I have steel broadhead adapters in 100 and 75 grains, 11/32" from several suppliers, they don't seat all of the way into the Grizzly ferrule, ( I assume the Grizzly is 21/64'). There is always about one "thread" on the adapter not seated fully into the broadhead.
I have tried 5/16" and they seem a little to small.
I have found a way to make the 11/32s work by chucking them into a drill press, and while they are spinning, I use a 12" wood ruler wrapped in course emory cloth and hold it against the adapter, mantaining the correct degree of taper.
It works but is time consuming and tedius.
Anyone know of a better way to get them to fit, or a supplier of steel adapters that will fit a Grizzly?
Thanks,
John
PDP used to make a 21/64 aluminum adapter but they were pretty soft. Not sure if they're still available or not but they did fit the Grizzly to a tee. They were available through Martin accessories dealers.
You are right the Grizzly, while advertised 11/32" is more like 21/64". The 11/32" don't seat quite as deep on them but there is no need IMO to mess with them (I never have) they work just fine as they are.
Grizzlies are not the only trad head that varies slightly off 11/32", but it's really not a problem for any of them as long as they are reasonably close.