Does Anybody Know What Is The Maximum Tolerance (if There Is Any) For A Bolt Face? Is The Tolerance A Precentage Of The Cartridge Base Diameter? Or Is It The Same Tolerance For Any Case Base....

Hmmmmmm......................:confused:

Hmmmmmm......................:confused:
Confused?. Well, there is a part of the bolt (at the front of the bolt head) that holds towards the chamber and around the case base. Remingtons have a hole that holds the cartridge, while Mauser-type rifles have a semi-circular protuberance that does the same work. So, the question is: What is the máximum tolerance of that hole in which, the cartridge base gets into?

I rather doubt there would be a standard SAAMI specification for that. It would be the sort of thing the manufacturer would come up with a tolerance for. It also seems like it might depend upon what sort of action it is. For example, there is no such geometry on a Ruger #1 or an NEF Handi-Rifle.

i think there will be lots of variables. for instance the rem 700 has an extractor built into the counterbore in the bolt face, which will not support the rim enough to limit rim expansion. controlled feed actions have part of the bolt face rim removed to allow cartridges to slide up under the extractor. actions with plunger ejectors may have different needs than actions with blade type ejectors.
the dimention you are asking about must be loose enough to accept the largest rim of it's particular cartridge, yet hold the small cartridge rims in solid contact with the extractor.
i think there will be a different ideal size here for each different action type.
this is just my thoughts but i haven't read anything on this subject so i'm kinda guessing.

monty

i think there will be lots of variables. for instance the rem 700 has an extractor built into the counterbore in the bolt face, which will not support the rim enough to limit rim expansion. controlled feed actions have part of the bolt face rim removed to allow cartridges to slide up under the extractor. actions with plunger ejectors may have different needs than actions with blade type ejectors.
the dimention you are asking about must be loose enough to accept the largest rim of it's particular cartridge, yet hold the small cartridge rims in solid contact with the extractor.
i think there will be a different ideal size here for each different action type.
this is just my thoughts but i haven't read anything on this subject so i'm kinda guessing.

monty
I'VE BEEN LOOKING FOR SOME LITERATURE ABOUT THIS ISSUE ON THE WEB, WITH NO LUCK. I GUEES IT IS AN EXPERT'S DOMINION TOPIC. UNLESS SOMEONE APPEARS TO KNOW AND GIVES US SOME LIGTH ABOUT IT.

I rather doubt there would be a standard SAAMI specification for that. It would be the sort of thing the manufacturer would come up with a tolerance for. It also seems like it might depend upon what sort of action it is. For example, there is no such geometry on a Ruger #1 or an NEF Handi-Rifle.
YOU MIGHT BE RIGHT. WHAT I'LL DO IS TO TAKE SEVERAL MEASURES OF AS MANY BOLTS AND CARTRIDGES AS I CAN GET. I'LL TRY TO FIND A RATE OR CONSTANT WITH THAT DATA. THERE MUST BE SYSTEMATIC WAY TO DESIGN BOLT FACES.

If we knew what bolt, and the cartridge it's fitted for now, and what you want to go to, you might find someone who's done it.
I'm doubtful that there is a standard number for tolerance- as others have said, gonna depend on the bolt type, etc.

If we knew what bolt, and the cartridge it's fitted for now, and what you want to go to, you might find someone who's done it.
I'm doubtful that there is a standard number for tolerance- as others have said, gonna depend on the bolt type, etc.

OK, I'D LIKE TO KNOW THE MAXIMUM BOLT FACE DIAMETER FOR BELTED MAGNUM CASES, SUCH AS .350 REM MAGN. OR OTHER SIMILAR. THE BASE DIAMETER FOR THAT CALIBER IS 0.532", SO I WONDER WHAT IS THE BOLT FACE DIAMETER FOR THAT PARTICULAR CALIBER.

OK, I'D LIKE TO KNOW THE MAXIMUM BOLT FACE DIAMETER FOR BELTED MAGNUM CASES, SUCH AS .350 REM MAGN. OR OTHER SIMILAR. THE BASE DIAMETER FOR THAT CALIBER IS 0.532", SO I WONDER WHAT IS THE BOLT FACE DIAMETER FOR THAT PARTICULAR CALIBER.
Might be possible to solicit members of this forum to get the dimension from their bolts. If you get enough of them, I imagine you can get a good feel for what you are trying to find. Unfortunately, I don't have a belted magnum at the moment so I can't help you.

I do know, however, that it is not a very tight spec.

For example, owners of Marlin 336's sometimes rechamber them to .307 Winchester. The external dimensions of a .307 are the same as a .308, except it has a 30-30 rim. These guys can reload with regular .308 brass, and it will reliably extract and eject with unaltered bolts and extractors.

I have found you can use an unaltered bolt on a Mosin-Nagant to extract and eject .410 shotshells.

ok, i can help you out a little now. my Remington 600 in .350 Rem mag has a bolt face recess of .550", and is .15" deep.

Monty

ok, i can help you out a little now. my Remington 600 in .350 Rem mag has a bolt face recess of .550", and is .15" deep.

Monty
Thanks, that can really help me. It's interesting. The case base diameter for .350 RM is 0.532", then there is a tolerance of around 3.38%. I'll keep looking for a constant. I guess magnums have a bigger recess.

Thanks, that can really help me. It's interesting. The case base diameter for .350 RM is 0.532", then there is a tolerance of around 3.38%. I'll keep looking for a constant. I guess magnums have a bigger recess.

In his book "The Mauser Bolt Actions" Jerry Kuhnhausen states that the commercial magnums have a recess diameter of .004" to .006" larger than the .532" case head diameter.
Never done bolt face work m'self, but Kunhausen is considered one of The authrities no Mauser actions.
Hope this helps.

In his book "The Mauser Bolt Actions" Jerry Kuhnhausen states that the commercial magnums have a recess diameter of .004" to .006" larger than the .532" case head diameter.
Never done bolt face work m'self, but Kunhausen is considered one of The authrities no Mauser actions.
Hope this helps.
OK, SO IF A MAUSER OR MAUSER TYPE BOLT IS TO BE OPENED TO ACCEPT MAGNUM CASES (.532" BASE) MUST NOT BE ABOVE 0.538". MY PROJECT REMAINS ON CONVERTING AN ARISAKA T38 TO 6.5 REMINGTON MAGNUM.

That would be my assumption on the sittuation, if the bolt face recess wre cut too large you would experience both feeding and extraction problems. Bear in mind ( if you're not already aware of it ) the extractor will also need to altered for that case head size.
If you need a gunsmith to do this work I will try to locate the ph# for Hammrick and Gibson, I've had them do some work for me and they are good.

couldn't find ph#,
e-mail at www.gunny@emeraldis.com

Hope this helps
Scott

That would be my assumption on the sittuation, if the bolt face recess wre cut too large you would experience both feeding and extraction problems. Bear in mind ( if you're not already aware of it ) the extractor will also need to altered for that case head size.
If you need a gunsmith to do this work I will try to locate the ph# for Hammrick and Gibson, I've had them do some work for me and they are good.

couldn't find ph#,
e-mail at www.gunny@emeraldis.com

Hope this helps
Scott
Ok, I'm aware of that, and thanks for advise about your gunsmith.