I did a quick preliminary run with both IMR 4198 and Hodgdon 4198 to see how the newly designed 8.5 grain bullets held up for stability. I ran them in my 14/221 Walkers to get some info for folks shooting them. (Both of the test guns I used for this testing are 1 in 7 twist rate Pac-Nor Stainless Super Match barrels with 3 land heavy groove.)
Both rigs showed great stability and decent grouping with the initial load of:
IMR 4198 = 16.2 grains , CCI BR4 primers, 8.5gr Extreme Accuracy Moly coated.
Hodgdon 4198 = 16.2 grains, CCI BR4 primers, 8.5 gr. Extreme Accuracy Moly Coated.
The chronograph started losing them and no longer reading as soon as I stepped above the 4700 fps range. The highest reading I could get was 4760 and it would only capture an occasional round. It was very frustrating to say the least.
Both rigs liked the Hodgdon H-4198 better for some strange reason. The IMR is usually the chosen powder in both of these test guns. Both also showed an improvement in accuracy as soon as I switched over to the CCI 450 small rifle magnum primers. Sadly the chronograph could not get a reading on those test rounds to let me know the speed range on them.
The primers and brass showed no signs of pressure and I was ready to step up the speed a bit but without a chronograph that would tell me where I was at I decided to wait until I have the strain gauge and laptop hooked up to them.
None of the bullets came apart even with a light rain starting to fall. With a 1 in 7 twist rate that put them well above the 480,000 rpm level. The J4 Jackets held up well and had zero failures. In the 1 in 9 twist 5000 fps should not be a problem from the RPM standpoint.
I’ll try to run them in the 14 Hornet Extreme and the 14 TCM Extreme on my next outing. It should give me both ends of the spectrum on the speed range for these 8.5 grain bullets.
I hope this info helps and as always stay on target,
Carl C.
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