RS 52 or 60

[Hillhunter]

Looking to get a starting load for 185 juggernauts , also would rs 52 or 60 be the best option , barrel is 1/10 , 32 inch Bartlein

[Swarovski1]

Viht n140, n150, n540 and n550 should be ok, go on lapua website for viht reloading data, a bloke in our club uses n550,26 inch 1b

in 12 twist gets around 2600fps, your long tube will get you up 2800fps plus, laurie woukd of posted plenty of info, go frew the pages and I am sure there will be info your after, I use n150 with 168's and rs 40 with 155s,

[Hillhunter]

Viht n140, n150, n540 and n550 should be ok, go on lapua website for viht reloading data, a bloke in our club uses n550,26 inch 1b

in 12 twist gets around 2600fps, your long tube will get you up 2800fps plus, laurie woukd of posted plenty of info, go frew the pages and I am sure there will be info your after, I use n150 with 168's and rs 40 with 155s,

Thanks Swarovski, I went back a good few pages and all I can see stated is that the preferred powder is n150 for this combo, I was hoping to use one of the reloader Swiss

[Swarovski1]

Go on reloader swiss website.click on grs and fps and what powder and bullet weight and that should give you info you need.rs 52 is a 308 powder.ive not tried it.n540 use to launch 175gr smk very nicely by the way

[Swarovski1]

I had a look on reloader swiss myself, in the bullet library they dont list berger bullets, the rs52 gave the best figures for a 180 bullet, from memory I thought the ft shooters used a stout load of n140, I could be wrong though, not sure but if you click on to lauries profile it may list all his posts, he is the the man to ask on this subject,

[Re-Pete]

If you post the case H2O capacity, and OAL, I'll run RS 52 and RS 60 through Quickload for you.

 

H/man

[Laurie]

The preferred powder for the 185 Juggernaut in FTR is Viht N150. MVs of 2,800 fps and above are available from a suitably throated 30-inch barrel if Lapua Palma small primer brass and an SR BR or magnum primer is used. Standard LR primed brass sees considerably lower MVs before excessive pressures appear.

 

Viht N550 was used with large primer Lapua and Norma brass prior to the appearance of the 'Palma' case, and would give 2,775-2,825 fps without wrecking cases too quickly. Unfortunately, it wrecked barrels pretty fast by 308 Win standards - 2,000 rounds if you were lucky, sometimes a lot faster.

 

So far as the Reload Swiss propellants go, RS52 is far preferable to RS60 (Elcho 17 / Alliant Re17) in this application. My experience with the latter is that it will give very high MVs with the 185, but it is difficult to get good groups. It needs heavier bullets, 208gn and up, in the 308 to settle down and perform consistently. Even then, most of the uber-heavy users prefer Viht N150/550.

 

RS52 is one of these propellants that seem to work in lots of small and medium size cartridges from 223 with heavy bullets to 308 with most bullet weights. A good quick rule of thumb as to whether it's likely to be suitable is to see what American shooters load in a cartridge / application. If it's VarGet / Re15, then RS52 almost invariably does well too, usually producing a bit higher velocities. And what is the favourite US FTR shooter's powder for 308 + the 185 Juggernaut? H. VarGet naturally, one reason why we struggle to get hold of the stuff.

 

Charge weights used are similar to VarGet / Re15 too in most applications (which is why people on UKV were incorrectly calling it 'Elcho 15' before it appeared in its proper RS52 persona) ........... BUT straight loads data substitution is never an option. It works very well in the 'Palma' case and as with N150 that should be the first choice. I use it, and nothing else now, with the 168gn Berger Hybrid in Palma brass, but haven't tried it with anything heavier, since I don't shoot anything heavier in FTR competition these days. I plan to give it a whirl from the bench later this year with some 195gn Berger VLDs I have kicking around, likewise Hodgdon CFE223 ball powder which I've found to be an impressive performer. (But only in standard LR primer brass - do not use CFE in the Palma case, needs more primer brisance!)

 

As with N540, Re15, and N550, RS52 is a 'high-energy' powder, and has nitroglycerin infused into the base nitrocellulose kernels during the manufacturing process. It is also one of Nitrochemie's advanced E.I. powders which lengthens the peak pressure period increasing velocities. If maximum velocties and pressures are used, it will kick sh*t out of the barrel, especially with heavy bullets. High-energy types are also usually more temperature change affected than plain NC propellants, so that may be an issue that appears in due course. (The Americans have become very leery of RS60 in its Alliant Re17 guise on this issue, finding that winter / spring load development can see pressure problems arise in their summers and somewhat (!!) higher temperatures than ours.) At around 4,000 KJ / Kg specific energy though, RS52 is somewhat less 'hot' than the Viht N500 series products, and is close to Alliant's Swedish (Bofors) Reloder powders in this respect.

 

Actual charge weights depends considerably on case make and type, also how the chamber is throated, as this makes a very substantial difference to pressures with the heavier bullets. There is no suitable 'official' data around yet for these powders in this sort of application, although people are currently working on it. I'm also rather (actually very!) leery of QuickLOAD results with this powder, so basically don't trust / use the program in this case.

[Re-Pete]

I've had some really close results from Quickload vs "real world".................However, where Quickload disagrees significantly, it usually predicts a lower MV (and hence, chamber Pmax !!!), so if it's used to get a starting point, it's advisable to come down at least 10-15%...................and try to get hold of a chrony.

 

H/man