DDM4/SLiM rail anti-rotation problem?

**Jwknutson17** · 11-08-16, 09:57

If you did this to a KMR it would have smashed in the sides and would be much more usless with irons then the DD.

Maybe the KMR wouldn't have rotated right at the rail, but it would be most likely touching the barrel where it took the impacts further down the rail. Or at least made the irons completely useless also.

Like you said. This is where fixed front posts have their advantages.

**awdxtc** · 11-08-16, 10:23

Im not really sure about that. My KMR seems pretty robust. I have about 5000 rounds through that gun with no ill effects. I am not about to go try to break it though lol

**Uprange41** · 11-08-16, 10:39

Originally Posted by Jwknutson17

If you did this to a KMR it would have smashed in the sides and would be much more usless with irons then the DD.

Maybe the KMR wouldn't have rotated right at the rail, but it would be most likely touching the barrel where it took the impacts further down the rail. Or at least made the irons completely useless also.

Handled being dropped fine.

**Jwknutson17** · 11-08-16, 12:42

I have had much different results with KMRs on a few rifles. Not getting into specifics or bashing/praising one company or another. From my personal experience I no longer run KMR rails on any rifles. I'm sure they work great for some, just not for me.

**lawusmc0844** · 11-08-16, 13:27

Rob Ski, keep up the great work!

Now I think about it, I remember the first gen DDM4V1 I bought back in 2009 had its Omega X FSP rail a little loose after a few hundred rounds, and this was a factory gun. I took a tiny hex key and tightened it back up without loctite and it didn't give me any problems the time I owned the rifle. My BCM BFH midlength rifle has an Omega rail installed as well with 10800rds through it. Recently I noticed POI shift to the left despite that never happening before as its supposed to be a free float but getting back home I checked the set screws to find some of them loose. I am still a big fan of the older Omega quad rails except for the tiny set screws they use, but not a problem blue loctite wont fix.

**Singlestack Wonder** · 11-08-16, 13:39

Proves once again that FSB's should be used for serious rifles, not rail mounted sights....

**joeyjoe** · 11-08-16, 17:40

Thanks for the info, guys. To be honest, my favorite and most used rail is the DD LITE III (DDM4). I run that thing on multiple uppers. My sample size of 3 has shown the rail to be very robust/rigid/reliable/predictable. However, I did use loctite on my bolts.
I gotta say, i was a bit surprised by the above mentioned test results.
Thanks to rob ski for doing to his rifles what i will not/cannot do to mine. Id be interested to see the test results after loctite has set up on the very same bolts.

**XM15M4Guy** · 11-11-16, 13:42

Well just as an additional data point, I checked the bolts on my new v7 check a few minutes ago while installing some rail covers and both the ones on the right side and the top left side one were loose. I have not had an opportunity to shoot the rifle yet so I'm sure it came this way from the factory. I tightened them but do not know what the proper torque should be and, unfortunately, don't have a torque driver at any rate. . Very concerning to say the least.
As was stated in the OP, For the price, which is certainly considerable for someone of my meager means, and considering the DD reputation, I expected better.
Having a great warranty is nice and we will take care of is great but it's also a weak retort to what has turned out to be a limited but obviously not totally isolated issue. However true the "most people mount an optic" statement is, quite frankly, irrelevant. The bolts should not be loose, period. YMMV