After struggling for most of this year with “vice grip” “gorrilla Grip”, which severely restricts my practice time, I stuck a bit of ‘blue tack’ (the sticky re-usable putty stuff for sticking things to walls etc. to my right thumb.
It came off on the chanter squashed flat like a postage stamp.
BUT
after resetting it a couple of times my hand has learned to relax its grip.
I can now practice for more than an hour without ‘vice grip’.
My ears are ringing now.
There’s always something.
Try some blu-tac 
Another tip I received once for curing deathgrip is to take a plastic drinking straw and practise on that as if it were the chanter. If you’re crushing the straw you’re pressing too tight.
Its all about getting the right feel, and then practising that until it becomes a physical habit. Nothing but time and constant repetition can do that for you.
djm
Sometimes an overly stiff reed can aggravate this problem. Learn how to diagnose and correct it for the conditions in which you are playing. I see a lot of beginners struggle unnecessarily with a reed that is too hard blowing but they are petrified of screwing it up. I fear that, for some of us, it may be necessary to ruin a couple of good reeds before we learn how much is too much.
For instance, if you are playing today and it is quite a bit more humid and rainy than yesterday, it’s possible for your reed to have opened up a bit, making it harder to blow. Closing it down SLIGHTLY helps. I just squeeze the blades together GENTLY with my fingers, pliers are not necessary. YMMV, All Sales Final, Tickets Non-Refundable, We Are Not Responsible For Lost Or Stolen Articles, Certain Restrictions May Apply, etc so be careful. If you overdo it you can wind up with the opposite problem - reed is too closed, back d will go flat and your first octave will be too quiet and weak, so then you’ve got to open it up again. Normally you can do this by squeezing the sides of the reed with your fingers; pliers should not be necessary in all but the most extreme conditions.
So learn do this only until the reed is comfortable to play and then leave it there.
And it’s best to figure this out while there’s still some humidity in the air - dryness increases your risks of cracking the reed.
Be sure you whole kit is airtight, too - bellows, bellows valve, blowpipe valve, blowpipe tenon, chanter top tenon, chanter top cap (if it’s removable), chanter tenon, mainstock tenon, all drone joints and tenons, all regulator tenons, key pads, and end caps…gets to be a lot of work with a full set, and something is usually leaking. Murphy of Murphy’s Law fame must have been a piper.
I tend to have this same problem. When I put down the chanter one can definitely see the chanter indention on my thumb of my bottom-hand (right hand). I am trying to make myself consciously use a lighter grip with my bottom hand.
It’s possible to play (on the knee, at least) without your thumb even touching the back of the chanter. Try it that way for awhile…
Bill
At this year’s edition of the Pipers’ Gathering, Anthony Santoro suggested this same technique, to practice with the chanter on the knee, without using your thumbs at all. Tape over the back D and go for it…
Bill stated:
It’s possible to play (on the knee, at least) without your thumb even touching the back of the chanter. Try it that way for awhile…
Jamie stated:
At this year’s edition of the Pipers’ Gathering, Anthony Santoro suggested this same technique, to practice with the chanter on the knee, without using your thumbs at all. Tape over the back D and go for it…
Great suggestions, but I have a question which is more likely just common sense. I take it that if you use this technigue and then need to lift the chanter off the knee for (D) that your only lifting with your left hand.
Thanx for the suggestions and advice guys.
It is much appreciated.
I will try the reed compression trick. I am working with six home made reeds at present on home rolled staples, I made six so that I could afford to lose a couple without trauma.
they all play after a fashion.
Try placing a wine bottle cork between the bottom hand thumb and chanter. You’ll soon lighten your grip or roll the cork off the chanter!
Rick