After only having this rifle in my possession for about 2 weeks, I believe it is a good time to start an early range report with my findings and discoveries so far.
My first outing last weekend was a combination of quick data gathering and function testing. Given data that I've obtained from here on the Hide mainly, I started load development at 127g of Retumbo for these 352g Cutting Edge solids. I am loading these .010 off of the lands, which works out perfect on the gas check location for these. OAL - 4.443". I can't provide ogive measurements because I do not have a comparator that these will fit into without bottoming out, even into the calipers themselves. Luckily, any CNC lathe turned bullet is going to be extremely accurate even measuring to the meplat.
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No pictures from last weeks trip, but I do have chrono data. I can attest that the groups from this load were acceptable at 1/2 MOA which is surprising because I literally pull Bertram brass out of the box - no sizing, no prep other than a slight chamfer/debur to prevent bullet shaving. I can tell you that the neck tension was heavy at nearly .007. There is a good reason for being forced to do this noted here. If the CCB shot is deleted, the numbers look much better - still surprising given the way the bullets felt being seated.
82F, sunny, 2400 DA, wind light 5-8 MPH 6 o'clock.
127g Retumbo - 4.443" OAL - FED. 215M Match - Bertram brass
Now, to current day... Started the day out doing some group testing.
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First, I wanted to get an offset for using new unfired brass with the appropriate neck tension this time. Turns out, there is no offset. Once fired but sized and factory new brass behave identically on paper and via velocity.
Conditions were fair: 66F, cloudy with some drizzle, 1440 DA, wind gusting variable 10-15 MPH from 6-7 o'clock.
128g Retumbo - 4.443" OAL - FED. 215M Match - Bertram brass
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This is a really great node. The first CCB shot was low, the rest essentially tore a nice $27 hole. I believe this will become my go-to unless I can find a node around the 3100+ mark. I doubt that I would want to beat the brass up like that though. 3060 fps is a good speed, especially with that SD I can work with it. I will most likely attempt to clean this node up a bit by shifting a few tenth grains down. Notice the zero offset below the center red diamond - this is from a barrel removal/reinsertion from the first range trip - about .2 mils down and .1 mils right. Not bad in my opinion especially for such a heavy tube. I get similar results with my AXMC's.
As seen below, timing is everything they say and that applies strongly with interior ballistics (referencing barrel timing). Look what 1g higher does to the groups (even though the chrono data states stability). I've said this for years - don't solely trust the chrono data! I only grouped 5 of them - the rest I wanted run at distance. They were a tad sporadic at 1 mile.
Conditions were fair: 66F, cloudy with some drizzle, 1440 DA, wind gusting variable 10-15 MPH from 6 o'clock.
129g Retumbo - 4.443" OAL - FED. 215M Match - Bertram brass
[IMG2=JSON]{"data-align":"none","data-size":"full","src":"https:\/\/image.ibb.co\/dVV2tv\/IMG_1033.jpg"}[/IMG2]
Brass/primers still look good and no ejector markings. No cupping, sticky bolt, etc.
[IMG2=JSON]{"data-align":"none","data-size":"full","src":"https:\/\/image.ibb.co\/gf8oYv\/IMG_1031.jpg"}[/IMG2]
Thanks to orkan and secondofangle for giving me a few pointers to get running with. More updates to come when time permits to do a little more load development for a higher possible node. For now, I will enjoy the 128g node and test brass resiliency at that charge.
My first outing last weekend was a combination of quick data gathering and function testing. Given data that I've obtained from here on the Hide mainly, I started load development at 127g of Retumbo for these 352g Cutting Edge solids. I am loading these .010 off of the lands, which works out perfect on the gas check location for these. OAL - 4.443". I can't provide ogive measurements because I do not have a comparator that these will fit into without bottoming out, even into the calipers themselves. Luckily, any CNC lathe turned bullet is going to be extremely accurate even measuring to the meplat.
[IMG2=JSON]{"data-align":"none","data-size":"full","src":"https:\/\/image.ibb.co\/ge9TYv\/IMG_0924.jpg"}[/IMG2]
[IMG2=JSON]{"data-align":"none","data-size":"full","src":"https:\/\/image.ibb.co\/ceBLfa\/IMG_0926.jpg"}[/IMG2]
No pictures from last weeks trip, but I do have chrono data. I can attest that the groups from this load were acceptable at 1/2 MOA which is surprising because I literally pull Bertram brass out of the box - no sizing, no prep other than a slight chamfer/debur to prevent bullet shaving. I can tell you that the neck tension was heavy at nearly .007. There is a good reason for being forced to do this noted here. If the CCB shot is deleted, the numbers look much better - still surprising given the way the bullets felt being seated.
82F, sunny, 2400 DA, wind light 5-8 MPH 6 o'clock.
127g Retumbo - 4.443" OAL - FED. 215M Match - Bertram brass
Units velocity | fps | Notes: |
Stats - Average | 3006.52 | |
Stats - Highest | 3041.26 | |
Stats - Lowest | 2985.05 | |
Stats - Ext. Spread | 56.21 | |
Stats - Std. Dev | 21.75 | |
Shot ID | V0 | |
1 | 3041 | CCB Shot |
2 | 3013 | |
4 | 2985 | |
5 | 2996 | |
6 | 2998 |
[IMG2=JSON]{"data-align":"none","data-size":"full","src":"https:\/\/image.ibb.co\/fjZTYv\/IMG_1029.jpg"}[/IMG2]
First, I wanted to get an offset for using new unfired brass with the appropriate neck tension this time. Turns out, there is no offset. Once fired but sized and factory new brass behave identically on paper and via velocity.
Conditions were fair: 66F, cloudy with some drizzle, 1440 DA, wind gusting variable 10-15 MPH from 6-7 o'clock.
128g Retumbo - 4.443" OAL - FED. 215M Match - Bertram brass
Units velocity | fps | Notes |
Stats - Average | 3060.37 | |
Stats - Highest | 3066.8 | |
Stats - Lowest | 3051.3 | |
Stats - Ext. Spread | 15.49 | |
Stats - Std. Dev | 5.81 | |
Shot ID | V0 | |
1 | 3067 | CCB Shot |
2 | 3059 | |
3 | 3063 | |
4 | 3051 | |
5 | 3062 |
This is a really great node. The first CCB shot was low, the rest essentially tore a nice $27 hole. I believe this will become my go-to unless I can find a node around the 3100+ mark. I doubt that I would want to beat the brass up like that though. 3060 fps is a good speed, especially with that SD I can work with it. I will most likely attempt to clean this node up a bit by shifting a few tenth grains down. Notice the zero offset below the center red diamond - this is from a barrel removal/reinsertion from the first range trip - about .2 mils down and .1 mils right. Not bad in my opinion especially for such a heavy tube. I get similar results with my AXMC's.
As seen below, timing is everything they say and that applies strongly with interior ballistics (referencing barrel timing). Look what 1g higher does to the groups (even though the chrono data states stability). I've said this for years - don't solely trust the chrono data! I only grouped 5 of them - the rest I wanted run at distance. They were a tad sporadic at 1 mile.
Conditions were fair: 66F, cloudy with some drizzle, 1440 DA, wind gusting variable 10-15 MPH from 6 o'clock.
129g Retumbo - 4.443" OAL - FED. 215M Match - Bertram brass
Units velocity | fps |
Stats - Average | 3092 |
Stats - Highest | 3107.5 |
Stats - Lowest | 3074.86 |
Stats - Ext. Spread | 32.64 |
Stats - Std. Dev | 8.7 |
Shot ID | V0 |
1 | 3075 |
2 | 3084 |
3 | 3096 |
4 | 3089 |
5 | 3091 |
6 | 3091 |
7 | 3097 |
8 | 3096 |
9 | 3107 |
10 | 3093 |
Brass/primers still look good and no ejector markings. No cupping, sticky bolt, etc.
[IMG2=JSON]{"data-align":"none","data-size":"full","src":"https:\/\/image.ibb.co\/gf8oYv\/IMG_1031.jpg"}[/IMG2]
Thanks to orkan and secondofangle for giving me a few pointers to get running with. More updates to come when time permits to do a little more load development for a higher possible node. For now, I will enjoy the 128g node and test brass resiliency at that charge.
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