340 shooting 295 at 70lb. with 29 inch draw and 390 grain arrow. Seems slow to me. Any suggestions on what to check or is that speed about right?

That is probably about right. My draw length is 28" and I can't get anywhere close to my bow's listed speed either. But every deer I've shot with it didn't know that. And they ended up just as dead. If your concerned, talk to the bow manufacturer and see what they say.

Thanks. And you're right, don't much matter to deer how fast that arrow was that got them.

I think this is why most bow companies give you an IBO speed range now. My Slayer was rated at 350 f.p.s. but at 72 lbs, 31" draw and 380 grain arrow, I can get best speed of 312 f.p.s. I know arrow is 30 grns over IBO but I am pulling 1" longer draw which should be a slight off set. Also 2 extra lbs of weight.

IBO speeds are a joke these days...

Bowsniper is right. Listed IBO is a joke. The bow companies use every trick in the book to get them as high as they can. You will never actually be able to even get close. Expect 40 to 50 fps lower at best. I wish they would be a little more practical (and honest) in thier testing. I also wish they would test and list IBO for 50 and 60 lbs.

My D340 shoots the same speed at 28" (just under 28.25" actual length) draw and 62# with a 365 grain arrow. These bows will shoot very near their IBO rating...You just need to take the time and energy to get them in spec, timed, and synced properly.

Glen

How do you change the ata on a destroyer?Twist strings, cables, or both? My ata is 33 and should be 32 3/8.