Lower rail out of spec?

Have any of you guys had trouble attaching items to the lower picatinny rail of your vector? I've tried a larue fug, and KAC aimpoint micro mount and nothing fits, but they both fit very well on the top rail. I've been waiting for over a year to get this SBR to me, i sincerely hope that I do not have to send it back in to have the rail worked on.

Hmm I havent had any issues. Im not familiar with those accessories. I do have a Larue mount on my surefire light. I can try mounting it on the bottom rail.

I normally mount my modified Magpul AFG or my Surefire M900 with SF M93 mount. No issues.

Looking at a pic of the KAC mount, it looks like it can adjust to non spec rails? Or am I wrong?

Oh yeah when you say Lower rail do you mean bottom rail? I assume so since you are mounting a grip.

Solscud007 wrote:
Looking at a pic of the KAC mount, it looks like it can adjust to non spec rails? Or am I wrong?

I don't think it will be able to adjust to non spec rails.. here's a picture of the bottom of it next to a larue tall mount.

Solscud007 wrote:
Oh yeah when you say Lower rail do you mean bottom rail? I assume so since you are mounting a grip.

Yes sir, mounting to the bottom rail. Trying to mount a larue forward grip.

I've tried the grip and the optic mount on my KAC AR-15 and top of the kriss as well trying to eliminate variables. Fits on both of those, so my thoughts go to the rail being out of spec

Do you have a set of digital calipers? if not I will measure mine when I get home.

Thanks, that'd be awesome. But no, I don't have a pair. I'm amazed I've made it this long without a pair, but a set is on on my list of things to pick up tomorrow. Already looked up the specs of milspec picatinny rails

From wikipedia:
"The Picatinny locking slot width is 0.206 in (5.23 mm). The spacing of slot centers is 0.394 in (10.01 mm) and the slot depth is 0.118 in (3.00 mm)."

Cool. I will check it out tonight.

Ok I checked my Vector and I can't fit my larue mount either. I believe it is the height of the rail that is out of spec.

However the Larue mou t is adjustable. Watch this.

https://www.youtube.com/watch?v=aBI3YOnNj7Y&feature=youtube_gdata_player

You might want to call KAC to see if your micro mount is adjustable.

Oh, i see what you're saying. My problem is a little bit different. Like, the teeth of the FUG are literally not lining up with the picatinny rail and everything else I try is having the same problem. Here's a picture of what I'm talking about. If you look, the picatinny rail is just ever so barely too large for the rail accessory to fit. Sorry for the bad pic, it was surprisingly hard to take.

take

Yeah the pic is confusing. So your FUG has two bars? And one of them doesn't line up properly?

Hmm. Sorry but if that is the problem, file one of them or the KRISS' rail. Hopefully you aren't committed to that grip. Return/sell it and try something else. Or use it for a different gun.

Why not try the Magpul RVG?

Or hack up an AFG like I did. Much better than vert grips in my opinion.

Solscud007 wrote:Yeah the pic is confusing. So your FUG has two bars? And one of them doesn't line up properly?

Yea, the FUG and aimpoint mount have multiple contact points and they're not lining up with the rail on the Vector, but line up with every other picatinny rail I have. In the picture I posted, the bottom bar of the FUG is just BARELY not making it. It almost appears like I could shave off a very small amount of the rail and make it work, but I'd rather not got hacking away at it just yet.

I know this my grip of my Kriss sbr won't work on my AR15

CatMostFeared wrote:I know this my grip of my Kriss sbr won't work on my AR15

well that does not sound promising... perhaps I'll call them tomorrow.

I honestly dont think there is much they can do. They might say, use their vertical grips.

I havent tried this one. But their AFG fits my bottom rail.

http://store.magpul.com/product/MAG412/39

Solscud007 wrote:I honestly dont think there is much they can do. They might say, use their vertical grips.

Surely, there is something they can do. To produce a picatinny rail that is out of spec is completely unacceptable. If this is not an isolated incident to just my vector, then the rail needs to be fixed and future guns. There really is no excuse to produce rails that are in spec everywhere else on the weapon except for here and try to pass it off as normal...

Im sorry to burst your bubble. But they are not going to make a change just for you. It is like recalls on cars. They only do it when a LOT of people complain.

They might say something to the company that machines it for them. I know some parts are not manufactured by them but contracted out.

The rails might be one of those things.

I know you are upset but you can use your FUG if you file down the front notch. Or sell it and save some money. Why spend $98 on a Laure grip when another grip will do just the same?

Solscud007 wrote:Im sorry to burst your bubble.

I'm not expecting them to fix it just for me. But think about it, for all the changes they've made, they haven't fix an out of spec rail? you would think there would be something individually wrong with my rail because that is a large problem. IF they are all out of spec, then this definitely needs to be brought to their attention.

Solscud007 wrote:
They might say something to the company that machines it for them. I know some parts are not manufactured by them but contracted out.

this is what I'm assuming. Again, if the case, then this needs to be brought to their attention so it can be changed for future models. Just send the correct specs to the manufacturer for further production

Solscud007 wrote:
Why spend $98 on a Laure grip when another grip will do just the same?

This isn't the point. I should be able to use any rail mounted accessory because the rail should meet the 1913 picatinny rail standards, not something proprietary.

GlocksInMySocks wrote:....I should be able to use any rail mounted accessory because the rail should meet the 1913 picatinny rail standards, not something proprietary.

Agreed! That's what the "spec" in Mil-Spec is for. It's met or it's not. :pale:

Well I always say "Squeaky wheel gets the grease" haha so let them know.

Is that rail an easily replaceable part?... What does Kriss have to say about it?

No it's not.mgi to kriss-tdi.com and read the armorer's course.

Solscud007 wrote:No it's not.mgi to kriss-tdi.com and read the armorer's course.

Just talked to KRISS. There was a run with lower rails being out of spec, so a new rail is being sent to me as we speak.

It's actually very easy to remove the bottom rail. Remove the roll pin and it literally slides off right in your hand

Interesting. Let me know how it works for you.

GlocksInMySocks wrote:Just talked to KRISS. There was a run with lower rails being out of spec, so a new rail is being sent to me as we speak. It's actually very easy to remove the bottom rail. Remove the roll pin and it literally slides off right in your hand

Thank you very much for chasing this down and posting the resolution for us. I'll also second Solscud007's request that you let us know how it goes when you get the part in your hands.

This is exactly the kind of participation I was hoping for with KRISS Talk!

no problem, I'll leave an update as soon as it comes in. I'm willing to bet a good number of people have this problem, but don't notice it because they are using forward grips from KRISS which only have one point of contact. Additionally, I think most people use other brands of vertical grips which have the screw tightening from the bottom or just one screw point of contact. As soon as you go to something with multiple metal mounting points such as a larue FUG or any quality optic mount, the problem becomes really noticeable.