Documented results from replacing the 12 FV factory stock with an Oryx Chassis

[CFJunkie]

This will be the last entry for a while. They just closed our rifle/pistol range, the skeet and trap ranges, our indoor and outdoor archery ranges, and the indoor air pistol/air rifle range because of the corona virus.
Even though the rifle/pistol range is an outdoor range with plenty of space to maintain separation, a majority of RSOs, who are mostly geezers like me, didn't want to be exposed. I can understand that, especially given the panic about the virus in Northern Virginia and in Washington DC.

The following data is from my last range visit on the 16th, the day before they closed the ranges.

Here is my most recent data.
Winds in the early morning were from 3 to 5 mph with temperatures rising pretty rapidly from 33 to 46 from 8 AM to 11 AM. The temps had risen to 36 degrees before I actually put the first round down range because I spent some time BSing with the RSO - a good friend.
I shot VV N140 powder, a temperature sensitive powder that I had loaded from 33 to 46 degrees based on my prediction of the temperatures over the time I intended to shoot. Even with the later than planned start, my predicted temperature was never off by more than 3 degrees from what I loaded for.

[hamiltonkiler]

This will be the last entry for a while. They just closed our rifle/pistol range, the skeet and trap ranges, our indoor and outdoor archery ranges, and the indoor air pistol/air rifle range because of the corona virus.
Even though the rifle/pistol range is an outdoor range with plenty of space to maintain separation, a majority of RSOs, who are mostly geezers like me, didn't want to be exposed. I can understand that, especially given the panic about the virus in Northern Virginia and in Washington DC.

The following data is from my last range visit on the 16th, the day before they closed the ranges.

Here is my most recent data.
Winds in the early morning were from 3 to 5 mph with temperatures rising pretty rapidly from 33 to 46 from 8 AM to 11 AM. The temps had risen to 36 degrees before I actually put the first round down range because I spent some time BSing with the RSO - a good friend.
I shot VV N140 powder, a temperature sensitive powder that I had loaded from 33 to 46 degrees based on my prediction of the temperatures over the time I intended to shoot. Even with the later than planned start, my predicted temperature was never off by more than 3 degrees from what I loaded for.

I’m I reading that the smk grouped better than the tmk?
Dang.


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[CFJunkie]

hamiltonkiler,

Very good question.

The Mar 16 session result with the 77 TMKs is probably the effect of shooter induced variation for this test.
I find that for any session, there is usually one load that is an outlier.
I just don't maintain concentration like I used to.
Actually, the long term results with all powders show that the TMKs have a slight edge (0.006 on average) but there are a lot more groups shot with the 77 TMKs than the SMKs.
Also, note that the 77 grain bullets (combined SMK & TMK) have a better long term average than the 69 grain bullets and that the 69 SMKs and TMKs perform almost identically.

Considering the standard deviations from 0.052 to 0.070, the TMKs are the more consistent bullet. but the

When you look at powder bullet combinations, the results vary some, but the overall results are still pretty darn good.


Note that the best loads with both the 77 SMKs and 77 TMKs with IMR4166 powder are identical and 0.002 better than the best average load 77 SMK using N140 powder. With this small a sample and such similar results, one or possibly two groups that were out of the norm could effect the results.

For the 69 grain bullets, the best load (0.248) is also shared by a 69 TMK and 69 SMK, but the best powder bullet average is with the 69 SMK using N140 powder is 0.006 better than the best TMK average using IMR4166 powder and 0.008 better than a TMK using N140 powder.
The N140 77 grain TMK overall average is the result of the Mar 16 data. The average for 77 TMKs with N140 powder was 0.293 prior to the March 16th session that made drove up the average to 0.302.