7.92x57 Mauser, Unsuitable for long range or merely unfashionable?

[meles meles]

We're contemplating a new barrel for our DTA SRS Covert to complement its current 16 inch, 1 in 8 twist, .308. We fancy something with longer legs and, rather than tread the well worn 6.5 path, are pondering the venerable 7.92x57 Mauser. It has a fair bit more oomph than .308, with heavier bullets, and so we think it might be worth using out to 1200 yards. Maybe a 32 inch barrel with a fairly tight twist...

 

The fall back plan is 6.5mm, but we'd value opinions on the 7.92 option.

[GeorgeB]

Not very feasible due to the lack of long range target bullets in 8mm.

 

The only one I know of is the 8mm 200gr SMK.

 

Why not try a 7.92x57 necked down to .30 cal? Norman Clark did one for me many years ago. It was very accurate, but now you have high energy powders like RS60, you can get just as much "oomph" out of a .308Win and avoid the faff of fire forming and special dies.

[Grum87]

What about 7x57?

 

My only experience with 7.92 is fired through K98's, which is certainly not a 1200 yard candidate....

 

A fun, aesthetically pleasing rifle, aswell as producing a decent thump that's amusing to introduce new shooters to.....but that's about it for me.

[Kalahari]

7 x 64?

 

David.

[meles meles]

The sensible thing to do would be either to buy a longer .308 barrel, or to go to 6.5 - in our case by x55 rather than x47 or Creedmore as we have dies and bullets aplenty for several other rifles we have in 6.5 Swe. However, we fancy something different but less than .338 as that would reduce the number of places we can use it. The 7.92x57 seemed to us potentially to fill that niche: a big, heavy round to buck the wind with plenty of power to keep it supersonic to 1000 yards.

[tackb]

I'd go with a big 7mm in your position

[gbal]

There are reasons the better 7mms are the cartridges of choice for 1000y(+) by those not wishing a big boomer 30 (mag),and realise the modest 6.5s are a bit lacking (as is 308)-the 7mm/284 is also very well served by that crucial component-high BC bullets; The 284Win is now well established,and is about where something close to a good balance of ballistics and shootability begins,with no fuss.There is a small 'fashion' component,but the ballistics have to work-generally 'neccessary,but not sufficient' for wider acceptance. Of course,some may want something a bit different from this fine,now standard choice,and there are plenty of others that will provide variably less satisfactory performance overall. 280 Rem hasn't been much explored,or 7 Rem Mag -and those omissions are a tad puzzling-though the 7WSMs and 7RSAUM have show that a bit more performance can be used rewardingly for 1000y + targets. Good luck if you opt for something outwith the above class of established 7s.

 

gbal

[meles meles]

We already have a 7mm Rem Mag (Rem700/AICS stock) and very much like it for longer ranges than our .308 DTA short barrel can manage. We just fancied something a little different as a long range barrel for the DTA.

[Soggy biscuit]

How about a 6.5x57 a fantastic underrated round with plenty of factory loads and brass.

 

Cheers s-b.

[Laurie]

The Sierra Infinity ballistics program using the company's G1 BCs shows the 200gn SMK as barely supersonic at 1,100 yards and subsonic at 1,200. That's with 2,700 fps. Loading it well up using RWS Brass and with 'high-energy' powders such as RS60, 2,800-2,900 fps might be possible out of a 30-inch plus barrel which would remain supersonic to 1,200 and nbeyond..

 

However, that prediction uses Sierra's stepped speed related G1 BCs which experience shows are usually optimistic at extended ranges. Still, the WW1 Imperial German Army and WW2 Wehrmacht had little trouble engaging much longer distance targets with machineguns with the 198gn FMJBT sS bullet, even if they weren't looking for match accuracy as opposed to 'beaten zones'.

 

Three issues - one as already mentioned hardly any bullet choice, really only the 200gn SMK readily available - Krank's website shows them in stock at £45 odd / 100.

 

Second, although sounding an impressive weight at 200gn, it's a low BC bullet compared to the alternatives in 6.5 and 7mm - down on the 142gn SMK 6.5 and 175gn SMK 7mm to take two similar older and successful models.

 

Third, the thing that always put me off stiff loads in 7.92X57 - recoil. Even in a heavy rifle, a full-house 200gn load will kick and then some.

 

If you follow it up, I'd talk to gunsmiths about reamers and chambers too. The long and tapered throat military 7.92X57mm IS chamber was all about getting maximum velocities for a near 200gn bullet from relatively crude propellants by today's standards and staying within 56,000 psi pressure, presumably maximising throat / barrel life too from what was a very hot load in its day. I've never found an 8mm Mauser that would shoot anything near as well as equivalent 6.5X55 and 7X57 service rifles - and I owned a mint Cz made Persian long rifle and equally mint BRNO KAR98k amongst others in my days of shooting historic service rifles.

 

It'd certainly be different though. (But so would 7X57 in a modern target rifle.)

[Shuggy]

If you want a bit more oomph, why not 30-06? And there is always the AI version. I gather that Steve Bowers is quite partial to building these for long range use.

[Andrew]

I shoot quite a bit of 7.92x57 and none of them military rifles. It is a finely accurate cartridge but not a 1200 yard choice in my opinion. An 8mm-06 is a pretty good round offering some legs over the standard 8x57 chambering but bullets are few and far between for target work. Along with the Sierra, Nosler makes a 200 gr Custom Competition but it offers nothing over the Sierra. I would look towards the 6.5.s. A 6.5-284 has some smack behind it. Might be worth considering.~Andrew

[gbal]

As per Andrew-the 6.5x284 has the track record as a 1000y cartridge,though now outclassed-and none of the 6.5x47 class are in it's class.A 6.5x55 AI will outshoot the x47 clones-fine though they are,but not leaders at 1000y.

Ditto the 7x57 class -a great cartridge,but not for Long range. 7-08 ditto-they are struggling ballistically. before 1000y.

 

The military 7.92- suffer from poor BC,as already said-and that is unlikely to change-'oomph and power' are not sustained at distance if the BCs are modest (but the recoil is!) We're talking presumably about a new barrel-semi custom-so there is no reason accuracy would be as modest as in basic models in any of the cartridges.

30-06 gives a bit more,even a 6.5-06,but once 30 cal comes in,a clear contender is the 300Win Mag,which is a serious improvement on 308/30-06 but short of the big 338s,or even the true super magnum 7s ; and often offered as the competent intermediary in military sniper rifles like AI to give more LR reach; if sniper cred has any appeal-the useable 300Win Mag has it.

All this of course is predicated on just what action lengths are feasible-or how exotic you might be tempted to be (but really the vom Hofes and so on are impractical in this application)....300Win Mag is off the shelf-it's recoil factor is 2.39 (30-06 is 2.19,7rem mag 2.06;the mil 7.92 kicker,just above 30-06,probably.)

 

So 300wm fits the bill rather well; indeed, by design...and probably available?

 

gbal

[Deserttech Europe]

I love the idea, one of the best parts of the system is being able to experiment.

 

I have way to many barrels personally (5 different .308 for example) but fancy the following:

 

6.5x55 Ai

.204 or .17 (I think its a tactical, the .223 backed down)

.300 blackout

.375 sledgehammer (.338 necked up and Bisley legal)

 

Ewen

[GeorgeB]

Ewen,

 

375 Sledgehammer is a new one to me. - What is the achievable MV with the 350gr SMK?

[Scrumbag]

280 Rem and 7x64 I think could take some exploring. Certainly intend to see what my 7x64 loaded with 160gr TMKs will do.

 

280AI has some following for shooting at longer ranges from my reading...

 

Hard to beat a Swede though in some ways. Long throat and mag box, plenty of hunting bullets and ammo if you want to use it for that...

[gbal]

Scrumbag,the 284win seems to be the starting ballistics currently for 1000y,anf for most entirely adequate-though the Shehane improves it a bit,and neithe can compete with the short magums on ballistic equality.

The 280 and 7x64 are just about in the same class-very rarely used though...280AI does help.

That's not to say the casual club user would not enjoy them....

The 6.5x55 Swede is a fine cartridge,but need the AI improvement to be a 1000y cartridge,though it was once ('club' user can enjoy....).All are excellent UK large deer cartridges.

 

Some CIP/SAAMI data will give an idea of the 7x64-you will be in this ball park (200 zero,10 mph wind)drop/drift " :

 

Norma 170 PP BC .378 @ 2723 500y 54/27 800y 224/81 1000 y 448/137.

 

The 280 is very close:Norma 170 PP @2707 500y 55/28 and 1000y 460/140

 

Lighter bullets for comparison in 7x64 and 280 Rem:

 

Norma 140 Nosler ACC Bond BC .48 @ 2953 500y 40/18 and 1000y 297/87

Fed 140g Nos BT BC .48 @2990 500y 39/18 and 1000y 287/85

 

and in the 6.5x55:

 

Lapua scenar 140 BC .51 @2740 500y 46/19 and 1000 340/90

 

The 7WSM indicates what improved performance is available-at a barrel cost:

 

Fed 140g Nosler BT BC .48 @ 3310y 500y 31/15 and 1000 228/74

 

All can be tweaked a bit with the best target bullets,more pressure,etc-but they all can,so differntials remain.

 

1200y+ gets most(not WSM/SAUM) into transonic complications...it'll get there,but exactly where is less predictable....no good for competitors,or sub 2moa gongs..... fun maybe.....? .....not as much as having at least a 50% chance of hits. :-)

 

gbal

[meles meles]

Hmmm, the 6.5x55 SWE is looking to be the favourite at the moment, but we're intrigued by the sound of the .375 Sledgehammer: it's a new one to us !

[gbal]

mm - there are a fair plethra of heavies in the 33 caliber- I think Nosler have just announced yet another (33Nosler)-some or most will be upwards of 4500 ft lb,as indeed are most Lapua 338 loads (The Dakota 300g loading for the Lapua @2800 is 5224 ft lb).

 

The 6.5 swedish is a fine round-and in Ackley Improved is still a capable 1000y performer-no longer competitive against the best 7 /30 short mags,etc but still a pleasure..... 1200y is sorting most out.....and where the 33s really begin their thing...

 

gbal

[Scrumbag]

Thanks gbal. I shall have a play and let you know how I get on

[Simon J]

8mm target bullets are available, but you have to look hard. I found some copper ones from Peregrine Bullets of South Africa at www.peregrinebullets.com. BCs are .473 for 180grain and .525 for 200 grain. I guess you'll find some made by a craftsman in Germany too. Bit obscure I grant you!

[meles meles]

Hmmm, after much thought, the 6.5x55 Swede is looking likely to be the next barrel for our DTA...