Request for .275 Rigby/7mm Mauser Load Data

[jbirdwell]

I just picked up one of the Ruger #1’s in 275 Rigby and was wondering if I can use published load date for the 7x57. I’ll be using 7x57 brass until I can find some of the 275 brass.

 

[hoytcanon]

I just picked up one of the Ruger #1’s in 275 Rigby and was wondering if I can use published load date for the 7x57. I’ll be using 7x57 brass until I can find some of the 275 brass.

One of my 7X57's is a No.1-A and I use the load that I listed earlier in this thread.

 

[franzfmdavis]

Well, the Rigby is off to JJ to open up the free bore so that I can chamber bullets heavier than 140g. Once I get it back, I should be able to use all of this great data that you all have been so kind to share!

 

[dchamp]

Did you try and measure the cartridge's over all length to the lands with Hornady’s o.a.l gauge. With that you can keep a bullet from jamming by seating the bullet deeper.

 

[Clodo Ferreira]

I don´t know why riflemakers want to improve on perfection...The original Mauser chamber configuration, set up for a 173 grs round nose full metal jacket military bullet, can handle the 140 and even lighter-shorter bullets as well as that original one. More so if the free bore section diameter is dimentioned correctly. The same with the original 1:220 mm (1:8,66...") rifling twist. Good for anything.

 

[grand veneur]

I never understand why people try to improve old cartridges. These old cartridges have proven themselves for a certain purpose, and that is how they should continue to be used. Anyone looking for more performance has the option of using many other cartridges available nowadays.

 

[Sika98k]

Those are just standardized recommendations... my load in two of my current rifles is 3.070" and there is still a jump. You have to determine what is best for your own rig.

Sure, I agree with you. The point I was making is that all the loads have the same overall length with the one exception.
My Rigby shoots Nosler Partitions 175gr perfectly well. H414,40gr. There is one bullet stuck on the skin on the opposite side of an oryx I shot.

 

[wswolf]

Since the 7x57 and 7-08 are nearly identical in case capacity, I used Hodgdon 7-08 data to work up loads for my Model 70. Since throat dimensions, and therefore pressures, vary considerably with individual rifles I took advice from John Barsness: "... I tend to load to a certain velocity level rather than a specific charge weight. With appropriate powders, velocity correlates strongly with pressure. In barrels 21-24 inches long, 2800-2900 fps with bullets in the 140-grain range is easily obtainable with modern powders, 2600-2700 fps with bullets in the 160-grain range and 2500-2600 with 175s." "But the powder charge required to reach those levels varies considerably from rifle to rifle". (The Big Book of Gun Gack, Barsness, 2015)

My best results were with 145 LRX and StaBall 6.5 at 2940 fps or 150 Nosler Ballistic Tips with StaBall 6.5 or Reloder 26 at 2850 fps.

 

[benchracer]

Since the 7x57 and 7-08 are nearly identical in case capacity, I used Hodgdon 7-08 data to work up loads for my Model 70. Since throat dimensions, and therefore pressures, vary considerably with individual rifles I took advice from John Barsness: "... I tend to load to a certain velocity level rather than a specific charge weight. With appropriate powders, velocity correlates strongly with pressure. In barrels 21-24 inches long, 2800-2900 fps with bullets in the 140-grain range is easily obtainable with modern powders, 2600-2700 fps with bullets in the 160-grain range and 2500-2600 with 175s." "But the powder charge required to reach those levels varies considerably from rifle to rifle". (The Big Book of Gun Gack, Barsness, 2015)

My best results were with 145 LRX and StaBall 6.5 at 2940 fps or 150 Nosler Ballistic Tips with StaBall 6.5 or Reloder 26 at 2850 fps.

The Barsness guidelines are very good guidelines to follow. Like you, I have found 7mm-08 data to be useful as a sanity check for my 7x57 (in terms of overall ballistic potential).

However, 7x57 case capacity is VERY different from 7-08 case capacity. Depending which makes of brass are being compared, 7x57 has anywhere from around 5.5% to 11%+ greater case capacity than 7-08. In general, because of its greater case capacity and longer neck, 7x57 works well with slower burning powders and heavier bullets than does 7-08.

 

[franzfmdavis]

Did you try and measure the cartridge's over all length to the lands with Hornady’s o.a.l gauge. With that you can keep a bullet from jamming by seating the bullet deeper.

I haven't tried that because I don't have such a gauge currently. Its with JJ now.