Author Topic: New Bullseye Powder VMD  (Read 820 times)

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New Bullseye Powder VMD
« on: March 13, 2020, 11:24:33 am »
As many of you know, I offer powder slides that accept interchangeable bushings, and I make custom bushings for the charge of your choice.   I calculate the hole size based on the published VMD data, (essentially the powder density).   Of course powders do vary from lot to lot, so the published VMD for a given powder may not match the VMD for your particular lot.  Usually it comes out pretty darn close, generally +/- 0.1 grains.  Some powders seem to vary more than others, but Bullseye has been pretty consistent.

A while back, I did  a test with a 00 bushing I had made to drop 2.7 grains of Bullseye.   I used three different lots with very different production dates (three different labels) and with the three lots I got charges of 2.65, 2.70, and 2.75 grains.

I was recently contacted by a customer who was using a bushing for 4.0 grains of Bullseye, and with his previous lot of Bullseye he was getting powder drops very close to the target charge.   However, with the newest version of Bullseye, he was getting 3.6 grains.    There can be a number of explanations for this, but I was wondering if anyone else was seeing a significant difference with charge weights for the latest version of Bullseye.

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Re: New Bullseye Powder VMD
« Reply #1 on: March 13, 2020, 12:18:19 pm »

I have found the older lots of Bullseye weigh more than the newer production lots.

Best approach is to buy a four pound jug and a chronograph.

Changing powder lots is one thing I do not look forward to.