drilling quartz monzonite?

Advice on how to drill it and install what kind of bolts?

Found a small crag couple of years ago looked like interesting climbing, so today I installed some two-bolt anchors that I could use with partners to explore different routes (at first on Top-Rope) -- see what if anything might be worth climbing again, or even bolting for Lead.
It was easy access, so if what I did was totally wrong, I can go back sometime soon and re-do it better.
. . . (but first I'd like to know the correct "better").

I've heard that the classic American quartz monzonite climbing area is Joshua Tree. But I've only climbed there a couple of days years ago, surely never tried to place a bolt there. So that didn't help me.

Last couple of days I first asked around what kind of bolts to use, and got a range of advice
from . . .
* whatever works for you in granite should be fine, like 3/8-inch wedge bolts, maybe even shorties.
to . . .
* "some of that quartz monzonite is junk", so maybe try 1/2-inch, or even glue-ins.

. . . (unfortunately my 1/2 inch Stainless sleeve bolts are five hours away, because I bought them for sandstone).

Out there today . . .
First I tried 2.75 x .375 inch Stainless wedge bolts, because they've worked for me in good granite.
Well . . . before touching a bolt, I noticed that the quartz monzonite _drilled_ noticeably easier than good granite or good quartzite. Next I found I did not need to tap in my shortie wedge bolt. And then it just spun in the hole.

So I went back down to my vehicle and got some 2.75 x .375 inch sleeve bolts - (unfortunately my 4 x .375 inch sleeve bolts are currently five hours away, ready + waiting for sandstone).

Next I found that shortie sleeve bolts worked better than shortie wedge bolts (at least they stuck in the hole firmly).

So next I tried longer wedge bolts: like  4 x .375 inch double-wedge.
And those worked better than shorty single-wedge. But usually it took a lot of turning of the nut to get the bolt stud to tighten, and then the stud was sticking way up out (like my experience of once trying wedge bolts in sandstone).

I decided that my strategy for "redundancy" would be . . .
one shortie sleeve bolt plus one longer double-wedge for each two-bolt anchor.

. . . (Even so, one time one of the sleeve bolts just spun in its hole. I could get it partway out with my fingers, then the handle of my wrench, then got out my small crowbar, managed to extract the hole thing. Drilled a new hole, and next time that same bolt worked just fine).

Flat placement for the hanger? Quartz monzonite rock surface is very coarse-grained. So I just pounded on it with my hammer to get it vaguely flat before drilling (sometimes improved it a bit after drilling).
Is there a better way?

so . . .
* What should I do for future anchors (or intermediate leading bolts) on the sectors of this crag that I have not touched yet?
. . . ? more precise drilling ? different hardware ?

* How much and how soon should I worry about what I installed today? Replace in five years? one year? immediately?

Thanks for your help,

Ken

Are you using a brand new bit? Your holes may get slightly smaller as your bit wears down making for a tighter fit and quicker engagement. I don't think anyone could be a good judge of the rock quality of your rock without more information. Glue-ins would probably be a better and more sustainable solution in the long run if you have experience placing them.

Good I'll keep using the same drill bit for a while -- until it gets difficult to tap in the bolt studs.

. . . (just have to remember to switch in a fresh bit when I get back to good granite).

Ken

Seemed like the drill bit wear down helped. By the end of today, "tapping" in the shorty sleeve bolt was more like driving a peg into the rock. Pretty strong hammering needed. Then almost no need to turn the bolt head with my wrench.

Ken