mickb wrote:Just adding this to my old thread rather than start a new one.
On ADI online I see a load for about 19 grains of 2207 with a 55 grain SP, 2850fps and pressure only 35K...
Was thinking this reduced load makes pretty good economy for sending the roo bullets out, probably bit lower blast too running 20kpsi lower than max. I dont need max velocities or ranges(200m most often). Worth trying some loads with it you reckon fellas?
Main questions would be
1. Will this bullet still expand in the low 2000's if its down to those speeds.
2. Any other reduced loads anyone can recommend? Not after pistol powder loads( blue dot, trail boss etc, the stuff is now too precious to waste in a rifle ha ha) but any rifle powder reduced loads would be interested. Possible to get any bullets closer to 22 hornet level?
Generally I've found most jacketed small game bullets specify around 1600fps minimum terminal velocity. I would stay above about 2000fps muzzle velocity if I want the bullet to deform out to about 100m. Adjust the load for accuracy so you can place it where it needs to be - the head. They won't blow a rabbit to pieces like a 3900fps 35gn bullet but they will definitely kill it. If you're using them in a tighter-twist barrel they'll deform more readily due to the much higher rpm.
I shoot the 55gn SGK (SuperRoo) at 3300fps in 8"-twist. By 250m it's down around 2000fps, and I'm confident it would be effective out there. By 300m it's down around 1750fps, and I would still consider it effective. Launched at 2000fps, it's down to 1750fps by about 50m, and 1600fps by about 100m.
I had a look at the Code of Practice for 'Roos and can't find any mention of velocity, but you can't use subsonic ammo. With no further information you could launch at 1125fps and it will be subsonic by about 3m from the muzzle. Only .22LR and WMR specify requiring an expanding bullet.
Yes, use AR2206H and you can go down to low subsonic if you want. I'm saving my Trailboss until I've switched all my reduced loads over to AR2206H, just in case TB never gets produced again.