gear

 

[Steve Blair]

I prefer to have my own reamer for consistency from barrel to barrel. You could accomplish the same thing if you know your gunsmith and what reamers he uses.

 

[Forum Boss]

It may be a good idea to get a custom die. But check first to make sure your chamBer is clean and that you don't have a build up of gunk that may be interfering with fit. Your load is not that hot for a Berger 95.

I would also try adding a little more bump and see what happens.... I'm not convinced you're getting a true read with the Instant Indicator.

 

[6BRinNZ]

I prefer to have my own reamer for consistency from barrel to barrel. You could accomplish the same thing if you know your gunsmith and what reamers he uses.

Thanks - fair call - I have managed to sneak in a couple of wins at the recent regionals so I should probably take the next step up and do as you suggest with the reamer regardless.

 

[6BRinNZ]

It may be a good idea to get a custom die. But check first to make sure your chamBer is clean and that you don't have a build up of gunk that may be interfering with fit. Your load is not that hot for a Berger 95.

I would also try adding a little more bump and see what happens.... I'm not convinced you're getting a true read with the Instant Indicator.

The dies are clean and the chamber etc has been bore scoped - I brush every time with Butches - while others can disagree from a pure accuracy point of view it meets my consistency needs.

I am concerned that if I bump more I will start to move towards an issue with case separation....With respect to the RIID; I have absolutely no issues chambering - a little bit of receipt paper (~.002") on the end of the case will produce a firm but closeable bolt.

 

[jonbearman]

Do you anneal and it would be interesting to compare a chamber cast to a fired case.

 

[thumper4fun]

I had the same problem when I used a redding die. Sent a couple pieces of brass that had been fire 3 or 4 times to Harrells and they sent me a semi-custom die. Problem solved for around $70 if memory serves me.

 

[shooter63]

harrells are very good would probably solve your problems regards shooter63

 

[BoydAllen]

If a die does not size the back of the case, with the proper amount of shoulder bump, get another die. My friends bought Redding dies for their custom chambered 6BRs, despite my recommendation that they go with Harrell's, and when they found that they had a problem, they became better listeners. If they had had factory chambers, the Redding dies probably would have worked. These were custom chambers that were obviously a little small at the back to be paired with stock dies.

 

[topwater225]

Edit: Sorry, I was under the impression that you were getting a CLICK at the top of the bolt lift. If that's the case then my post below will make sense, if not and you are just talking about a stiff bolt lift, then it may be just a shoulder bump issue.........

I've also ran into this with 2 BR based chamberings.....a 20BR and a 6BRX. A good test and possibly even an easy solution would be a .308 or .243 small base die. It solved the problem for both calibers, but I hated the extra step and possibly sizing them more than I wanted. You may even find that you only have to run 'em through the small base die every other or 2 firings. In the end a custom die would be the ultimate solution.

BTW...you may already know this, but the CLICK is not from the shoulder needing to be bumped more.....The cause is the base is not getting sized down enough. That is why a small base die will more than likely work for you as well.

Good Luck....I know and have felt your pain 8)

 

[260Ravage]

I'm with ForumBoss on this. After a few firings with a particular shoulder bump, I get hard bolt lift. I simply push the shoulder back .001,,,viola! back in business! I use use die shims so it is easy to adjust. just say'n.
Terry

 

[Steve Blair]

I'm with ForumBoss on this. After a few firings with a particular shoulder bump, I get hard bolt lift. I simply push the shoulder back .001,,,viola! back in business! I use use die shims so it is easy to adjust. just say'n.
Terry

[br]
It's not a question of hard bolt lift, but the click at the top as the bolt handle cams the case to the rear. As was noted several times, it is caused by insufficient base sizing. My 6BR did it with annealed cases and accurately measured shoulder bump. Drag throughout the bolt lift is evidence of shoulder impingement.

 

[jonbearman]

You nailed it sleepygator.I will remember that now,thanks for the imfo for all of us.

 

[Terry]

Things to try before buying new dies.

Anneal the brass.

Set your die to cam over. By that I mean to set the die deeper in the press. The last part of the stroke will be harder, then it will cam over.

Lastly change shell holders. These permit you to very shoulder length.

http://www.midwayusa.com/product/525874/redding-competition-shellholder-set-1-308-winchester-30-06-springfield-45-acp

 

[BoydAllen]

If a case is too long at the shoulder, it will cause hard bolt closing, I believe that the initial post was about a situation that involved tightness at the top of bolt lift. Also, the Redding Competition shell holders are equal to or taller than standard, in increments of .002. which would cause the bump to be less not more. Bump should be gauged. Setting bump by feel with a die that does not adequately size the base of cases, pretty much guarantees that the shoulder will be set back too far. As a matter of fact, it is this very situation that best explains why measuring is the right approach. I have a turned down shell holder that I use when sizing heavily work hardened cases for my 6PPCs, but the die is set with a gauge to bump shoulders .001 or less from the measurement of a case that is at the maximum for that particular chamber.