What issues could cause arm slap. Got a new curve and even at an 8" brace its tearing up my arm. It's got a medium/ high grip, and I shoot 3 under if that has any meaning. Also of note is when bare shafting, the arrows that oughta be correct spine are kicking hard left and going right showing weak. It's worse the harder I catch my arm.  I think its torque on the string but any ideas guys? I've had this before and had to work my way out of it over time by varying my grip and just basically learning to shoot the new bow.

Dave

I used to have the same problem. Try holding the grip on the meaty part of your thumb pad, then rotate your bow arm elbow to 9 O'clock (right hand shooter). I began doing this and can now shoot without an arm guard.

Try opening up your stance a bit if you're very perpendicular to the target.  It helps.

Also keep a slight bend in the bow arm elbow and keep your bow arm steady.

going to need pics or video to help with correction.  Sounds like your getting your arm in the way from a hand position problem but without pics we are just guessing.

Mike

You mentioned your arrow acting weak.Try a stiffer spined arrow.My experience has been a  too weak spined arrow will cause string slap to the arm.

Archeryprof... I was hoping you'd say that as I was only using Velcro for a strike plate and even my fletched shafts are hitting right of normal. The bow is cut 1/8" past center and pretty snappy.

I am gonna build out my plate a bit and see if that helps tonight. I tried my shafts with 225gr up front full length and cut them down 1/4" at a time only to get way shorter than I wanted and yes the arrow marched left on target but not far enuff when cut all the way down. So I started with a stiffer spine same point weight and did same. The bow is at 60lb at my 29" draw and it showed weak as well. Cut it down to see improvement but not enough to hit with fletched shafts. I shot quite a bit bare and fletched and just didnt wanna cut that much off the arrow as I'm a instincta gap shooter.

String materials can cause arm slap on some bows (particulary dacron), too much weight on the string can be one cause also, nock too tight,string torque,bow torque,bad form etc...

Sounds like you are on the right track.If you can find an arrow that you feel certain is more than sufficient spine for the bow try it and see if that solves the problem .Either way you can eliminate that from the equation.I have found that some bows due to their design or performance might require a different arrow spine than one of similar weight.I am a solid believer in bare shafting as well and I also shoot 3under.I also tie a nockset below the arrow nock to insure the arrow does not slide down upon release which can create all sorts of tuning issues.

Arm slap for me is always a bow arm/bow hand issue. Too extended, and/or wrong grip; bending my wrist out. I'm sure all suggestions so far are valid also.