Belted Mag Headspace Question

[M-61]

Yes, the barrel is stamped 8mm Mag. Im going to try the scotch tape method on a factory round and do a chamber cast. Im not firing this thing until i know exactly what is what about it.

That is a very wise decision.

 

[fguffey]

http://www.midwayusa.com/Product/156824/ptg-headspace-no-go-gage-belted-magnums-300-winchester-magnum-7mm-remington-magnum-338-winchester-magnum-458-winchester-magnum-535-base

I would neck up the 8mm Remington case to 350 Remington then start sizing the case to reduce the distance from the shoulder to the case head. If I wanted to know the difference in head space and case head belt clearance I would cut the case body from the case head.

F. Guffey

 

[fguffey]

Bolt does not even begin to close on the Go gauge. I will get some scotch tape and try Preachers method with a factory round to see how many layers

If the bolt will not close on the go-gage adding tape will not make it any easier-to close the bolt. Adding tape to the case head will not help if the case shoulder is hitting the shoulder of the chamber.

The head space gage is one or the other, it does not measure both the shoulder of the chamber and belt clearance.

F. Guffey

 

[agr516]

If the bolt will not close on the go-gage adding tape will not make it any easier-to close the bolt. Adding tape to the case head will not help if the case shoulder is hitting the shoulder of the chamber.

The head space gage is one or the other, it does not measure both the shoulder of the chamber and belt clearance.

F. Guffey
[/quote]

I understand what you're saying. Preacher suggested adding layers of tape to the case head of the factory rounds (which do chamber just fine), not to the go gauge.

 

[fguffey]

I understand what you're saying. Preacher suggested adding layers of tape to the case head of the factory rounds (which do chamber just fine), not to the go gauge.

Understood: I am not the fan of using loaded ammo,

There is something called minimum length/full length sized. There is something called go-gage length, there is something called no go-gage length. And there is my favorite, the field reject length. You have factory loaded ammo, factory loaded ammo comes under the category of 'minimum length'/full length sized. The difference between minimum length and go-gage length is .005".

Again, I will not use loaded ammo as a gage, I do not shoot gages, I shoot loaded ammo. Back to taping the case head, your head space gage does not contact the shoulder of the chamber.

I have 8mm Remington cases, I have no problem cutting the case body off of the case head in front of the belt. I have no problem necking up the 8mm Remington case and forming a new shoulder ahead of the old shoulder. I want to know the length of the chamber from the shoulder of the chamber to the bolt face.

I suggest you remove the firing pin assemble before chambering a loaded round.

F. Guffey

 

[Greyghost]

You guy do understand that if this was chambered excessively deep, that the belt would be excessively deep and that there wouldn't have been any problem with it closing on the go gauge.

If it was chambered for anything other than the 8mm Rem. Mag. the 8mm Rem. Mag. cartridge wouldn't allow the bolt to close. Don't know of any other belted mag 8mm cartridge that would allow this cartridge to chamber. If chambered for a non belted 8mm cartridge the belt on this cartridge still wouldn't chamber.

You know you have a tight fit on the belt.... if you've never fire formed a cartridge before and afraid to fire a live round, pull the bullet, and fill with a filler then top of with some bathroom chalking, let it dry and fire it. That fired round will give you everything you want to know.

As I said this is going to get interesting.


Phil

 

[Ggmac]

Phil sorry to pop the bubble , but it could have started life as a 8x 68s or any of the European large case magnums , which would allow the belt to enter , also the case though . It is a Sako and 8x 68 along with some romed 8 mm were available .
Just going off memory so please disregard if not all is correct.

 

[Greyghost]

8mm Rem. Mag. is a longer cartridge, and has a larger shoulder diameter, wouldn't have chambered.... keep going.

Anybody that would have chambered a rimmed cartridge so deep that it would allow a belted mag. cast to chamber sure phucked up!


Phil

 

[Ggmac]

Yes but if someone RECHAMBERED as the OP said it would both chamber and be dangerous . Heck keep coming .

 

[Ggmac]

Waiting ....... Still waiting .....

 

[fguffey]

Yes, the barrel is stamped 8mm Mag.

8MM mag, that does not mean it is an 8mm Remington magnum.

You guy do understand that if this was chambered excessively deep, that the belt would be excessively deep and that there wouldn't have been any problem with it closing on the go gauge.

I do not know who "you guy" is, I understand the reamer is one piece. I have inside and outside caliper/transfers, I have blind hole micrometers.

And I have presses with threads, I have dies with threads and I have case forming dies. I do not assume the tools I have are common tools used by others.

F. Guffey

 

[Greyghost]

How's it going to be dangerous, they both use the same .323 bullet, and if the Rem. Mag. chambers and it has a tight head-space, the only thing it could possible do is fire form to chamber specs.

As I said if it was chambered for the 8x68, the Rem. Mag. wouldn't have chambered......

 

[Ggmac]

Well said Fguffey too many young keyboard smiths that never had to render first aid to a rifle exploding because the shooter THOUGHT it was something else .
Gary
Because the 8x68 has a non belted larger case . Which means a case rupture at the unsupported belt line . Look research and than post .

 

[Greyghost]

He wasn't trying to chamber a 8x68 into a 8 Rem. Mag. Yes that would have fit loosly, and if it was able to fire it might have ruptured. But the 8mm Rem. Mag. which is a longer and wider case and he was able to chamber and which won't fit into a 8x68 chamber...

Phil

 

[Ggmac]

OK once again s l o w this time . If it started as 8x68s then rechambered to a 8 mm rem Mag the 8 mm rem mag would fit and fail if fired . Even if it was fired real real cautiously , I guess that means you pull the trigger slowly maybe with your eyes closed ? I don't pull the trigger unless I know what it is I'm shooting , no would I want to sit next to some cautious shooter like that . I've been retired many years from rifle smithing ans STILL carry liability ins for people that think 50-60 thousand pounds of pressure and 5 thousand deg can be held by being cautious when pulling the trigger .

 

[Ggmac]

I'm done your understanding or lack of has worn my old fingers out .
Gary
Many , many 8 mm mags . Some even based on the LAPUA case !

 

[Greyghost]

OK, Please tell me how its going to fail................ 8x68 approx 64,000 psi, 8mm Rem. Mag. 65,000 psi. again approx.

Hell I wouldn't purchase a rifle from any of you. and I'm also older than you and been there done it.


As I said going to get fun, but has become obnoxious!



Phil

 

[Ggmac]

Oh crud now you've done it , made me mess myself ,now the nurse has to come and clean me up and change this nappe .