anyone reload 7.5x55 with varget?
- Thread starter mnw357
- Start date
CAUTION: The following post includes a suggested loading approach not covered by currently published loads for this cartridge. USE AT YOUR OWN RISK. Neither the writer, The Firing Line, nor the staff of TFL assumes any liability for any damage or injury resulting from the use of this information.
I don't have a 7.5×55, but Hornady lists a 150-155-grain bullet getting a maximum of 46.1 grains of IMR4064, a 165-168-grain bullet getting a maximum of 43.2 grains of IMR4064 and a 180-grain bullet getting a maximum of 41.5 grains. As always, knock those down 10% and work up. QuickLOAD thinks, based on those data points, that 42.0-grains would be maximum with the 175-grain Sierra MatchKing. For Varget, the estimate would be 41.0 grains.
The reason I mentioned 4064 is Varget was originally designed to compete with it, so if 4064 works, so should Varget, in principle. They are not identical, though, so one approach is to get some 4064 and work up to those loads, then see if Varget can get you to the same velocities without pressure signs. I've done this in the .30-06 with good results.
For a calculated estimation, the graph below shows the starting and maximum loads for 4064 and Varget in the .30-06 with bullet weights from 110 grains to 220 grains taken from Hodgdon's data. The .30-06 is essentially a close caliber and case capacity pairing, and the Swiss at 55,000 psi maximum average pressure falls between the starting and maximum load pressure ranges for the .30-06, so I think the comparison is valid.
Basically, if you take 4064 maximum load data for the Swiss and multiply the powder charge weight by 0.98, that is going to be a very close estimate of the Varget maximum charge weight in this cartridge. You then knock 10% off the result and work up toward it in increments of 2% while watching for pressure signs. Note that this is not a universal formula. I have only checked that it is applicable to 30 cal cartridges close to 30-06 case capacity. Anything else would need to be checked, and, obviously, actual published data will be more reliable than this kind of estimate.
I don't have a 7.5×55, but Hornady lists a 150-155-grain bullet getting a maximum of 46.1 grains of IMR4064, a 165-168-grain bullet getting a maximum of 43.2 grains of IMR4064 and a 180-grain bullet getting a maximum of 41.5 grains. As always, knock those down 10% and work up. QuickLOAD thinks, based on those data points, that 42.0-grains would be maximum with the 175-grain Sierra MatchKing. For Varget, the estimate would be 41.0 grains.
The reason I mentioned 4064 is Varget was originally designed to compete with it, so if 4064 works, so should Varget, in principle. They are not identical, though, so one approach is to get some 4064 and work up to those loads, then see if Varget can get you to the same velocities without pressure signs. I've done this in the .30-06 with good results.
For a calculated estimation, the graph below shows the starting and maximum loads for 4064 and Varget in the .30-06 with bullet weights from 110 grains to 220 grains taken from Hodgdon's data. The .30-06 is essentially a close caliber and case capacity pairing, and the Swiss at 55,000 psi maximum average pressure falls between the starting and maximum load pressure ranges for the .30-06, so I think the comparison is valid.
Basically, if you take 4064 maximum load data for the Swiss and multiply the powder charge weight by 0.98, that is going to be a very close estimate of the Varget maximum charge weight in this cartridge. You then knock 10% off the result and work up toward it in increments of 2% while watching for pressure signs. Note that this is not a universal formula. I have only checked that it is applicable to 30 cal cartridges close to 30-06 case capacity. Anything else would need to be checked, and, obviously, actual published data will be more reliable than this kind of estimate.
Attachments
ligonierbill
New member
Get a can of Reloder 17. It's the only powder I've tried that matches the GP11. And yes, load the 175 SMK. I'll be shooting GP11 for awhile yet, but when I run out, that's my load.
lonniemike
New member
Use your/the best 308 load that can find. Start low and work up. I probably raised a few hackles last time that I posted 7.5Swiss and 308/7.62NATO are ballistic clones. They are both push 175 grainers about 2550 fps out of 26 inch tubes. Maybe some of those wild 308 pressures are moderated by by extra wide and longer Swiss cases. Any loads that work well in a 308 will most likely do well in the 7.5 Sierra,s book with 7.62/7.5 info shows real close data for the same speeds and weights. Be safe, Work up, and Check out SwissRifles.com BestAll
ligonierbill
New member
Case volume: 7.5x55 66.5 gr water
.308 Win 56.0
SAAMI MAP: 7.5X55 55,114 psi
.308 Win 62,000 psi
No, they are not the same. They are not close. Sierra's manual has 7.5x55 data. Hornady's manual has 7.5x55 data. Why would you use .308 data?
.308 Win 56.0
SAAMI MAP: 7.5X55 55,114 psi
.308 Win 62,000 psi
No, they are not the same. They are not close. Sierra's manual has 7.5x55 data. Hornady's manual has 7.5x55 data. Why would you use .308 data?
lonniemike
New member
When anyone publishes a max velocity(2400fps) out of a rifle with 5 extra inches of barrel that is 200fps slower than the 31's 26" military tube, then it is time to consider other sources for better info. It is called work up. And the larger Swiss case will not have the pressure issues ligonierbill so worry"s over. With any approximate 52Kpsi NATO load, this same load in a Swiss chamber will produce approximately 47CUP. And most importantly this is not a starting point. work up. The K31 is very strong. And if it were pushed to 62Kpsi, the rifle would hold together and the speed that this hypothetical 175 grainer would be probably 500 fps faster than that 308 load at 2550-2600fps. Why do Swiss reloading with pre1911 rifles use 30/40 data instead of 308 data? I believe that they figured it out. No the 7.55X55 and the 7.62NATO are not the same, but they are very very close. Work up. Use 308 in lieu of no data.
lonniemike
New member
I forgot visit SwissRifles.com lots of data over there. Let someone there know that they should not push there 7.5X55 with any 308 data. BestAll
mnw357: Both Hornady and Sierra have good lists of loads for the 7.5.
R17 is not on it oddly enough but its the GP11 powder.
The 7.5 is almost identical to 30-06 case capacity. Pressure is not though. Or at least what was settled on for the old 1911 and the much newer K31.
I have had the Savage I built up to pressure area and well below max 30-06 loads.
Case wise it more resembles today's Short Magnums.
Start low and work up.
R17 is not on it oddly enough but its the GP11 powder.
The 7.5 is almost identical to 30-06 case capacity. Pressure is not though. Or at least what was settled on for the old 1911 and the much newer K31.
I have had the Savage I built up to pressure area and well below max 30-06 loads.
Case wise it more resembles today's Short Magnums.
Start low and work up.
Check the Hornady Manuals ....Hornady #1 (1967) #2 (1970) and #8 (2010) all have data for 7.5 Swiss aka 7.5 Schmidt-Rubin . If Hornady has carried the data since 1967 , my newest is #8 but I would bet money it's also in their #9 and #10 manuals.
In 1967 Hornady was the only company that had 7.5 Swiss data ... Hornady manuals are still my favorite .
Speer manuals contain none for it.
Although I have reloaded the 7.5 Swiss a long time I've never used Varget...never could find the stuff when powder shopping . My go to is H4895 .
Gary
In 1967 Hornady was the only company that had 7.5 Swiss data ... Hornady manuals are still my favorite .
Speer manuals contain none for it.
Although I have reloaded the 7.5 Swiss a long time I've never used Varget...never could find the stuff when powder shopping . My go to is H4895 .
Gary
Varget isn't listed by Hodgdon on their site. Mind you, they don't list any IMR or Winchester powders either. Probably because they didn't test 'em. There might be data in their manual though.
Might be an idea to ask 'em though.
http://www.hodgdonreloading.com/contact
Might be an idea to ask 'em though.
http://www.hodgdonreloading.com/contact
I was shooting H168ZMX with H4895 this last weekend. That was out of Hornady 10.
As noted, other Hornady manuals have 7.5, sometimes they change out the powders so you can wind up with a wider range than just looking at a single boo.
Working around mid, I had some promising results.
Looking at GP11, they seated it deep and its the pointiest bullet on the planet.
I am still playing but ELD types would seem to come the closest to the GP11 projectile shape (and even then they still are not the same shape, just closer)
As noted, other Hornady manuals have 7.5, sometimes they change out the powders so you can wind up with a wider range than just looking at a single boo.
Working around mid, I had some promising results.
Looking at GP11, they seated it deep and its the pointiest bullet on the planet.
I am still playing but ELD types would seem to come the closest to the GP11 projectile shape (and even then they still are not the same shape, just closer)
lonniemike
New member
mnw357, I was looking at other things at SwissRifles.com again and I saw that the reloading forum has your topic of interest-Varget and the 7.5X55. The Best from ten years ago.
lonniemike
New member
IIRC, a some guys at SwissRifles used varget at 44grn for a max. Life is an experiment. Extrapolating '06 data for use in 7.5Swiss. Unclenick comes up with a start of 39.9grn and a max load of 41. grn. Which might be a bettet choice? '06 or 308 data? From Hodgdon's site today, it shows varget+308(175grn) start load at 42.0 with pressure at 42.6KCUP and max load at 45.0(compressed) with pressure at 48.6KCUP. I and others had these 308/7.5 discussions/threads at SwissRifles more than a decade ago. Will the longer skinnier and fatter case have less pressure than the 308? Most assuredly. Work up. Be safe. And another shout out for the use of Re 17 powder.
BestAll
BestAll
Best is Hornady or Sierra data as both have the 7.5 and a reasonable number of powders.
I have crossed powders from 7.5 to 30-06 using a common powder and being vary cautious with staying low to start with.
I use 30-06 if I go there as its case capacity is identical to 7.5 and I expect the performance to be closer than the much tighter packed 308 case (but then I don't have Quickload either)
At least in my build 7.5, I get to higher pressure sooner than with 30-06, so I take it with a grain of powder and go low and work up.
Unclenick may be able to explain it, 7.5 is a shorter fatter case.
I have crossed powders from 7.5 to 30-06 using a common powder and being vary cautious with staying low to start with.
I use 30-06 if I go there as its case capacity is identical to 7.5 and I expect the performance to be closer than the much tighter packed 308 case (but then I don't have Quickload either)
At least in my build 7.5, I get to higher pressure sooner than with 30-06, so I take it with a grain of powder and go low and work up.
Unclenick may be able to explain it, 7.5 is a shorter fatter case.