Re: First Velocity test with the Wildcat .224\" 100 gr ULD RBBT.....
Kirby, Great to hear that you got 3200+ fps using 8700 with the 100 grain Wildcat, as I was planning to use my supply of H870 with them once the bullets arive and my rifle gets built.
However, some of those test loads with Re25 and H Retumbo that gave leaky primers at 42.0 grains have me mystified.
I found in my recent test with the 25/06AI with the 142 grain ULD, that at maximum pressure, HRetumbo was only 4.0 grains faster burning than H870. Using that experience as a basis, and that you believed that 56.0 grains of 8700 was about maximum, I would have thought that about 50.0- 51.0 grains of HRetumbo would have been a conservative maximum. Yet you were getting leaky primers at 42.0 grains, which to me doesn't add up.
The same applies to your load of 42.0 of Re 25 producing leaky primers, to me it also doesn't add up, as I would have thought you should have had a maximum of around 49.0 - 50.0 grains with Re 25.
About 1 week ago I loaded up my 25/06AI, using the 142 grain Wildcat with H870, HRetumbo, VihtN170, and Re25 to test the relationship between the burning rates of my lots of those powders. Hopefully the weather will be better this weekend, and it will be interesting to see the results, especially with VihtN170 and Re25.
Like GG, I was also interested in how you throated the barrel, for the 100 grain Wildcat.
I am also interested in the case capacity of your 22/6mmAI, and note that you worked up to 59.0 grains of 8700, and wondered whether that was anywhere near the base of the neck? As a comparison in my .224 Clark it took 60.8 grains H870 to fill to the base of the neck, and about 56.0 grains of H1000.
I have to admit that I am also surprised that your 1 in 8 twist barrel stabilised the bullet enough to get round holes at 25 yards. Other 22/6mmAI users have reported that their rifles struggled to stabilise the 90 grain JLk with a 1 in 8 twist. Yet the 90 grain JLK is about .070 inches shorter than the 100 grain Wildcat. It certainly will be interesting to see how the 100 grain Wildcats go at 100 - 500 yards with that twist.
Looking forward to further reports. Brian.