9x21?

1a. I am looking to load to the long end of OAL to help keep some The 9x21 is supposed to be loaded to the same OAL as the 9mm (1.161 I believe). Can I seat the bullet out a little farther and take advantage of the extra case length? If so, how long can I load and still get the rounds to feed through the Glock mags?

I would say load as long as you can get to feed in the glock mags with the bullet you choose. this will help with the excessive pressures.


1b. Can/should I ask my barrel maker (KKM or Barsto)to do any special reaming of the throat(leade)area?

It can be done, I had this done a long time ago on a colt 9mm I used to make major with 162 lrn bullets...this allowed the bullet to chamber without touching the rifling.

2. Any barrel length suggestions?

As long as you as you can get..This will help keep you velocities up without having to put more powder in the case.

3. Any suggestions on the compensator?
Sorry, I don't..no experience trying to make a glock race.
I have tried these on a 1911 based gun.
-hybi-comp with 3, 4 or 5 chamber comp
-same with aluminum comp
-4 chamber with chambers cut a 10degree reverse angle
-2 chamber
-3 chamber

They all work to point..but the extra weight effects the cycling of the gun as well as the handling. The unfortunate ting about playing with comps is it is expensive lessons to learn. What I found is as long as you make the dot do the same thing everytime and it is predictable and it can shoot to your ability and timing.It is a good comp. In addition to how the comp works is the springweight, number of buffers you use, powder and bullets choice and overall weight of gun.

Sorry, this isn't that easy..I use to lose a lot of sleep over all this...fortunately I had a good gunsmith/friend that always had time for me and my ideas...

Good luck on your project...