I have been in the process of testing the GS414gr solid, GS425gr HV and the Cutting Edge 350gr hunting, 377gr MTAC, 402gr MTAC. I'm using a 375 Snipe Tac in two 32 inch Brux barrel twists...1-10 & 1-8.25.
My initial tests were all with the heavier bullets using the 1-8.25 twist. The smaller Cutting Edge 350's will be tested after my other 1-10 twist rifle is complete next week.
Dave Viers is the creater of the 375 Snipe Tac and although he did not build my rifles, he has provided many of the components in the process. I would encourage anybody who wants to build a snipe tac to look him up...http://www.blackdiamondrifles.com/
<span style="font-style: italic"><span style="font-weight: bold">The GS414 & GS425HV bullets</span></span>....I ordered these bullets for load development to be completed last summer. They were 2 months late on delievery (shipped from S Africa). By the time I received them, it was hunting season and I had very little time for load development. I did not get a chance to take the bullets out past 1,000 yards like Dave Viers did, but I will share my initial results.
For the 425gr HV's, I started my loads at 142grains of US869 and increased the loads by 1 grain increments all the way up to 150 grains. At 150 grains, I saw my first pressure signs and at 500 yards the bullets were unstable creating football shaped holes, this was just over 3,000 fps. I backed down the charge to 146 grains and got my best groups (1 minute). At this point I didn't go much further bc I didn't like the groups. My next step was to try 50BMG powder.
GS only sent me a handful of the new GS414's. I only tested a few of them at 100 yards and they seemed to like 146 grains of US869. I saw pressure signs at 150 grains so I backed them down again to 146. My next step here was to take them out to 1,000 plus yards, but the longer lead times of the GS bullets discouraged me from completing my test.
<span style="font-style: italic"><span style="font-weight: bold">Cutting Edge bullets</span></span>......Right off the bat, I am very impressed with Dan at Cutting Edge. When I told him what I was doing, he sent me 50 each of the 350's, 377's & 402's for the 375 Snipe Tac for testing.
3 days later the Cutting Edge bullets showed up at my door step. All of the bullets were individually packed insuring that each bullet was protected from dings during shipment.
My starting load with the CE402 MTAC was 142grs of US869, and I increased the load by 1 grain increments all the way to 150grs. I seated them for a .020 jump with the seating band just kissing the top of the case.
At 145grs and 146gr I saw 1/4 inch 2 shot groups at 100 yards initially. As I shot 3 & 4 shot groups for validation, the 145 & 146 grain spread out to between 1 inch & 1 1/4.
I saw some similar results with the 377grain bullets. My next step is to switch powders to 50BMG to see if I can get the ES down to single digits to get better groups and consistancy...............
More to come next week!!
zman
My initial tests were all with the heavier bullets using the 1-8.25 twist. The smaller Cutting Edge 350's will be tested after my other 1-10 twist rifle is complete next week.
Dave Viers is the creater of the 375 Snipe Tac and although he did not build my rifles, he has provided many of the components in the process. I would encourage anybody who wants to build a snipe tac to look him up...http://www.blackdiamondrifles.com/
<span style="font-style: italic"><span style="font-weight: bold">The GS414 & GS425HV bullets</span></span>....I ordered these bullets for load development to be completed last summer. They were 2 months late on delievery (shipped from S Africa). By the time I received them, it was hunting season and I had very little time for load development. I did not get a chance to take the bullets out past 1,000 yards like Dave Viers did, but I will share my initial results.
For the 425gr HV's, I started my loads at 142grains of US869 and increased the loads by 1 grain increments all the way up to 150 grains. At 150 grains, I saw my first pressure signs and at 500 yards the bullets were unstable creating football shaped holes, this was just over 3,000 fps. I backed down the charge to 146 grains and got my best groups (1 minute). At this point I didn't go much further bc I didn't like the groups. My next step was to try 50BMG powder.
GS only sent me a handful of the new GS414's. I only tested a few of them at 100 yards and they seemed to like 146 grains of US869. I saw pressure signs at 150 grains so I backed them down again to 146. My next step here was to take them out to 1,000 plus yards, but the longer lead times of the GS bullets discouraged me from completing my test.
<span style="font-style: italic"><span style="font-weight: bold">Cutting Edge bullets</span></span>......Right off the bat, I am very impressed with Dan at Cutting Edge. When I told him what I was doing, he sent me 50 each of the 350's, 377's & 402's for the 375 Snipe Tac for testing.
3 days later the Cutting Edge bullets showed up at my door step. All of the bullets were individually packed insuring that each bullet was protected from dings during shipment.
My starting load with the CE402 MTAC was 142grs of US869, and I increased the load by 1 grain increments all the way to 150grs. I seated them for a .020 jump with the seating band just kissing the top of the case.
At 145grs and 146gr I saw 1/4 inch 2 shot groups at 100 yards initially. As I shot 3 & 4 shot groups for validation, the 145 & 146 grain spread out to between 1 inch & 1 1/4.
I saw some similar results with the 377grain bullets. My next step is to switch powders to 50BMG to see if I can get the ES down to single digits to get better groups and consistancy...............
More to come next week!!
zman