05-03-2022, 01:51 PM
I also think you've got a short chamber, seating in to 2.13 +/- is much shorter than Hornady lists for the coal of the 129 sp.
They list oal as 2.245. So you could definitely be into unknown pressure spikes at the load you're trying to start with.
Grendel is hard to model in my Grt, which I use for advice... and AR comp is a slightly faster version of RE-15 according to Alliant...
IMO you would be better advised to begin with a ball powder like BLC2, AA2520, or CFE223 and work up from the low starting point in the Hornady load data.
My starline brass that I have is pretty close to Hornady in volume etc, so that could be basically a wash if you start from the low.
And definitely use a chrono because especially in your case, without it you are driving blind down a foggy windy road in the country.
They list oal as 2.245. So you could definitely be into unknown pressure spikes at the load you're trying to start with.
Grendel is hard to model in my Grt, which I use for advice... and AR comp is a slightly faster version of RE-15 according to Alliant...
IMO you would be better advised to begin with a ball powder like BLC2, AA2520, or CFE223 and work up from the low starting point in the Hornady load data.
My starline brass that I have is pretty close to Hornady in volume etc, so that could be basically a wash if you start from the low.
And definitely use a chrono because especially in your case, without it you are driving blind down a foggy windy road in the country.
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