7.5 Swiss Loading Modern Bolt Action Rifle - Page 2

RC20 · June 24, 2017, 02:23 PM

Ok guy, to keep this on tract.

1. I am NOT going to load the K31 up past its design. Actually I am working on lower loads as I want that gun to last forever. You can't re-barrel it and maintain the originality.

2. Upper reaches on the Savage are to explore to see if there is a node there, not turn it into the next super short magnum (though I think it has possibilities there, those are not for me to explore!)

And lastly, the 308 is 62,000 PSI rated. My curiosity is tweaked.

It uses the same base cartridge as the 30-06, it has the same bolt faces, lugs as a 30-06, the case is no larger or smaller, barrel chamber has the same OD

So it seems to me, that when you come out with a completely new cartridge, the designers take advantage of the fact that it won't get loaded into an old gun as it can't and they move up the pressure to take advantage of that (or in the case of the 7.62 make act more like a 30-06)

I am not jumping up and down and saying violate all the rules we know for safe reloading, but it does seem to change that aspects of a load that can be used in any rifle vs one that is exclusively used in a modern rifle made out of modern materials using modern methods.

Jim Watson · June 24, 2017, 02:36 PM

We did get off track.
I see no reason not to load a 7.5 bolt action to the same pressure as any other round the action will hold.
The question remains, how do you know where you are at on pressure?
Quickload? Case expansion? Velocity vs other cartridge of similar volume?

RC20 · June 24, 2017, 03:36 PM

Gather as much information from all sources as possible and make as best a decision as you can.

Certainly 30-06 limits can be used as a rough guideline.

While I do not advocate anyone do this, 308 would seem to be of interest as well.

One factor not listed is it is a larger diameter round overall than 30-06.

Chamber material will be that much thinner.

Savage found the short magnums had some issues and cam out with a larger shank barrel to use on those and adding the other magnums as the rifle changes.

On the other hand it lived with the old size barrel shank with all the magnums until the shorts came out.

The 7.5 seems to have more aspects of a short magnum than anything.

Always interesting.

June 24, 2017, 02:23 PM	#26
RC20 Senior Member Join Date: April 10, 2008 Location: Alaska Posts: 7,014	Ok guy, to keep this on tract. 1. I am NOT going to load the K31 up past its design. Actually I am working on lower loads as I want that gun to last forever. You can't re-barrel it and maintain the originality. 2. Upper reaches on the Savage are to explore to see if there is a node there, not turn it into the next super short magnum (though I think it has possibilities there, those are not for me to explore!) And lastly, the 308 is 62,000 PSI rated. My curiosity is tweaked. It uses the same base cartridge as the 30-06, it has the same bolt faces, lugs as a 30-06, the case is no larger or smaller, barrel chamber has the same OD So it seems to me, that when you come out with a completely new cartridge, the designers take advantage of the fact that it won't get loaded into an old gun as it can't and they move up the pressure to take advantage of that (or in the case of the 7.62 make act more like a 30-06) I am not jumping up and down and saying violate all the rules we know for safe reloading, but it does seem to change that aspects of a load that can be used in any rifle vs one that is exclusively used in a modern rifle made out of modern materials using modern methods.

June 24, 2017, 02:36 PM	#27
Jim Watson Senior Member Join Date: October 25, 2001 Location: Alabama Posts: 18,539	We did get off track. I see no reason not to load a 7.5 bolt action to the same pressure as any other round the action will hold. The question remains, how do you know where you are at on pressure? Quickload? Case expansion? Velocity vs other cartridge of similar volume?

June 24, 2017, 03:36 PM	#28
RC20 Senior Member Join Date: April 10, 2008 Location: Alaska Posts: 7,014	Gather as much information from all sources as possible and make as best a decision as you can. Certainly 30-06 limits can be used as a rough guideline. While I do not advocate anyone do this, 308 would seem to be of interest as well. One factor not listed is it is a larger diameter round overall than 30-06. Chamber material will be that much thinner. Savage found the short magnums had some issues and cam out with a larger shank barrel to use on those and adding the other magnums as the rifle changes. On the other hand it lived with the old size barrel shank with all the magnums until the shorts came out. The 7.5 seems to have more aspects of a short magnum than anything. Always interesting.