Well, my contacts are curved now slightly by my 10" wheel which is what I use to make the 7 to 8 degree pitch contact. I don't wish to increase the % of the pitch angle more than it is now. I see a lot of knives for repairs and in the ones I've seen with sharper pitch angles and sharper curvature to the contact it does stop the lock from moving in as far as it wants to but there is a draw back to that and the draw back is the lock slides back toward release on the contact with spine pressure on the blade and it slides back to a flatter area.
This is blade play basically without the click but its also an indication to me that if the lock slides toward release under load due to that kind of contact being made that the lock may jump off the contact on the blade completely with some sudden shock and a little momentum behind it which could really hurt someone's fingers. I'm not going to get into companies or makers names but when I see a knife done that way just to keep the lock from self correcting naturally with wear to prevent the owner of said knife from mailing it in for a repair it really makes me wonder if they need their heads examined! I mean what is more important? Keeping the lock up solid and reliable all the way across no matter how fast it wears, or trying to cheat a little more time at the cost of reliability and safety? Thats my feelings about this anyway.
I know what you are asking me and I see them all the time done this way. Some come here solid, some not so much but generally speaking the knives I get mailed to me with contact pitch angles greater than 10 degrees are the ones that have the most likely chance of defeating under shock or steady pressure. I could make the contact 10 degrees but thats the steepest angle you'll get from this maker.
As for blades. The only blades I have ready to use right now are the 12C27 blades at 60 Rockwell. The only exception will be the D2 which will be at between 61-62 Rockwell. Its going to be a while before I have any other blades including the D2 done. I have too much going on to mess with them.
The ball wears flat on some no matter the spring tension. I've seen thin liner locks with flattened balls. The blade and ball are the same hardness so they should wear pretty well together. I've not had to replace one for that at this point.
Thanks for asking
STR