Neck Tension & Group

[Shynloco]

I have read about the size difference here that Redding is undersized from what is stamped. There was another company mentioned that has steel bushings only. I got a few for my .223. I don't have the equipment to actually measure the bushings but the new ones have a slightly easier pull on the ram when sizing.

I think what really matters is what do the necks on your brass measure once your resize them plus the actual size of your chamber (whether tight or loose).

Alex

 

[Coolhand]

I take it that this is a 220 Swift AI.(?)
My curiousity is how you selected R17 as your candidate for powder? Strictly by QL or did you try other powders before settling on this one?

I've been casually (low priority) trying to get R17 to work in my Swift with 50, 52, and 55gr bullets off and on for 3 years and what I encounter is just about what you are seeing in the way of groups. Blinding speed, but unstable groups at this point. WD

Wyle , unlike the US we don't get the broad selection of powders you blokes do. Alliant supplies are sporadic and when it is available we tend to stock up big time. VV is no more apparently the importer can't find a shipper that will transport it down here. Winchester is available but I never play with it as it is a third more expensive compared to the ADI offerings. I use ADI in my .260 REM , I chose RL17 for the .220AI to begin with as I got a bucket load of it CHEAP !

I have recently got the 52 Grain Bergers FB HP Varm to shoot .5" groups the load was 46.4 grains of RL17 PMC Russian Primers, Norma Cases, bullets seated to mag length.
The first load was 46.2 grains of RL17 group was strung horizontal and measured 1-1/16" an increase of 0.2 of a grain really tightened up the group. I will freely admit my bench technique is agricultural and have just installed a Calvin Elite trigger which I think will help my ham fist trigger release.
I have also tested 50 & 55 grain Sierra Blitzkings which show real potential which prompted me to start this thread. I think both of the Sierras will shoot really well in my rifle once I find that combination of neck tension and seat depth which is limited to mag length of course. Plus a change of primer might be worth a try to.

BTW , the Magnetospeed told me the 52 gr Bergers were doing on average 4035 fps from a 26" Krieger 1:14 Rem Varm Profile barrel. And yesterday I bought a Pac -Nor Super Match 1:12 #5 profile for me light walk around .220AI. I hope to shoot the 53 gr Vmaxs for it and am told that they can be finicky with seat depth.

regards
Mike.