Well guys,
I promised I'd get this done today, so was able to sneak away from the chain gang, this afternoon at 4'ish.
Yesterday I used a Remington 700 ADL for testing. The bullet OACL was pushed slightly into the lands.
What I grabbed today, was the Ruger 77 VT. It is long throated, so these loads had less pressure than the SP primered loads of yesterday's test. These used S&B Small rifle primers. The long throat, meant less pressure which is shown in the velocity results here. I also added H 4198
Bullets used again were Speer 55 grain SPs. Each charge was 15 grains, this was what a 60% of max load is in a 223, with H 4895, considering a max load being 25 grains. 5 shots with each powder.
1. H 4198, S/B primer, 55 gr Speer SP.
a.) 2023 fps b.) 2277 fps c.) 1978 fps d.) 1957 fps e.) 2274 fps.
2. IMR 4198, S/B primer, 55 gr Speer SP
a.) 2052 fps b.) 2056 fps c.) 2103 fps d.)2097 fps e. ) 2081 fps.
This shows why I prefer IMR 4198 in this type of service. H 4198 gives a velocity deviation of 250 fps. IMR 4198 gives a velocity spread of only 50 fps or less. That is why I say it is more consistent than Hodgdon/ADI's version.
3. H4895, S/B primer, 55 SP Speer.
a.) 1610 fps b.) 1561 fps c.) 1577 fps d.) 1578 fps e.) 1713 fps
4. IMR 4895, S/B primer, 55 Speer SP.
a.) 1899 fps b.) 1817 fps c.) 1865 fps d.) 1794 fps e.) 1891 fps
As can be seen, the Ruger 77/ VT saw less velocity, having a longer throat. This increased with the 15 grains of 4895 loads, but more with Hodgdon/ ADI vs. IMR's.
each case was severely covered in blow back, covering much of the cases in black oily soot. It did not clean up very well just using Steel Wool. They are now getting tumbled, using mineral spirits in with the Tumbling media. I usually leave these tumbling over night, and they will be generally pretty darn clean the following morning.
I'll let you guys draw your own conclusions. I do think a 60% load of H 4895 is too inconsistent and also has extreme velocity spreads, which is probably why it is not what I call consistently accurate. IMR 4895 does much better, even if Hodgdon tells us not to use it...
both 4198s are better candidates for reduced loads in this range. More consistent accuracy, and more consistent velocity spread, than either of the 4895 powders. The brass with the 4198 powders also has MUCH less blow back on them.
Hence easier to clean.
cheers,
seafire.
August 2023.
