17 April 2017
OK I am not really arguing here but rather thinking out loud. First if I can continue to get anything close to the two groups above, it is going to be hard to get me to try another alloy. Second I have 3 pots sitting on my casting bench. One contains pure lino, one contains foundry 92-6-2 and one contains a secret mix (just kidding) that measures exactly BHN 11.5. For the last three months I have shot either pure lino or pure hardball (92-6-2) in these 243s. These are BHN 20-22 and BHN 16-18 respectively. I have shot them slow and I have shot them fast. I have been rewarded with an occasional 1.25” group and have shot a bunch of 1.5” - 2.0” groups.
There is no magic here but rather well over 800 rounds through 3 rifles using two foundry pure hard alloys and at least a half dozen powders. According to my notes the best groups have usually been in the 1700 fps range using loads which are closer to minimum that maximum. The Lyman manual I have been following notes that best accuracy with the 243 is usually obtained below 1750 fps. That has been my experience also.
I have retired the two faster twist rifles to so they can pursue other interests. Since the slower twist barrel was the most accurate, I decided why not try it with a softer alloy ahead of a slightly gentler load. Why not indeed? If I can get a 7 1/2# sporter to shoot a 9/16” group in a 15 mph wind and then follow it with another sub 1” group, the load will have my undivided attention.
I have been shooting registered CBA matches for over 20 years. I know that conventional wisdom is that small bore gas checked bullets need to be hard. I have measured some really good groups which were shot using linotype bullets. We compete comfortably in the knowledge that when in doubt, try a harder bullet.
Maybe so, maybe not so. I usually like to believe what my eyes tell me and I have seen very few groups shot with conventional equipment that are any better than that one above. Does one group prove anything? Not much except maybe when it is a tight as the .57 group. Do 2 groups prove anything? Prove - no. Indicate - probably.I believe these are the best 2 groups I have gotten since starting this project. You can be sure I will shoot several more groups before relying heavily on this load but I am unlikely to abandon it before it has been thoroughly tested. I do remain aware of the fact that the warmer weather may be contributing to better performance now. It is also true that I have solved the lube problems I was experiencing early on. Both of these facts could be giving this load an edge relative to the harder alloys I was shooting in February.
Anyhow this is getting too long. I apologize for sounding irritated but I was. If someone would like to join me in this effort, feel free to say so. PM if you wish. Now that spring is here I will be unable to continue to commit this much time to testing loads.