Flat top

[Victor Zulu 58]

Got a little down time at work, so I thought I'd play around with the receiver stub that was attached to the barrel in my parts kit.
What I'm shooting for is a continuous rail, starting from the gas block and terminating at the rear sight. This is to be on the same plane as my railed receiver cover. This will be attached to the gas piston cover, cantilevering up to & over the rear sight block. One 10-32 or two 8-32 screws will anchor the rail to the rear sight block.
The front sight post will be absent (I gotta weld a muzzle brake on the barrel anyhow). Iron sights will consist of flip ups, on the same plane. Front will be at the gas block, rear will be back on the railed cover. A red dot will also reside on the railed cover and (hopefully) be a true cowitness with the irons when they're popped up.
If it's too much rail up front I might weld the front post to the gas block, put the optic on a short rail screwed to the rear sight block, and keep the flip up rear sight on the railed cover.
As soon as I figure out how to post pics, I'll attach them. Turned out nice, only 0.0008? difference in height front to back. Side to side is dead on.

[Victor Zulu 58]

I attached the gas piston cover, and the cover is 1/8" taller than the rear sight block. I have had the Bonesteel setup on for so long that when I was envisioning this thing, I had forgotten the height differences in foregrips. I have a feeling this is going to go through its fair share of revisions before completion.

[RSR]

Sounds awesome.  Can't wait for pics!

[Victor Zulu 58]

You may be waiting a while - trying to figure out pictures on here...

[Holz]

Magwedge from Canada is going to release this Saturday following rail. I was wondering that actually it could be longer and running from gas block to the end of receiver. That way it would be one piece  continuous rail.

[Victor Zulu 58]

My guess is that the rail doubles as a case deflector? Holy crap.

[Holz]

According to manufacturer, yes it does. If I would design this thing, I would have beveled edge on the rail over ejection port that would help avoid ejected cases falling back into receiver.

[CitizenPete]

According to manufacturer, yes it does. If I would design this thing, I would have beveled edge on the rail over ejection port that would help avoid ejected cases falling back into receiver.

I believe the military prototype has a replaceable plate that ejecting shells come off of that appears to be held in place by screws.  Look closely at the posted prototype pictures.

This top rail has gone around in my head a bit ever since I read the translated Czech post (ibid: Bren section - post by RSR) .  One of the true advantages of the VZ58 over the AKM is that you cant jam it as hard as you might try.  I posted last summer that the instructors in a tactical rifle class I attended tried to jam my VZ58 during a jam-and-clear drill. ARs - they just held a mag behind the charging handle - done -- out can the Leatherman tools. AKs just hold a mag in front of the port - done shell case is jammed.  Two instructors: a LEO and and Ops guy from Afghanistan both tried to jam my VZ for 20 minutes - could not do it.  So, what I wonder is: are the functional gains (not arguing there aren't gains) of the flat top rail potentially introducing other issues?

[Victor Zulu 58]

I think the last thing I would ever do with my vz would be to bridge the gap. If you want an ak, buy an ak ;-)

[Horse]

I also agree - why mess with a critical thing like ejection. 

[Victor Zulu 58]

This may or may not link to pics... I'm better at making things than this internet crap.
https://flic.kr/s/aHsk4UC39i
Yup, it works sort of... pictures aren't in order, of course. Maybe there will be a way to sort them - it's not very user friendly.
(edited a few times because I'm fighting with the bleeped image hosting thingy & end up deleting the pictures)

[CitizenPete]

I also agree - why mess with a critical thing like ejection.

I think the last thing I would ever do with my vz would be to bridge the gap. If you want an ak, buy an ak ;-)

UPDATED

Hi guys,
I can see a few real benefits for the full flat top rail, esp. with optics (NV, long scopes, etc.).  The rail idea is as part of a VZ modernization gives us the same flexibility as other military type rifles being produced today.  Some POSP style scope options are available with a deflector for directing case ejection away from damaging the optics tube.  If the rail is designed "right" it may not be an issue under "normal" circumstances, however as mentioned I can see getting into the AK types of issues (albeit rare).  Height, angle and other variables  might all effect a rail adoption of this type.   

Another thing that I think about is the angle that rounds come out of a VZ -- UP, forward, and to the right at a decent distance.  I have a brass catcher designed for AKMs  that I utilize on a SIG 556R rifle that makes it convenient for case clean up, but also valuable for brass collection (esp. when shooting something like Lapua boxer primed brass), but the device wont work on a VZ.  VZ case ejection is nothing like an AK.   Having said all that, it doesn't necessarily mean that a deflector cant be designed to effectively angle out the cases.

The other ejection issue I had, that Dan at Czechpoint figured out for me, was cases were not ejecting at all -- or so I thought.  I posted pics on this phenomenon here: pics below,  I was using a RS Regulate side rail mount with a optic and Killflash that sat back BEHIND the bolt carrier opening.  Some of the cases were actually hitting the bottom of the Killflash (even though it did not protrude over the carrier opening) and going back into the action. I thought this was a failure to eject (FTE) problem, but it was a fraction of a second ricochet or the spent case back into the action.   Removing the Killflash from the optic solved this.

Then the last issue I though about about is additional noise,  While the all the rifle cycling mechanics are obviously all making noise, there might be addition noise added from deflecting cases? Probably over thinking this.

A solution with a removable rail section held in place with screws might also be a good option?  That way it can be utilized when required.

Just sharing thoughts here guys.

UPDATE:  thought I posted these prior but couldn't find them in the forum. So I will post the pics here to support the topic.

[RSR]

This may or may not link to pics... I'm better at making things than this internet crap.
https://flic.kr/s/aHsk4Tv66w
Yup, it works sort of... pictures aren't in order, of course. Maybe there will be a way to sort them - it's not very user friendly.

Very cool. Thank you.

[CitizenPete]

Will the real Jim Winton please stand up?

I was really hoping to open up some discussion and brain storming with my last post below regarding ejection issues with a flat top design. 


... crickets chirping ...   


If one simply does a brief visual study a slow motion (or super slow motion) of how the cases leave the 58 with the standard bolt and extractor configuration, it begs the question: 

Can a deflector be designed for the VZ58 to reliably and consistently eject spent casings sideways out of a  side port?



http://youtu.be/7PqAk-qianA?t=2m51s


http://youtu.be/NfZMn39FKWw?t=17s



IMO case ejection is the numero uno design issue to overcome with a flat top rail and a right side ejection port without delving into any carrier, bolt, or extractor design modifications -- which would not make any retrofit of existing 58 rifles feasible from an economical perspective alone.  May as well redesign the receiver and FCG at that point and then it will be a cousin to the 58, like the Bren.

If the goal is to make a mockup to hang on a wall, then design it on CAD/CAM and 3D print it.

[Victor Zulu 58]

My vision of a Vz58 flat top doesn't bridge the gap from the rear sight block to the receiver cover.
I want rail from the gas block to the back end of the rear sight, on the same plane as my railed receiver cover. That's my 'flat top Vz58'.