I'm wondering if my technique has gone awry or if the powder I'm using (VVN160) is less suited to a measure. I'm getting variances of .6gr in charge weights which is much worse than previously with VVN135 where charge weights were within the accuracy tolerances of my scale (+/- .1gr)
VVN160 is a little larger than VVN135. Charge weights seem to reduce as the level in the bottle reduces.
Posts: 2258 | Location: Bristol, England | Registered: 24 April 2001
I never let my tube/bottle get less than half full just to keep the weight on things. Mine is a Redding and is real accurate +-.1 but can at times go over .5 so I just throw and check on the RCBS PP digital. Longer the grain the more the pain. The Redding cuts them easily though, but nothing meters like ball.
VV-160 goes through my Redding fairly smoothly -- much more so than something like 4350 or 4831. My weight variations with it probably are less than .2 grain.
Posts: 13347 | Location: Henly, TX, USA | Registered: 04 April 2001
1894 I have one and I see that sometimes also. Not sure just whats happening. I have seen that the tempo with witch your charge is thrown affects the accuracy. Keeping it full all the time did not appear to change anything for my results. I am interested to know if others are experiencing the same issue with the Harrells Culver?
I do not like to hear that this to rank device produces these variances. Next to a half full tube you need consistency in throwing the powder. Lyman (and some others) add a knocking device which helps to avoid the powder to bridge. I think, but I am not sure, that a feeble, instead of a rigid, powder stand can be helpful for consistancy as its inherent vibrations make the powder flow smoothly.
Posts: 367 | Location: former western part of Berlin, Germany | Registered: 25 August 2001
I was surprised myself. With VVN120 and 135 I was so confident that I loaded direct from the measure checking every 10 rounds or so. These loads had more leeway being a good bit less than max.
With the VVN160 I'm only half a grain off max load. A test series yielded too much variance to load direct from the measure and so I threw onto the scale. A knock at either end of the cycle helped but given that I'm only loading 50 or so rounds I'll stick with checking each charge.
Posts: 2258 | Location: Bristol, England | Registered: 24 April 2001
I use that powder and the Harrell measure to dump 74g of that propellant. Never have had any problem keeping within .2g. It dumps about the same as similar Alliant powders.
Posts: 1261 | Location: Placerville, CA, US of A | Registered: 07 January 2001