I now have a KKM barrel - it's 4.55" in length. I shot (6) double tap 200gr. Montana gold rounds through it the other day to test it before I had the Wolff 21# spring set installed.
My initial sub sample of a test showed the barrel shoots with very good precision - accuracy with the d.t. loads were @ the same point of impact as my stock Glock barrel and it seems to load the D.T. cartridges without a hitch. I still have a lot to test though, since this lot of D.T. cartridges were loaded to a shorter COAL than I load mine to (1.24" vs. 1.26" respectively).
I installed the Wolff 21# springs and immediately I could tell a difference when putting the slide together and then racking it - definitely more resistance there. That's a good thing - because I think the slide was being pushed beyond the resistance of the stock spring using most loads I have shot out of this gun so far. The stock spring is made for sissy loads (as many of us have expected). I still haven't tested this rig with the new springs yet, but I expect it to perform superior to the stock setup.
As I stated earlier in this thread, I am going to attempt to get 200gr. XTPs flying at 1225 fps avg. muzzle velocity using 800x - and these will be "+p, +p+, or +p++" (that is if there was such a category) loads - much of these safely within the "nuclear" category. I have everything I need here right now except a chronometer, which I hope to borrow or rent from someone soon.
So far, I have loaded 50 rounds of 200 xtps using 800x; 10 each @ 7.4, 7.6, 7.8, 8,0, and 8.2. Today I will be loading at least 50 more; 10 each @ 8.4, 8.6, 8.8, 9,0, 9.2, and then 40 more; 10 each @ 9.4, 9.6, 9.8, and 10.0 grains. I am using CCI 350 magnum primers and new top brass (Scharch) cases.
Based on what I have read regarding others experiences, 10gr. is about as far as I want to push these bullets. - Of course, I won't know the results until I see how they work.
As some of you are aware, IMR's max load with XTPs and 800x powder is listed at 7.8 grains.
As some of you may expect, I am hand weighing the powder one cartridge at a time. (this takes a long time).
My plan is to record measurements of the following:
(7+ samples of each loading)
(7+ samples of each loading) - (@ 50' using OSU 50' slow fire pistol targets based on the NRA comp. targets)
Penetration and expansion
(3+ samples of each loading) using milk jugs as the medium (cheapest and I have been saving these up for a few years in large garbage sacks.)
I will be inspecting the cases and primers carefully after each relay before moving onto the next.
I will also be noting how far the brass flies on each relay. (using a giant tarp for this)
I will also be noting weight retention of the bullets.
The purpose of this experiment is to develop a maximum load for hunting big game with this compact, fully concealable pistol.
: It is my understanding that double tap rounds usually do not replicate the advertised velocity listed on the company's boxes. I have not tested them personally, but for sure different climatic and environmental conditions and different firearms are going to result in different numbers.