NZ, can I ask why you don’t care for double base powders? I genuinely would like to know, because I don’t really know the difference between the two. Thanks.
I don't hunt much anymore. Far too old for trudging up hills and there seems more uphill than downhill slopes thee days. Must be due to climate change. When I did, I mostly used a 308, which, according to lore, should only be loaded with W748. Latterly, I used s 280AI, filled to the brim with R22. Awesome deer killing calibre, BTW. (yes, calibre is the correct spelling - you know that I'm a Pom, right?) Don'cha hate it when the press say "high=calibre rifle"?
I was introduced to TR by some friends, who also shot ISSF/UIT pistol. I shot UIT Pistol in the UK, before moving to NZ in the 80's - back when the UK allowed it!. I didn't get the TR bug and continued with handguns for a while - and varmint shooting became the summer evening pastime - so loading for the 222, 223 and the Swift.
The most common powders in NZ are made in Australia, by, at the time Mulwex, now ADI and Winchester, imported from the US. Alliant powders were around in smaller quantities. Vihtavouri powder did appear from time to time - mostly for pistol and shotgun - mainly as the importer was a shotshell manufacturer.
Anyway - during my short flirtation with TR - I learned that most of the shooters were using powder (and projectiles) supplied by the NZNRA at lower than retail price. They had gone through a period of AR2201 - a not very temperature stable single base, being the recipe, and moved through W748 ( "you need a hotter primer to get it lit properly.") and had settled with AR2206, at the time the Aussie military 223/308 powder and following it's introduction, AR2208, which we now know as Varget. AR2206 was adjusted following a request from Hodgdon's to AR2206H, to become H4895. As we also know, AR2209 is H4350. ADI do not manufacture double based powders. After AR2201, temperature stability became key to their powders, due to the environments the Aussie military were working in. There was another popular one-AR2214, which was magnificent in the 7mm and 300 magnums, but was discontinued in favour of AR2217 (H1000). All the slow powders, AR2225 (Rotumbo), are of course, not made for "us", but are propellants for large calibre canon shells of the 30mm variety..
What I also learned from the TR guys - and my own reloading is that the single base powders are easier to tune. While making hunting loads, I was happy with 1 minute of deer. In the North Island, shots are mostly under 200yds and I have stood on more sleeping animals, than shot them - well, maybe.. Loading for varmints, I learned to develop loads, especially for the 223, that were minute of rabbit at 300 yds, and that I would get overpressure "spikes" when loading 748, the H4895, providing a more linear pressure, when getting close to maximum velocity. I also noticed that the lower temperature caused less carbon in the first 3 inches of the bore and cleaned more easily. This was confirmed when, due to the recent great powder famine, and having acquired a 6mmbR, was forced into developing a load using IMR4166, being the only powder available, that although I could get an very accurate load, the velocity at 28.5g was not what I wanted, and that 28.8, caused every pressure sign in the book. It's a terrible powder - and yes, I used it for 2 seasons. I have never had to clean a rifle so much. During the famine, I also stocked up on R17 and Staball - all 3. You never know when you will need them. I only use R17 in an older Ruger Precision, which I shoot on occasion, but generally let my grandson shoot ( and clean), keeping the loads to a moderate level.
So - given the experience, when I took up FTR =, only 4 years ago, I decided to stick with the ADI single base powders. Varget for the 308. I went through the 155g thing, but my latest, new, rifle Barnard with a KS Arms barrel, ( having used a 2nd hand gun previously ) prefers 185's and 190's. It would probably like Berger 208's, but I need to eat. The Creedmoor thrives on H4350, as does the 6.5SLR and the 6mmSLR likes H4831. All the ADI version, you understand. All were simple to develop - one ladder session at the farm, and length testing at 500 yds - I load long at home and take a press to the range. I also bought 5 kilos of 2206H/4895, for the BR. Start testing as soon as my new barrel arrives .I'm trying Alpha brass this upoming season , too. The older barrel, now a 6BRX will likely run on Varget. I expect to get 4000 rounds through the BR before needing to replace it., the BRX...well, I may get a season out of it - It's had over 3000 rounds of BR already.
As I am typing, my Garmin chrono just got delivered. So I guess load testing starts soon. Our season will hopefully kick off at the end of September. I have to make a short trip to Europe, so I'm hopeful that the rain holds off next week to get a bit of trigger time .before I go..
