OK. I will try to explain a way to find out what is best for "that" handgun.
There are 2 ways to figure out "that" handguns Max. OAL & then you can reduce from there down to the SAAMI OAL, or the manuals listed shortest OAL... if you can find it.
Remember, if you go "Longer" than suggested OAL, you will be "Reducing" pressure, since you are leaving "more" space inside the case. As you reduce the space inside the case by seating the boolit deeper & making the OAL shorter, you will be adding pressure since you are reducing the space that will be in the case as the boolit goes in further.
What you want to do is find out the MAX OAL that "that" particular handgun will allow & then use that info to work your way down to where you want it to be, as long as you do not go shorter than manual/SAAMI OAL.
There are a couple of ways to do this & I am going to use 2 of our members here descriptions on methods as they explain it better than me to type it out.
Once you have figured out what the MAX OAL is for THAT particular handgun( every firearm can be different), then you can use that info to determine what OAL you want to use, as long as you do not go Shorter than safe manual/SAAMI specs...
Before I go further, you should look at the below illustration. It is a chart that shows how to look at the "hood" of a bbl. to do a plunk test, if you were not already aware of how to do it. ( I don't remember who knows & who doesn't know what a "plunk test" is, when I try to pass on this info... So everyone will usually get it). It is for a 45ACP, but the principle is about the same for a 9MM & other semi auto handguns about where to set the "rim" of the round as you try to determine OAL. You will have to figure out what is the right place for YOUR handgun , but this helps describe what to look for... A factory round will aid in ID-ing the place to look on the barrel if necessary... Third example from the Left is what you would like to see. :
Here are the 2 methods copied/pasted from the 2 members , Kenstone, & Dusty Bannister:
From Kenstone:
Dusty Bannister & the "Dowel Method"( Cleaning Rod method):Simple way to determine max OAL
OAL
Find a fired case that the bullet just slips into with some resistance.
With the bullet barely into the case push them into the barrel with the shortest throat. You'll feel the bullet hitting the rifling, continue to push until you feel the case hit the chamber shoulder.
Carefully remove the case/bullet assembly, pinch the case/bullet juncture between you thumb/index finger, and measure the OAL with a caliper.
That measurement is the max OAL for that bullet in that barrel.
Source:http://castboolits.gunloads.com/show...=1#post4573543
Now, after you have used one or the other methods to check "YOUR", or "THAT" handgun for Max. OAL, then you can go from there to determine the next step.Cleaning rod/dowel method of finding cartridge OAL
This is what I use for my guns to determine the max OAL and this eliminates any question of the crimp, incorrect case prep, or other operator induced error.
This method works well on rifles and single shot pistols as well as Semi-autos. You can use a flat tipped cleaning rod, or flat tipped dowel rod. You will also need a sharp pointed pencil, a short dowel and a bullet sized but clean, of the type you are going to load.
For Rifles
Make sure the chamber is empty. Close the bolt, and be sure the firing pin is retracted into the bolt. Insert the dowel or cleaning rod and hold it against the face of the bolt. Mark the rod at the face of the muzzle. Remove rod, open bolt and remove it from the action. Insert the bullet into the breech and hold it snug into the rifling. While in that position insert the dowel or rod again, and with it firm against the nose of the bullet, mark the rod at the face of the muzzle.
The distance between the center of those two marks is the max cartridge OAL for that rifle, with that bullet sized to that diameter.
For Semi-autos
Remove the barrel from the slide and make sure it is clean and free of leading or other debris in the barrel and chamber. The dowel or cleaning rod needs to be longer than the barrel. Hold the barrel, muzzle up, and place the barrel hood on a flat surface like a table top. Insert the dowel or rod from the muzzle and mark the rod exactly flush with the muzzle. Remove the rod and insert the bullet you intend to use into the chamber and lightly press and hold it in place with the short dowel. Place the assy muzzle up on the flat surface. Insert the rod/dowel into the muzzle so it rests on the nose of the bullet and again mark the rod exactly flush with the muzzle. Remove and set the barrel aside. The distance on the center of the two lines is the cartridge OAL. Seat a dummy round to this length, or slightly shorter and begin to apply the taper crimp until the dummy passes the plunk test. This is the optimum cartridge OAL length for this bullet in this gun.
You may need to adjust the seating die to shorten the OAL if this does not feed from the magazine, but generally this will be a great fit. Remember, if you seat and crimp in one step, you might force a slight ridge ahead of the case mouth and that will screw up your seating.
Dusty
Source: http://castboolits.gunloads.com/show...=1#post3560663
Before you continue though, make up a "Dummy Test Round", using the Max. OAL but do not taper or roll crimp the projectile so you can adjust it shorter if necessary. You want a dummy round that you can adjust to do the following, but not too loose so it can stay in position, but at the same time not so tight that you have issues with seating it a bit deeper to find the necessary OAL for that firearm.
Next....
What, OAL is the Max. that "FEEDS" from your magazine into the chamber of "that" handgun.
You will likely have to work out in small increments , shorter & shorter, to find the Max. OAL that feeds , that fit "under" the Max. OAL for the chamber.
Once you have done that, it is time to do a "Cycle Test". Put the dummy round into the magazine, then put the magazine into the firearm, then draw back the slide to "cycle the round" into the chamber" then "Cycle the slide back as if you fired the round & see if it ejects. <<< a "Cycle Test". ( You can pull the trigger on a dummy round without issue, but it is not necessary to do the test most of the time.)
Once you have done the above, you should have found a "range" of OALs that will work for THAT firearm, & can then decide just where you want to set the OAL for THAT firearm.
If you still have room to shorten the OAL of that round to what a manual/SAAMI specs allow, then that is fine as well. You may have even more range than what you found by the Max.OAL for the chamber, as well as the Max. OAL allowed for the magazine to feed & cycle.
Just remember not to go less OAL than those suggested specs in the manual/SAAMI..
I am going to stop there as I may be overwhelming you & to be honest, I am tired of typing...
LOL
Just trying to help & it will not surprise me if someone else, like Kenstone & Dusty Bannister have done, & come in & describe what I typed in a better way to understand...
I hope what I just tried to do helps...
G'Luck!