Unity Tactical Atom Slide for 4th Gen Glock 19

This is my Glock.  There are many like it...

Glock 19, ATOM Slide, Trijicon RM06 

This is a difficult review to write.  It's less of a review as much as a story.  My experience with the Unity Tactical Atom slide has been a two-sided affair.  Do you like 1911's?  Do you enjoy patiently fitting and troubleshooting parts?  Can you fit a 1911 barrel?  Do you have a steady hand with a file and access to a mill or machine shop?  I do.  That's why even though it has been the most frustrating thing I've ever put on my Glock, I'm glad for the experience.

My EDC is a Gen4 Glock 19 MOS.  The trigger is from Apex, the connector a Ghost 3.5 Evo.  A Glockmeister grip plug, Vickers mag release, and OEM extended slide release round out the new parts.  All springs are factory weight.  I swapped the factory craptastic sights with a raised set from Dawson Precision.  I mounted my Burris Fastfire 3 on the slide with the provided adapter plate.  One 350 round range trip confirmed 2 things.  Glocks are boringly reliable, and I'm really starting to like the red dot.  I knew I'd need a lot of practice to be able to find the dot as quickly as my irons out of the holster, but the increased hit probability at 25 yards and speed of follow up shots past 7 yards made me realize the red dot would stay.  I had doubts about the Burris unit surviving an upcoming Sage Dynamics Handgun course.  Would it survive 1000+ rounds, being used to rack the slide one-handed.  I also noticed the rear sight kept grabbing my attention away from the target.  I thought about sending my other G19 slide to Agency Arms ($$$!) or AETI, but knew I would'nt get it back before the class.  I knew of the Unity Atom slide, but they were sold out at every online retailer.  Then I happened to find one on Gunbroker and jumped on it.

ATOM w/ RM07 - Front sight completely blended with background

On paper it sounds perfect.  17-4 stainless, interchangeable optic plates, a la MOS, rear sight forward of the optic, front serrations, raised sights, and the same weight as a factory slide with an RMR mounted.  When I received the slide all was right in the world.  I wanted black, knowing that the FDE finish would wear as badly as my FNX 45 Tactical, but since I planned to use this at a Sage Dynamics Handgun course, I knew that no pistol would come though without a few battle scars.  Plus FDE was all they had left.  The sights were perfectly centered.  My factory barrel and slide internals all went in without a hitch.  I installed the slide on the frame and pulled the slide to the rear.  It stayed back. Locked open about 1/4 inch from fully to the rear, stuck in both directions.  The slide stop was not engaged in the notch.  The slide was simply stuck.  There was no movement in the barrel either.  Shit.

I banged on the rear of the slide and it shot forward.  I removed the slide inspecting the barrel lugs and locking block for debris or wear.  There was nothing out of the ordinary.  The top of the slide however had a pronounced wear line on the front of the hood.  The barrel was not dropping down far enough and as the slide retracted, it was wedging the barrel between it and the locking block.  I tried the slide on my other non-MOS Glock 19, also a Gen 4 and the slide hung up but didn't get stuck.  It was plenty loose on my G26.  I tried swapping barrels, and locking blocks with the same results.  So either the slide was out of spec, or Glocks tolerances are looser than an 1973 MG.

Wear on barrel hood from contact with slide

I called Unity Tactical and described the problem.  They said the slide might be out of spec and I could send it to them.  The problem was, I had already sold my MOS slide to buy the Atom, so my RMR would be out of commission for the Sage Dynamics course in 2 weeks.  There also wasn't enough time to have my other G19 slide sent out for milling.  I decided to put my experience with building 1911's to the test.  I broke out the calipers and took some measurements.  The top of the Atom slide was 0.012" thicker than the Glock slide.  I popped into work on the weekend and set the Atom in the jaws of our mill.  The mill is a 3000 lbs monster with computer controlled axis.  I programmed the mill to remove a pocket in the slide.  I didn't not want to touch the barrel lockup area and effect the vertical orientation of the barrel.  I set the depth to 0.015" and started the program.  When it was done I reinstalled the barrel and tested it.  The slide moved fully to the rear, but there was almost no wiggle in the barrel.  Normally, it rattles around when locked to the rear.  I mounted the slide again and took off another 0.010".  Success!  The barrel locked up as tightly as before, with as much factory wiggle as my other G19 when locked open.  While I was there, I mounted my frame and milled accelerator cuts for my support thumbs.  I had plans for the frame as well

Milled pocket for barrel clearance

At home I mounted the RMR to the Atom mounting plate without issue.  Then I tried to get the adapter plate on the slide.  It wouldn't fit.  Crap.  I removed the RMR and stuck the plate in the freezer for an hour but I still couldn't get it started on the slide.  No review or video I'd seen had this problem.  Once again my 1911 skills were called up.  I began filing the angled front and rear sections of the plate with a #2 swiss file.  I was careful to remove metal from both ends to keep the left side retaining screw hole centered. When the plate would barely start, I switched to a fine arkansas stone and finally a ceramic x-fine stone.  The plate slipped in smoothly needing just a light tap from a plastic hammer to seat.

Finally I could actually shoot the thing.  Dry-fire all evening revealed no problems.  Having the rear buis in front of the RMR really helped me stay focused on the target, and the black front no longer distracting me like the fiber optic had on the MOS slide.  The next morning, I lubed everything up with Slip EWL and packed up for the range, bringing a 350 round box of Blazer Brass.  I loaded up a mag and shot a 5 round group at a 6" Shoot-N-C target at 25'.  2 clicks left and one click down were all that was needed.  5 more rounds.  The irons were spot on.  Confident, I moved the target back to 25 yards.  One shot then click...  The slide was just slightly out of battery.  Probably need to break it in I thought.  I pulled the slide back to reset the trigger.  It sounded and felt like someone had thrown sand into the action.  I disassembled the gun, finding no debris.  Maybe a brass shaving fell out when I stripped it.  I reassembled the gun and racked the slide.  It chugged into battery.  I fired a round, the slide seems to recoil in slow motion and empty brass barely made it a few inches out of the slide, which was once again out of battery.  I disassembled the gun again and saw the tell-tale marks on the disconnector cam lobe on the slide.  I felt the connector for a burr and felt a slight bump under my fingernail.  I've used Ghost connectors in all my Glocks with no problems.  This particular one had a slight gouge in the disconnector lug.  Dryfire had not been enough to reveal it, but the violence of live ammo peened the gouge, raising a burr that was now eating into my $500 slide!  I felt the eyes of everyone one on the range, pitying a man with an unreliable gun, a Glock no less, the same look parents give when someones child is having a tantrum in public.  I was a bad parent with a spoiled child.

Gouges on connector cam lobe

Once home, I dove into 1911 troubleshooting mode.  I popped a different Ghost connector in the frame.  I broke out my trusty #2 file and began addressing the drag marks from the slide.  I didn't remove them completely as I didn't want to disable the disconnector, just smoothed them out.  I grabbed a 600 grit sanding stick and polished the now unfinished stainless.  I reassembled the gun, racking the action with as much force as I could muster.  While it wasn't glass smooth, the gritty feeling was gone.  I headed back to the range.  I fired the remaining 300+ rounds of Blazer Brass.  Success! Relief! Vindication! All was well...

But not perfect.  I have a few niggles about the slide.  Ignoring the issues I had, the FDE PVD coating is not as robust as I'd like, though this is not unexpected.  After just a few draws from my Guncraft Cloak kydex holster, the finish has rubbed off the corner of the muzzle, and a wear line is forming below the extractor.  It is no where near as tough as Tenifer, Melonite, DLC, Nitride, etc.  The front serrations are too close to the muzzle in my opinion and I wish they had cut 1 or 2 more lines.  The sides of the adapter plate are cut at an angle to match the profile of the slide, but since the RMR is wider than the slide, they should have left them square and added matching serrations, like on Glocks MOS plate, to provide more support for the RMR.  The stainless steel bottom cover provided for the RMR had very sharp corners for the RMR side cutouts.  I broke the corners with a Dremel and a chainsaw stone to prevent cutting my fingers on it.  The front sight is not serrated and glare makes it hard to find in certain lighting.

RMR gap due to slide bevel

Holster Wear

As for the issues I experienced, maybe I got a lemon.  Maybe Gen4 Glock tolerances are looser than Gen3?  Unity Tactical was more than willing to fix the problem for me, but I didn't want to loose time shipping the slide, or going through the hassle of shipping my frame with it.

I leave for Sage Dynamics 2-Day Defensive Handgun class this weekend.  If the slide makes it through, I'm going to cut additional front serrations and send the slide off for DLC re-finishing at a local metal coating company.  All told I'll have nearly $500 in the slide, including the $275 I got back when I sold the factory MOS slide.  For $800 I could have sent my factory slide to Agency Arms, or AETI for about $500 and had the RMR cuts, front serrations, and a refinish job done.

Glock 19, ATOM Slide, Trijicon RM06

Was it worth it?  To me yes.  I'm currently on my 4th 1911 project, a Caspian 9mm CCO.  I enjoy the challenge of building a 1911, fitting every part as perfectly as possible.  This is NOT something you should experience with a Glock, nor would I want to.  A Glock should just work.  But I appreciate a learning experience no matter how frustrating the lesson.  My Glock now has something that I thought only a 1911 or my M1 Garand could have.  My Glock has a soul, a personality.  Mine.  The stipple job was done for my hands.  The accelerator cuts are positioned and angled for my thumbs.  The trigger bar and connector angles were stoned and polished by me.  I radiused and polished the striker safety plunger.  Even the Atom slide has my handiwork in it.  This is my Glock.  There are many like it, but this one is mine.

-Carry On.

Update - The slide made it through the Sage Dynamics Defensive Handgun 2-day class with zero problems.  This will definitely be my EDC.  I did have a problem with the RMR dot turning off but that's a known issue that was fixed with some electrical tape.  The dot held zero all day and I was able to get hits at 25 yards with the irons.  I will probably replace the front sight with a serrated green fiber one from Dawson, as the glare off the front ramp makes it hard to make out.