H4831SC Alternative

[Brillo]

On the range yesterday we were discussing best powders for the .284 in the light of the absence of H4831SC. A few of us are using RS 60 / Elcho 17 / RL 17 and some of us are trying H4350. The latter powder is giving me very good accuracy but at the expense of lower MV.

Someone mentioned that he had heard that RS 62 was very close to H4831SC both in grain size and performance. Can anyone verify this?

 

Because I have found anomalies with the RS plug-in in QuickLoad for RS 50, 52 and 60 I don't trust the results given for RS 62.

 

Thanks

[Laurie]

RS62 is basically RS60 (Re17 / Elcho 17) without nitroglycerine added. So, as well being a lower energy powder, it'll likely burn a little faster than RS60 unless Nitrochemie has tweaked the deterrents to compensate. In Nitrochemie's burning rate chart, it's placed one line below (slower) than RS60, but that's likely neither here nor there. FWIW that chart places it on the same line as IMR-4350 / Accurate-4350 and one line above (faster) than H4350.

 

RS62 should do well with the lighter 7mm bullets in .284 but will likely lose a (little) bit of velocity to H4831sc with 180s, (likewise RS60 / E17, but it'll gain on barrel wear without the NG content). The Reload Swiss powder to really look at for 284/180 is RS70, a little slower burning than H4831 and lying between the 4831s and IMR-7828 and shown as comparable in this attribute to Viht N165, Norma MRP, and H. SUPERFORMANCE. I've been using N165 a lot in the 284 and it works very well indeed, but it's a very low energy propellant, so it's a case-full to break 2,800 fps. (Barrel life is reported as substantially increased though by American users as it's the coolest burning rifle powder generally available.) Stuart Anselm has tried SUPERFORMANCE, a hot ball powder and got small short-range groups and very high MVs but didn't work out well in L-R matches. I'll try RS70 soon, but another Diggle competitor is using it with very good results and very high MVs. (It's another high-energy job though so may, no will, be a bit of a barrel burner if its full performance potential is utilised.)

 

Other alternatives to RS60, RS70 and H4831 are N560 and Re22, both high-energy added-NG jobs, and IMR-4831 more commonly found than the H versions these days. I've tried the IMR powder in my 284 and wasn't 100% happy with 180s, but found it a very good choice with the 168gn Berger VLD being a little faster burning. Another possible in this (H4831) burning rate bracket is the old Accurate-3100 single-base extruded powder, still sometimes available as Lovex SO71.

[Brillo]

Thanks Laurie - just the sort of information I was hoping for. Whilst looking for comparisons using QuickLoad it looked like Re19 could have potential for the 284. You didn't mention this but suggested Re22. Where does this fit in the scheme of things?

[Laurie]

Yes, Re22 should be another possible. I'll shoot some two-round batches for basic MV / pressure tests soon with Re22, RS70, and N560 in my Shehane as well as seeing what N165 can do with higher charges. I'm currently getting small groups and excellent elevations with the 180gn Scenar-L and N165, but the MVs are far too low. The current charge weight was based on what it'd do in a 'straight 284' with a different make of barrel, but it looks like the combination of the small increase in case capacity and a 'slower' barrel will see a compressed, maybe heavily compressed, load needed to get to where I want to be. Hence the look at the high-energy jobs.

 

Incidentally, the 180gn Scenar-L quite patently has nothing like its manufacturer claimed 0.332 G7 BC (which would make it near identical to the Berger VLD ballistically). I've had to use much greater come-ups from a 100 yard zero for 800 yards than expected / predicted. Although I've not calibrated the scope adjusters' actual change-values, Sightron 8-32 S3s have always been been very accurate in this respect when Vince B and I have tested them in the past. Taking the scope clicks at face value, the BC is somewhere around 0.295 which is what I'm using now in the ballistic program before I shoot with it at a new distance.

 

(I've also got to say I'm not surprised. Put the Scenar-L alongside the VLD and it's blunt up front with a much shorter neck section. It shoots very well in a Benchmark barrel though.)