Well I had to stop shooting for about 6 months due to a motorcycle accident. Now that I'm back though I figured I would share the results of the first trip to the range with my latest rifle. It was built by William Roscoe at Louisiana Precision Rifles and he did an amazing job from what I have seen so far. Many thanks to him for the effort and attention he put into this stick. Anyhow, here are the specs for the rifle:
-6.5x47mm Lapua shooting 123 gr Scenars over CCI BR-4 primers, between 35.2 and 38.8 grs of Varget, held together by Lapua brass, seated to COAL of 2.704" to be touching the lands.
-McMillan A-5 stock
-Krieger fluted 5R barrel 22" with 1:8.5" twist in stainless steel, contour #7
-Surgeon Round action
-Huber 2-stage trigger set to 2 lbs.
-CDI bottom metal
-Harris bipod
-Nightforce 3-15x F1 in Seekins rings
-Assembled, coated, and bedded by William Roscoe of Louisiana Precision Rifles
I made 38 rounds that were identical except for varying powder charges. 12x 35.2grs and then 3x of 35.6, 36.0, 36.4, 36.8, 37.2, 37.6, 38.0, 38.4, and 38.8 grs.
I zeroed at 100 yards and only shot one 3- shot group which resulted in a .274" group. Not bad seeing as I was trying to get zeroed and not trying for outright accuracy. By the way, this target was rotated 90* to the right for your viewing pleasure. The group was actually low and centered, not left and centered elevation-wise. I dialed in another .2 mil elevation and called it good when I was in the circle.
After that I drove out to 400 yards and started shooting 3 rounds at a time and recording the impacts on a seperate sheet. I was simultaneously watching for pressure signs but there was nothing consistent other than flattened primers. Had a little primer cratering on the hottest loads and one of the medium loads. Also had a couple rounds that made a small indentation from the ejector and slightly heavy bolt lift.
Looking at the target there was a spread of about 6.5" of elevation through the course of firing all the different loads. Things topped-out after about 36.4grs and didn't really climb significantly higher. My guess is velocity wasn't increasing much after this point and I was just making higher chamber pressures and a bigger flash out the end of my barrel with all the extra powder. Interestingly, two of the hottest loads completely seperated from the the rest of the groups and migrated to the right side and displayed a lot of vertical spread.
Unless someone can convince me otherwise I am planning on doing further load development with 36.8grs of Varget. Higher power loads didn't impact much higher so I'm thinking they didn't have much more velocity. Plus the accuracy of some of the hotter loads were much worse. On the other hand, everything below 36.4grs is obviously giving up some velocity. I know I'm only supposed to be concerned with vertical spread right now but it is hard to walk away from a group size of 1.2" at 400 yards that doesn't exhibit much vertical spread, doesn't beat-up my brass, is near the max velocity for my rifle, and is in a node where adding or dropping some powder doesn't make a big difference either way.
Feel free to ask questions or share thoughts/opinions. I already know I didn't execute a proper ladder test but I would say I got solid enough results to determine a good direction to pursue.
-6.5x47mm Lapua shooting 123 gr Scenars over CCI BR-4 primers, between 35.2 and 38.8 grs of Varget, held together by Lapua brass, seated to COAL of 2.704" to be touching the lands.
-McMillan A-5 stock
-Krieger fluted 5R barrel 22" with 1:8.5" twist in stainless steel, contour #7
-Surgeon Round action
-Huber 2-stage trigger set to 2 lbs.
-CDI bottom metal
-Harris bipod
-Nightforce 3-15x F1 in Seekins rings
-Assembled, coated, and bedded by William Roscoe of Louisiana Precision Rifles
I made 38 rounds that were identical except for varying powder charges. 12x 35.2grs and then 3x of 35.6, 36.0, 36.4, 36.8, 37.2, 37.6, 38.0, 38.4, and 38.8 grs.
I zeroed at 100 yards and only shot one 3- shot group which resulted in a .274" group. Not bad seeing as I was trying to get zeroed and not trying for outright accuracy. By the way, this target was rotated 90* to the right for your viewing pleasure. The group was actually low and centered, not left and centered elevation-wise. I dialed in another .2 mil elevation and called it good when I was in the circle.
After that I drove out to 400 yards and started shooting 3 rounds at a time and recording the impacts on a seperate sheet. I was simultaneously watching for pressure signs but there was nothing consistent other than flattened primers. Had a little primer cratering on the hottest loads and one of the medium loads. Also had a couple rounds that made a small indentation from the ejector and slightly heavy bolt lift.
Looking at the target there was a spread of about 6.5" of elevation through the course of firing all the different loads. Things topped-out after about 36.4grs and didn't really climb significantly higher. My guess is velocity wasn't increasing much after this point and I was just making higher chamber pressures and a bigger flash out the end of my barrel with all the extra powder. Interestingly, two of the hottest loads completely seperated from the the rest of the groups and migrated to the right side and displayed a lot of vertical spread.
Unless someone can convince me otherwise I am planning on doing further load development with 36.8grs of Varget. Higher power loads didn't impact much higher so I'm thinking they didn't have much more velocity. Plus the accuracy of some of the hotter loads were much worse. On the other hand, everything below 36.4grs is obviously giving up some velocity. I know I'm only supposed to be concerned with vertical spread right now but it is hard to walk away from a group size of 1.2" at 400 yards that doesn't exhibit much vertical spread, doesn't beat-up my brass, is near the max velocity for my rifle, and is in a node where adding or dropping some powder doesn't make a big difference either way.
Feel free to ask questions or share thoughts/opinions. I already know I didn't execute a proper ladder test but I would say I got solid enough results to determine a good direction to pursue.
