7x64 Brenneke handloading tips

[Hobbit]

Hi 

a potentially niche question - lets see how this goes

I am getting a 7x64 barrel for my Blaser R8 -  and wanted to canvas any tips on reloading - use will be mixed  but objective of reloading is an accurate, long range round that is reliable in a straight pull - (so FL sizing) and makes the best of a 23 inch barrel

I can get Lapua brass so that is a good start - the R8 barrel has a sensible twist rate (1/8.5) which is not always the case in Blaser barrels so I can run the heavier, higher BC ELD-X which is then multi purpose (I like to find one bullet/powder/charge weight combo per barrel/rifle and then focus on getting to know it and using it well)

I am interested in thoughts on dies - not a huge choice - my go to redding match bushing dies are not available - what do people use? are redding deluxe any good, can you vary neck tension?

Any tips/ recommendations on powder (I tend to go Vhit or RS for 'security of supply') , other bullet ideas, tips and tricks welcome

Thank you kindly

H

[Laurie]

The 7X64 is very close dimensionally and ballistically to the 280 Remington although neither brass nor loaded cartridge is interchangeable. (Actually, it's the other way round as 7X64 is very much senior to the US upstart near-copy!) The advice on loads is to use 280 Rem data and subtract 5% from the maximum for safety. So look up pet loads on the 280 if you don't find much on the Brenecke.

Redding Deluxe are standard non-bushing dies. Good quality IME. If the neck tension is too high, remove the expander in the sizer die and get or if you already have one use, a mandrel type expander die which allows interchangeable mandrels designed for expanding the neck before neck-turning. I use the Sinclair expander die body and the same company's 28E model expander on all my match sevens and the degree of neck tension is just where I want it. The K&M equivalent should be fine too. Lube the inside of the neck before use, or else shell out for a very expensive carbide mandrel.

https://www.vihtavuori.com/reloading-data/rifle-reloading/?cartridge=82

I'd have thought N160 is well suited to the cartridge, N165 for 170gn and heavier.

 

[Hobbit]

Laurie

Thank you - I was hoping you would jump in 

That is a great tip on the mandrels - does this mean the 7mm mandrel for example leaves the brass just sub 7mm in diameter so there is some neck tension??

Thanks

[Scotch_egg]

I have got an R93 7X64. 

The Redding FL  works well in the Blaser chamber. I have only used 120gr Nosler Balstic tips as that’s what I had on the shelf. 

I will certainly not be getting enthralled with mandrels and other anal loading techniques.

The Redding dies will be more than adequate, I have some 162gr ELD-M I will be loading in the future. 

 

As for powder I will be going to a Vihtavuori N550-N560 due to the shorter barrels Blaser use and the fact I’m  not putting several rounds down at a time causing heat. 

[Laurie]

37 minutes ago, Hobbit said:

Laurie

Thank you - I was hoping you would jump in 

That is a great tip on the mandrels - does this mean the 7mm mandrel for example leaves the brass just sub 7mm in diameter so there is some neck tension??

Thanks

 

Yes

[Laurie]

21 minutes ago, Scotch_egg said:

As for powder I will be going to a Vihtavuori N550-N560 due to the shorter barrels Blaser use and the fact I’m  not putting several rounds down at a time causing heat. 

You may encounter considerable muzzle blast and flash with anything under a really high pressure load.

[Scotch_egg]

2 hours ago, Laurie said:

You may encounter considerable muzzle blast and flash with anything under a really high pressure load.

Laurie please expand on this. I have only ever loaded .308 size cases and below. I had formed the opinion a stiff load of the N500 series would afford better velocity. 

Could you recommend a better alternative? 

[Laurie]

I should have qualified my reply to say N560 which is very much slower burning than N160, and in fact often acts as a slower burning powder than N165. My experience is that it can be finicky and also need max pressure loads to perform consistently. In sporter length barrels, one symptom of it being unhappy is muzzle flash like I've never seen with anything else! Viht doesn't list this powder with any bullet weight in the cartridge.

N550 should be happier, but if you look at the recently revised Viht data, both N550 and N160 are shown for the 160gn Nosler Accubond, the nearest to what you're using. N160 perhaps a little surprisingly gives another 50 fps over N550.

Hornady in its most recent manual has data--sets for both 280 Rem and 7X64, but no Viht powder loads - in fact there is not much Viht data in this manual anymore and recent additions like the 6.5 Creedmoor have none at all (likewise Sierra). Both it and Lyman 50th just out (for the 280 alone here) show best results from IMR-4350 and for best MVs IMR/H4831.

So, this gives an indication of post-Reach alternatives:

IMR-4451 (for 4350) and when it arrives IMR-4955 (for the 4831s)

Viht N160 which despite being shown as equivalent to IMR-4831 in most burning rate charts often acts more like the 4350s and at the least is somewhere between the 4350s and 4831s. See Viht's data.

Viht N550

Ramshot Hunter (Hornady lists 52.6gn max for its 162s for 2,600 fps in a 22-inch barrel Sauer 101, not the highest MV in the table) QuickLOAD computes another 90 fps from this combination for nearly 2,700 fps and a very good match to the cartridge and bullet. (Using the 162 AMax as I don't have the ELDs in my version.)

Alliant Re19 and 22 should both work. QuickLOAD suggests Re19 is an excellent match ballistically, but if you're chasing MV several more grains Re22 and a compressed load gives almost as high MVs as you can safely get.

Reload Swiss lists loads for the 7X64 but the nearest bullet to the Hornady 162 is the 168gn Sierra MK and shows loads for RS60 / RS62 / RS70 / RS80. (80 is hopeless - far too slow burning.) QuickLOAD suggests RS62 and RS70 are excellent matches.

 

 

[Scotch_egg]

Laurie thank you for taking the time to provide such detailed information. I had got it very wrong being in the belief it was faster burning. 

 I think I will go with the RS62 or 70.

[Gandy]

15 hours ago, Laurie said:

You may encounter considerable muzzle blast and flash with anything under a really high pressure load.

I can vouch for this. 

[jcampbellsmith]

For dies I would go to Whidden. Regards JCS

[Scotch_egg]

1 hour ago, Gandy said:

I can vouch for this. 

That was the fault of the muzzle brake

[Gandy]

1 hour ago, Scotch_egg said:

That was the fault of the muzzle brake

It virtually singed my eyebrows. 

[Hobbit]

Just wanted to follow up on this and share my findings

I experimented with the redding dies and the sinclair mandrel

With the redding FL die I was getting 4 though run out on the necks fairly consistently and what looked like high neck tension

With the FL die but with sizing button removed and a sinclair carbide mandrel (as Laurie suggested) I got consistently sub 2 though run out and a nice smooth bullet seating that suggested the expected 2 though neck tension. So thank you Laurie. I only wish they did  lee collet dies in this caliber.

I am only using a Lee classic turret press as I find setting up the dies on the turrets very handy so this may have an effect and I am not the most skilled loader but it was a fair direct comparison.

[TacsterDK]

Old topic, but just want to share my experiences,

I have been loading 7x64 Brenneke for quite a while - mainly for LR purposes. For that, I have used 162gr and 180gr ELD-Ms

One should now the anatomy and design of the 7x64 - especially the throat. If the 7x64 chamber is cut as a standard chamber the throat will have a very gentle lead angle = long freebore, making it impossible to seat bullets close to the lands. The design was made to keep the pressure down and to boost velocity. I shoot a modified Tikka T3 with AICS LA magazines. I load all my ammunition to a COAL of 87.00mm which gives me a crazy long bullet jump. Taking the design into consideration one should focus on concentricity and an optimum guiding of the bullet by utilizing full contact between bullet bearing surface and case neck. It can to some degree be compared to the 6.5x55 which also accepts very long bullet jumps.

Dies: In the absence of FL bushing style dies I bought a standard FL RCBS sizer die. I got my gunsmith to ream the neck section out so that it would only size the body and push the shoulders back. Fireformed brass will be sized so that shoulders are pushed back 0.002". I size the neck with a 7mm Rem Mag, Lee Collet Neck Sizer - yeps it is generic and works perfectly! You can buy different mandrels to play around with neck tension, brass brands etc... I have two - one for Lapua brass and one for GECO/Ruag brass. Concentricity is kept at or under 0.002" runout.

For seating, I use a Forster BR seater - very nice die! Forster actually makes a Bump, bushing die for 7x64 Brenneke. This die will only push the shoulders back and size the neck. It will not resize the body.

About powder choices;

N560 has been a nightmare to work with. No matter what I did I could never get ES under 10m/s. There would always be pressure spikes. I always use premium brass, primers, load techniques. I load to very tight tolerances and even tried annealing, but nothing helped. I should say that I have loaded for one rifle that shoots like a dream. It is also a custom TIkka T3 with a 24" Lothar Walther barrel, 1:9" twist. It shoots 180gr ELD-Ms loaded with N560 through one hole with MV of 835ms. ES is very low. This is the only rifle chambered in 7x64 in which I have managed to get good results with N560

I have used N165 and 160 but velocities are low and max pressure is reached too fast...

After changing to RS70 things got much better. For my own rifle, I load 162gr ELD-M on top of 56.1gr RS70, Lapua brass, COAL 87.00mm, RWS 5333 magnum primers, trim to 63,70mm, neck tension 0.002". The barrel is a 21" Schultz&Larsen 1:8.5" twist. MV is 863ms...

So far temperature sensitivity has been ok - but I haven't put it to extreme tests yet.

J.

 

[Scrumbag]

I have used RS70 to good effect with 180ELD-Ms

Others speak highly of RL-26 (Though for me I found this gave rather full cases)

N160 often good for hunting loads and when I have shot through the factory I have I will probably load Sierra 160gr Gameking SBT with N160.

ATB,

Scrummy

[Hobbit]

Just following up albeit a couple of years late

my accuracy load in the blaser r8 barrel (22.8”)

was an 162gr eld-x over 54.3gr of RS62 giving 2780fps

i noticed a 25fps drop off in me in cold weather - is this normal?

 

[Scrumbag]

On 3/21/2021 at 11:22 PM, Hobbit said:

Just following up albeit a couple of years late

my accuracy load in the blaser r8 barrel (22.8”)

was an 162gr eld-x over 54.3gr of RS62 giving 2780fps

i noticed a 25fps drop off in me in cold weather - is this normal?

 

In colder weather I'd have thought a 25fps wouldn't have been that bad

So, usuing your data, Gordon's Reloading Tool gives an

MV of 2,786fps @ 15c powder temp and 97.4% burn

If we lower the temp to -5C (Your ammo after sitting in a high seat for an hour or 2 on a frosty morning)

MV of 2768 and a burn of 95.9%

So would seem in line with expected data and at deer stalking ranges I certainly wouldn't worry about it. Probably not that vital for LR targets either as after a couple of shots the powder temp will be raised by the chamber being warm

 

[Hobbit]

51 minutes ago, Scrumbag said:

In colder weather I'd have thought a 25fps wouldn't have been that bad

So, usuing your data, Gordon's Reloading Tool gives an

MV of 2,786fps @ 15c powder temp and 97.4% burn

If we lower the temp to -5C (Your ammo after sitting in a high seat for an hour or 2 on a frosty morning)

MV of 2768 and a burn of 95.9%

So would seem in line with expected data and at deer stalking ranges I certainly wouldn't worry about it. Probably not that vital for LR targets either as after a couple of shots the powder temp will be raised by the chamber being warm

 

Ok - that makes sense

thank you

[Hobbit]

For fans of the Lee collet neck dies I have found that the Lee 280 remington/7mm express collet die will do a job, as Laurie suggested, on the 7x64 neck after FL sizing. I have not done a side by side comparison with the sinclair mandrel on run out etc