Here he is! :^)
Good afternoon, Matthew.
This is a touchy subject in some circles, so I'll do my best to avoid any coloration of the history.
I've been working with Swiss rifles since the late 50s. I've been developing load data since 1963 as the manuals then extant were erroneous in their representaion of both pressures and strength of the receivers. For whatever reason, the manual publishers were basing all of their load data on the Schmidt Rubin model 1889. The GP11 cartridge was the issue cartridge for the Schmidt Rubin beginning with the 1911sr. This is the same cartridge issued today for the PE57 autoloader and the predecessors, 1911, k11, k31 and the Sniper zfk3155.
Does it not then stand to reason that the 1911 and k31, being designed to fire the same cartridge as the PE57, would have receivers of a strength equal to the modern autoloader? Would it surprise you to know that the factory in Bern offered the k31 in 7.5 Swiss, .308, 30/06 and 300 Winchester Magnum? It still is. You can buy one today from the Hammerli facility. But I digress.
Early reloading manuals assumed that the bolts on the 1911s, k11s and k31s were identical to the 1889. Not so at all. The 1889 could NOT stand the pressures developed by the GP11 and therefore the publishers relegated all data and warnings to all of the Schmidt Rubins! Gross error! I dioscoverd this error very early on, called Bern, spoke to an armourer, explained my theory, he agreed and I began a lifelong search for the elusive MOA loads for the SRs. BTW......... I found it. In fact a number of them.
The locking lugs on the earlier SRs were at the back of the bolt itself. This meant that the case head of the cartridge was largely unsupported, but with the advent of the 1911 the lugs were moved midway up the bolt proper and provided more than enough support for the case head. The 1911 receiver was also substantially stroner than the 1889, in fact strong enough to allow importers in the late 70s/early 80s to convert a large number of imported 1911s to .308. CUP for the 7.5 is around 42,000. The .308 is 50,000+, so that should also tell you that the 1911 receiver/bolt combo is plenty strong.
The k31 amd the zfk3155 have the strongest of the bolt/receiver combinations. The locking lugs were moved forward right to the head of the bolt. The 30-06 and 300 winmag are no problem for this rifle. Enough preface.
The dies. I was asked to develop a forum for these rifles about 4 years ago. I spent a tremendous amount of time educating new SR owners who had not a clue as to proper load data or accurizing. (I won't get into the accurizing thing at this point) Having been supplied with load data, a number of these folks began reloading the caliber. Wihin one month I had 3 incidents of "gas blow-by" from those usnig Lee 7.5 Swiss dies. The bolt of the SR provides a channel directly to the rear, allowing blow-by gasses to "kiss" the face of the shooter! Three more incidents followed with another 4 months. FAR too many for coincidence.
Lee makes an excellent die. I've also been told that the circumstances surrounding the SRs don't happen with all Lee 7.5 dies. I don't know. I also have never had an interest in testing these dies. There's no point. I do assume that there is an inherent problem with using the die for this caliber. I can tell you that my daughter is not allowed to use Lee dies for reloading her 7.5 Swiss brass. In the past 5 years not one single incident of blow-by has ever been reported to me on swissrifles.com involving RCBS 7.5 dies.
I can't tell you how many thousands of rounds in that caliber I've reloaded in 40 years, but its a bunch. Never one single failure involving the die has ocurred.
For a detailed explanation may I direct you to http://www.swissrifles.com/ammo/reload1.htm
I'm loathe to retype the whole thing here as its quite long, but please do read that page before proceeding with reloading for your rifle. It will give you needed insight into the whys and wherefores.
Thank you..... Pierre St.Marie
Good afternoon, Matthew.
This is a touchy subject in some circles, so I'll do my best to avoid any coloration of the history.
I've been working with Swiss rifles since the late 50s. I've been developing load data since 1963 as the manuals then extant were erroneous in their representaion of both pressures and strength of the receivers. For whatever reason, the manual publishers were basing all of their load data on the Schmidt Rubin model 1889. The GP11 cartridge was the issue cartridge for the Schmidt Rubin beginning with the 1911sr. This is the same cartridge issued today for the PE57 autoloader and the predecessors, 1911, k11, k31 and the Sniper zfk3155.
Does it not then stand to reason that the 1911 and k31, being designed to fire the same cartridge as the PE57, would have receivers of a strength equal to the modern autoloader? Would it surprise you to know that the factory in Bern offered the k31 in 7.5 Swiss, .308, 30/06 and 300 Winchester Magnum? It still is. You can buy one today from the Hammerli facility. But I digress.
Early reloading manuals assumed that the bolts on the 1911s, k11s and k31s were identical to the 1889. Not so at all. The 1889 could NOT stand the pressures developed by the GP11 and therefore the publishers relegated all data and warnings to all of the Schmidt Rubins! Gross error! I dioscoverd this error very early on, called Bern, spoke to an armourer, explained my theory, he agreed and I began a lifelong search for the elusive MOA loads for the SRs. BTW......... I found it. In fact a number of them.
The locking lugs on the earlier SRs were at the back of the bolt itself. This meant that the case head of the cartridge was largely unsupported, but with the advent of the 1911 the lugs were moved midway up the bolt proper and provided more than enough support for the case head. The 1911 receiver was also substantially stroner than the 1889, in fact strong enough to allow importers in the late 70s/early 80s to convert a large number of imported 1911s to .308. CUP for the 7.5 is around 42,000. The .308 is 50,000+, so that should also tell you that the 1911 receiver/bolt combo is plenty strong.
The k31 amd the zfk3155 have the strongest of the bolt/receiver combinations. The locking lugs were moved forward right to the head of the bolt. The 30-06 and 300 winmag are no problem for this rifle. Enough preface.
The dies. I was asked to develop a forum for these rifles about 4 years ago. I spent a tremendous amount of time educating new SR owners who had not a clue as to proper load data or accurizing. (I won't get into the accurizing thing at this point) Having been supplied with load data, a number of these folks began reloading the caliber. Wihin one month I had 3 incidents of "gas blow-by" from those usnig Lee 7.5 Swiss dies. The bolt of the SR provides a channel directly to the rear, allowing blow-by gasses to "kiss" the face of the shooter! Three more incidents followed with another 4 months. FAR too many for coincidence.
Lee makes an excellent die. I've also been told that the circumstances surrounding the SRs don't happen with all Lee 7.5 dies. I don't know. I also have never had an interest in testing these dies. There's no point. I do assume that there is an inherent problem with using the die for this caliber. I can tell you that my daughter is not allowed to use Lee dies for reloading her 7.5 Swiss brass. In the past 5 years not one single incident of blow-by has ever been reported to me on swissrifles.com involving RCBS 7.5 dies.
I can't tell you how many thousands of rounds in that caliber I've reloaded in 40 years, but its a bunch. Never one single failure involving the die has ocurred.
For a detailed explanation may I direct you to http://www.swissrifles.com/ammo/reload1.htm
I'm loathe to retype the whole thing here as its quite long, but please do read that page before proceeding with reloading for your rifle. It will give you needed insight into the whys and wherefores.
Thank you..... Pierre St.Marie
