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Reloading 6mm Br - Help

Posted: Thu Mar 12, 2015 5:34 pm
by nigelc
Just bought a Savage 12 F Class in 6mm Norma Br and made a couple of "dummy" rounds to check that they cycle in the action etc. However, I am experiencing a stiff bolt when chambering the round. Don't get me wrong, I do not have to use heavy force to close it - but it is stiff at the point the bolt first turns down to close. The "dummy" rounds cycle out of the action without a problem. I have checked all the key measurements and they meet the relevant spec.

I have also tried chambering a new case and have had the same problem. I have even run the case through a Forster FL sizing die and it makes no difference.

The spec for the "dummy" rounds is as follows:
- New Lapua brass
- 107gr Sierra MatchKing
- COAL 2.375
- Case length 1.55

Any help or advice would be appreciated.

Re: Reloading 6mm Br - Help

Posted: Thu Mar 12, 2015 5:44 pm
by Alpha1
Trim all your cases to a uniform length.
Use a cartridge overall length gauge to find your correct seating depth. If you don't all ready have one I recommend ovenpaa,s cartridge over all length gauge.
If you are shooting F class and loading 6mm Norma I guess you are pretty clued up on re loading.

Re: Reloading 6mm Br - Help

Posted: Thu Mar 12, 2015 5:54 pm
by knewmans
It may just be the resistance in the system.

Try cycling without the firing pin. Just drop the bolt handle enough to engage the extractor. Withdraw the bolt a little to check its engaged and then chamber the dummy. Hopefully then the handle will go down with very little effort.

Re: Reloading 6mm Br - Help

Posted: Thu Mar 12, 2015 6:14 pm
by The Gun Pimp
nigelc wrote:Just bought a Savage 12 F Class in 6mm Norma Br and made a couple of "dummy" rounds to check that they cycle in the action etc. However, I am experiencing a stiff bolt when chambering the round. Don't get me wrong, I do not have to use heavy force to close it - but it is stiff at the point the bolt first turns down to close. The "dummy" rounds cycle out of the action without a problem. I have checked all the key measurements and they meet the relevant spec.

I have also tried chambering a new case and have had the same problem. I have even run the case through a Forster FL sizing die and it makes no difference.

The spec for the "dummy" rounds is as follows:
- New Lapua brass
- 107gr Sierra MatchKing
- COAL 2.375
- Case length 1.55

Any help or advice would be appreciated.
I assume these were brand-new Lapua 6BR cases - not ones fired in another rifle?

Re: Reloading 6mm Br - Help

Posted: Thu Mar 12, 2015 6:21 pm
by nigelc
Yes, all new Lapua cases - all of the same length - the gun and cases have never been fired

Re: Reloading 6mm Br - Help

Posted: Thu Mar 12, 2015 6:54 pm
by 1066
Is this a new rifle or just new to you? Bearing in mind the Savage barrel is screwed on and the headspace adjusted by the lock nut it would be worth checking with go/no gauges to see if it's set up correctly.

Re: Reloading 6mm Br - Help

Posted: Thu Mar 12, 2015 9:10 pm
by nigelc
Yes, its a new unfired rifle - will check it. Thanks for the advice.

Re: Reloading 6mm Br - Help

Posted: Thu Mar 12, 2015 11:09 pm
by The Gun Pimp
What happens when you chamber a new unfired case without bullet? New cases are always slightly under-size - it should fly in. If it does, then it's a bullet problem.

Re headspace - the rifle will have been fired at proof of course so I doubt there is a headspace problem.

Re: Reloading 6mm Br - Help

Posted: Fri Mar 13, 2015 11:48 pm
by nigelc
It is the same when I chamber a new Lapua case (no bullet) - a stiff bolt at the point it starts to turn down. However, it ejects with no problems at all.

Re: Reloading 6mm Br - Help

Posted: Sat Mar 14, 2015 9:11 am
by 1066
nigelc wrote:It is the same when I chamber a new Lapua case (no bullet) - a stiff bolt at the point it starts to turn down. However, it ejects with no problems at all.
I have a Savage 12F in 6br - Shoots a treat.

I take it there's no resistance without an empty cartridge loaded?

Is the chamber clean/degreased?

Because of the design of the savage bolt head there is slight resistance when you close the bolt - The "floating" bolt head is quite sloppy, this is one of the factors that contribute to the inherent accuracy of the design. The "slop" is taken up by a spring "wave" washer between the bolt body and the baffle. When the bolt is closed the baffle remains stationary and the bolt head turns. The resistance you can feel when a case is inserted could well just be this friction of the compressed spring washer.

With no cartridge the spring is relaxed with less pressure. This part is usually polished and smoothed/greased as part of a bolt tune up.

http://www.switchbarrel.com/BOLTHEAD.htm

http://www.savagearms.com/accuracy/

One of my Savages:
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