I purchased two Speedlock Hammers (because the 1st one worked so well) which is also a drop in part for $29.95 at www.Hawktecharms.com
(also one of our sponsers).
I have been very pleased with it & my friends like it so much they are buying one too. I've have been tring to get a comparason on this forum between the Volquartsen & Speedlock hammers but no one has done it yet. I've have read on the forum that the Volquartsen hammer has gritty, jumpy, unpredictable pre-travel. This can be resolved by the JB Weld trick & the pen spring trick.
I have not shot a Volquartsen hammer. There is losts of praise of the Volquartsen hammer, but it seems you have to do other things to make it sweet.
I have not noticed any gritty or pre-travel with the speedlock.
Another plug, the speedlock was developed by 8-Time National High Power Champion, David Tubb.