7x57 versus 7-08


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1948CJ2A
May 4, 2012, 05:27 PM
I've seen this debate come up time and time again so I thought I would offer up some interesting information I recently came across. First, here is some background on my experience with both.

I built my first deer rifle circa 1993-1994 on a German M98 mauser. It was originally chambered in 8x57. We decided to re-barrel and re-chamber to 7x57, as this was a better deer cartridge in our minds. The rifle turned out great and I shot my first deer with it that fall.

At around the same time, a neighbor down the street who was my age was also getting into deer hunting. His dad bought him a Remington 700 BDL 7mm-08. That's the point where the debate (for us) began. We would always argue back and forth as to which cartridge was faster, flatter, and just outright better than the other. He would always point to his Remington Ammo factory ballistics charts, which clearly showed the 7mm-08 to have higher velocities. I would then turn around and reference my Hornady reloading manual and argue otherwise.

Fast forward to present. I don't talk with that guy much anymore these days but the debate still persists within hunting camps today. One thing that seems to have noticeably changed since the mid 90's is the reloading data. With each new reloading edition (regardless of brand) the ballistics data typically shows a retreat in velocities, especially when examining the 7x57. I started to look deeper into this.

Briefly, lets look at the history of both rounds. The 7x57 dates back to the late 1800's (1892 to be exact). The first rifles built for the 7x57 were pre-98 Mausers such as the original 1893 (M93) Spanish Mauser. The 7-08 was originally wild-catted in 1958, known then as the 7mm/308 (as this cartridge is simply a 308 Win. necked down from .308 to .284). In 1980 Remington decided to stamp their name on it and make it a factory offering in their 700 rifles.

If you look up the SAAMI cartridge dimensions for both rounds, you'll immediately notice that the 7-08 is 1/5 of an inch shorter. This allows the rifle manufacturer to chamber a 7-08 using a short action. The 7x57 on the other hand requires a standard long action (or intermediate on some actions). The end result is more cartridge capacity for the 7x57, which in turn yields more velocity right? Not according to the reloading manuals or factory ammo data. Why is this? The answer is pressure tolerances.

According to SAAMI, they list the max pressure limit for the 7x57 Mauser at 51,000 PSI. For the 7mm-08 Remington, the max pressure limit is listed at 61,000 PSI. That's a full 10,000 PSI difference. Why is this? Well the answer is debatable but most attribute it to the attorneys for the ammo and handloading companies. They don't want to make ammo or publish ballistics data that could cause a shooter to "blow-up" a firearm component resulting in civil suit. I'll buy this explanation to some degree as it makes sense, especially when considering the age of the 7x57 versus the 7-08. Still, I tend to believe that firearms manufacturers these days love to cut costs. Just look at the number of plastic stocks and short actions today. They dominate the market. It costs less for the manufacturers to mass produce a rifle chambered in 7-08 compared to a rifle chambered in 7x57.

At the end of the day, both of these cartridges are excellent whitetail rounds. They both produce mild recoil and both are terrific cartridges to handload. But that's really where the similarities end. If you really want to know which one is faster and has more energy, go out and put both on a chrony using handloads and you'll see the difference. The 7x57 wins out when you use load data that hasn't been "gimped" down. Just be sure you're using a modern rifle.

End Rant :)

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firesky101
May 4, 2012, 05:38 PM
yup, not a whole lot of terminal difference.

GCBurner
May 4, 2012, 05:44 PM
The manuals tend to load the 7x57 Mauser light, due to the huge number of older guns chambered for it that weren't proofed for high pressure loads, like the Remington Rolling Block and the pre-98 Mausers. Fortunately, it works just fine at moderate pressures and velocities, which makes it cheaper to reload for, and easier on the recoil.

ritepath
May 4, 2012, 05:51 PM
7x57 wasn't offered in a youth single shot rifle for my 7yo son. However.com this past fall he found out the 7mm08 did a fine job on whitetail.

Remington doesn't even offer the 7x57 in their hunting AR platform.:scrutiny:

1948CJ2A
May 4, 2012, 05:58 PM
7x57 wasn't offered in a youth single shot rifle for my 7yo son. However.com this past fall he found out the 7mm08 did a fine job on whitetail.

Remington doesn't even offer the 7x57 in their hunting AR platform.

I don't think Remington has chambered the 7x57 (excluding their custom shop) since the 700 Classic was chambered in it back in 1981. Somebody else here correct me if I'm wrong there. Why would they want to chamber it since it would directly compete with their proprietary 7-08?

As for the AR, I'm not aware of any long action cartridges chambered in such a configuration.

Art Eatman
May 4, 2012, 09:17 PM
Some of those early 7x57 Mausers were single-lug bolts. Those are said to be limited to chamber pressures of 40,000 psi. SFAIK, factory 7x57 ammo is/was/used to be limited to 40,000. Dunno about now.

When handloaded to equal pressures, the 7x57 could easily equal or maybe even exceed the muzzle velocity of the 7mm08.

Float Pilot
May 4, 2012, 10:11 PM
My first center-fire smokeless rifle was a 1935 Mauser in 7x57mm. It was a cav carbine in full military trim. But the chamber was a touch over-sized and after I took a hand-loading class in 10th grade, I decided that I needed an accurate 7x57mm Mauser rifle. So I re-barreled it with a Douglas 7mm barrel blank which we chamber reamed to a nice tight match grade chamber. Then I bough a stock blank from the old Herters catalog and commenced to carving...

I stated out using the PO Ackley manuals and a book by one of the old African hunters who liked 7x57mm. So my loads used to be hot as heck until recently when I backed them off.

It only has a 20 inch barrel with a #5 taper. But it still shoots nice groups after 45 years of use.

I like the long neck of the 7x57mm.

chas3stix
May 4, 2012, 10:27 PM
It's similar to why there are three different and separate loading tables for the .45-70.
The ammo manufacturers want to limit their responsibility if Joe Sixpack loads rounds meant for Ruger #1's and fires them in an 1870's vintage trapdoor Springfield. Yes, I've noticed that the latest reloading manuals "load down" their recipes compared to those of 10 to 20 years ago.

303tom
May 4, 2012, 11:05 PM
The only difference being the 7x57 will shoot a little heavier bullet that`s all....................

BCRider
May 4, 2012, 11:47 PM
So what about the fact that deer have been taken down by everything from .357 handguns and .204 rifle rounds up to 45-120 and even .45 and up round ball pushed by common black powder?

Sort of makes arguing between two rounds as close to each other as these a bit nonsensical, no? Although I can think of worse things for a topic of discussion around a hunt camp fire.....

1948CJ2A
May 5, 2012, 12:28 PM
FloatPilot - I agree the long neck is great for reloading. You can really make use of increased case capacity especially when seating the bullets a good bit out.

Nice rifle!

The only difference being the 7x57 will shoot a little heavier bullet that`s all....................

Not so much.

So what about the fact that deer have been taken down by everything from .357 handguns and .204 rifle rounds up to 45-120 and even .45 and up round ball pushed by common black powder?

Sort of makes arguing between two rounds as close to each other as these a bit nonsensical, no? Although I can think of worse things for a topic of discussion around a hunt camp fire.....

Sure whitetail may have been taken by a wide range of options there but are those rounds you named ideal? Not where I hunt.

highlander 5
May 5, 2012, 01:02 PM
I don't own a 7mm 08 but I do own a 700 in 308 and the action is the same as for a 30'06,they just put in a filler strip to make up for the shorter cartridge so action length is moot.

Boxhead
May 5, 2012, 03:05 PM
As stated, six of one, a half dozen of another. A 140 gr AB worked fine on this oryx and will head to Africa next month for kudu, wildebeast and the like in front of my 13 year old son's shoulder. No worries here.

http://i1197.photobucket.com/albums/aa437/boxhead61/OryxHuntCatsFireplace011.jpg

GooseGestapo
May 5, 2012, 04:59 PM
The difference in case capacity is nearly nil. Actual net difference is about 3-4% with that even varying between make and lot# of cases.
Actual difference if everything else is equal, (it never is) is 30-40fps in favor of the 7x57.

However, individual differences between barrels, chambers, and even range conditions make such a small difference insignificant.

I've owned both and currently I have a Rem. Mod-7 in 7mm08. I got it orginally to rebarrel/rechamber to .284wcf, but after chronographing some factory ammo decided that the small/possible difference wasn't worth the cost/effort.
I easily get 2,900fps with a 140gr bullet from a 20"bbl and have seen individual shots go over 3,000fps with safe pressures and decent accuracy.
My rifle prefers 150gr bullets and I get 2,8xx fps with 45.0gr of RL17.
An argument between the cartridges is meaningless/pointless. If I was rebarreling a M98 action or similar such, I'd do it with a 7x57chamber. If a short action such as M700 or Mod7, ect. I'd do the 7mm08 and worry more over which bullet to use...... Stocks, ect.

They really are two "peas in a pod"....

1948CJ2A
May 5, 2012, 05:06 PM
I don't own a 7mm 08 but I do own a 700 in 308 and the action is the same as for a 30'06,they just put in a filler strip to make up for the shorter cartridge so action length is moot.

Action length is moot? The 308 and it's children (243 Win, 260 Rem, 7-08, & 358 Win) is a short action cartridge plain and simple. The 30-06 (and 7x57) is a long action cartridge. The longer the cartridge, the more case capacity, which in turn yields higher velocities and energy.

My entire point of this thread is to educate those who simply pick up a factory ballistics table or reloading manual and brush off the 7x57 either as the 7-08's equal or inferior, neither of which are correct assumptions. I'm not trying to put down the 7-08 (or any in the 308 family) as a bad round. It is a nice short action alternative to the longer 7x57 or 7 magnums.

SlamFire1
May 5, 2012, 09:35 PM
According to SAAMI, they list the max pressure limit for the 7x57 Mauser at 51,000 PSI. For the 7mm-08 Remington, the max pressure limit is listed at 61,000 PSI. That's a full 10,000 PSI difference. Why is this? Well the answer is debatable but most attribute it to the attorneys for the ammo and handloading companies. They don't want to make ammo or publish ballistics data that could cause a shooter to "blow-up" a firearm component resulting in civil suit. I'll buy this explanation to some degree as it makes sense, especially when considering the age of the 7x57 versus the 7-08. Still, I tend to believe that firearms manufacturers these days love to cut costs. Just look at the number of plastic stocks and short actions today. They dominate the market. It costs less for the manufacturers to mass produce a rifle chambered in 7-08 compared to a rifle chambered in 7x57.
There is nothing wrong with a 7 X57 and in modern actions it will exceed anything a 7mm-08 can do in terms of velocity.

It is my recollection that the 7mm-08 started out in steel silhouette competition back in the 70’s or 80’s. If you had to shoot a rifle offhand, you wanted something with a good trigger, quick lock time, lots of accessories, and a short action M700 made sense. If you wanted less recoil than a 308 and more lead on target than a 6.5, a wild cat 7mm made sense.

But in a hunting rifle, the examination of alternatives stack the priorities differently.

As for accuracy, I have a bud, who is now a F Class National Champ, he was winning matches with a 7mm Mauser in across the course matches. Then Sierra changed the ballistic coefficient (down) on their 168 SMK’s and he lost all confidence in the cartridge.

I remember Mitch Maxberry won a Camp Perry National Championship with the 7mm-08 but a couple of years later, as he told me “I know the 6.5’s are shooting inside me”. I don’t know what it is doing with Berger bullets, it still may be a viable target cartridge.

As for pressures, because of the strict liability laws in the US, manufacturer’s have to take into account all those pre WW1 7mm rifles out there. There are all sorts of M1892’s, M1895’s, M1910’s, floating around and being shot. The load for a M1892 Spanish was a 174 grain bullet at 2200 fps, and I think that was a 29” barrel. These rifles were made out of steel that today is so cheap and crude that it is used for rebar. Period ammunition was loaded to lower pressures than modern, anyone selling 60K psia ammunition is risking a real lawsuit if their ammunition is fired in one of those antiques.

Rifle Magazine Issue 159 May 1995 Dear Editor pg 10
http://www.riflemagazine.com/magazine/PDF/ri159partial.pdf

Author Ludwig Olsen

Mauser 98 actions produced by Mauser and DWM were proofed with two loads that produced approximately 1000 atmosphere greater pressure than normal factory rounds. That procedure was in accordance with the 1891 German proof law. Proof pressure for the Mauser 98 in 7 X57 was 4,050 atmospheres (57, 591 psi). Pressure of the normal 7 X 57 factory load with 11.2 gram bullet was given in Mauser’s 1908 patent boot as 3,050 atmosphere, or 43, 371 pounds.

While many Mausers in the 1908 Brazilian category will likely endure pressures considerably in excess of the 4,050 atmospheres proof loads, there might be some setback of the receiver locking shoulder with such high pressures.

Bwana John
May 6, 2012, 11:11 AM
I don't think Remington has chambered the 7x57 (excluding their custom shop) since the 700 Classic was chambered in it back in 1981. Somebody else here correct me if I'm wrong there.

I have a Remington 700 Mountain Rifle in 7mm x 57mm Mauser that was bought new in ~1991.

1948CJ2A
May 6, 2012, 11:29 AM
Good input from all the contributors in this thread. However, I still refuse to write off both as being close enough for it not to matter. It should be noted though that I'm writing this from the perspective of someone who has a bunch of rifles. If you were just picking one rifle and your choices were between these two rounds, both would be great choices.

The difference in case capacity is nearly nil. Actual net difference is about 3-4% with that even varying between make and lot# of cases.

Since the Mauser is 1/5" longer than the 7-08, I would think the displacement/capacity would be greater than 3-4%. I don't have a 7-08 in my garage to test but will definitely add this to my "to-do" list someday.

To me, this argument is very similar to the 6mm versus 243. The 6mm Rem is a ballistically superior cartridge to the 243. Same goes for the 7x57.

I have a Remington 700 Mountain Rifle in 7mm x 57mm Mauser that was bought new in ~1991.

Cool rifle! Thanks for sharing.

1948CJ2A
May 6, 2012, 11:56 AM
I just saw this post on another thread and thought I would share it. This is exactly why I wrote this thread. People out there actually believe this:

If you think the .308 based 7mm-08 might be too much, the 7x57 mauser is a little less power with comparable loads (hornady as my reference). It still has a bit more than the magic 1500fpe @ 200yds for elk (hornady 139gr interlock), but starts out about 400fps slower than 7mm-08. Different loadings will vary, but it gives you a good idea of the comparison.

400 FPS slower than the 7-08? Blasphemy!

35 Whelen
May 6, 2012, 12:08 PM
The 7mm-08 and 7x57 loaded to like pressures are as different as the 243 and 6mm Rem., the 260 Rem. and the 6.5x57. etc.
I've never owned a 7mm-08, but have owned and loaded for two different 7x57's for nigh on 30 years. What I have noticed with regards to loading data for the 7-08 and the modern 7x57 is that the former somewhat loses ground to the latter when bullet weigh exceeds 150 grs., much as the 308 loses to the '06 with heavier bullets.
One other advantage the 7x57 has over the 7-08 that is rarely mentioned is this:
7x57's are mostly barreled to long actions and 7x57 chambers typically have long throats due to the original 173 gr. loading. This long throat coupled with the long magazine means bullets, especially heavier examples, can be seated further out of the case which of course increases useable case capacity which in turn increases velocity potential.
One of my 7x57's is a sporterized Venezualian '98 Mauser and its chamber has a looong throat.

35W

Pilot
May 6, 2012, 12:28 PM
I reload, and I've always looked at the reloading data on these two cartridges, and figured "toss a coin" relative to ballistics. Both are very capable rounds.

However, I've learned something in this thread. The advantages of a longer cartridge seem logical, plus it is just cool to use a cartridge this old, that has this much capability.

1948CJ2A
May 6, 2012, 01:56 PM
The 7mm-08 and 7x57 loaded to like pressures are as different as the 243 and 6mm Rem...
Yep!

However, I've learned something in this thread. The advantages of a longer cartridge seem logical, plus it is just cool to use a cartridge this old, that has this much capability.

Bingo!:D

joed
May 6, 2012, 04:41 PM
According to SAAMI, they list the max pressure limit for the 7x57 Mauser at 51,000 PSI. For the 7mm-08 Remington, the max pressure limit is listed at 61,000 PSI. That's a full 10,000 PSI difference. Why is this? Well the answer is debatable but most attribute it to the attorneys for the ammo and handloading companies. They don't want to make ammo or publish ballistics data that could cause a shooter to "blow-up" a firearm component resulting in civil suit. I'll buy this explanation to some degree as it makes sense, especially when considering the age of the 7x57 versus the 7-08. Still, I tend to believe that firearms manufacturers these days love to cut costs. Just look at the number of plastic stocks and short actions today. They dominate the market. It costs less for the manufacturers to mass produce a rifle chambered in 7-08 compared to a rifle chambered in 7x57.

At the end of the day, both of these cartridges are excellent whitetail rounds. They both produce mild recoil and both are terrific cartridges to handload. But that's really where the similarities end. If you really want to know which one is faster and has more energy, go out and put both on a chrony using handloads and you'll see the difference. The 7x57 wins out when you use load data that hasn't been "gimped" down. Just be sure you're using a modern rifle.

End Rant :)
Don't buy into the explanation that the guns and cartridge are old and that's why it's being downloaded. Every couple years the .38 Spl and revolver rounds seem to be down loaded. I expect the .357 Mag to end up not being as powerful as the 9mm in the future. And the 9mm that has been out since 1900 has never been down loaded. Why? Because the gun mfgs sell lots of guns in this cartridge.

The answer is SAAMI, older cartridges are downgraded so the gun manufacturers (also members of SAAMI) can push their new wonder cartridges. The world should hunt down and kill all members of SAAMI!

wlewisiii
May 6, 2012, 08:06 PM
I'm not so sure about the downloading thing.

I was perusing a copy of Lyman's 44th (1967 IIRC) and comparing it against my copy of the current, 49th, edition. The only loading that is different are the loads for IMR-4895 where the old minimum is now the maximum (139 gr SP then 38 to 43 grains while now it's 34.5 to 38 grains.) yet all the others remain the same. I'd guess that after all the surplus ran out, the new stuff was a bit different.

That said, the rest is exactly the same 40 some years ago. So if downloaded, it's been that way for a long time.

I'd love higher pressure based loads for a modern made rifles but it's not exactly easy to find information.

firesky101
May 6, 2012, 08:11 PM
I just saw this post on another thread and thought I would share it. This is exactly why I wrote this thread. People out there actually believe this:



400 FPS slower than the 7-08? Blasphemy!
Hey now dont go taking me out of context. That suggestion was for a non-reloader. The examples I listed in that thread are from comparable loads from the same manufacturer. I have a 7x57 and not a 7mm-08, I believe in the old mausers capability. If you will refer to post #2 of this thread, I note there is not a whole lot of difference (since you handload as you imply in the original post).

oldcelt
May 6, 2012, 09:29 PM
I agree with comments in post #23. I have an old handloading guide from the mid 30s by Phil Sharpe and there conciderable differences in loads for both guns

1948CJ2A
May 6, 2012, 10:17 PM
Hey now dont go taking me out of context. That suggestion was for a non-reloader. The examples I listed in that thread are from comparable loads from the same manufacturer. I have a 7x57 and not a 7mm-08, I believe in the old mausers capability. If you will refer to post #2 of this thread, I note there is not a whole lot of difference (since you handload as you imply in the original post).

Sorry firesky. Not trying to ruffle feathers. Your comment about the 7x57 being 400 fps slower than the 7-08 in comparable loads (assuming factory ammo) was an example of the common misconception on the differences between these two rounds. Even if one doesn't handload, when choosing a rifle, wouldn't you want something with more potential? Who knows perhaps someday that person might get into handloading and make use of the extra case capacity.

Of course the problem today is that the 7x57 is not nearly as common as the 7-08 in new rifles. And because of that, I can see why you would recommend that to a newbie or someone looking for one deer rifle. Still if I could have only one hunting rifle, I'd say the 7x57 would be near the top of the list.

firesky101
May 6, 2012, 10:24 PM
Its alright, I just did not want to people to think I did not like the 7x57. The other thread was dealing with a specific problem for someone who does not reload. I am sure with handloading you can far exceed the hornady loadings for either cartridge.

GooseGestapo
May 7, 2012, 01:10 PM
According to Lee#2, the useful volumn of the 7mm08 is 3.32cc.
The useful volumn of the 7x57 Mauser is 3.68cc, or a 10% difference.
Hence, at the same pressure, the 7x57 will get 2-3% more velocity, if everything is equal, but it never is.....

Also, everyone "knows" the .308 is vastly inferior to the .30/06.... (not!). Because it has a 22% lower "useful" case capacity.... 3.43cc vs. 4.38cc.
As most know, the difference between the .30/06 and .308 is only observable with a chronograph with bullets 180gr or heavier.....

Looking at my Lyman#48 manual, they list 8 loads with the 7mm08 getting 2,800fps or more with a 139gr bullet and a 24"bbl. and one gets over 2,900fps . With the 7x57 they list 3 loads getting 2,800fps+ and that's with a 29" bbl.....
So much for the supposed "much greater potential" of the 7x57..... Like I said previously, IF everything is equal, the difference is perhaps 30-40fps in favor of the 7x57. Or, about like the standard variation between one shot and the next.... from the same box of ammo..... Truly insignificant !!!!

Why don't we "argue" over something really significant; like how many angels can dance on the head of a pin.........

1948CJ2A
May 7, 2012, 02:59 PM
Goose - in post 14 you said:

The difference in case capacity is nearly nil. Actual net difference is about 3-4% with that even varying between make and lot# of cases.

Then today you said:

According to Lee#2, the useful volumn of the 7mm08 is 3.32cc.
The useful volumn of the 7x57 Mauser is 3.68cc, or a 10% difference.
Hence, at the same pressure, the 7x57 will get 2-3% more velocity, if everything is equal, but it never is.....


So how are you figuring 10% more case capacity yields 2-3% more velocity? Or is that just based off your reloading manual?

RickMD
May 7, 2012, 03:02 PM
The difference is the same as between the .243 Winchester and the 6mm Remington. One functions in a short action and the other has a longer neck and is more conducive to reloading. Other than that there isn't enough difference between them to concern yourself about.

Lone Star
May 8, 2012, 01:53 AM
The late gun and hunting writer Jack O'Connor liked the 7X57mm and one was his wife's favorite rifle.

BUT...he went primarily to the .270 because the 7mm was usually throated for 175 grain bullets and using it with shorter bullets tended to wash out barrel throats sooner.

On the other hand, those longer, heavier bullets are the sole advantage that the 7X57 has over the 7mm-08, and in factory ammo, the newer round is normally loaded hotter, unless you get Euro ammo or some special higher velocity ammo from the few companies who offer it. Both Federal and Hornady have done this high velocity thing, but I forget what they call those loads. I think Remington may also have their version.

Today's barrel steels are tougher than what O'Connor encountered in the 1930's-1950's, so I don't know how soon using 139-145 grain bullets might wash out a modern barrel throat.

BTW, I guess everyone here knows that the famed .275 Rigby is just a 7X57mm loaded with Rigby's patented bullets, which were genuinely better than most in their day. Of course, Karamoja Bell used full jacketed bullets to kill those elephants that he shot with 7mm rifles.

interlock
May 8, 2012, 05:06 AM
both are great rounds.

the 7mm08s case shape and design may make it more efficient with faster burning powders where as the 7 x 57 has a longer case and different shape that may make it better with heavier bullets and slower powder.

7mm bullets have really good ballistic coefficients (broadly speaking).

both are excellant proven game killers

oldcelt
May 8, 2012, 04:11 PM
I fail to see what has been proven by this dicussion.
My hunting partner hunts with a 7m/m 08 and I with a 7x57 but at the end of the day the results are equal,the quarry was swiftly dispached.

1948CJ2A
May 8, 2012, 04:46 PM
I fail to see what has been proven by this dicussion.
My hunting partner hunts with a 7m/m 08 and I with a 7x57 but at the end of the day the results are equal,the quarry was swiftly dispached.

My reasons for writing this thread have already been stated. Sorry you didn't get more out of it. Perhaps next we'll do a 243 Win versus 6mm Remington thread and everyone can say how both are equal. I of course will argue that all day long.:)

GooseGestapo
May 9, 2012, 04:52 AM
10% capacity vs. 3-4% velocity increase is simple physics. And my earlier comparison was not based on actual published capacities but my experience with comparing the two based on my experience with the 7x57 with brass that was mil-spec/mil-suplus from the '60's in comparison to the current factory 7mm08 brass. Current commercial 7x57brass has approx. 5% greater volumn than the mil-spec brass I had experience wtih. Hence, I used Lee's published data..... in the subsequent posting....

With an upper limitation of 65,000psi chamber pressure due to limitations of brass and gun steel, an increase of 10% more powder, or approx 4.5gr of powder in the case of 7x57 vs. the 7mm08 ususally only results in a net increase of 3-4% velocity. Several writer/technicians have written treatises over the years documenting this phenomenon. It applies to any cartridge comparison....

It's why it takes the .300WinMag case to get a significant increase in performance over the .30/06. Whereas the "little" .300Savage comes within 3-6% of the .30/06 with bullets 150gr and lighter..... And explains the origin/developement and existance of the 7.62x51 aka 7.62 Nato, aka .308 which is the parent case of the 7mm08.....
I actually have no preference between the two cartridges other than the rifles that are available.

However, in the case of the 7x57Mauser, factory pressure levels are held to lower limits than with the 7mm08.
For a more similar ballistic comparison of the two, look at the Speer #8 manual. They load the 7x57 to 50,000cup and the 7mm08 to 52,000cup or very close. But, then the 7x57 has a 22"bbl vs. a 24"bbl for the 7mm08, which results in the 7mm08 giving higher velocities on the average of ~100fps.....
Like I said, it's never a 1:1 comparison, even in the best of comparisons.....
And of course we've done nothing but restate and rehash the obvious.....

1948CJ2A
May 9, 2012, 12:46 PM
10% capacity vs. 3-4% velocity increase is simple physics.

I'd like to see you formulas for this statement. Assuming both rifles are shooting identical bullets, operating within the same max pressure limits (both modern rifles), and assuming identical environmental conditions. My experience with college physics and projectile motion was never simple. To calculate this accurately you would have to do the formulas and conversions by hand, as using computer software and/or reloading data will be skewed with differing pressure tolerances (as previously covered in this thread). I'm not saying you're wrong but I'd like to see the math you did to come up with those numbers. You can work backwards using simple math. Taking 4% of 3000 fps (just an example) would be 120 fps. That seems logical but like I said before, to really figure out the relationship between case capacity and MV, you'd have to setup multiple complex physics equations to truly get a scientific answer.

For a more similar ballistic comparison of the two, look at the Speer #8 manual. They load the 7x57 to 50,000cup and the 7mm08 to 52,000cup or very close. But, then the 7x57 has a 22"bbl vs. a 24"bbl for the 7mm08, which results in the 7mm08 giving higher velocities on the average of ~100fps.....

According to SAAMI, for velocities between 2501 & 3000 fps, barrel length increase per inch yields approximately 20 fps additional MV. So adding 2 inches using this information yields a 40 fps advantage, not 100 fps.

Like I said, it's never a 1:1 comparison, even in the best of comparisons.....

I agree.

Hey at the end of the day here, like I've said multiple times already in the thread, both are great rounds. And the difference between the two is minimal in the grand scheme of things; however, I'd like to think that these minimal improvements were part of the driving force behind the great efforts from folks like P.O. Ackley.

Haxby
May 9, 2012, 12:58 PM
"... 10% difference... at the same pressure... will get 2-3% more velocity..."

Yep.

35 Whelen
May 10, 2012, 12:05 AM
<snip>
It's why it takes the .300WinMag case to get a significant increase in performance over the .30/06. Whereas the "little" .300Savage comes within 3-6% of the .30/06 with bullets 150gr and lighter..... And explains the origin/developement and existance of the 7.62x51 aka 7.62 Nato, aka .308 which is the parent case of the 7mm08.....


:confused:

I understand the point you're trying to make, sort of, but the 300 Savage does not come within 3-6% of the '06 with 150 gr. bullets...more like 15%. On the other hand, the '06 comes within 7-8% of the 300 WM. So the '06 is quite a bit closer to the 300 WM than the 300 Savage is to the '06.

As I stated in an earlier post, I've never loaded a 7mm-08 but have load the 7x57 quite a bit. In my Dad's 700 Classic, a 139 gr. Hornady will do a little over 3000 fps (roughly 4-5% over Hodgdons 7-08 published data with the same bullet). A 154 gr. Hornady right at 2900 (5-6% over Hodgdons 7-08 data ). FWIW, I used this load for my first bull elk. Both these loads were chrono'ed a few times over the years on first a Pro Chrono then later on a CED.
My old sporter'ed Venezuelan with a 22" tube would run a 150 gr. Nosler SB at 2889 with one load, 2915 with another...roughly 5% faster than the 7-08.
So seriously, in the field there's maybe 50 yds. difference in the two, right?
Are we splitting hairs yet?:D

35W

1948CJ2A
May 10, 2012, 10:56 AM
On the other hand, the '06 comes within 7-8% of the 300 WM. So the '06 is quite a bit closer to the 300 WM than the 300 Savage is to the '06.

This has to do with cartridge efficiency. There is that analogy of the law of diminishing returns (economics). When you have a cartridge that starts nudging into the overbore category, it begins to take increasing amounts of powder to see minimal gains in velocity. A good example of this is the 7mm STW. Nosler did a write-up on this in their 6th Ed Reloading manual.

Neither the 7-08 nor the 7x57 fall into this category. And I agree with you in reference to the 300 Savage vs 30-06 percentages. I have looked at the comparisons in a couple of reloading manuals.

And yes we are splitting hairs.

denton
May 10, 2012, 11:30 AM
In a modern firearm in good condition, there is no reason that you cannot operate the 7x57 at 30-06 pressures. The firearm cannot read the headstamp.

John Barsness' rule, which seems to work well, is that if you get X% more case capacity, you'll max out at 1/4X% more muzzle velocity. So by that rule, 10% more case capacity gets you 2.5% more MV. Estimates of 2-3% are right on in the case of the 7x57. All other factors equal, the 7x57 will always exceed the 7-08, but not by enough to make much practical difference.

The 7x57 works perfectly in intermediate length Mauser actions, like the Yugo 24/47 or 48. If you're converting one of those, 7x57 is a better choice than 7-08.

The 7x57 does seem to have a small advantage with heavier bullets. In my instrumented 7x57, I get 2750 FPS with a 162 grain bullet at pressures in the mid 50 KPSI range. That's a very capable hunting round.

They are both outstanding rounds. I would not feel undergunned with either of them for just about anything in North America. I have a couple of 30-06s, but rarely shoot them since I built my 7x57.

1948CJ2A
May 10, 2012, 12:49 PM
John Barsness' rule, which seems to work well, is that if you get X% more case capacity, you'll max out at 1/4X% more muzzle velocity. So by that rule, 10% more case capacity gets you 2.5% more MV. Estimates of 2-3% are right on in the case of the 7x57. All other factors equal, the 7x57 will always exceed the 7-08, but not by enough to make much practical difference.

The rule he uses is called the 4-to-1 Rule. Here's a link to the article where he describes this rule: http://findarticles.com/p/articles/mi_m0BQY/is_4_55/ai_n31392893/

If you applied his rule to this debate, you would have to use the 7-08 published MV since he's using factory & reloading data (assuming identical pressures in 2 modern rifles). According to Remington's factory ammo ballistics table, the 7-08 pushes a 140 gr at 2860 fps. The case capacity of a 7-08 is 55 gr. The 7x57 capacity is 60 gr. By dividing 5 (the difference in capacities) by 55 (the smaller 7-08 case), you get 9.1% more capacity in the 7x57. Applying his 4-1 rule, you divide .091 by 4 and get 2.3%. If you multiple 2.3% by the 2860 MV of the 7-08, you should see a MV increase of approx 65 fps in the 7x57 (everything else equal). If you wanted to use reloading data and used 3000 fps as your starting point on the 7-08, you would get a 69 fps increase in the 7x57 (everything else equal). Increasing the MV of the smaller round increases the difference in fps between the 2 but the percentage stays the same of course.

I'd still like to see the math this guy used to come up with his 4-to-1 rule. It would seem to me that all cartridges would be slightly different. Plus if the smaller of the two cartridges you're looking at has a lower SAAMI max pressure, then this rule won't work. Example of this is the 300 Savage versus the 30-06 Springfield. If you apply his rule, you come up with 7% increase in MV for the 30-06 over the 300 Sav. If you multiple that by the published 300 Sav Remington factory load (2630), you get 184 fps. Add that to the 2630 and you get 2814 fps. But then reference the 30-06 (same table) and you'll see a published MV of 2910. That's almost a 100 fps difference. This is because the 300 Sav max pressure is 47,000 psi versus 60,000 psi in the 30-06.

One more example and then I'm done. If you look at the 30-06 versus the 300 Win Mag and apply his rule here, you end up another 100 fps shy of the actual Remington factory table data. I'll show the math again if someone wants to see it. The SAAMI max pressure differences between these two cartridges is 5,000 psi (much less than the 13,000 psi diff between the 300 Sav and the 30-06). Interesting...

How does the 1/4 rule apply to the overbore cartridges? It would seem that using just one rule of thumb for projectile motion would be rather obtuse. It might get you pretty close but it doesn't take into account different max pressures. In college physics I remember there being 4 different equations for linear motion. You had to examine the specifics of the experiment in order to determine which one or which combination of them you needed to use. I would think this to be no different.

denton
May 10, 2012, 01:19 PM
Barsness is a very capable fellow, but math and physics don't seem to be his strong suite. This is most likely an empirical formula.

Just looking at it from an energy standpoint, you are converting the chemical energy of the powder into kinetic energy of the bullet. But kinetic energy is .5*mass*velocity^2. So you'd expect muzzle velocity to go up as the square root of the ratio of available energies. Assuming the 7x57 has 10% more case capacity (for round numbers), you'd expect a muzzle velocity change on the order of square root 1.1, or 1.048. That exceeds John's rule, but not by a lot.

The real situation is undoubtedly more complicated than this. You have more surface area to rob more heat energy out of the propellant gas for one thing.

1948CJ2A
May 10, 2012, 02:02 PM
The real situation is undoubtedly more complicated than this.

Yea. In the end the 7x57 Mauser has greater potential and yields greater muzzle velocity and energy than the 7m-08 (assuming everything else equal including max pressure in modern rifles). It may not be much but the increase does exist. Based-off the information provided in this thread, those results should be apparent.

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