Home Forums Hunting & Shooting Ask The Gunwriters 7x57 vs. 7-08 load data

I'm sorry because I'm sure that this has been covered multiple times in relation to other topics, but I've never seen one devoted to the question so I thought I'd toss it out there.

Providence shined upon me this week when I scored an unbelievably classy 7x57:

http://www.24hourcampfire.com/ubbthreads/ubbthreads.php/topics/5082563/1

I've got another 7x57 that is my first complete custom job nearly finished, so while I have no desire to push things in this rifle (I'm looking for a good load running 175 or 154 RN Interlocks & IMR-4350) my inspection of the loads mentioned in many threads on this site as well as in the manuals made me curious.

The Hornady manual says that they used a modern rifle in developing 7x57 load and asks for caution using their info, yet it is still far below the 7-08 loads in the same manual. Now I recognize that this is because of the difference in SAAMI specs for each cartridge, but aren't those numbers themselves built around the recognition of the lack of strength inherent in certain pre-98 actions? Is there any reason why I couldn't use 7-08 numbers as a starting point for building full-power 7x57 loads, since it ought to yeild a bit more capability running at equal pressure between the 2 cases?

Just to be clear here, I'm not looking to hot rod the 7x57 I picked up earlier this week (although I doubt there would be a problem if I did). I'll be doing more load work w/ this cartridge later this summer and would like to get a better idea of where to start with that rifle... a small ring '98 that has been completely customized including a heat treating.

Thanks a lot all,

efw

NOT a gunwriter, but I did stay at a Holiday Inn last night....

If it is in a modern action, I would not worry about using 7/08 loads for a 7 mm Mauser...

when the 260 first came out, and load data was not around... I used the data for the 6.5 x 55 and worked up from there...

Like the 260 vs 6.5 x 55, I found out by filling both cases being used, with H 380 just to see how similar their capacities were, there was not as much difference as one would initially think...

efw,

I'm not a gunwriter either, but I have lots of experience with both the 7nm/08 and the 7x57. I suppose that it is human nature to want to get all there is out of a cartridge.... But my thought is that if you need a .280, then that's what you should build... If not, then you should accept the 7x57 for what it is and not try to make it something it isn't...

Personally, I don't view it as a problem with the action or the rifle, it's more the limitations of the brass and the inherent design.

The 7x57 was designed at a time when the designers wanted a rifle to perform under a variety of conditions and climates... Thus, it was designed with a fair amount of case taper. I expect this was because they wanted it to have dependable extraction under various conditons. Remember that smokeless powder was in in's infancy at the time. Pressure spikes were not uncommon...

In today's world with today's powder, we have much more consistent burn rate; thus, we don't have to contend with pressure spikes. The straighter the case taper, the more the case can "grip" the chamber walls, and exhibit less pressure. I suspect that is why the 7nn/08 can be loaded hotter. However, in the real world, there is little the 7mm/08 can do that the 7x57 cannot... Hope this helps....

If you think the 7x57 isn't enough gun as it is, you might refer to JOC's writings.... He tells of his wife, Eleanor, killing 15 head of game in Africa, with 17 shots.. 14 of those, were one-shot kills. The one that took three shots would have expired with any of the three, it just didn't know it was dead... That in itself is high praise for the 7x57....

GH

In my experience the slight difference in case taper doesn't make any difference in "perceived" pressure. If there are apparent high-pressure signs in a modern 7x57 with 7mm-08 data, it's due to soft brass--or some other factor that produces false pressure signs, such as locking lugs that aren't quite square.

What really makes a difference is the widely varied throat lengths in 7x57's. But even in a short-throated 7x57 there's still more powder room than in a 7mm-08, so it's safe to use 7mm-08 data in a modern 7x57.

Well.... That blows that theory! I'll take your word for it...

With the 7x57 cartridge, I always recommed 760/H414, because I never saw another powder exceed it for velocity or accuracy with all bullet weights from 140 to 175 grains.

45 grains would be a light load for 140 grainers and a top load for 175's from what I have experienced.

John

MD,

As AGW suggested I hear a lot about the 7x57 and H-414.

I'm wondering what amount of testing you've done with Hunter in this cartridge? I'm trying to use the "KISS" method of powder stocking and don't have another rifle that "likes" 414 but I do have a couple that do well w/ Hunter.

Seems to me based upon the little that I know of Hunter, if 414 does great in this cartridge, Hunter might do greater?

Hunter does very well in the 7x57 with heavier bullets, above 150 grains. It's slower-burning than 760/414, in fact in most applications it's a little slower than IMR4350. But its such a dense ball powder that you can get more in the case.

With lighter bullets Big Game is outstanding. The burning rate is pretty similar to 760/414 but it burns a lot cleaner.

Ramshot doesn't list any 7x57 data but does for the 7mm-08, a good starting point in the 7x57. The Nosler manual lists Big Game as the fastest powder with 140's in the 7-08, and Hunter as just about tied with RL-19 for fastest with 160's and 175's. With all three bullet weights Big Game and Hunter are listed as much faster than H414.

efw,

If you really want to keep it simple here in west Michigan, just use H4350. It is commonly available here, and it is a great powder for 140-175 grain bullets in the 7x57.

I have found that the maximum 7x57 loads in Speer reloading manual #13 coincide very closely to what I would consider maximum in my Ruger M77MkII. Exceeding those loads by 1 grain produces pressure signs in my rifle. Staying at or below those max loads does not produce pressure signs in my rifle. I know that sounds very simplistic to this audience of extremely advanced rifle experts we have here on the campfire, but that is exactly the truth, no more, no less.

HOWEVER, my other 7x57 rifles have longer throats and can tolerate a bit more powder. This agrees with what JB has posted. I don't care to load individually for each rifle in the same caliber, so I load all my ammo to be safe in the most sensitive rifle, then fire the same loads in all like-chambered rifles. It makes my life simpler.

Here are my max 7x57 loads. Start low and...well, stay low if you want. It's you're rifle:

145 grain Speer Hot Cor, 50 grains H4350, Fed 210 primer;
160 grain Speer Hot Cor or Mag-Tip, 46 grains H4350, Fed 210 primer;
175 grain Hornady spire point interlock, 45 grains H4350, Fed 210 primer.

You found a very nice rifle there, efw. Congratulations, and good shooting!

Not arguing for a 70k psi 7x57 but I don't recall JOC loading ANYTHING moderately.

He used to load the .257 Bob with 39.5 grs. of IMR 4064 under a 100 gr. bullet. Said the cases would fall out of the gun and last at least 30 reloads. E

I emailed Ramshot and got the following:

Ramshot Info

Caliber: 7x57 Mauser.

Barrel length: 24"

Powder: Ramshot - BIG GAME(r). (1st Choice)

Bullet weight: 100-110 grains.

Start load: 47.7 grains (2975 - 3075 Ft/p/sec)

Maximum load: 53.0 grains (3275 - 3375 Ft/p/sec).

Bullet weight: 120 grains.

Start load: 45.0 grains (2700 - 2800 Ft/p/sec)

Maximum load: 50.0 grains (3000 - 3100 Ft/p/sec).

Bullet weight: 130 grains.

Start load: 43.7 grains (2575 - 2675 Ft/p/sec)

Maximum load: 48.5 grains (2875 - 2975 Ft/p/sec)

Bullet weight: 139/140grains.

Start load: 42.0rains (2500 - 2600 Ft/p/sec)

Maximum load: 47.0 grains (2800 - 2900 Ft/p/sec)

Bullet weight: 150grains.

Start load: 40.8 grains (2400 - 2500 Ft/p/sec)

Maximum load: 46.0grains (2700 - 2800 Ft/p/sec).

Bullet weight: 160grains.

Start load: 40.5 grains (2350 - 2450 Ft/p/sec)

Maximum load: 45.0 grains (2600 - 2700 Ft/p/sec).

Bullet weight: 175grains.

Start load: 39.6 grains (2300 - 2400 Ft/p/sec)

Maximum load: 44.0 grains (2500 - 2600 Ft/p/sec).



Powder: Ramshot - HUNTER(r).

Bullet weight: 140grains.

Start load: 46.8 grains (2550 - 2650 Ft/p/sec)

Maximum load: 52.0 grains (2850 - 2950 Ft/p/sec). LD ca 102%

Bullet weight: 160grains.

Start load: 43.7 grains (2350 - 2450 Ft/p/sec)

Maximum load: 48.50 grains (2600 - 2700 Ft/p/sec).

Bullet weight: 175 grains

Start load: 42.0 grains (2300 - 2400 Ft/p/sec)

Maximum load: 47.0 grains (2550 - 2650 Ft/p/sec).LD ca 99%


BigRedHead- Have you been to Schantz's supply down in Otsego? They have Ramshot stuff for only $17/lb or $140/8 lbs the last I was down there. All their stuff is priced right, including Nosler, Hornady, and Speer bullets.

I was able to fire the new rifle a few times yesterday and it looks like it is going to do nicely w/ Hunter & 175 gr RNs. This baby is made for deer hunting from the front seat of my canoe...
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efw - Good Info, thanks!
I have a 7x57 and I like the 120NBT in it, mine doesn't have such a long throat, so it shoots well.

Thanks for the Ramshot Big Game load data. My rifles like H4831SC with the 160 gr BTHP Sierra

If you really want to blow that taper theory out of the water, check out the spec for a full throttle 300 H&H.

54,000 CUP, which correlates to just shy of 64,000 PSI.

The main reason JOC's loads were often considered hot was that most of the time he was loading surplus H4831, which was quite a bit slower than the current variety. He often loaded 62 grains with a 130 in the .270, couple grains more than we can make work with current H4831. The 7x57 is pretty rifle specific, due to the varying throat lengths in the chambers. Most of the Rugers are long, I once had two rifles, a Ruger and a Win Featherweight M70 PF, the loads for the Win went 2875 with 140's in the Win with 4350 were under 2700 fps in the Ruger with ammo from the same box. I can almost get .280 velocities with the Ruger, would be way hot in the Winchester. I can't say I have ever seen this kind of a variation in any rifle, which is why I am a little hesitant to post my 7x57 loads with H414. I'm gonna have to try Hunter with 160's. I have shot so many of these loads in my Ruger, they were so far over book maximum, I eventually bought a pressure trace, and loaded some as hot as 53 gr H414 with 140's in Win cases only. They show no signs of pressure and velocity was 3013 from a 22 in. barrel! The pressure trace was set up very carefully and consistently read 64-65000 psi, which was pretty hot, but certainly not dangerous, probably less than factory WSM ammo. The end result is, if you use a suitable powder and quit when the 7x57 hits 2900 fps with 140's, 2750 fps with 160's, you should be within reason, no matter how much powder is in it or how long the throat is. When the weather warms up I'll load some 160's with Hunter and check them with the pressure trace and do a report on pressure and velocity.

Nick Harvey's Reloading Book listed 52.5 grains of 760 as max with 140's in the 7mm Mauser and I, like you, found my Wincehster needed a little less powder and my Rigby swallowed it easilty.

2940fps was about it but in reality, even if the loads were dropped to around 2800fps, the little 7mm would still take the same animals you would hunt with the cartridge.

That is one of its endearing factors. It just works and balances wonderfully with standard C&C bullets.

John

jstevens - I am envious of your 53grs H414 with 140's at 3013 fps. I can obtain that velocity with 130gr Speer's in two of out of my three 7x57s. How is case life with that load?

I wouldn't be jealous. ....I'd just get a 270 or 280 and get better velocities with either bullet rather easily without running either cartridge hard.....

I agree with AGW in that the 7x57 is splendid at 2850 or so with 140 gr bullets.....

I notice one of the tendencies of some 7/08 and 7x57 shooters is the first thing they try to do is make a 270 or a 280 out of it......either by running lighter bullets and saying "See, it's the same thing!" .....or loading to higher pressures with the heavier bullets...........and this is fine if that's what you want to do, but it always seemed to me that if I wanted the higher velocity I'd just get a rifle chambered for the larger case.....YMMV

I believe this is sound advice, don't try and make something into something that it's not. 7mm Mauser into a .280, or even better a 7mm Remington Magnum.