Tim K
10-06-2017, 08:44
Right? I hate loading, so I decided to try anyway. I just bought a new JP to use in the carbine role at team matches. Behind it is its predecessor, a gun I put together with a White Oak barrel.
http://i66.tinypic.com/10ggpcm.jpg
After reading JP's loading document, I decided to try TAC and 77 SMKs. I did exhaustive development, like to the tune of 200 rounds. I did all this measuring powder to the nearest 0.02 grains on a lab scale. I found a nice wide node that's about 0.5g wide. Incidentally, I ran a seating depth test at the beginning and found the gun likes 0.020" shorter than mag length. Surprising.
My final load is 23.5g of TAC, 77g SMK, CCI 450 SRM primers in Prime brass. Velocity out of the 20" JP was 2725fps, right where it should be. With the precisely measured charges, I saw SD = 11. It shot a little better than 1/2 minute.
The final step was to try it in my Dillon 650. With TAC, I was seeing a total spread in charge weight of only 0.08g. Promising. SD's on that ammo were more like 15, accuracy was still 1/2 minute.
As you can image, I was pretty stoked to find a load I can run at 500+ rounds an hour vs 50 rounds an hour individually weighing.
On a whim, I decided to try this load in the old rifle. How sweet would it be if it show well in that one, too?
Here's a group with the JP, the rifle I used for all the development.
http://i68.tinypic.com/2u57s6e.jpg
Here's a group with the White Oak barreled home build.
http://i68.tinypic.com/2h6soww.jpg
Amazing! One load that shoots 1/2 minute in two different rifles. Loading it at 500 rounds an hour? Too good to be true. I have two more rifles to try this in. I'll let you know what I see when I test them.
http://i66.tinypic.com/10ggpcm.jpg
After reading JP's loading document, I decided to try TAC and 77 SMKs. I did exhaustive development, like to the tune of 200 rounds. I did all this measuring powder to the nearest 0.02 grains on a lab scale. I found a nice wide node that's about 0.5g wide. Incidentally, I ran a seating depth test at the beginning and found the gun likes 0.020" shorter than mag length. Surprising.
My final load is 23.5g of TAC, 77g SMK, CCI 450 SRM primers in Prime brass. Velocity out of the 20" JP was 2725fps, right where it should be. With the precisely measured charges, I saw SD = 11. It shot a little better than 1/2 minute.
The final step was to try it in my Dillon 650. With TAC, I was seeing a total spread in charge weight of only 0.08g. Promising. SD's on that ammo were more like 15, accuracy was still 1/2 minute.
As you can image, I was pretty stoked to find a load I can run at 500+ rounds an hour vs 50 rounds an hour individually weighing.
On a whim, I decided to try this load in the old rifle. How sweet would it be if it show well in that one, too?
Here's a group with the JP, the rifle I used for all the development.
http://i68.tinypic.com/2u57s6e.jpg
Here's a group with the White Oak barreled home build.
http://i68.tinypic.com/2h6soww.jpg
Amazing! One load that shoots 1/2 minute in two different rifles. Loading it at 500 rounds an hour? Too good to be true. I have two more rifles to try this in. I'll let you know what I see when I test them.