I've been running 8208 XBR in my 20" Shilen barrelled AR and have measured velocity while running ladder tests. I finally settled in on 28.5 gr of 8208 XBR as it resulted in very good accuracy and about 2500 fps velocity (using 123gr Lapua Scenar bullets). A week ago I picked up 8 lbs of CFE 223. Knowing that it is a little slower than XBR, I anticipated a bit more velocity, but that hasn't been the case. I worked my way up from 24.9 gr to 31.8gr in .3 gr increments. Average velocity is as follows:
Powder 29.4 29.7 30.0 30.3 30.6 30.9 31.2 31.5 31.8
Velocity 2335 2347 2367 2386 2417 2441 2455 2484 2512
Increase +12 +20 +19 +31 +24 +14 +30 +28
All rounds were seated to 2.25, and running the same 205M primers and Lapua Scenar bullets. In other words the same as my 8208 XBR testing. Temperature was within 7 degrees (67 F) as the XBR test (60 F). Brass and primers looked good at all levels with no signs of excessive pressure. No evidence of a velocity spike. There were two accuracy nodes, one at 30.3 gr and the other at 31.8 gr.
I haven't seen many CFE 223 loads exceeding 31.8 gr, and I'm looking for input from others before proceeding with increased levels. Everything I have seen realtive to CFE 223 would indicate that it generally has a bit more velocity than 8208 XBR, however I was surprised to see that in order to achieve the same velocity, I had to go as high as 31.8 gr of CFE 223. I'm tempted to test starting at 32 gr, and move up in .3 gr increments to 32.6 to see if there is any primer flow or other indications of pressure, but thought there may be others out there that have already been through this. I would think that moving above 31.8 gr will create a very compressed load. Any others tested above 31.8 gr of CFE 223? Thanks in advance for your input.
Powder 29.4 29.7 30.0 30.3 30.6 30.9 31.2 31.5 31.8
Velocity 2335 2347 2367 2386 2417 2441 2455 2484 2512
Increase +12 +20 +19 +31 +24 +14 +30 +28
All rounds were seated to 2.25, and running the same 205M primers and Lapua Scenar bullets. In other words the same as my 8208 XBR testing. Temperature was within 7 degrees (67 F) as the XBR test (60 F). Brass and primers looked good at all levels with no signs of excessive pressure. No evidence of a velocity spike. There were two accuracy nodes, one at 30.3 gr and the other at 31.8 gr.
I haven't seen many CFE 223 loads exceeding 31.8 gr, and I'm looking for input from others before proceeding with increased levels. Everything I have seen realtive to CFE 223 would indicate that it generally has a bit more velocity than 8208 XBR, however I was surprised to see that in order to achieve the same velocity, I had to go as high as 31.8 gr of CFE 223. I'm tempted to test starting at 32 gr, and move up in .3 gr increments to 32.6 to see if there is any primer flow or other indications of pressure, but thought there may be others out there that have already been through this. I would think that moving above 31.8 gr will create a very compressed load. Any others tested above 31.8 gr of CFE 223? Thanks in advance for your input.
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