Got to head back to the Rock Pit again this morning. I really wanted to get more familiar with the 45 DISC Extreme. I really was not satisfied with the results of the outing the other day other than the fun part at the end shooting clay pigeons.
I decided on a somewhat differt approach to my testing today, although - I really wish i had grabbed the chrono.
The primary test today was to see which sabot might perform the best with the different bullets that i was using. Either the Harvest smooth Light Blue or the MMP Light Tan - both in the .40/45 variety. It should be noted that the MMP Light Tan is not listed as a HPH sabot it is listed back in the regular sabot section. In the package on the suggested loads it suggests that with a 170-180 grain bullet or with a 200 grain bullet - the loads may be 60/70 or 80 grains. To me in the modern inline ML these are really light loads. The advent of the high performance SST/SW, Barnes, Lehigh and even the XTP - you will shoot greater capacity loads than listed on the package.
I was surprised that the MMP did shoot as well as it did considering that was was overcharging the sabot. I do not believe I got a sabot failure all day although sabot stress could help explain some of 'out of group' shots but mostly I truly believe they were more my fault than the sabots.
Here is a comparison picture of the sabot. I think you can see the stress cuts that are in the cups of the MMP sabots. They were definitely stressed.
This single picture might show it better...
A second test was to see if i could tighten the groups up a bit from th other day.
You can see I shot five different targets, using the Harvester and the MMP. I also made a change in the powder charge due to the grouping in the first target.
I started with the Hornady 200 grain XTP as it has always been an excellent shooter for me from any of my 50 cals. I started again with 120 grains of T7-2f, because of my thinking I need to shoot that stiff a load to get the Lehigh's to perform from a 1/30 twist. Well, I hated the spread in group #1, with both sabots. I also have to admit shot numger three of any group really gave me fits today as I would get a decent two shot group and then screw up #3 -
Semi - I am sure has a rule for that. I hope you can see what I am trying to show with the different shots and different sabots.
After group#1 I decided maybe I would not force feed it and reduced the load to 110 grains. Well that seem to be what it might need as the next group of XTP's tightened up quite a bit (except for the flyers which really could be me and probably is. I continued to use 110 for all the rest of the shots.
You can see the rest of the groups and how they developed. But what I really want to point out is the Lehigh's the recuction of powder really helped them and I really thought that it would have the opposite effect in the slow twist of the Knight bore. This is where I really wished I had the chrono - I would really have liked to have a velocity read out on them. If it were a 50 cal I could give a real good estimate, but these 45's are an all new ball game for me.
Here is the target from todays session...
