powder temp sensitivity question(s)
#11
TLS, you'll be absolutely fine in the 2450-2500 range. If it's like other courses, you'll spend most of your time in the 400 to 800 range. They always advertise the 1k since it's a milepost and you will get it, but I doubt it will be the focus. I did the JP PR1 with an 18" Grendel and factory Amax with a BC of 2.3 something at 2450 and got plenty out of it - and I did get the 1k. Don't go crazy on worrying about equipment - you need to be prepared, but the one thing you really learn is what you really need. Don't worry about the bolt gun guys with their bolt thingies either. You'll have an advantage in some ways by having less recoil, but you'll never have their velocity or trigger lock time - and they don't have to deal with a bolt slamming back into the battery as your trying to spot your shot and maintain your position. (I personally enjoy that additional challenge).

With respect to single base powders, I hate to let out my secret, but I am now firmly in the crowd that believes Shooters World Precision is BETTER than Varget (which they unabashedly state that it is a clone of). I don't have any loads that would be apples to apples comparisons in terms of accuracy and SDs, but I give a small edge to Precision and it is also as temp insensitive and meters better. Plus it's made in a country (Czech Republic) that isn't under a seemingly permanent lockdown like Australia. With my H4350 jug getting a little light, I tried it with 123 grain Scenars in my 6.5 CM PRS match rifle and got this with 3 shots per charge (top is velocity, middle is SD and bottom is ES). 
   

All groups were a little under MOA with Magneto strapped on. They were also done with a Chargemaster drop only - I've been struggling to get an SD of 10 with my latest keg of H4350 when I trickle onto a balance beam.  I worked up more in the middle range and did this with 37.9

   

It was off a slick cement bench and the first group was with the big aiming point (I used that since the rifle is zero'd to my current (now former) 130 load. The big aiming point is harder and some of the vertical dispersion was me, but it's still about 0.75 MOA. The big ragged hole is 5 shots and measures about 0.4 MOA, and if it was juxtaposed on the other, they'd be right on top of other. The main point is that Shooters World Precision rocks! Just don't tell anyone else - let them keep fighting over the dribs and drabs of Varget that make it to our shores. I'll note that I didn't even bother with the other charges I dropped - at 2870, that's flatter than the Berger Hybrid 130s I was doing at 2740 and has no practical difference in wind drift out to 1k. I'll use them for practice.

I also saw Alliant Reloder 15.5 on the shelf of my local supply store, so it's finally hit the market. It's also the same burn rate as Varget and has a special coating to reduce temp sensitivity. I have no idea as to bulk, but it has to be similar since they use Varget as a reference point. It's made in Sweden. I contemplated grabbing a pound, but decided against it since I'm more than happy with what I have in that class.
#FJB
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RE: powder temp sensitivity question(s) - by StoneHendge - 10-01-2021, 02:06 AM

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