Reload Swiss Powder choices

[basingstokebulletdodger]

Hello to all.

 

I am shooting FTR and FOpen out to 1000yds, and am currently using Viht powders, N550 for the 308 with 185gr Berger Juggernauts, and N560 for my 6.5x284 with Lapua L 136gr.

 

Does anybody have any advise on the Reload Swiss Powders that will suit both rifles? I have heard that they burn cleaner and perform very well.

 

Many thanks

 

 

[henryo]

RS60 (Reloader 17) is very close to N550, but I'd have thought it's marginally slow in 308 with the 185s?

 

You could also try RS52 with that combination it's a very good powder.

 

Judging from quickload RS70 is the one you want for the 6.5x284.

 

These are all double base powders like the Vihtavuori N5x0 series.

 

If you wanted sigle base think about RS50 for the 308. There is the single base RS62, but it looks to slow for the 308 and too fast for the 6.5

[basingstokebulletdodger]

Henryo

 

Many thanks for your advice, not sure to try the RS or stick with the Viht!

[Laurie]

I suggest you try Viht N165 with the 6.5, a cleaner burner than N560 that fills the case and is a cool burning number that enhances barrel life.

 

People have used RS60 in the 308 in its Elcho 17 guise, but it's better suited to the 208gn and still heavier numbers and is generally but not universally regarded as inferior to N550 in this role. Viht N150 is the majority choice for the 185gn Juggernaut and usually gives very good results with MVs that are good enough and not too far behind N550 in practice. If you want to try a Reload Swiss powder, RS52 would be the one for this combination.

[basingstokebulletdodger]

Laurie

 

Many thanks for the info

 

Regards

[Laurie]

Oh .... and whatever you end up using, go for Lapua Palma small primer brass if you're not already using it. It makes a big difference, believe me.

[basingstokebulletdodger]

Laurie

 

I already use the 308 palma brass, with CCI BR4 primers

[furrybean]

Quick question about the aggressiveness (sp?) of these two powders.

Would RS52, being an impregnated single base powder, be much harder on a barrel compared to the N150?

[GeorgeB]

RS52 is much faster and hotter burning than N150

[Laurie]

Quick question about the aggressiveness (sp?) of these two powders.

Would RS52, being an impregnated single base powder, be much harder on a barrel compared to the N150?

 

Yes, if both are run at the full 62,000 psi SAAMI maximum pressure. On the other hand, RS52 will give another 100-200 fps to a 155gn bullet over N150 from a 30 to 32-inch barrel, which is why people use this sort of powder.

 

As George says in the previous post, RS52 and N150 aren't really comparable propellants, except insofar as they can both be used in successful 308 Win loadings. (But so can around another 40 propellant grades )

[furrybean]

Thanks Laurie.

 

What about the scenario where you load both powders to achieve the same velocity so the RS52 does so at a lower pressure. Would it be advantageous to us the RS instead of 150 if accuracy was the same in each load?

[gbal]

Furrybean, Good question,in theory-but getting complex,I think. I've never seen comprehensive data across the desirable velocity range for temperature/pressure interactions (leaving aside 'equal accuracy'-probably an individual rifle outcome-or chimera).

 

Barrel throat (especially) wear is primarily a function of high temperature and duration of that temperature above the critical steel structural tolerance of temperature-before it 'cracks' etc.but pressure may complicate if excessive (whatever that means in a throat!!)-assuming it remains 'safe'...who knows what that is ? :-)

In the 'scenario' you outline,there probably isn't much in it for barrel life-but no-one has been restrained enough to do it,I suspect ,for the several thousand rounds needed.

Most settle-deliberate choice or otherwise- for easier increased velocity (and erosion) or longivity. (A longer barrel might hedge bets a bit for the cautious-indeed may be competitive pre-requisite for cartridges near their limit...cf 308w).

 

No free lunch,but a balanced diet? Bon apetit !

 

g

[Laurie]

Thanks Laurie.

 

What about the scenario where you load both powders to achieve the same velocity so the RS52 does so at a lower pressure. Would it be advantageous to us the RS instead of 150 if accuracy was the same in each load?

 

 

As the other George says .... Who knows?

 

However, let's put it this way. If I had the choice of same MVs (assume same ES/SD too, here) and precision, I'd choose N150. It's a nice stable cool burning single-based powder. What's not to like? Personally, it's long been a favourite when ultimate speed isn't vital, even with 155s. I've always preferred it to the more popular Viht N140 in the cartridge.

 

That's not to say a combination of heavy bullet, heavy loads, and high pressures won't see a barrel out in short order with N150 too. Firedoc on this forum got just over 2,000 rounds from max pressure N150 FTR loadings under the 185gn Juggernaut in a Bartlein match barrel. (That compares with only 1,300 or so from The Gun Pimp, myself and A.N. Other in the early days of FTR from three identical Bartleins ordered together from a 155gn Lapua Scenar / Viht N540 combination!)

 

The only clear answer is that going the last few yards in the performance mile can cost VERY dearly.

[Laurie]

Another point to bear in mind is that double-based and 'high-energy' powders often need high pressures to perform well. It's not unusual to see a bit of an 'MV hike' at a certain charge level, and for ES values to also reduce at that point. A greater temperature sensitivity is pretty well accepted for these types too.

 

Here is a charge to MV string for some two-round pressure / function test loadings of RS52 with the 155gn Berger Hybrid making a large (40 thou') jump in a 308 Win FTR rifle using Lapua 'Palma' small primer brass:

 

45.1gn ...... 2,921 av ...... 10 ES

 

45.5gn ...... 2,944 av ....... 2 ES

 

45.9gn ....... 2,961 av ...... 2 ES

 

46.2gn ....... 2,981 av ..... 6 ES

 

46.5gn ....... 3,006 av ...... 23 ES

 

46.8gn ....... 3,040 av ..... 6 ES

 

47.1gn ....... 3,054 av ..... 1 ES

 

47.3gn ....... 3,069 av ..... 3 ES

 

47.5gn ....... 3,088 av ..... 4 ES

 

'Something' happened over the 46.2 / 46.5 / 46.8gn steps with a larger than expected MV increase. From 46.8gn velocity increases went back to the expected step changes associated with around 50-60 fps change per 1.0gn powder change usually seen with 308 Win and 155s plus mid burning rate powders.

 

This tends to make 'reduced loads' with such powders a bit academic as they may not perform very consistently anyway. (The pattern is even more marked with some ball type powders which are all true double-based types.)

 

Note - these loads are shown purely for illustration - they must not be copied. They are relatively high being used in a high-freebore chamber cut for 185s using COALs which see considerable bullet jump and which use small primer brass with its different and less aggressive ignition characteristics.

[furrybean]

Laurie you are a gent and a squire, thanks very much.

Now I need to find a cheap source of 150

Anyone want to split a barrel

[gbal]

Thanks ,too Laurie- it always seemed to be one of those almost intractable 'interactional' factors...and probably not "nicely linear';

( either /or in overly simplified terms.)

 

Throw in some (personal) conservatism (new fangled...hmmmm) and realism (am I cutting edge?) and we approach an asymptote of ...'pays your money and buys your new barrel"....or in student speak "can I turn pro ?" .remembering that "semi pro..is semi paid'..* and that's on a good day... :-)

 

Ref * Toby Keith "Honky Tonk University"

 

g

[blaser308]

Another point to bear in mind is that double-based and 'high-energy' powders often need high pressures to perform well. It's not unusual to see a bit of an 'MV hike' at a certain charge level, and for ES values to also reduce at that point. A greater temperature sensitivity is pretty well accepted for these types too.

 

Here is a charge to MV string for some two-round pressure / function test loadings of RS52 with the 155gn Berger Hybrid making a large (40 thou') jump in a 308 Win FTR rifle using Lapua 'Palma' small primer brass:

 

45.1gn ...... 2,921 av ...... 10 ES

 

45.5gn ...... 2,944 av ....... 2 ES

 

45.9gn ....... 2,961 av ...... 2 ES

 

46.2gn ....... 2,981 av ..... 6 ES

 

46.5gn ....... 3,006 av ...... 23 ES

 

46.8gn ....... 3,040 av ..... 6 ES

 

47.1gn ....... 3,054 av ..... 1 ES

 

47.3gn ....... 3,069 av ..... 3 ES

 

47.5gn ....... 3,088 av ..... 4 ES

 

'Something' happened over the 46.2 / 46.5 / 46.8gn steps with a larger than expected MV increase. From 46.8gn velocity increases went back to the expected step changes associated with around 50-60 fps change per 1.0gn powder change usually seen with 308 Win and 155s plus mid burning rate powders.

 

This tends to make 'reduced loads' with such powders a bit academic as they may not perform very consistently anyway. (The pattern is even more marked with some ball type powders which are all true double-based types.)

 

Note - these loads are shown purely for illustration - they must not be copied. They are relatively high being used in a high-freebore chamber cut for 185s using COALs which see considerable bullet jump and which use small primer brass with its different and less aggressive ignition characteristics.

Laurie would i be correct to think the velocity spike is start of next node and the 47.1g charge would be optimal at that speed range & probably offer best accuracy & tighter vertical for long range.

[Laurie]

This particular rifle / barrel tends to perform best with 155s at ~3,050 fps irrespective of powder, assuming it is one suitable for the application and obtaining that MV is somewhere within its efficient pressure range. As these were only two-round batches, and as a MagnetoSpeed was fitted, it's not possible to draw any conclusions from this initial test other than pressures look fine and MVs are where I was expecting / wanting them. Moreover, the 155 Hybrid was still a barely known entity to me, still is in fact. (It seems to need a lot more jump than other 155s.)

 

I've not got around to doing the next stage that sees 5-round groups and will cover 46.8-47.2gn. I would expect something to perform well in that range.

[blaser308]

Thanks for info Laurie, PM sent.