6mm Dasher questions (ReloadSwiss RS52 powder experience, 105gr Scenar 1000y performance...)

[macdeerhunter]

I live in EU and last few years is really hard to find Hodgdon powders, specially Varget. I recently build 6mm Dasher and try to find the best load for it (21" 1:8" L.Walther barrel, lightweight tactical rifle which I occasionally use on FClass matches). After bottle of Varget which worked perfectly with #450 primer and Norma sorted no turned brass, I need to turn to Reload Swiss (Nitrochemie) and Vihtavuori powders which is really easy to get here. I bought RS52 (in simulation I took it seems to be best equivalent to Varget) and N140 and after initial testing I found that RS52 give me at least 100fps more speed (for the same pressure sign) than Varget and much more than N140 (N140 left visible trace of powder residue, RS52 less, but Varget had completely clean burning). So I picked up RS52. Without load developing, just playing with speed and pressure I got .3-.6 MOA 5 shot groups with 105gr Scenars, Nosler CC and 107gr SMK pointed bullets, and under 300m everything was fine. The problem I experience was high ES of speeds which become a problem when I tried it at 1000m, giving high vertical dispersion in 20% of flyers. I need to try different primers and see what will get, but what I also note with RS52 powder is that in days above 32C (90 F) I got 50-60fps more speed than I measure in 15-20C (60-70F) temperature range and this starts to worry me too (hopefully POI or group size @100m did not change with this speed increasing).

So I will really appreciate to hear experience of other members with ReloaderSwiss powders (Reloader 17, 26... is his product too) and temperature stability issues, also if someone try RS52 in Dasher it would be the best. If someone tried 105gr Lapua Scenar or Scenar L at 1000yards I will be happy to hear their experience too.

Thank you very much in advance

 

[Laurie]

IME, where H. VarGet works, RS52 works equally well, or in some cases even better, at similar (but not identical) charge weights That applies to some three or four cartridges to date, but not so far the Dasher. (For this winter's Diggle 600 yard BR series in the north of England, I will use a 40-deg shoulder bastard Dasher and hope that RS52 works as well as I confidently expect.)

However, it is a 'High-energy' powder, ie a nitrocellulose base with subsequent nitroglycerin infusion. It also uses Nitrochemie's patented EI deterrent infusion production methods to better control and prolong initial combustion, so the enhanced performance if used will wear your barrel throat out faster. Likewise, as a 'double-based' product, it will be more temperature affected than single-base powders and even more so the Hodgdon / ADI 'Extreme' grades.

The answer to both issues is straightforward if you are worried - download to the next lower accuracy node and give some performance up. (I have used it in 308 Win with the 168gn Berger Hybrid with very good results and barrel life is looking good compared to what people are getting from current 185 and 200gn bullet FTR loadings with supposedly cooler burning powders.)

When you say 'simulated', I presume you mean modeling in QuickLOAD? If so, DO NOT USE QL results data as produced - IME, it very seriously understates actual pressures. I use H. VarGet in QL for my RS52 starting loads and then go by results forgetting the program thereafter.

Most Alliant ATK 'Reloder' brand rifle propellants are supplied by Bofors from Sweden including the latest temperature insensitive and high performance grades such as the new Re16 and Re26. Three or four are rebadged Nitrochemie RS products, the best known and selling being Reloder 17 (Reload Swiss RS60 in Europe) and a couple of very slow burning grades. Re17's fantastic performance is well known, but also its equally large potential downsides if abused - short barrel life and hot weather problems. RS52 is basically the same product with the same up and downsides in a faster burning grade equivalent at a mid-way point between VarGet and Re15/16.

Incidentally, it is a superb powder in 223 for FTR with 90gn bullets outperforming VarGet and Re15 and less temperature affected than the latter IMO.

Also, thanks to our wonderful EU Commission's obsessions with health and safety and an EU wide initiative called Project REACH, forget VarGet unless you find a cave somewhere with enough tins stored in it to see your barrel out. If you think supply is bad now ... well, this is just the start!

 

[macdeerhunter]

Thank you very much for the helpful answer Laurie. I hope you will have a lucky with RS52 in this winter.

By my modest study RS52 had also little more density than Varget, and with obvious greater temperature sensitivity otherwise I can't find any downsides, so it's really good to know that you have good experience with RS52, one more big plus for using it. I'm little worried about big velocity dispersion which I got but I will try with different primer than #450, maybe BR4 or to try something different, what you think?

I will download speeds for the lower accuracy node as you said, I have no problem with giving up little performance, otherwise I would not cut my barrel to 21" if I hunted every detail of performance gain (my freebore length is also short, 0.080", because I wanted magazine feeding in my rifle with every bullet, my magazine is 2.350" long, but with next barrel I will go with FB .120", whole rifle is completely based on really small mini action).

My loadings before was actually mild, I used 31gr of Varget for 2760fps with 105gr bullets, now I play around 31.5gr of RS52 for 2860fps with the same bullets and #450 primer without any sign of pressure. I used for a try 32.5gr Varget and also tried 32.5gr of RS52 without a problem with pressure. I have not tried yet to find accuracy node with RS52, I will do that in upcoming days.

With first 350 rounds with Varget my freebore went up for the 0.010", last 130 rounds with RS52 freebore moved up additional .003", I will continue to measure and notice what happen in the future.

Oh such a stupid laws in EU... For the next few years we will not be able to import anything.

Interesting story how I decided to go for RS52... First when I was at IWA this year I spoke with RS engineer who gave me advice to use their QL powder base for prediction, and after few days he wrote me email, sent me his suggestion and QL computation. His suggestion was RS40 and RS50... I started simulation too but looked also on experience of other shooters who were able to try RS powders in different cartridges which use VarGet primary, and with that information and pressure - velocity related data from QL I concluded that RS52 would be the best Varget alternative (RS50 also seamed to me like good low energy alternative). I also had access to Piezzo/EPVAT pressure barrel for 7.62x51, so at the end it help me to decide what to choose (I know that every cartridge is different story, but this is only possible way for me to conclude something).
What I founded out too that QL data which stated how much grain of powder give me which velocity is completely incorrect for RS52 powder (with latest powder base downloaded from their website), I can say that is inaccurate for 1.5-2gr (QL show more powder needed for actual velocity). But from experience with EPVAT tests I can say that QL is pretty close with pressure-velocity estimation, in 7.62x51 of course, but with logic I can't see any problem why in any other cartridge pressure-velocity prediction would not be the same related with the same powder, or maybe I wrong? What is also interesting that QL simulation for Varget gave me exactly true weight-velocity data, but with my previous barrel (same barrel length, 1:10" twist), for the same speed I need 1gr Varget more. All in all, you are right, QL Varget prediction for RS52 is closer to real world scenario then real RS52 QL database.

In side by side comparation of really mild load of 30.5gr N140, VarGet and RS52, with 107gr SMK, average velocity of five bullets from 21" barrel was:
N140-2746 fps (becoming hard on bolt)
Varget - 2730 fps
RS52 - 2785 fps

 

[Laurie]

RS50 was initially sold in the UK as 'TR140' being bulk imported and locally bottled. There was no loading data, just an advice to use Viht N140 data with caution. In fact, in 223 Rem and 308 Win at least, side by side tests I did of the pair gave MVs so close that they might well have been different production lots of the same product. I like this powder a lot, but have only used it in two or three cartridges to date. I may try it in the base 6BR where it should do well, but I'd be less hopeful in the Dasher. But .. as always in handloading, who knows? Things sometimes don't work out as logic suggests they should!

RS40 is really a 5.56 military cartridge propellant being the canister version of that used in the Swiss GP90 version of the NATO cartridge and as such is on the fast burning side for the Dasher IMO. I have used it with 155gn bullets in 308 Win - it does that very well indeed, but should NOT be used in this cartridge with heavier bullets as pressures spike with frightening rapidity even with small charge weight increments. It was fashionable here for a while to use it in 155gn class bullet 308 FTR loads in Lapua Palma small primer brass where it gave MVs that approached - in a few cases hit - 3,200 fps MV from 31-inch barrels. I tried it, but soon dropped it as being far less consistent than RS52 or H4895/VarGet/IMR-8208 XBR in the application. I don't know what it did for barrel life for those running at 3,150 fps plus - nothing good I should think.

If you fine-tune your loads, I think you should get RS52 to work well in the Dasher ..... but as I already said, who knows?

Nitrochemie is producing an excellent range that I increasingly use. I tend to use slower burners than RS50/52 these days and have found the single-based RS62 to be an outstanding performer in small to mid size 6.5s and 7s, such as the Hornady Creedmoor. I'm told there may be one or two new powders in the pipeline too, so the choice will improve further it seems. Other than RS52, I prefer to stick to the single-based grades though. I simply cannot afford too many new barrels.

 

[expiper]

try N-150,,,you should be able to get it in Europe,,,,Roger

 

[Liven The Dream]

R-15 and N-150 Work Will 105 Berger HB
This is Using the New Norma F-Class Brass and a 30" Barrel
R-15 and Wolf SRM Primers gives the best at 3025 to 3050

 

[Laurie]

N150 is probably the most popular standard 6BR powder in the UK these days for 105-108gn bullets - I use it myself. I have seen Dasher users on this forum though say that it doesn't suit the improved cartridge. This has been recently confirmed to me by friends who have just had rifles built or rebarrelled for the Shiraz / Norma Dasher brass using the approved reamer.

 

[macdeerhunter]

Interesting and valuable information, I will give a try to RS50 in application where I often use N140.
I will play with RS52 in the future and see what happen.

In my case with 21" short barrel and short freebore, N150 is anyhow to slow, I think.

Hm... it sounds really weird that anyhow "slow" N150 work on small capacity cartridge like BR and refuse to work in larger capacity imp version... but as Laurie said, who knows why?

Thank you all for the answers.

Ono more question, anybody tried 105gr Scenar beyond 600y, how it perform?

 

[Liven The Dream]

The Lapua 105gr Scenar is a very uniform bullet and ultra-accurate, but the max diameter is 0.24285, compared to 0.2433+ for some other brands. Accordingly the Scenars may prefer a tighter bore. They shot superbly in this editor’s PacNor 8-twist and a .236-land Krieger tested by Jackie Schmidt.

 

[Pakratt99]

Deleting my post as I now realize I confused some of the RS to RL conversion numbers and don't want that information being spread.

 

[Laurie]

You also may want to take a look at RS62 as its the same as RL16 which gives REALLY good results for a lot of people in the Dasher.

No, No, No!! Re16 and Swiss RS62 are not the same thing. Re16 is made by Swedish company Bofors and sold in bulk to Alliant ATK in the US. It is a very recent introduction and ticks all the boxes for today's handloader - shortcut, treated to be temperature insensitive, anti copper fouling additives. As with most Bofors propellants, it is a 'high-energy' type - initially made single-based then infused with nitroglycerin. Re16 does not have CE certification and therefore cannot be imported into any EU country.

Nitrochemie's RS62 is a long established rather long-grained single-base powder originally developed for the 270 Winchester. It is only available in Europe.

The pair have similar applications akin to those of the old '4350's - 270, 30-06, mid size 6.5s etc. Look at the manufacturers' data though and maximum charges are not the same, or even close to being the same. RS's RS62 maximum for the 270 Win with the 150gn Sierra GameKing is 2.2gn higher than that of Re16 with the same bullet, but giving a significantly lower MV.

RS60 and Re17 are by contrast one and the same thing and the much more widely available Re17 data can be safely applied to RS60 if needed. In fact when originally introduced into the UK and locally bottled and marketed, it was branded 'Elcho-17', with the instruction to use loads data for Alliant Re17.

RS62 may or may not be suitable for the Dasher. Its long kernels certainly work against its use in this application. A quick look using QuickLOAD shows a compressed load runs in the low 50 thousands psi with the 105gn Berger VLD against a PMax 10,000 psi higher with the traditional favourite H. VarGet in common case-filling loads.

 

[Laurie]

Just adding to the above, a recent post in a Facebook UK precision shooting closed group stated that Hodgdon says H. VarGet data may be substituted for the new IMR-4166.

What Hodgdon actually says is that 4166 may substitute for VarGet and doesn't mention data, but the general rule is that powder or bullet manufacturer's tested data must be used for each and every individual powder except in those few cases such as RS60/Re17 where two names are used for a single product. (Winchester 760 and Hodgdon H414 is another longer standing example of this.) Look at Hodgon's 4166 and VarGet data and they definitely vary even though the pair's characteristics make them potentially suitable for the same jobs and therefore substitution in applications applies.

It is becoming increasingly common for people to make generalisations or assumptions about this sort of thing and getting it wrong could pose dangers, or at the least some cases fit only for the scrap bin.

 

[Pakratt99]

Laurie, I edited my previous post to reflect the error I had made. Prior to RL16 being introduced in the states I remember reading an article that Re17 and RS60 were essentially the same so the thought process was Re16 would be also available as a RS powder. I also use Quickload and remember RS62 making some sense as a powder for the Dasher which may have only added to the confusion.....

 

[Laurie]

RS60 / Re17 seems to generally work really well with the enhanced capacity sixes. When I shot a 6XC, I couldn't find anything better for good MVs without pressure signs, small ES, and good group sizes with 105-108s. The roughly comparable Viht N550 produced some excellent initial results, but pressures were just a bit too high at the node I wanted to be at, and a hot day would likely have produced big problems. As it was, expensive (in time prepping it as well as monetary cost) Norma XC cases didn't last any length of time. In our cool climate, the much reported RE17 / RS60 temperature sensitivity issues usually didn't arise at the pressures we were running and it seemed the best of all worlds.

Unfortunately, IME and that of some other 6mm users I know, it really does kill barrels with XC and 6-6.5X47 size cartridges. Maybe OK for 5-round group BR matches, but far too short a barrel life for F-Class. Whether that would apply to the smaller capacity Dasher ........ ??

 

[macdeerhunter]

Thanks to all, very valuable information. Today morning I conducted Ladder test for RS52 with my Dasher... I will post result in another thread with appropriate name...