Spanish Mauser 7X57 reloads

[kcw]

KWC,

Too bad this thread is buried under the current title. This is pretty valuable info that lots of troubled shooters who don't know about would find useful.

Merc

It's a little bit on the order of a poor man's Stoney Point Bullet Depth Comparator. You can pretty much do the same thing with a cleaning rod with a blunt end jag on it. Have a second set of hands press the bullet forward against the lands with the easer end of a pencil while you insert the cleaning rod until the jag contacts the tip of the bullet. Scribe the cleaning tight against the muzzle crown with a VERY sharp pencil. Knock the bullet out and place a complete round in the chamber. If it is a live round have the second set of hands push it forward in the chamber. If it is dummy round you can close the bolt on it and lightly push the round back against the bolt face with the cleaning. Once again scribe the cleaning rod. (The second method will encompass the head space into the measurement). Measure the distance between the two pencil marks with your micrometer. This method won't give you the precision of the Stoney Point tool, but it's probably good to within .005" I'd think. I used the second method to set the depth on my 25-20 Winchester with the Sierra 75gr. spire tip, HP, flat base bullet, commonly used in the 22-250, out to about .010" of the lands in my old Savage 23B bolt gun. Loaded out that far it's way too long to work through the action, but it does allow for the use of more ACC 1680 powder to bring the velocity up to around 2,250fps with no pressure issues. That muzzle velocity ends up being good enough to fully open the bullet @ 125yds on chucks and coyotes. It would probably makes a good turkey round where allowed.

[Sunray]

"...didn't seem to like boat tails..." No. 4 Rifles are like that. Accuracy with 'em is usually more about bullet vs barrel ID though.
I'm wondering if your Mauser has some kind of bedding issue. Or a muzzle damage thing.

[Merc]

It's a little bit on the order of a poor man's Stoney Point Bullet Depth Comparator. You can pretty much do the same thing with a cleaning rod with a blunt end jag on it. Have a second set of hands press the bullet forward against the lands with the easer end of a pencil while you insert the cleaning rod until the jag contacts the tip of the bullet. Scribe the cleaning tight against the muzzle crown with a VERY sharp pencil. Knock the bullet out and place a complete round in the chamber. If it is a live round have the second set of hands push it forward in the chamber. If it is dummy round you can close the bolt on it and lightly push the round back against the bolt face with the cleaning. Once again scribe the cleaning rod. (The second method will encompass the head space into the measurement). Measure the distance between the two pencil marks with your micrometer. This method won't give you the precision of the Stoney Point tool, but it's probably good to within .005" I'd think. I used the second method to set the depth on my 25-20 Winchester with the Sierra 75gr. spire tip, HP, flat base bullet, commonly used in the 22-250, out to about .010" of the lands in my old Savage 23B bolt gun. Loaded out that far it's way too long to work through the action, but it does allow for the use of more ACC 1680 powder to bring the velocity up to around 2,250fps with no pressure issues. That muzzle velocity ends up being good enough to fully open the bullet @ 125yds on chucks and coyotes. It would probably makes a good turkey round where allowed.

Well, I checked throat erosion on my three old rifles using the above method. With the bolt removed, I inserted a bare bullet, point first, into the bore through the receiver and pushed it forward with a short cleaning rod until it stopped and engaged the rifling. I held it in place with the short cleaning rod and inserted a wood dowel in through the muzzle until it reached the point of the bullet and I marked the dowel with a pencil at the end of the muzzle. I popped the bare bullet out with the dowel rod and then held the live round inside the receiver with my fingers and took the second measurement by again inserting the dowel rod in the muzzle and making a second mark on the dowel rod at the end of the muzzle after it made contact with the point of the bullet. The gap between the two marks represents the amount of throat erosion present. The wider the gap, the more throat erosion has occurred. My results are mixed but interesting:

Good news first:

Early Winchester M1917 Serial Number 65030 - There is no detectable gap between the bare bullet and the live cartridge (zero erosion). I'm shooting 150 grain boat tailed soft points and the rifle is accurate. I didn't expect to see much of a gap since the rifle looks practically unused, but no measureable gap is still pretty amazing for a 98 year old rifle and confirmed my belief that it was never used during the war. I'm still shooting the first box of factory loaded .30-06 soft point ammo and will be reloading 150 grain FMJ boat tails.

1944 Lee-Enfield No. 4 Mk 1* - There is a .250" gap between the bare bullet and the live cartridge. I'm shooting 150 grain flat based soft points and the rifle is still accurate. OK, a .250" wide gap is not exactly good news, but it's a war-time rifle that has probably seen it's share of action and may have fired 5000 or more bullets. The fact that it's still capable of shooting nice tight groups at 100 yards with .250" gap is still pretty special. I'd mentioned before that it didn't shoot boat tails accurately and maybe the .250" gap is the reason. I can try to lengthen the current COL to the maximum COL for the 150 grain bullet to decrease the gap although it won't be by very much and probably won't have much of an effect on accuracy. This might be a good indication that a rifle with a gap as wide as .250" can still be fired accurately if certain types and combinations of hand loaded ammo is used.

Now the bad news:

1931 Spanish Mauser - There is a .435" gap between the bare bullet and the live cartridge. I'm shooting 139 grain flat based soft points. The Mauser's gap is .185" longer than the No. 4's gap and the rifle is less than accurate but still can hit within a 12" circle at 50 yards. Right now, my cartridge overall length is 2.895". My new Sierra Reloading Manual says that I can go up to 2.975" with a 140 grain bullet but I would need to stretch the COL out to 3.080" to match the No. 4's .250" gap which might represent the maximum tolerable throat wear. I've seen other 7X57 cartridge diagrams that show a maximum COL of 3.065" but involves using larger bullets. I'll try lengthening the COL to the maximum for 140 grain bullets and see what effect it has. My current powder charge is only one grain over the starting load so I have room to increase the charge a little.

So, my rifles are in the three stages of their life span as shooters. One is minty, one is worn but is still capable of shooting accurately and one is probably worn beyond its useful life as an accurate shooter unless I can find a combination of bullet length and powder charge that works better than what I'm using now. However, if my experience is typical, it would indicate that some degree of throat erosion might be tolerable. This experience will have far reaching benefits when I find other old military rifles that I want to buy.

Merc

[Vern Humphrey]

My technique is to use an unsized case, and seat the bullet with a bit of toilet paper to make a good fit, then chamber the round and eject.

[Merc]

My technique is to use an unsized case, and seat the bullet with a bit of toilet paper to make a good fit, then chamber the round and eject.

We discussed the seated bullet method so that was an option. Either method apparently works. Shopping around for old military guns got a lot more complicated but should at least allow us to separate the shooters from the wall hangers.

Merc

[joem]

You might try a much heavier bullet. That's what I load. Of course my barrel is a sewer pipe but it does OK.

[Merc]

You might try a much heavier bullet. That's what I load. Of course my barrel is a sewer pipe but it does OK.

Joe,

That's what I was thinking. A longer bullet would help suck up the some of the excessive barrel space. I've never heard of the possibility util recently. It but it might a worth be a try

Merc

[Vern Humphrey]

That's often the solution with early smokeless powder rifle cartridges. I have a 6.5X55 Swedish Mauser. That rifle was originally designed to shoot a 160 grain bullet. Remington 140 grain bullets in 6.5mm have two canelures, and I always seat the bullet so the rear canelure is flush with the case mouth. This causes the bullet to be WAAAAY out there, and closer to the throat -- and that's what the rifle likes.

[Merc]

Has anyone ever had success shooting round nose bullets in rifles with excessive throat wear? My Spanish Mauser came with a few old round nose 174 gr Remington's from the 1950s with the lead ends either distorted or missing so I never fired them.

Merc

[Vern Humphrey]

Yep. I bought a Spanish M1916 in 1956. The only ammo you could get was those old Remingtons or the equivalent Winchester-Western. They would hold about a 3" group with the issue iron sights, which was all I had.