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Firearms and Gear => CZ Handguns => Topic started by: PappaWheelie on January 19, 2016, 03:33:31 PM

Title: RAMI BD Trigger Job -Temporary Tutorial Alert (now resolved- strikethrough text)
Post by: PappaWheelie on January 19, 2016, 03:33:31 PM
Hi all, I'm a CPL Newbie who just successfully completed a CGW Short Reset/Thick Trigger transformation of my already beloved RAMI BD. I now enjoy a silky smooth 6.5#DA/3.25#SA pull (was a bit uneven 9.4#DA/4.6#SA, and the stock trigger dug into my fingertip, which engages it at a bit of a downward angle).

The process was made very doable thanks to a very valuable Tutorial for Decocker link on CGW's website to which they direct you in the Short Reset Kit's literature sheet. However, I found two instances where, whether by typo or dyslexia or difference in platform (it was written for a CZ 75 SP-01), the information was exactly opposite of correct, and am posting this alert for the interim until the tutorial is corrected or replaced with more RAMI BD-specific directions because one, the first, risks frame damage.  Please let me know, anyone who observes the correction having been made to the tutorial, so I can delete the below, which is basically lifted from an email to CGW's David Milam.  Text in triple quotation marks was copied from the Tutorial.

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Starting midway through Point 6 of Post #26 "'The sear pin
must be driven out from right to left, and goes back in right to left. The sear pin itself has a flat end, and a slightly rounded end. When putting the cage back into the frame, the rounded end goes to the right, flat to the left.'"

The CZ 75 SP 01 pictured in this tutorial has a different left side of sear pin appearance than does my RAMI (fixing insert 63), so I can't speak with certainty about the 75, but from my "CPL newbie yesterday to expert today" experience with my RAMI, the above red-highlighted text is exactly backwards, and, if followed, risks frame damage if persisted upon.

Presumably you [i.e., David @ CGW] are in a position to communicate with the author if indeed this is correct; if so, it would be further helpful to refine the descriptions of the sear pin ends to something like "a slightly convex but substantially flat end" (the left, currently described as "'flat end"') and a "truly flat end having its OD locally rounded" (the right, currently described as "'slightly rounded end"'). The RAMI frame's sear pin hole chokes down its diameter on the right side to fit the locally rounded OD of the pin, thus preventing further rightward travel; following the above Tutorial directions means attempting to insert the unrounded OD of the sear pin's left end into this choked-smaller hole!

"'7. Going to show using a slave pin to drive out the sear cage pin, just use a punch instead if you so desire...again, push out from right to left!In this pic, I've already pushed the slave pin in, and you can see the sear pin coming out the right hand side."' The photo being referenced shows the slave pin ~flush with the right hand (=lower in the photo) "choked hole" side of the frame, and the sear pin coming out the left (=upper in the photo) side of the frame, exactly backwards from the above red-highlighted text.
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Now that you know, be encouraged about your own trigger job; YOU CAN DO THIS!

Supplementary info: the very light trigger pulls cited above are the result of 1.) polishing the broach marks out of my hammer's SA ratchet tooth face, 2.) the CGW Blue spring AND 3.) my ~1.5mm upward relocation of the spring-registering shoulder of the Main Spring Strut, which I did because I observed the Blue spring going coilbound at fully cocked, something I've learned you're not supposed to do to a spring generally.  I figure I can always restore part or all of the preload by a (1/8" copper tubing?) spacer collar above the spring without major disassembly if needed.  I'll shoot lots of my go-to personal defense ammo (Lehigh Defense 70g HERO https://youtu.be/JULgWoLJGmQ (https://youtu.be/JULgWoLJGmQ)  https://youtu.be/yrPZfBvPniQ (https://youtu.be/yrPZfBvPniQ) ) to be sure I haven't lightened up too much, of course!

My trek was started by firing pin sticking after practicing indoors with a laser bullet (they don't make the "primer" pads of stiff enough rubber); I've installed the CGW heat treated (spring pin) retaining pin but also ordered a pack of McMaster-Carr's half again stronger than standard heat treat Mil Spec spring pins, and will report later whether the former or the latter seem to hold up better under dry firing.  My stock retaining pin was the rolled-up style and my firing pin had eaten a notch halfway through it. I rounded the contact edge of my new CGW extended firing pin a tad before assembly to dull its "bite."97855A170 (http://www.mcmaster.com/nav/enter.asp?partnum=97855A170) Military Specification Slotted Spring Pin, Black Phosphate Steel, 1/8" Diameter, 3/4" L, MS16562-130, Packs of 25
Title: Re: RAMI BD Trigger Job -Temporary Tutorial Alert
Post by: PappaWheelie on January 20, 2016, 11:13:57 AM
Addendum;

I also polished (600 then 1500 then 2000 grit wet-or-dry sandpaper on flat surface) the broach marks of the sear's engagement "face" (which is radiused but not concentric to the sear pin bore), and used a spot of Anti-Seize in the trigger's SA notch at assembly to assure "high spots only" break-in.  I've since wondered if perhaps the Anti-Sieze might be playing a big role in the amazingly friction-free SA result.

Btw, the hammer's SA notch is acute, i.e., angled more sharply than 90 degrees, so the recommendation seen elsewhere of using a "stone," (assuming a square-edged one) to polish the sear-engaging notch face can't help but deform what is originally a planar surface, by necessarily cutting more at the notch's tip than at its root, thus creating an unstable-near-release convex (or else two-plane) notch face. A square stone corner just can't get to the base of the notch.

I used wet-or-dry folded about the cutting edge of a paring knife that I'd sharpened to have >2mm wide planar (flat) surfaces back from its cutting edge.  This knife/abrasive polishing "tool" is held parallel to the trigger pin bore and pretty much aiming at its center, as if to slice through to it (scope out the requisite "parallel to notch face" blade angle before adding the wet-or-dry).  This triangular support/wet-or-dry configuration, unlike a stone, enables switching to the finer grits as soon as the broach marks are nearly gone, minimizing the removal of case depth.

I didn't shorten the hammer tooth to change trigger stroke, or change its angle; it exhibits normal (albeit now enhanced by the polishing) "go back home" stability for the entire SA pull stroke, yet is so exceedingly silky smooth that the small (cocking direction) hammer displacement contributes seemingly nothing to SA-mode pull force.

I've enjoyed trying out a couple of different Czechmate 75 TS pistols in gun shops, btw; their trigger pulls are akin to the click of a computer mouse (only a tiny exaggeration) but IMHO the RAMI's stock tooth length and angle are "just right" for the real world if smoothed by polishing and lightened by CGW's Short Reset Kit's springs.

FYI I didn't order the McMaster-Carr Mil Spec pins blindly; the furnished-online drawing showed the same OD as the CGW spring pin's measured OD.  I installed the CGW pin with Anti-Sieze for assembly lube, Fwimbw.

In case you can't tell, I really like my RAMI BD!  Did a lot of studying before purchase, and no handgun I've handled since feels or shoots anywhere near as "right" as the RAMI BD with its extended (14+1) magazine and "safe" land for my right thumb between the slide release and decocker lever, as provided by its internal rails design architecture.  The "B" model (safety instead of decocker) doesn't have such a generous thumb land, nor the BD's TruDot Tritium night sights.
Title: Re: RAMI BD Trigger Job -Temporary Tutorial Alert
Post by: PappaWheelie on January 30, 2016, 10:53:06 PM
Firing Pin Retaining Pin Inspection Update:

After ~2 weeks of evening target practice with my 9mm laser bullet, and more than one instance of simply cranking off ~100 dry fires for the cause, I pulled the CGW retaining pin for inspection.  It was pristine, having shiny spot "discoloration" (from original black oxide finish) evident from the slightly rounded edge of the new CGW extended firing pin, but no (unmagnified) visual derangement of its "OD." Yay, CGW, problem solved: I may or may not ever even need the McMaster-Carr Mil Spec spring pins!  I'm certain the "cinnamon roll" type original retaining pin would have been locally deformed at least somewhat, and so well on its way to sticking, by this much dry firing.

On another positive note, my new CZ 97 BD is in the queue (on backorder) at an Authorized CZ dealer now: I've decided to do a "strictly stock" trigger job on it when it comes in, polishing its hammer SA notch face and sear engagement face only.  Sort of like "blueprinting" an engine?

I believe the CZ 97 BD is an under-recognized Flagship handgun: in addition to its known attributes ("soft" shooter, accurate, easily racked) and its stunningly handsome "flat" aluminum grips, its decocker lever (besides having more desirable functionality than a safety which can be forgotten under pressure) leaves room, because it extends rearward, for the shooters right thumb, safely away from the internal slide (as is also the case with the RAMI), and its
trigger reach is in a class by itself, suitable for those with large hands like myself, as is documented in this review http://www.realguns.com/articles/276.htm (http://www.realguns.com/articles/276.htm) -yet nobody stocks them!?!?!

David Milam of CGW has advised that the OEM "Thick" Trigger (as he sells them), now comes stock on CZ 97 B and BD.  What a gorgeous piece: the CZ-USA website image doesn't (currently) do it justice.  https://goo.gl/photos/jK1Dgqp44SgBredg7 (https://goo.gl/photos/jK1Dgqp44SgBredg7) (google photos link worth waiting for even if it takes a long time to load)

Btw, my Peachboy son sent me this video https://youtu.be/lcBu6q61G3M (https://youtu.be/lcBu6q61G3M) which evidences ~2 orders of magnitude EP capability advantage over the "comparables" tested: the test rig doesn't stall at ~10X the applied load, and the Weapon Shield specimen's load area is only ~1/10 that of the "comparables'" bearing area in doing so!  Wow: it's possible such EP lubricant potency could translate into increased muzzle velocity if established on the barrel ID.

"Homeboy" CZ 97 BD: Underwood Ammo's .45 ACP +P develops 592 ft.lbs muzzle energy from (a quieter?) 23,000 psi compared to the +P 9mm's 432 ft.lbs from (logically louder b/c 67% higher) 38,500 psi although both are supersonic. The Lehigh Defense .45 ACP Maximum Expansion may be better for home use, being subsonic, at least under some conditions...  http://handloads.com/misc/saami.htm (http://handloads.com/misc/saami.htm)  Pressures chart for reference.
Title: Re: RAMI BD Trigger Job -Temporary Tutorial Alert (now resolved- strikethrough text)
Post by: PappaWheelie on March 08, 2016, 12:30:07 PM
Not mentioned in above trigger job discussion: In preparation for my 1st "gunsmithing," I bought a set of Wiha metric punches. These are stunningly good, with sizes just under the nominal/labelled size and material essentially mirror-polished tool steel painted with chip-resistant enamel.  I had also gotten the CGW "D/c'er Install Kit with Slave Pin," which includes their "Forged Steel, made in the USA 1/16" Starter Punch."  Both were excellent values.

And shortly into the reassembly process I realized that I had roughly one hand too few, so built a frame-holding fixture comprising a magazine-section wood stick beveled on a ~45 degree angle, heat glued to an ~8"X 10"X 3/4" base board so as to hold the frame in easy-to-get-to laid over, horizontal barrel )orientation. I also found a couple of the dentist picks that I've gathered over the years helpful in manipulating the teeny little springs.  At some point I'll drill and screw the magazine-section stick's joint with the base board for long term robustness.

I love my RAMI! The P-01 looks sexier, but is thicker, heavier, and doesn't have Tritium Tru Dot night sights.

I have since also fine-tuned my rear sight to center my 30 yard pattern almost perfectly. The combination of the sneakily surprising silky trigger and the rear sight tweak has made a HUGE difference in my "lead on the target" success and confidence.  You don't flinch when you absolutely can't predict the release point.