JDinFbg
Member
For over the past 50 years my 22 Hornet load for my Winchester Hi-Wall rifle has been 9.5 gr. of Hercules 2400 (and yes, I mean Hercules as I still have some of the old stuff but about to run out) driving a Sierra 40 gr. Hornet bullet. This has always given me acceptable results. From reading posts on the various forums, many have raved about the performance in their 22 Hornet using Hornady V-Max bullets, so I gave them a try. I was not impressed with the results I got, but then came across this blog from Berger Bullets:
https://bergerbullets.com/vld-making-shoot/
Since the Hornady V-Max is a secant ogive bullet and falls in the VLD camp, I decided to give these bullets a re-try following the Berger jump-test method. In other posts on the Berger website, they have clarified that in doing their jump test with VLD bullets one should use the starting powder charge for the particular powder one tries and look for the jumps that give the minimum vertical dispersion. I also switched to trying Hodgdon Lil'Gun powder since many had noted very good results with it and I was recently able to get my hands on some.
For my jump tests with the Hornady 40 gr. V-Max, I first established the point at which the bullet touched the lands and measured the CBTO length. I determined that in my rifle the maximum jump I could possibly use with this bullet was about 0.080" since much beyond that jump the ogive of the bullet would be inside the case mouth. For my jump tests I opted to start at a 0.005" jump and work up to a 0.050" jump in 0.005" increments, and then performed one last test with an 0.080" jump.
My results are shown in the attached PDF file. When looking at the raw data (table), I was having difficulty identifying a "sweet spot" band based on the results of the two test targets I shot with each bullet jump. In most cases, the vertical spread from one 3-shot group at a given jump would be small, and the second 3-shot group would have a large vertical spread. The 0.030" jump was the only case where both 3-shot groups had a consistent and relative small vertical spread. As I looked at the data I decided to take the smallest vertical spread from the two targets for each jump distance (highlighted in blue in the table) and plot those. This is when some clarity occurred, and this suggests that my "sweet spot" jump will be a band from 0.030" up to 0.045", or 0.015" wide. This differs from what Berger indicated, saying VLD bullets often have a "sweet spot" band 0.030" to 0.040" wide. The theory of VLD bullets having a jump band is that one does not have to worry about 'chasing the lands' as a barrel erodes, but I'm not sure that barrel erosion in a 22 Hornet rifle would be that significant an issue. So now the goal will be to lock in on the 0.030" jump and find the powder charge of Lil'Gun that produces the smallest group size.
https://bergerbullets.com/vld-making-shoot/
Since the Hornady V-Max is a secant ogive bullet and falls in the VLD camp, I decided to give these bullets a re-try following the Berger jump-test method. In other posts on the Berger website, they have clarified that in doing their jump test with VLD bullets one should use the starting powder charge for the particular powder one tries and look for the jumps that give the minimum vertical dispersion. I also switched to trying Hodgdon Lil'Gun powder since many had noted very good results with it and I was recently able to get my hands on some.
For my jump tests with the Hornady 40 gr. V-Max, I first established the point at which the bullet touched the lands and measured the CBTO length. I determined that in my rifle the maximum jump I could possibly use with this bullet was about 0.080" since much beyond that jump the ogive of the bullet would be inside the case mouth. For my jump tests I opted to start at a 0.005" jump and work up to a 0.050" jump in 0.005" increments, and then performed one last test with an 0.080" jump.
My results are shown in the attached PDF file. When looking at the raw data (table), I was having difficulty identifying a "sweet spot" band based on the results of the two test targets I shot with each bullet jump. In most cases, the vertical spread from one 3-shot group at a given jump would be small, and the second 3-shot group would have a large vertical spread. The 0.030" jump was the only case where both 3-shot groups had a consistent and relative small vertical spread. As I looked at the data I decided to take the smallest vertical spread from the two targets for each jump distance (highlighted in blue in the table) and plot those. This is when some clarity occurred, and this suggests that my "sweet spot" jump will be a band from 0.030" up to 0.045", or 0.015" wide. This differs from what Berger indicated, saying VLD bullets often have a "sweet spot" band 0.030" to 0.040" wide. The theory of VLD bullets having a jump band is that one does not have to worry about 'chasing the lands' as a barrel erodes, but I'm not sure that barrel erosion in a 22 Hornet rifle would be that significant an issue. So now the goal will be to lock in on the 0.030" jump and find the powder charge of Lil'Gun that produces the smallest group size.