So I have been experimenting with the heavy arrow combos all off season and finally settled things up yesterday.
@Isaacorps and I have a running text thread on this, so I wanted to share the results we've discussed here for others to learn from.
I've been shooting a 500-ish grain FMJ that's roughly 10.5% FOC, and I've been shooting a 600-ish grain Axis that's almost 12% FOC. The first night I shot them side-by-side, I was shocked at the pin difference between the two. The 600s were a whole pin different, so my 20 became my 30, 30 my 40, and so on. When we hit the chronograph, the 500s were at 260 and the 600s at 240. The 500s patterned better, but I was in love with how the 600s impacted, so I was still on Team 6-Hundo.
At this point, I start to scratch my head a little and do a once over on my bow. I knew my string was near it's end, so I orded an ABB Platinum, then waited and waited and waited for it to arrive. It got here last week, so I measured the specs on my bow and sure enough, my ATA was 0.25" out and my brace height was off 0.125". As mentioned, I swapped the string and got the bow back in spec, then paper tuned with the 600 grain arrow. Last night I installed my peep and shot my broadheads and the 600s were impacting spot on with my "500 pins". When I checked the chronograph, I was bumping above 255.
The moral of the story here is to give due respect to your string and don't be afraid to spend a little $ on a good one. At $180, the ABB Platinum hurts, but after seeing the rejuvenation it gave my bow, it was $ well spent. My other string was from a company I've used for a long time, but I feel their quality has went way down hill. I wore that string out in less than 1K shots. I'm admit to being hard on stuff, but that's still not acceptable IMO. I put a premium string on a 13 year old bow and she feels brand new! And who can argue with a Switchback XT that still shoots a 600 grain arrow at 255 fps!