Glock replicas slide to frame fitment offset

[NonEx]

Feel free to add in information, theories, experiences and practical tips on this.

 

WARNING: This is a proof of concept only. Do NOT do this without reading the entire post and thinking about it!

 

 

Top image: Slide to frame fitment/offset before modding the hop up housing.

Middle image: Mods made to hop up housing.

Top image: Slide to frame fitment/offset after modding the hop up housing.

 

So, as we all know, some Glocks have offset slide to frame fitment in terms of front of slide to front of frame etc. It just looks bad and is really annoying.

 

So I thought about, "what is determining where the slide aligns?".

 

And the answer that I came up with is this;

 

The hop up housing, locks into the slide lock plate in the frame, making the hop up housing and outer barrel not fall off, forwards. That's what happens if you pull down on the slide lock lever, right?

The slide is pressing the outer barrel onto the hop up chamber locking mechanism, holding the slide and outer barrel in place.

So, if you make the hop up housing lock in place on the slide lock plate further back, then the slide should also be moved further backwards, compensating for the offset?

 

So I had a spare WE hop up unit for my WE G19 A1A AGC build that I had a look at.

 

Turns out the hop up unit locks in two places.

 

The most obvious one being the slide lock plate cutout in the middle/bottom of the hop up housing.

If you remove material from the front face of that cut out, and add in material at the rear, you are effectively moving the lock up position further back in the frame.

 

The second position I found is the cut out at the rear of the hop up housing, which mates with the rearmost part of the front inner frame.

You have to remove the corresponding amount of material here as you do in the slide lock cut out.

 

The amount removed and added should be the same amount as your slide to frame offset is.

 

So, as you can see in the picture, this works for getting the slide in place.

 

But there are some downsides to this;

 

1. The hop up housing lock up fit is critical to the guns accuracy. This is what holds the inner barrel in place when the gun cycles. This means the modified cuts and added material have to be very accurate!

 

2. You are moving the hop up housing BB loading ramp rearwards in the gun. Might cause feeding issues and what not?

 

3. You are, indirectly, moving the slide rearwards over the hammer mechanism. The cutouts in the blow back housing will now be interfacing "sooner" with the trigger bar and valve reset knocker. Might cause issues.

 

4. Potentially you will mess up accuracy, functionality and overall timing of the entire gun in doing this...

 

 

Let's just say this proof of concept mod is totally pooh and doesn't really "work" other than illustrating the point.

My other thought is this. Leaving the hop up housing intact, and instead trying to make the outer barrel not move as much forwards on it's "caming axel" (?) over the hop up housing. Should have similar results, but keep the hop up housing in place.

 

I have to look into this some more. Feel free to contribute.

[mimesis]

In the bottom left picture, it now looks as if there's a bigger gap (vertically) between the front of the slide and the front of the frame.  In the top picture the fitment looks flush.

[hitmanNo2]

Solved one issue, created another heh.

[Dj_komodo]

None of my we g19's has that problem, none of my we 17 or 18c either for that matter. Strange...

 

[NonEx]

In the bottom left picture, it now looks as if there's a bigger gap (vertically) between the front of the slide and the front of the frame.  In the top picture the fitment looks flush.

 

Good catch. I didn't explicitly state it but in the before picture the recoil spring is not installed because I didn't have an unmodified hop up housing to demonstrate with. So the lack of space at the front there is due to me hand positioning the slide in that place without the recoil spring guide in place. I simply manually replicated how it looked before the mod.

 

There was a bigger gap originally than depicted in the vertical position. Possibly not as big as in the after picture.

 

 

But, due to my proof of concept cuts being very poor in terms of angle and precision, they cause the hop up housing to slant back and up a little bit more than it should after the mod, and that's why you see that extra gap in the vertical gap in the second picture.

 

To be honest I rather have flush fitting front to back than no gap up and down. Real Glocks have gaps up and down

 

 

 

DJ. What the? Those all look perfect... :| 

 

Did you replace hop up housings and/or slide lock levers on those?

 

What are the specs on your builds?

 

My WE G19 with Maple Leaf hop up housing and A1A SAI slide kit is almost perfectly flush at the front. But this Agency slide kit was not, at least not with the stock internals.

 

Come to think of it, the AGC build still has G23 internals in it. Where as the G19 has, well G19

[Got Wood?]

I have the same. My WE is perfect, but my TM, and 2 KJW, all with Guarder frames, have the gap st the front

[Dj_komodo]

DJ. What the? Those all look perfect... :|

 

Did you replace hop up housings and/or slide lock levers on those?

 

What are the specs on your builds?

 

My WE G19 with Maple Leaf hop up housing and A1A SAI slide kit is almost perfectly flush at the front. But this Agency slide kit was not, at least not with the stock internals.

 

Come to think of it, the AGC build still has G23 internals in it. Where as the G19 has, well G19

The hk3p g19 is complete stock, the rest has the GunsModify extended slide lock. The SAI slide has the maple leaf hop up housing.

[NonEx]

RE Glock airsoft replicas slide to frame fitment offset - PART 2 - New discovery

 

OK. So the original idea I had about the hop up locking position on the slide lock was not entirely correct.

 

As I mentioned at the end of my first post, what if, instead, you could make the outer barrel stop from sliding forwards on the hop up unit sooner?

 

The rear end of the chamber of the outer barrel is effectively what is stopping the slide from moving any further.

 

Turns out, outer barrel and hop up unit sort of move independantly of one another.

 

Or, to be more correct, the hop up unit and inner barrel does not move.

 

The outer barrel does move over the hop up unit.

 

So, what is stopping the outer barrel from sliding forwards?

 

The "outer barrel slide lock ledge interface", as i dubbed it.

 

You can see in the picture how the cut out stops the outer barrel from moving past the slide lock.

 

With the setup I had for these tests the differences were minimal. But the math kind of confirms it.

 

The slide to frame offset difference is the same as the difference between the "outer barrel slide lock ledge interface" difference between these two barrels.

 

If you have wear on the rear right hand side of your slide lock lever, or wear on the right hand front face of your "outer barrel slide lock ledge interface", the outer barrel will start creeping forward.

 

Solutions: 

 

Decrease the depth of the "outer barrel slide lock ledge". Not very easy to do considering the small surface area and the impact and stress it has to take when the gun cycles.

 

But this is as from as far as I can tell what determines the position of the slide in relation to the frame when in full battery.

 

I am kind of scratching my head as to how I could get results from the hop up unit modifications I posted about earlier. But I dunno

EDIT: Actually that is where the small "cam pin" on the left-hand side of the hop up unit comes into play. It stops the barrel from moving up and over the hop up housing.

 

Also someone mentioned that he saw improvement on his by loosening the screw of his blow back unit/rear sight screw and moving the blow back unit forwards or backwards (play between BBU in slide). I do not have any such play to work with in my Ace 1 Arms Agency Arms slide with Ace 1 Arms blow back unit.

 

 

Full size image: http://lh3.googleusercontent.com/-YAZNsiGm2Us/VxqlQh4BztI/AAAAAAAAF2U/cdPY_GS4Nio-6RfPui6JvT4PcfugsqUSQCCo/w3562/nx_g_series_slide_frame_offset_large.jpg

 

Small size image: http://lh3.googleusercontent.com/-qEXl4Ak99Hg/VxqlSDJ3SAI/AAAAAAAAF2Y/I5GCiEORwwYIllaagzfmkSEvTBnp3c9tQCCo/w1600/nx_g_series_slide_frame_offset_small.jpg