ive used mechanicals for many years and have had great luck with them..vortex 2 blade 2" cut 100grain is my number 1 choice they have never failed me..

I'm very big into seeing how things work, I'd probably even take one apart to see how it works and see about replacing blades.

I use Grim Reapers without question!!!!! 100grn RazorTip and I have been shooting them for 5-6 years now and have taken over 37 deer and hogs with them and am still shooting 7 of the original 12 I bought!!!!!! I have 3 on the mounts in the LR and 2 are in tree trunks on pass throughs!!!! I have watched over 90% of all the animals taken drop within sight and have never had one go over 100 yds.
I took a near World Record Catalina Ram then (was an 1-3/8ths short of the record) and have it on video. It went 41 yds from impact to drop!!!!! I have a 10pt at home that FD at 247 pounds that took a GR at 17yds that blew a vertabrae into 4 pieces, went 8 inches into the chest and only broke one blade!!!! I shot a Mathews Q2 at 63# with a BlackHawk Vapor 4000 arrow, weighing 425grn with BH and LumaNock at 280 fps.
Go to their website and see what they show. GrimReapers do not use a rubber band, take longer angle shots than any other expandable. Penetrated a new 55gal steel drum and was still operable aftewards, and then the plywood penetration tests. Nuff said!!!!!!!

I'm running an '01 PSE Nova, 29" draw, 70lbs. or so. arrows are gold tip hunter xt 5575, only because Gander Mtn. didn't have 7595.

Reposted for emphasis. ;) Even if you're shooting mechanicals, make sure your bow is tuned.