UPDATE: 6.35.43mm (257/223) project
I am running the gun with the gas port turned off to see how it runs before I the port in. Here are some new results.
Load Data: (standard disclaimer as with any wild-cat, use at own risk and work up slow)
75 gr Hornaday V-Max (16-inch barrel)
for starting load reduce powder charge by 5%
21.9gr IMR4227 = 3020 fps
Primers were round and brass look good.
87 gr Speer TNT (16-inch barrel)
for starting load reduce powder charge by 5%
21.9gr IMR4227 = 2840 fps
Primers just starting to flatten edges and brass look good. For my rifle, I would reduce this load by 0.2 to 0.5gr for general use.
These results seem to confirm that H4895 and W748 powders are too slow for this caliber at this barrel length.
320pf
Quote:
Originally Posted by 320pf
I had a chance to try loading(W748 in the 25-223AR*
*.223 parent brass opened up to .25-cal; shortened to 43mm; maintains .223 body taper, same body shoulder junction height, does't require fire-forming.
Load Data: (standard disclaimer as with any wild-cat, use at own risk and work up slow) Note: The powder was loaded into the case using an eight drop tube. This facilitated a more dense/compact powder column.
100 gr Speer SPBT (16-inch barrel)
25.5gr W748 = 2350 fps
26.0gr W748 = 2411 fps
26.5gr W748 = 2435 fps
27.0gr W748 = 2475 fps
27.5gr W748 = 2510 fps
28.5gr W748 = 2548 fps
No signs of high pressure. Am interesting phenomena occurred with this load. The ejected brass was was cool to the touch. The barrel was was only mildly warm after each five shot string. SO this powder must burn pretty cool. There was NO powder residue in the barrel after each shot so W748 must also burn fairly clean. In addition, all 30 round from this test grouped within 3-inches over the 200 fps velocity spread. I was not trying to shoot for groups.
I used the published loads for BL-C(2) in the 6x45mm found the Hodgdon reloading manual for a starting reference. The Hodgdon web site shows that W748 is ranked at 82 and Hodgdon BL-C(2) is ranked at 83 on their burn rate chart.
For example Hodgdon lists:
6x45mm
85 gr SPR SP BL-C(2) (24" barrel)
Start: 25.5gr.-2566 fps; Max: 27.5gr.-2811 fps
90 gr SPR SP BL-C(2) (24" barrel)
Start: 25.05gr.-2523 fps; Max: 27.0gr.-2744 fps
100 gr HDY SP BL-C(2) (24" barrel)
Start: 24.5gr.-2404 fps; Max: 26.5gr.-2619 fps
320pf
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Threaded Mode