Thread: 6.5x55 142gn Accubond Long Range loads

Hi Quentin, I ran your previous load through QuickLOAD while using the QuickLOAD 6.5x55 specs, so that is the 140AMAX with 44.7gr of 2209 from a 22.5" barrel, and the predicted velocity is very close to your measured value at 2645ft/sec. Estimated peak pressure for this load is down at 48k9 PSI. This is reassuring and indicates QuickLOAD is likely (not guaranteed) to give satisfactory approximations for your rifle when we go and change things a little.

Confirming the earlier post, IMR4350 and H4350/AR2209 have somewhat different parameters and are not interchangeable. QuickLOAD then predicts that 43gr of IMR4350 would give very close to 2600 ft/sec with the 142gr bullet from a 22.5" barrel, peak pressure 49k6 PSI. Not that we think you are interested in IMR4350, but it does seem that the velocity given by Nosler is significantly high, at least for your barrel length. According to QucikLOAD a 27" barrel length is required to deliver their velocity figures.

Looking instead back at AR2209 and the 142gr; 45gr is predicted to result in 2660 ft/sec for 50.5kPSI peak, 46gr gives 2720 ft/sec for 54kPSI peak, and 47gr gives 2770 ft/sec for 57k8PSI peak, which is above the max spec for the case. And if the 2209 behaves more in line with current H4350 then the burn rate will be faster and for 47gr the pressure could be up around 65kPSI peak giving over 2800 ft/sec which is where significant web expansion is going to start to kick in, so just be cautious with other batches. With that powder anything over 2700 ft/sec is starting to get hot! If you can get what you want to get done at 45gr of 2209 then you should be good. Proceed with all the usual cautions, usual disclaimers etc etc...