VLD Bullet Jump Testing in 22 Hornet

[JDinFbg]

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.

 

[JDinFbg]

I've now had a chance to do some additional testing with my 22 Hornet using the Hornady 40 gr. V-Max bullet using the 0.030" jump determined to likely be optimal for my rifle based on the jump test summarized above. For these additional tests, I loaded up rounds for shooting two, 3-shot targets with charges of Lil'Gun varying from 11.8 gr. up to 13.2 gr. in 0.2 gr. increments. Things didn't start to look promising until I got up to 12.6 gr. of Lil'Gun, but I did not get the consistency I was looking for from the two, 3-shot groups at each powder charge. This could have been due to my shooting abilities, and with only shooting 3-shot groups It is hard to totally distinguish a true pattern. However, when I started to reprocess the fired brass I noted that my case lengths varied quite a bit and some had out-of-square case mouths, so that could have also lead to the inconsistency. The cases have now all been annealed and trimmed for the next shooting outing where I plan to shoot two, 5-shot groups with each powder charge varying from 12.6 gr. up to 12.9 gr. in 0.1 gr. increments. Hopefully that will be more telling and allow me to truly identify the optimum load.

 

[GooseGestapo]

I wish you luck and look forward to reading your results.

However, it’s a fool’s errand in my .22Hornet. It’s a Ruger M77MkII KBZ (24” heavy barrel, tan laminate and stainless steel.).1.5” @100yds is about its best. Too many issues and limitations.

In my rifle, I load the 40vmax over 12.5gr Lil’Gun at 1.780” to feed through the magazine. (I’ve slightly modified it). It gets 3,000fps +/- and 1.5moa. Does what it needs to do...

 

[JDinFbg]

I wish you luck and look forward to reading your results.

However, it’s a fool’s errand in my .22Hornet. It’s a Ruger M77MkII KBZ (24” heavy barrel, tan laminate and stainless steel.).1.5” @100yds is about its best. Too many issues and limitations.

In my rifle, I load the 40vmax over 12.5gr Lil’Gun at 1.780” to feed through the magazine. (I’ve slightly modified it). It gets 3,000fps +/- and 1.5moa. Does what it needs to do...

I don't know what bullet jump you have in your rifle loading to 1.780" COAL, but you might want to investigate doing a jump test by seating the bullets a little deeper in progressive stages to see if you can get smaller groups. In my Model 43 Winchester in 218 Bee, I couldn't use the V-Max bullets because they were so long that in order to feed through the magazine the bullet ogive was inside the case mouth opening. Since I had a box of the V-Max's left over from my 218 Bee experiment, that's why I started trying them in my 22 Hornet single-shot rifle. I have a 30-06 rifle that shoots the best with a 0.125" bullet jump, so it is surprising how varying bullet jump can affect results.

 

[GooseGestapo]

Well, good thoughts, but, given the typical Ruger tolerances, the jump is substantial at 1.78”. With the longish Vmax.

I’ve found as you have that with MOST production products, that seating the bullets to 1-bore diameter depth (ie .22” bullet bearing surface insertion) that accuracy is improved.
With the .22Hornet with that bullet, insertion is adequate.

With another.22Hornet Ruger carbine (20”bbl), the 35Gr Vmax seated deeply was considerably more accurate. It even wanted cases expanded with a Lyman M-die, and a maximum load of H110 to really shoot. Also, neck turning cases helped, too...
But, those same loads in my current rifle would pierce primers and stick cases! Unsized cases wouldn’t even chamber in my new rifle... cases looked like swollen coke bottles after firing and weren’t symmetrical!
Ruger refused to rebarrel it under warranty! I refused to pay $250 plus shipping for a new barr3l (circa 1996)...

 

[kmw1954]

I would suggest not going to the .1gr increments yet. Try to find an accuracy node first since you have already established a seating depth range.

I say this because last summer I went thru a lot of components doing load work-up for my 223. To the point that with group size and chrono tests I moved to shooting in .3gr increments until I found an accuracy node and then loaded in between those levels at .1gr... I loaded and shot enough rounds in this gun to determine that .1gr either way did not matter. It did not change my group size or POI.

What I have finally done for my 223 is to load 18 of each that has shown promise and then do multiple firings. Such as I will load 3 different levels at a time and then set up 3 separate targets each with 3 bulls. I will then shoot 3 shot strings of each load and then mark each target then repeat so that the target has 6 shots on it. I then repeat this 2 more times for a total of 18 shots on 3 targets.

With the paper targets I use I can then overlay them and more or less superimpose the targets to get a composite of the 18 shots. This practice in my mind gives a truer picture of what you and the loads are doing instead of just shooting one 18 shot string. Then once I have found a couple loads that are very promising I will repeat this whole exercise.