Pressure limits in older european calibers, - do they make sense with modern actions and brass??

[Scipio]

Hello @Andy seatrout , - 3273 fps with a 120 grn in a swede!!! - did you perhaps mean with a 100grn ??

But yes, i think most of us agree that there is little reason to chase 7x64/280 performance with a 7x57 , or look for 25-06 speed using the same bullet in a 257 roberts. If someone wants that, then they should probably just buy a 280 rem og 25-06 to begin with.

But the choice to load a swede or x57 case to its modern potential isnt necessarily anything of that extreme ilk either, as examplified with handBs 7x57 loads, or with how John Barsness uses his 7 mm Mauser.
Here i dont think we're talking chasing silly gains vs the case capacity but rather labout loading and old caliber and cartridge to it's modern potential, when it is used in a strong action with good brass. And we're probably still talking lower pressures than what a 270 for example operates at.
But again, each person should be critical, inform themselves to the maximum degree, and then in the end make their own decisions about what to do.

 

[25 Sharps]

I’ve been home loading 6.5x55 since last summer, sticking to the reloading data with RS60 powder. Using Hornady Superformance SST 140g as a benchmark (2653fps, 2200fps energy with SD of 13.5) but with 1-2 grains less than maximum stated with the same bullet I was putting out 2789fps SD 20...... with the copper Hornady GMX 120g 2874fps with 2220fp and 21.8 SD......

Looking at the ‘fast for copper’ I pushed up to 3273fps with 120g GMX ( this is in a Sako 85) 2700+ in energy - felt recoil was increased, pressure sign on the case, primer not flattened but ‘smile’ on face, bolt opened fine....but I don’t feel like paying for a new barrel or losing my fingers, and the accuracy was not so good at this speed/ pressure.....so I’ll come down from that..... my firing range with bench etc is only 100 yards from my pheasant pen- so load development was paused in October and will resume in feb.

Looking at it generally I can’t see why I can be shooting a 2750fps 140g lead bullet producing 2200 fp in energy and as a non lead alternative a copper GMX going just around 2900fps 120g producing near enough 2200 fp again. If I look at some of the reloading data it’s obvious that modern actions can take a bit more, some of the Swedish load data is pretty ‘tame’ for reasons of old actions on old rifles - look to European data and pick the SCAN page.

But how much is enough? I don’t intend to shoot deer at long range at all (120 yards personal limit) in common with many of the comments on here, If you want more or faster buy a bigger more modern caliber.....

Sounds like you were plenty over pressure. What length barrel, COAL and what charge weight of RS60 for the GMX?

The 6.5x55 isn’t a 2700 + ft-lb cartridge in anybody’s book

 

[Andy seatrout]

Sounds like you were plenty over pressure. What length barrel, COAL and what charge weight of RS60 for the GMX?

I think I was, tbh my reloading book is in the cellar, where I’ve recorded it all down. think it was overcharged, the COAL was just under the three inches and under the recommendation for the longer copper bullet....I fired three rounds of the ten I’d made..... and dissembled the other rounds.

 

[Andy seatrout]

Sounds like you were plenty over pressure. What length barrel, COAL and what charge weight of RS60 for the GMX?

The 6.5x55 isn’t a 2700 + ft-lb cartridge in anybody’s book

I’ll start again in February and get something more reliable in terms of data .....the 2700 was what the Caldwell chronograph app calculated....

 

[25 Sharps]

I’ll start again in February and get something more reliable in terms of data .....the 2700 was what the Caldwell chronograph app calculated....

Looks like that was out.



My point was that you can play with various powder and bullet combinations but those tend to hit a service/safety ceiling of a common muzzle energy, a bit like your 140 gr lead vs 120 copper comparison above at 2200 ft-lb.

At just shy of 2900 you were grossly over the safety ceiling for the cartridge and luck my not to have caused yourself or someone next to you an issue.

 

[Andy seatrout]

Hello @Andy seatrout , - 3273 fps with a 120 grn in a swede!!! - did you perhaps mean with a 100grn ??

But yes, i think most of us agree that there is little reason to chase 7x64/280 performance with a 7x57 , or look for 25-06 speed using the same bullet in a 257 roberts. If someone wants that, then they should probably just buy a 280 rem og 25-06 to begin with.

But the choice to load a swede or x57 case to its modern potential isnt necessarily anything of that extreme ilk either, as examplified with handBs 7x57 loads, or with how John Barsness uses his 7 mm Mauser.
Here i dont think we're talking chasing silly gains vs the case capacity but rather labout loading and old caliber and cartridge to it's modern potential, when it is used in a strong action with good brass. And we're probably still talking lower pressures than what a 270 for example operates at.
But again, each person should be critical, inform themselves to the maximum degree, and then in the end make their own decisions about what to do.

No defo 120g, was supposed to be 45.5gr load, but after three shots it felt different and I didn’t fire the remaining rounds, bolt opened fine, primer not flattened but small ‘smiles’ on the base of the case.......stopped there, must have made an error in the powder measurement..... so scrapped the rest, ignore the grouping as I was focusing on getting the bullet through the chronograph and checking the reading on the phone so breaking my hold....

 

[Scipio]

No defo 120g, was supposed to be 45.5gr load, but after three shots it felt different and I didn’t fire the remaining rounds, bolt opened fine, primer not flattened but small ‘smiles’ on the base of the case.......stopped there, must have made an error in the powder measurement..... so scrapped the rest, ignore the grouping as I was focusing on getting the bullet through the chronograph and checking the reading on the phone so breaking my hold....

Ok mate, Maybe this site can help you out for the next go: BBT
But yeah, something might have gone wrong when measuring the powder doses, because even loading for modern brass and actions, i definitely dont think a 6.5x55 or x57 sized case should yield 3200 fps with 120 grain bullets.

This a quote from John Barsness, the american gunwriter i mentioned earlier

6.5x55mm Mauser: The powders that work in the .260 also work in modern rifles chambered for the old “Swede.” Up the powder charges 2 to 3 grains with the same bullets for about the same muzzle velocities.

https://loaddata.com/articles/PDF/Handloads%20That%20Work.pdf

Maybe, if you have access to a chrono when shooting your loads, you should lean on 260 velocities, with a few more grain powders as he suggests.

 

[Andy seatrout]

Looks like that was out.

View attachment 236989

My point was that you can play with various powder and bullet combinations but those tend to hit a service/safety ceiling of a common muzzle energy, a bit like your 140 gr lead vs 120 copper comparison above at 2200 ft-lb.

At just shy of 2900 you were grossly over the safety ceiling for the cartridge and luck my not to have caused yourself or someone next to you an issue.

I think you’re right, so I’m not going to argue with you, three rounds and I stopped.... What would the safety ceiling be then? The data I was using is from the RS website:

 

[25 Sharps]

No defo 120g, was supposed to be 45.5gr load, but after three shots it felt different and I didn’t fire the remaining rounds, bolt opened fine, primer not flattened but small ‘smiles’ on the base of the case.......stopped there, must have made an error in the powder measurement..... so scrapped the rest, ignore the grouping as I was focusing on getting the bullet through the chronograph and checking the reading on the phone so breaking my hold....

Looking at the data for RS60 under a 123 grain reloader Swiss topped out at 2890 fps from a 26” barrel so a mile over at 3273

 

[ejg]

On the continent the 7x57 never seemed that popular as a hunting cartridge, even many decades back. They often talked about the universal hunting cartridge being the 7x64. into 270win territory. Then over time in Germany the 30-06 took over as being the most popular, in recent times it might be more distributed between 308, 8x57, 30-06, 9.3x62. Experimenting a bit more since the monometal aera.
edi

 

[25 Sharps]

I think you’re right, so I’m not going to argue with you, three rounds and I stopped.... What would the safety ceiling be then? The data I was using is from the RS website:

Posted at the same time! You’d have to look through a range of data and see what the average upper limit is but at a guess 2400-2500 ft-lb

 

[Andy seatrout]

Ok mate, Maybe this site can help you out for the next go: BBT
But yeah, something might have gone wrong when measuring the powder doses, because even loading for modern brass and actions, i definitely dont think a 6.5x55 or x57 sized case should yield 3200 fps with 120 grain bullets.

This a quote from John Barsness, the american gunwriter i mentioned earlier

Maybe, if you have access to a chrono when shooting your loads, you should lean on 260 velocities, with a few more grain powders as he suggests.

Thanks for BBT link.....

 

[Andy seatrout]

Posted at the same time! You’d have to look through a range of data and see what the average upper limit is but at a guess 2400-2500 ft-lb

Given the stalking I’m likely to do, 2200fp of energy is plenty.....

 

[Scipio]

I think you’re right, so I’m not going to argue with you, three rounds and I stopped.... What would the safety ceiling be then? The data I was using is from the RS website:

you're welcome for the bbc link

well the norma data seems to suggest leaning towards what John Barsness suggested, ie. working up safely from low, but using 260 load data, adding 2-3 grn to 260 loads and expecting more or less 260 velocites.

here is a link to their load data: Reloading data

here is an example of a suggested 260 loads:

and here is a 6.5x55 one:

Of course you can also just look for modern manufactorers loads made directly for the 6.5 x55, for example from Norma.

 

[25 Sharps]

Given the stalking I’m likely to do, 2200fp of energy is plenty.....

Yeah, that’s what I load my 6.5x55 to and it kills everything it hits

 

[25 Sharps]

you're welcome for the bbc link

well the norma data seems to suggest leaning towards what John Barsness suggested, ie. working up safely from low, but using 260 load data, adding 2-3 grn to 260 loads and expecting more or less 260 velocites.

here is a link to their load data: Reloading data

here is an example of a suggested 260 loads: View attachment 236993

and here is a 6.5x55 one: View attachment 236994

Of course you can also just look for modern manufactorers loads made directly for the 6.5 x55, for example from Norma.

Why not just use 6.5x55 load data?

 

[Scipio]

On the continent the 7x57 never seemed that popular as a hunting cartridge, even many decades back. They often talked about the universal hunting cartridge being the 7x64. into 270win territory. Then over time in Germany the 30-06 took over as being the most popular, in recent times it might be more distributed between 308, 8x57, 30-06, 9.3x62. Experimenting a bit more since the monometal aera.
edi

Yep, i have read similarly, but think it was quite popular in south africa and perhaps in other parts of africa too, and of course as the .275 rigby in the UK.

 

[Scipio]

Why not just use 6.5x55 load data?

hey 25 sharps, well, i agree - but perhaps you missed the last line of the post you quoted.

This said, i dont know if more manufactorers load data (for more bullet types and powders) exists for the 260 than for the swede. If so, using 260 loads as a rough guide can perhaps be useful for @Andy seatrout .

 

[25 Sharps]

hey 25 sharps, well, i agree - but perhaps you missed the last line of the post you quoted.

This said, i dont know if more manufactorers load data (for more bullet types and powders) exists for the 260 than for the swede. If so, using 260 loads as a rough guide can perhaps be useful for @Andy seatrout .

No I didn’t, I just don’t understand where the suggestion comes from in the first place as the data is nigh on identical in terms of velocity. In terms of the data I think the .260 has even less of a following than the 6.5x55, there’s plenty of data out there for the x55 in either case

 

[Scipio]

No I didn’t, I just don’t understand where the suggestion comes from in the first place as the data is nigh on identical in terms of velocity. In terms of the data I think the .260 has even less of a following than the 6.5x55, there’s plenty of data out there for the x55 in either case

well, i think i answered that already in the last 2 lines of the post you just quoted above.