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View Full Version : DD M4 or AR15 Lite Rail? Can't decide


kgcabs
06-01-2009, 10:20 AM
I know the M4 is a couple ozs. lighter but any other differences beyond esthetics?

Thanks

RECCE556
06-01-2009, 10:36 AM
The Lite rail has a better mounting system that doesn't rely on the barrel nut to be indexed which means you can torque the barrel nut right to spec and not worry about having to over or under torque it for the gas tube hole to line up.

The Lite rail also offers a bit more finer alignment of the rail to the top rail. With the M4 rail, you're stuck with where ever the barrel nut is so if the barrel nut is just a little bit off, your rail will be off too. You can, of course, go back and re-align the barrel nut but that's a PITA compared to the way the Lite rail mounts. Also, the rail high (up/down) is not adjustable at all on the M4, the Lite has a little bit of adjustment in this area.

Another advantage of the Lite rail is that it gives you a pseudo-continuous rail whereas the M4 rail has a gap between the upper and rail.

A disadvantage of the Lite rail is that the bolt up system isn't compatible with every upper. If you have an "odd" shaped upper (like some older Sun Devil billet uppers) which aren't relived up front to USGI sizing, then the bolts on the Lite rail may prevent proper installation.

The final difference goes back to the way the rails are attached. On the M4 rails, it's possible that you can loosen the barrel nut when you strap wrench the lock collar since the lock collar tightens in the OPPOSITE direction of the barrel nut. So if your barrel nut isn't torqued to a higher spec than what you're trying to tighten the lock collar to, you'll loosen the barrel nut.

deez
06-01-2009, 10:37 AM
The top rail on the DD Lite extends to the receiver rail to make one long continuous rail (which allows for more flexibility when mounting optics).

The top rail on the DD M4 does not, so you'll have a gap between receiver rail and DD M4 top rail.

fatass
06-01-2009, 10:43 AM
i went with the DD Lite, great system, mounts up very secure and actually looks cooler in my opinion

kgcabs
06-01-2009, 10:49 AM
Thanks guys. I see the lite.

bender152
06-01-2009, 2:14 PM
I just installed a lite rail on my upper and am happy with it.

If you're in the Bay Area, I have a lite rail wrench and an upper receiver block I can loan out.

kgcabs
06-01-2009, 2:17 PM
Thanks for the offer. I have the wrench and am waiting for the vice block from Midway.

Karl

fatass
06-01-2009, 2:23 PM
bender! where were ya last week, i didn't have any tools so i just had irvington arms do the install for me.

we actually met once, you sold a cmmg upper to my buddy around stanford

TZL
06-01-2009, 2:29 PM
Bender, I'm going to take you up on that offer soon, I'm going to install an DD lite rail and am located in next-door Woodside



I just installed a lite rail on my upper and am happy with it.

If you're in the Bay Area, I have a lite rail wrench and an upper receiver block I can loan out.

aplinker
06-01-2009, 6:06 PM
I know the M4 is a couple ozs. lighter but any other differences beyond esthetics?

Thanks

Actually, the M4 is only lighter as a carbine rail. I think it matches at 9" and then becomes heavier beyond that.

One thing not mentioned by RECCE is the difference in barrel nut material - the M4 is Aluminum, while the Lite is steel. This is the difference in weight. The reason the Lite ends up lighter at length is the aluminum rail itself is lighter.

bender152
06-01-2009, 6:21 PM
bender! where were ya last week, i didn't have any tools so i just had irvington arms do the install for me.

we actually met once, you sold a cmmg upper to my buddy around stanford

What's up man, I remember you.

Sorry, I just installed the rail this past weekend. I didn't even have the receiver block until Friday afternoon.

Bender, I'm going to take you up on that offer soon, I'm going to install an DD lite rail and am located in next-door Woodside

No problem, just let me know (PM me). I also have a punch set if you need it... torque wrench too.

Do you have a vice to mount the block in?

I didn't have one, so I ghetto-rigged a wood jig that held the block and screwed the jig into a work table.