Vihta Vuori reloading data on 6BR

[marchx]

I frankly don't understand the min.-max. reloading data on e.g. 105gr Scenar published on VV website:

Rifle reloading data | Handloading | Rifle calibers | Centerfire Rifle bullets | Reload your own ammo - Vihtavuori

Vihtavuori offers rifle reloading data for numerous calibers and bullets for match and hunting purposes. Never exceed maximum loads.

www.vihtavuori.com

They indicate 28.9gr of VV N140 and 2694fps as maximum load. I think it's overconservative. 2694fps is rather slow.

 

[std7mag]

25-1/2" barrel. Feels about right.
Their numbers seem consistent between the N140 & N150.
Even if you look at the next set of data above (the 100gr) it's fairly consistent.

 

[JFrank]

I frankly don't understand the min.-max. reloading data on e.g. 105gr Scenar published on VV website:

Rifle reloading data | Handloading | Rifle calibers | Centerfire Rifle bullets | Reload your own ammo - Vihtavuori

Vihtavuori offers rifle reloading data for numerous calibers and bullets for match and hunting purposes. Never exceed maximum loads.

www.vihtavuori.com

They indicate 28.9gr of VV N140 and 2694fps as maximum load. I think it's overconservative. 2694fps is rather slow.

That does seem a bit conservative but I would have to run a charge/pressure ladder to confirm where my set up runs best.

 

[Kurz]

I frankly don't understand the min.-max. reloading data on e.g. 105gr Scenar published on VV website:

Rifle reloading data | Handloading | Rifle calibers | Centerfire Rifle bullets | Reload your own ammo - Vihtavuori

Vihtavuori offers rifle reloading data for numerous calibers and bullets for match and hunting purposes. Never exceed maximum loads.

www.vihtavuori.com

They indicate 28.9gr of VV N140 and 2694fps as maximum load. I think it's overconservative. 2694fps is rather slow.

A couple of thoughts:

VV runs under the C.I.P. system for pressure testing and results. This means that the high pressure level is 58,740 psi. Their 6mmBR ammunition is balanced for that same pressure level.

As has been noted in multiple posts, published reloading data is necessarily conservative due to the litigious society we live in. VV is certainly no different especially considering the socialist society.

Now, to most of us reloading the 6mmBR for competitions, I would bet that we exceed that C.I.P. pressure by several thousand psi and don't give it another thought. As long as the brass hold up and we achieve the level of accuracy we desire, no one bothers to use their data.

Use the VV starting loads for safety then work up your loads watching for signs of pressure and the best accuracy.

Enjoy the process!

 

[Laurie]

Viht's data have been compiled over a very long period, and apparently as a result, can sometimes seem inconsistent with recent additions more 'adventurous' than older loads. The main giveaway is the bullet. Scenars loads are nearly always older, and recent additions are things like TMKs, ELD-Ms, Berger Hybrids and similar.

I'd say looking at this table that it's not been updated in at least 10 years, more likely 20. Unlike many other cartridges like 308 Win that have four times as many bullets listed as they once did, this is meagre fare and bar a sole all-copper Barnes bullet that has been available for 15 or 20 years, the only other non Lapua bullet is the 70gn SMK, a near standard choice for a light 6mm match bullet.

That's not to say one can blithely ignore the table's maximum load values, rather to note it's possible they're on the conservative side. Some recent data for other cartridges has veered in the opposite direction IME and I'd rate some combinations I've looked at recently as being distinctly 'hot', to the point of being worryingly so.

The other factor I'd mention is that Viht appears to serially provide data for its powders that makes most, but not all, of them appear as being slower burners in burn rate charts/lists than they actually are. (This sometimes affects QuickLOAD and GRT too with their default values.) Norma's old list that is based on actual pressure gun readings using a same charge weight 308 Win load puts N140 as slower burning than H4895 and marginally faster than H335 and IMR-4895, with a growing divergence (faster) from IMR-4064, and very much faster than Norma 203-B/Alliant Re15. (In Hodgdon's list type chart, N140 is slower burning than Re15 by contrast.) Unfortunately, the Norma list doesn't include H. VarGet.) Many European 6mmBR Norma shooters prefer N150 with 105-108s, and this grade appears to suit the combination very well despite not being listed at all in the Viht data.