RA-Tech Steel Mk23

[RacingManiac]

http://en.ratech.com.tw/product/html...ork_ksc007.php

Not quite Inokatsu 1911 price, but I am pretty sure this shoots better....

This is after their many Glock and USP releases. Not a fan of their Glock slide as the engraving looks a bit goofy, but their H&K stuff seems more accurate to the real gun...

[ILLusion]

I've shot a few RA-Tech upgraded steel pieces, and they generally shoot like crap (very sluggish compared to what I'd consider to be "optimal").

I can't see this shooting better than the Inokatsu 1911, considering the Ino 1911 has a propellent source that has a psi that is 5 times more powerful to move a slide that's just as heavy.

[RacingManiac]

I dunno....this looks pretty good...

KSC MK23 with RA Steel Slide 7 Barrel - YouTube

Original thread posted:
http://www.arms-cool.net/forum/thread-106283-1-1.html

12kg Propane, the same stuff we have here, the OP has done some polishing to the slide rail and frame rail. And he changed around the recoil springs....

[ILLusion]

That does look pretty good

[Coresair]

However, there is a significant drop in FPS when fitted with the steel slide, as sown in their own video : RA-TECH KSC MK23 STEEL SLIDE & WE AK74U WOOD KIT - YouTube.

I know you don't need massive amounts of FPS on a pistol, but going from 350ish to sub 290 sure is a lot. In 3 shots : 274, 285 and 264. 20 fps in variation.

The kick on it looks insane though.

[Pinard]

Originally Posted by Coresair

However, there is a significant drop in FPS when fitted with the steel slide, as sown in their own video : RA-TECH KSC MK23 STEEL SLIDE & WE AK74U WOOD KIT - YouTube.

I know you don't need massive amounts of FPS on a pistol, but going from 350ish to sub 290 sure is a lot. In 3 shots : 274, 285 and 264. 20 fps in variation.

The kick on it looks insane though.

they don't show the difference between the steel slide and aluminium slide... they show the difference between green gas and red gas

[Coresair]

Originally Posted by Pinard

they don't show the difference between the steel slide and aluminium slide... they show the difference between green gas and red gas

I know this, I'm not comparing those. I'm comparing with the factory data provided by KWA. And even there, I'm being conservative since they clock it @ 360-380 (which sounds a bit farfetched)

http://kwausa.com/products/gbb/hk-mk23-ussocom/

[Steven]

Originally Posted by Coresair

However, there is a significant drop in FPS when fitted with the steel slide, as sown in their own video : RA-TECH KSC MK23 STEEL SLIDE & WE AK74U WOOD KIT - YouTube.

I know you don't need massive amounts of FPS on a pistol, but going from 350ish to sub 290 sure is a lot. In 3 shots : 274, 285 and 264. 20 fps in variation.

The kick on it looks insane though.

That just me, or does the slide seem to move VERY slow? Seems like you could pull the trigger again before the slide was even half cycled.

[Coresair]

Originally Posted by Steven

That just me, or does the slide seem to move VERY slow? Seems like you could pull the trigger again before the slide was even half cycled.

of course it does, if you watch closely, the steel slide weights almost twice the original one.

That's why it's "advised" to upgrade to high-flow valves for magazines.

[RacingManiac]

Arms-Cool post in Chinese(along with the first Youtube video), also mentioned that while RA-Tech provides the "150%" spring for the recoil spring, its still not strong enough for the heavy slide. So the OP in that thread found a combination of springs available to him that upped the rate more. The RA-Tech's own vid you can kinda see the the sluggish nature of it...

Also RA-Tech's vid doesn't exactly state the the BBs used or the the temperature....in Taiwan they don't exactly use central heating in winter, it can be 15-20 C indoor...

Heavy slide should not affect outright FPS of the gun, but it may well affect shot to shot power as the gas reservoir size is limited(MK23 though does have a big mag), and heavier slide takes more gas to cycle(after the BB has been expelled), which will have more cool down, and more % variance in reservoir pressure....

[Coresair]

Originally Posted by RacingManiac

Arms-Cool post in Chinese(along with the first Youtube video), also mentioned that while RA-Tech provides the "150%" spring for the recoil spring, its still not strong enough for the heavy slide. So the OP in that thread found a combination of springs available to him that upped the rate more. The RA-Tech's own vid you can kinda see the the sluggish nature of it...

Also RA-Tech's vid doesn't exactly state the the BBs used or the the temperature....in Taiwan they don't exactly use central heating in winter, it can be 15-20 C indoor...

Heavy slide should not affect outright FPS of the gun, but it may well affect shot to shot power as the gas reservoir size is limited(MK23 though does have a big mag), and heavier slide takes more gas to cycle(after the BB has been expelled), which will have more cool down, and more % variance in reservoir pressure....

you mean in terms ok make or weight? because they do state they are using .20s.

[RacingManiac]

Didn't hear the weight, rewatched it and heard he said .2 bb....

[Adamlxlx]

I have a KWA mk23 and saw these steel upgrades. I may go with the barrel but will stick with the stock slide for now. Gas consumtion on these things is pretty damn good. You can rapid fire the whole mag no problem.

[kullwarrior]

Originally Posted by RacingManiac

Arms-Cool post in Chinese(along with the first Youtube video), also mentioned that while RA-Tech provides the "150%" spring for the recoil spring, its still not strong enough for the heavy slide. So the OP in that thread found a combination of springs available to him that upped the rate more. The RA-Tech's own vid you can kinda see the the sluggish nature of it...

Also RA-Tech's vid doesn't exactly state the the BBs used or the the temperature....in Taiwan they don't exactly use central heating in winter, it can be 15-20 C indoor...

Heavy slide should not affect outright FPS of the gun, but it may well affect shot to shot power as the gas reservoir size is limited(MK23 though does have a big mag), and heavier slide takes more gas to cycle(after the BB has been expelled), which will have more cool down, and more % variance in reservoir pressure....

I have a KSC USP match with steel slide. Let me go through it.

at 15C it will cycle and lock back if magazine only have 15-20 (cool down issue)

at 20C or higher it will cycle and lock back with a 25 rounder magazine easily

HFC134a will not work to cycle the gun

The USP match video shown is using stock recoil spring AFAIK

Using Stock spring...
-Cycling is sluggish when shooting parallel to the ground
-Cycling/racking can have a failure to return to battery if its perpendicular to the ground

Using Shooter Design 150% recoil spring and buffer spring...
-Cycling is not as crisp as stock slide, but ROF is the same between the two slide (stock slide & spring vs upgrade slide & spring)
-Cycling/racking is pretty sluggish if its use perpendicular to the ground

Using H&K USP 9mm/40S&W recoil spring with stock buffer spring...
-racking is extremely crisp...big surprise
-spring is so tense it does NOT chamber the next round when cycling
-cutting off 6 coils (a coil is define by having the spring complete 360 degree rotation) will give you a recoil spring that can has a crisp cycling much like stock H&K USP 9mm/40S&W spring but it can chamber the next round. However, it does NOT lock-back and it is possible to have the gun 1-2mm out of battery if you point the barrel perpendicular to the ground facing the sky.
---> USP .45 spring probably is more tense since the slide is heavier, that is why I chose USP 9mm spring

In short,
RA-Tech steel slide
Stock spring is not enough
150% spring will give you back about 80% of the stock crisp cycling
H&K USP 9mm/40S&W is too much even if you cut down the coil to the bare minimum

PS: I HATE YOU KSC! KSC's USP .45 IS NOT base on USP .45 the frame, magazine dimension are base of USP 9mm/40S&W. This is ID through USP .45 base plate being wider than KSC's USP .45.