7x64 Brenneke

[ne1022]

I am looking for load data for a Sako AV in 7x64 Brenneke. I have Speer, Hornady, Sierra and Lyman manuals containing nothing on the round other than referencing the 280 Remington as a starting point. There isn't much out on the internet either so while I generally don't post much on forums I would be appreciative of any ideas here or via PM.

Thanks in advance.

 

[misako50]

ne1022- You can use the load data for the 7mm Remington (Non Mag) or the .280 rem. They are interchangeable and the cases have very similar dimensions. Just be cautious and start low.Therre are websites such as IMR Powders from DuPont that should get the info to you with that cartridge. Just looked at that site and there is nothing for the 7x64--HOWEVER--- I checked in at Accuratereloading.com and found some data for it there.-Misako

 

[stonecreek]

As Misako says, the .280 Remginton (at one time called the 7mm Express Remington, not to be confused with the 7mm Rem Magnum) is so similar to the 7x64 that loading data is interchagable. There will likely be as much difference in two rifles chambered for .280 Rem as between a rifle chambered for 7x64 and one chambered for .280 Rem.

For whatever reason, .280 Rem SAAMI standards are kept to a lower pressure than several of the other cartridges on this case. As a result, data found in most sources for the .280 is somewhat conservative. That rather conservative data will be similarly conservative in a 7x64. It is likely that you can reach somewhat higher velocities than most data sources show without creating unsustainable/unsafe pressures.

By the way, congratulations on owning a Sako in 7x64 -- they're somewhat difficult to find.

 

[ne1022]

Stone and Misako - thank you for your replies. Curiously, I assumed this to be 7x64 Brenneke. When looking at gauges on Midway's website I find 7x64 Brenneke and 7x64 CIP. The barrel marking simply states Sako 7x64 (note the omission of Brenneke). The rifle has a long freebore and I now wonder if my assumption on Brenneke may be inaccurate. Any clarifications?

 

[stonecreek]

If this is a factory Sako then I would be extremely surprised if it were anything other than the 7x64 Brenneke. I'm unfamiliar with a 7x64 CIP and don't find it listed in the source of cartridge drawings I usually rely on.

 

[ne1022]

It appears that CIP in Europe is what SAAMI is here. What I find odd is that the headspace gauges at Midway (same manufacturer) are different, one for Brenneke and one set for CIP. The CIP gauges are a couple of bucks a piece higher in price. I am thinking that Sako manufacturers to the CIP standards which would account for all the freebore...so, I should get the CIP gauges, not Brenneke...right?

 

[gspsmoke4]

Data from Hornady suggests that 49.3 grains of IMR 4350 powder will drive a 139 grain bullet to a MV of 2600 fps, and 54.7 grains of IMR 4350 will give a MV of 3000 fps.

Also according to Hornady reloading data, their 154 grain bullet can be driven to a MV of 2500 fps by 46.9 grains of IMR 4350 powder, and 2900 fps by 52.9 grains of IMR 4350. A Hornady Spire Point Interlock bullet at 2800 fps would have the following trajectory (Hornady figures): +1.9" at 100 yards, 0 at 200 yards, and -8.3" at 300 yards.

 

[stonecreek]

ne1022: I'm not sure why you would need to purchase a headspace gauge. Sako is not going to build a rifle which has headspace greater than the accepted standards for the ammunition for which it is chambered, and presumably there would be no occasion for a recent Sako to have suffered abuse which would increase its headspace. Assuming you intend to handload for this rifle, then you should set your resizing die such that it barely kisses the shoulders of a fired case. In other words, the fired case becomes your headspace gauge.

The amount of freebore has nothing to do with headspace, so a headspace gauge would tell you nothing in that regard. Greater freebore will allow the rifle to digest slightly heavier charges of powder, all things being equal, thus you might expect to need to use a bit more powder to achieve the same velocities (and pressures) that a chamber with a shorter leade would require.

Or perhaps I'm missing something here in your inquiry. If so, please don't be bashful in explaining or correcting me. Sometimes I misread or misinterpret.

 

[ne1022]

gspsmoke4 - is your load data from the 7x65mmR table or did your manual actually have 7x64 loads?

stonecreek - What has got me wondering is the following statement I ran across:

"In contrast, the 7x64 CIP chamber specification calls for a long freebore. In rifles with short magazines but long freebore, top velocities are usually still obtainable, providing the faster 4350 burn rate is used to avoid powder cramping."

I didn't give it much thought until I ran across the CIP version of the 7x64 headspace gauges at Midway. They have one set for 7x64 Brenneke and one for 7x64 CIP. I have assumed my Sako was Brenneke and bought Brenneke dies. Since there does not seem to a lot of information out there on the 7x64, I thought I'd buy the gauges to be 100% certain of what I had. I would prefer not to spend the extra $60-70 if someone here had some prior experience to share. The money would be better spent toward a chronograph which I have yet to purchase.

 

[gspsmoke4]

ne1022:

Came across the info while researching caliber for possible purchase. Some links I saved below.



http://www.norma.cc/en/Ammunition-Academy/Loading-Data/7x64/




http://www.chuckhawks.com/7x64_Brenneke.htm




http://www.saami.org/PubResources/CC_Drawings/Rifle/7x64%20Brenneke.pdf




http://www.accuratereloading.com/764brenneke.html




http://www.reloadersnest.com/detail.asp?CaliberID=128&Powder=Somchem&LoadID=9608




http://www.reloadersnest.com/detail.asp?CaliberID=128&Powder=Somchem&LoadID=9607

 

[ne1022]

gspsmoke4 - hey thanks...I will go through all the above this evening when I have some time.

On another note...I had a conversation this morning with the headspace gauge manufacturer. They actually make three different gauges for the 7x64 (ECJ, Brenneke and CIP). He understood my confusion on the Sako and thought it odd that they did not differentiate. In the end, he confirmed there was less than a thousand's (0.0009) difference between them and I would be wasting money buying gauges to try and distinguish exactly what I have, i.e., Stonecreek was right on when he mentioned there might be more diffence in one rifle chambered for the same round.

He also mentioned that I could use the 7x65 data in the Hornady manual as it was basically the same round but rimmed. He had worked up tooling for Hornady for their introduction of 7x64 Brenneke ammo they recently started manufacturing. He thought it odd that while CIP was dropping the use of Brenneke that Hornady chose to include it. Maybe they saw it as a marketing opportunity to include it while the European's are dropping it. He agreed that it has caused confusion. Lastly, he agreed that I might have some accuracy problems with the long throat length on this round (I can take a empty case, start a Nosler BT and chamber it w no signs of engaging the rifling).

So back to my initial question of load data... I will use the 7x65 data in the Hornady manual as a starting point. My apologies for boring everyone here.

 

[Deleted member 14372]

Sent from my iPhone using Tapatalk

 

[Deleted member 14372]

I recently had good luck w 51 grains of IMR 4350 behind 154 grain Interbond. 5/8”.

Sent from my iPhone using Tapatalk