7x64 Brenneke - Opinions

well, the idea is a righty for my daughter, and a lefty for me. Any lefty in 280 Rem is going to be a custom gun, which will wind up costing about the same as just buying a Sako 85 Hunter. I love my Tikka, so I expect I'll love a Sako even more.

One of my friends (a German) once described the 7x64 to me as "The Gentleman's .270".

I find it hard to disagree.

Once I shoot out this current .270 barrel, I'll be having a serious think about whether my rifle comes back from the smith as a 7x64...

Hi,

I am reading this thread. Interesting.
By the way, the chamber standards for 7x64 DO have freebore. And one of the longest of all sporting cartridges. Plus, of course the gradual lead angle of the lands. Both entirely different of the .280 Rem, that have one of the shortest freebore!!!
Here are the C.I.P. drawings for both. Very clear.
Best!
CF
7x64 https://bobp.cip-bobp.org/uploads/tdcc/tab-i/tabical-en-page34.pdf
Commencement of Rifling (G) 34 mm
.280 Rem https://bobp.cip-bobp.org/uploads/tdcc/tab-i/tabical-en-page103.pdf
Commencement of Rifling (G) 4,75 mm

Many years ago I had, for 4 years, a beautiful 7x64, a Mannlicher-Schoenauer GK 60 cm barrel lenght. Of course it had that loooong freebore and was extremely accurate with any 154 to 177 grs bullets loads.
I like this european chamber designs in hunting rifles.
By the way, here is the C.I.P. 7x57 chamber standard. It has a 19,2 mm freebore. I like it!

7x57 https://bobp.cip-bobp.org/uploads/tdcc/tab-i/tabical-en-page33.pdf

About my experience handloading both cartridges, the 7x57 and the 7x64 in standard lenght actions like the M98 Mauser and that M-Sch. one:
The 7x64 cannot be loaded with an OAL much longer than the factory ones. Just a little, being the magazine lenght the limiting factor.
The 7x57 CAN be loaded MUCH longer than the factory ones in a Std. M98 magazine lenght, still with enough freebore.
Doing that, I couldn't get more than 50-75 f/s in favor of the 7x64! With that 154 to 177 grs bullets.
This long 7x57 is a kind of 7x57 Creedmoor in concept....
Best!

CF

The power of the cartridge 7x64 Brenneke are the long and heavy 7mm bullets. The recommended twist-rate for the cartridge 7x64 is 22mm / 8.75 "and not 24.1mm / 9.5" as for the cartridge 7mm Rem Mag. That's why both cartridges are conceptually not comparable. Does not mean that you cannot shoot light bullets with the one or heavy bullets with the other.

Hi kfj,

Yes, IT is!

It is not the cartridge that kills the game... it is the BULLET. The 7mm has been proven on smaller and medium game for over 100 years and works well. Match the bullet to the game and go hunting. Most best result have come from shooting 140 to 160 grain bullets in this caliber.

clodo,
interesting posts.
freebore and throat angles can affect pressures in a big way.
obviously the 7x64 chamber will allow stiffer loads, all else being equal.
whether this means more velocity, only testing would reveal.
your comment re 7x57 in a 30/06 length action reflect a question I have re the 9.3x64 if it were chambered in a 375 length action.
it would certainly free up powder space for the long 286 gn barnesx.
bruce.

Fastrig said:

... but if you were going to pair one with the 9.3 Mauser, which would you choose? Go all German with the 7x64 and 9.3x62 in the Merkel

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Yes.

From Roe buck to Croc, no problem with 160gr Federal NP

All this discussion about 7mm rifling twist rates makes me wonder... does a faster twist rifle shooting the same weight bullet at the same speed as a slower twist rifle give the bullet more stability IN game? or is there any difference in expansion / wound cavity / killing power?? Is it possible that's why the old style 6.5mm rifles seem to kill better than paper ballistics would indicate? or, What's your experience and theories?

Longwalker said:

All this discussion about 7mm rifling twist rates makes me wonder... does a faster twist rifle shooting the same weight bullet at the same speed as a slower twist rifle give the bullet more stability IN game? or is there any difference in expansion / wound cavity / killing power?? Is it possible that's why the old style 6.5mm rifles seem to kill better than paper ballistics would indicate? or, What's your experience and theories?

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It does matter at moment of impact. GS Custom bullet maker has written some notions about it. After the bullet deforms it retains stability with slower rotation.

If you think a spinning top. Narrower is harder to keep upright than wider. That’s remotely comparable to situation where bullet encounters the skin of the game. If the bullet was marginally stable in flight, at high velocity impact it destabilizes like spinning top at the end.

Now the resistance of air and living tissue are different. Air resistance is distributed load that applies pressure to whole frontal area and underpressure to rear of the bullet. In tissue, the forces concentrate on nose of the bullet. As result, in flight, faster is more stable. On impact faster is less stable.

As result, twist rate for ensuring stability at point of impact, until diameter expansion is sufficient is higher at close range. Impact velocity seems to be determining factor there. At longer distance it is necessary for the bullet to tilt along with trajectory so less stability is desired. Also with lower impact velocity the need for higher stability decreases. Now as the twist rate is fixed with the rifle, it’s necessary to consider the bullet chosen for the job.

Twist rates of factory barrels being designed for lead core bullets those have rarely any issues. The stability depends on the length, shape and diameter of the bullet, less on density as long as it’s reasonably uniform. As less dense material copper results in longer bullet, requiring higher twist rate. If hunter uses same 180gn bullet in 308 in copper as they used to do with old softpoint, the bullet is more than likely to destabilize on impact and hunter blames the bullet when they picked wrong tool for the job. Lead bullets used to be limited for velocity they can withstand for controlled expansion, for copper that isn’t an issue and in some calibers same goes for bonded core bullets.

Where bullet strength is solved, at short range, lighter bullet and higher velocity will always do more damage unless it’s question of marginal caliber where ability to cause large temporary cavity is sacrificed to ensure penetration.

Hello samu,

Well written. In the great book "African Dangerous Game Cartridges" by Pierre van der Walt, there are extensive information about this mater, both for solid and expandable bullets.
Best!

CF

I think I follow your explanation samu, but I'm not sure of the practical application of those principles. To sum up, please explain - would you predict the ability of of a 7mm expanding bullet to remain stable as it penetrates inside game is always better with a faster twist?
Or for instance in my 7x64 rifles, the Sako M85 is made with a slower twist, and my Steyr Mannlicher has the traditional faster twist. Should I choose to shoot only 160 grain lead core / 140 grain copper bullets in my Sako or would 170-175 grain bullets of either construction be OK ?

I may have partially answered my own question. GS Custom did have some good information... see this quote
"QUESTION:
Will you be able to manufacture a 175gr hollow point, boat-tail spitser in 7mm? I have a 7 x 64 and I want the heaviest possible bullet available as I want the velocity to remain below 2700ft/sec.

ANSWER:
We would be happy to make 175gr 7mm monometal bullets as we have been asked for them on numerous occasions. The only snag is we know that they cannot work in standard commercially available 7mm barrels. Any manufacturer who supplies such a bullet is simply responding to an uninformed demand from the market. Here is why: A 7mm 175gr monometal spitser boat tail bullet will be 18% longer than a similar bullet of conventional construction. That means that it will be about 42mm long and will require a twist of 1 in 7.3" to stabilize. Some rifles may shoot reasonable groups with such a bullet but when it strikes, it will tumble instantly, with the resultant unpredictable penetration and massive meat damage a tumbling bullet brings. A 175gr round nose flat base bullet can be made to stabilize, but will not expand, and will be too slow for decent momentum and energy levels as are available from the lighter and faster HV bullets."

Longwalker said:

I may have partially answered my own question. GS Custom did have some good information... see this quote
"QUESTION:
Will you be able to manufacture a 175gr hollow point, boat-tail spitser in 7mm? I have a 7 x 64 and I want the heaviest possible bullet available as I want the velocity to remain below 2700ft/sec.

ANSWER:
We would be happy to make 175gr 7mm monometal bullets as we have been asked for them on numerous occasions. The only snag is we know that they cannot work in standard commercially available 7mm barrels. Any manufacturer who supplies such a bullet is simply responding to an uninformed demand from the market. Here is why: A 7mm 175gr monometal spitser boat tail bullet will be 18% longer than a similar bullet of conventional construction. That means that it will be about 42mm long and will require a twist of 1 in 7.3" to stabilize. Some rifles may shoot reasonable groups with such a bullet but when it strikes, it will tumble instantly, with the resultant unpredictable penetration and massive meat damage a tumbling bullet brings. A 175gr round nose flat base bullet can be made to stabilize, but will not expand, and will be too slow for decent momentum and energy levels as are available from the lighter and faster HV bullets."

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Just as they said. Sako and Lapua are still sellin copper bullets in traditional weights because you can’t sell a light bullet to hunters who have been told decades to go heavy.

Important notion. The stability issue happens only at very short moment where bullet tip encounters resistance of game but has not yet expanded. Problem is that if the bullet tumbles it is unlikely to ever expand properly.

Proper monometallic bullet weight for 7mm seems to be around 140-150gn and it can be used just like 180gn lead core bullet when MV is increased in proportion. Only thing that needs consideration is to ensure sufficent impact velocity. Next season in Finland will allow 115gn lead free bullets to be used on moose and brown bear. Will be interesting to see reports on how they perform. Many reloaders considering 130gn TTSX for .308.

Well I pulled the trigger (pun intended) and purchased a Zastava in 7x64. I wanted a stainless CRF rifle in .280 Rem/AI or .30-06 so was looking at Kimber Hunter/Montana. But the Zastava is about as real as stainless Mauser can be, this one also comes with a nice B&C stock and the 7x64 should be more than OK. It is a bit rougher than any Mauser or CZ I have had but slick enough. Fit and finish is decent and I may end up polishing the lug raceways, feed ramp, magazine well, etc. a bit but maybe I will just shoot it a lot. Got some Hornady, Norma and PPU ammo. Already bought the dies to reload so I'm re-reading this with interest. I may in the end stick to my 7x57 but this could be a cool cartridge to shoot. Tested it with friend's 280 and the 280 will chamber the 7x64 ammo but not the other way around (as the dimensions would suggest). Almost wish I had the 280 as I think firing the 7x64 in it should be safe. But in the end this is a very cool cartridge. Can't wait to shoot it and compare it to the 7x57.

You will like that round, I have had several and currently have one of the Zas rifles and man it shoots. With limited testing it shoots half inch. Mine is one of the Euro imports, rough looking but good shooters. For some reason the 7x64 seems easier to get to shoot than either the .280 Rem or the 7x57, just my experience.

yes...oddly enough I too feel the 7x57, as great as it is, is not the most accurate round I have seen. I will see what handloads can do but if it becomes hard to find the sweet spot I will leave it alone.

Milan said:

yes...oddly enough I too feel the 7x57, as great as it is, is not the most accurate round I have seen. I will see what handloads can do but if it becomes hard to find the sweet spot I will leave it alone.

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The throat length and twist length matter a great deal.

Vintage/military rifles (and custom vintage rifles honoring their tooling specs) love heavy for caliber 7mm projectiles. That usually means 175gr is the sweet spot, 180gr FMJ works great, and 156gr Oryx is the floor. The new 140gr and 150gr barnes copper TTSX has the same volume as the 175gr lead core ammo so it also works well.

But when you start shooting 120gr-140gr lead ammo no every 7x57 reacts well to that.

My knowledge of 7x64 brenneke is limited to only one gun and only two ammunitions: The barnes TTSX 140gr and the remington 175gr weldcore. (drawing a blank...whats the classic remington ammo called?). Both shot quite well. My 8 year old shot a record book oryx at 244 yards with the barnes ammo satisfactorily. We have not tried handloads or lighter bullets that may present more troubles.

Reminder: a barnes bullet is not considered a light bullet. Ignore their weight, pay attention to their volume! Treat their volumetric equivalent to lead ammo as a guide for whether they are likely to shoot well.