175 grain Sierra Game kings and the 7x57 mauser

H

hooligan1

New member
Hey fellas, has anybody tried these bullets in their old mauser rifles?
I picked up a handsome Brazilian mod 1908 in original condition, other than barrel and bottom metal has been cerakoted.
I have tried 140 Sierra HPBT Game Kings already but it shot these like 18" high at 100 yds, so I want to try the heavier bullet, which this rifle was built for heavies moving at about 2300.
 
My guess is they're still gonna shoot high. IIRC, military sights at they're lowest setting were set for a point blank range of something like 300 meters, maybe more. The thing was aim at your opponents belt buckle and you's his him somewhere. :rolleyes:
My 7x57s are all either commercial (2) or custom (1) but do have long throats.
I don't know what velocity level you loaded to with the 140's but the 139/140 gr. military ammo was loaded pretty hot for that Mauser. According to an article by the late Jack O'Connor they did 2900 FPS from a 29" barrel.
An older Winchester loading booklet shows 44.0 gr. of W760 doing 2400 FPS at 44,500 C.U.P. (about 50KPSI I believe). I loaded 5 rounds for each of my rifles with that charge and the 175 gr. Hornady round nose and ran them over the chronograph.
Ruger #1A 22" BBL 2310 FPS
Winchester M70 FWT 22" BBL 2340 FPS
Custom Mauser 23" BBL 2450 FPS
That Mauser has a tight chamber and tight match grade barrel and shows higher pressure using the same loads. Loads I have for the other two are all way too hot for the Mauser.
Groups with the Hornady bullet were MOA or smaller.
I did run a few 175 gr. Hornady spire points through the M70 the ran right at MOA but again velocity was in the 2350 FPS range.
Hornady book says 43.1 gr. W760 for 2300 FPS
My Sierra book #V doesn't even give data for a 175 gr. bullet. :confused: Earlier editions did but used a rifle with 29" barrel. They don't cheat fair. :rolleyes:
Paul B.
 
If you're using the original sights, you should know that the "battle zero" for many of the military rifles of similar age was 300 yards. There are higher front sights available to correct this.
In the handgun world, often heavier(slower) bullets quite often hit higher than lighter(faster) bullets. This sin't always the case in rifles. One of my old 30/06 rifles grouped 110 and 180 bullets about 6" higher than 125/150 bullets for reasons I couldn't ever determine.
In 7x57, I found that 175 grain factory ammo hit 7-8" higher at 100 yards than my 140 grain handloads but I can't say it was due to bullet weight, velocity, or leprechauns.
 
I put an S&K Instamount on this rifle so I could put a Scout scope of some kind on it, open sights are hard for me to see, and focus the target.
I'm hoping to be able to hunt now and again with it, so moa at 100 with good hunting bullets is my goal,.
This rifle is a sweetie pie to shoot!!
 
"I have tried 140 Sierra HPBT Game Kings already but it shot these like 18" high at 100 yds, so I want to try the heavier bullet, which this rifle was built for heavies moving at about 2300.
I put an S&K Instamount on this rifle so I could put a Scout scope of some kind on it,"

So, is the problem with the ammo shooting so high the scope and/or mount can't make enough adjustment? I had one those "rear sight scope mount bases" and it had a screw that was cranked down to support part of it. When that was tight, the base was severely biased at an angle that would have sent bullets to the moon. I had to do some "customizing" to allow a solid mounting while still basically aligned with the boreline.
 
2300 fps is above max loads for a 175 according to Hodgdon's site. Except for Hybrid 100V that maxes at 2300 fps.
Wouldn't worry about that until you sort out the sights though. I'm thinking your S&K Instamount isn't level. Gotta a 6" level? That'll tell you quickly. Assuming you have the right mount in the first place. Large vs small ring Mauser. Apparently a small ring will be the same diameter front and rear. I'm guessing you have a large ring and the mount is lower in back that it is in front. http://www.brownells.com/GunTech/The-Long-and-Short-of-Mauser-Actions/detail.htm?lid=11029
 
The original sights I do understand are just what Mobuck says.
The instamount sets fine, I haven't purchased a Scout scope to put in that base yet so how it does is still undetermined.
I'm following a Lyman data sheet that uses the Jacketed GSSP, and reduced the load 20% from max so in actuality, it'll be between 2250 and 2300 fps, and under 43,700 CUP. And the way it reads from the onset these loads tested in Mauser actions with 29" barrels.
 
"2300 fps is above max loads for a 175 according to Hodgdon's site. Except for Hybrid 100V that maxes at 2300 fps."

Yes and no. Most data, if not all is kept on the low side because of the old 1893 and 1895 Mausers. So is most factory ammo, stuff like Hornady Light Magnums being the exception to the rule. A 1908 Mauser is an 1898 style firearm and strong enough to handle cartridges in the .270 and even .300 Win. mag. range after testing of heat treatment. Factory 175 gr. ammo doesn't even come close to 50KPIS let alone the 60KPSI of say a .270 or .308 Win. I don't mess with 175 gr. bullets other than for test purposes but while Winchester 145 gr. factory says it's 2645 FPS a chronograph says different. It's not too hard to push a 140 gr. bullet to 2800 FPS from a 22" 7x57 and I do it with a 140 gr. Nosler Ballistic Tip. I expect I can do the same with a 140 gr. Partition as well, just haven't had time to work up the load. Currently that load works just fine in two rifles but is too hot for the custom Mauser which I believe has a slightly shorter throat. I know one gentleman who gets 2900 FPS from his 7x57 with 150 gr. Partitions, an M70 FWT like mine. I asked him for his data but didn't have any Partitions at the time so worked up using Nosler Accubond Long Range 150 gr. bullets and yes it is doable. I wasn't quite comfortable with the load though so will reduce it to around 2700 to 2800 FPS.
To be very frank, if the 7x57 had been properly loaded to it's full potential early on, the 7-08 would probably never have existed past the wildcat stage if even then.
Paul B.
 
Tim Mullin wrote that there are thousands of people now alive because their grandfathers were missed by WWI military rifles with 400 yard sights.
 
Get a model of 1917 and you have a raised peep sight and it can go down to (200 I think)

Fill in the hole a bit and you can bias it down more.

that said, 1903 is something like 550 yds battle sight, 1917 shorter at 400 or some such.

and an aside, what got most people was artillery and machine guns.
 
I gave up trying to make reloads match military sights long ago. I do have a 7x57, but on an Arisaka action. I had been in a "Heavy bullet" stage for a few years and used 175 grains in it. I switched to 140 Grain bullets and was surprised that both seemed about the same in accuracy. If I remember correctly, I was using 175 Grain Hornady RN. I really don't see a difference in killing ability on deer either. It is probably the most accurate hunting rifle I own.
 
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