Geissele / Light Alum Rails Unreliable? Per Internet...

[Wake27]

I heard some of this stuff when it was going around too but Army SF has been issuing the URG-I uppers with Mk16 rail for a while now. Have there been reports of these issues from field use or just these third hand reports from some initial testing?

None that I'm aware of.

Not only are SF issuing the Mk16 upper, the 75th Ranger Regiment is also issuing them as well now. I'm going with another case of internet rumor blown out of proportion. I followed it all fairly closely at the time and there was a lot of speculation and people pretending to have inside knowledge about contracts being cancelled, etc. that never came to be.

I hadn't heard Rangers picked them up, where did you get that info?

Don't use a giant low profile gas block, and you'll be much less likely to impact the sides of the handguard (it's not a rail, guys); they were using MK12 gas blocks during the tests, IIRC, which barely fit under. Deflection is not just an issue of the rigidity of the handguard itself, but also how it interfaces with the barrel nut, how long the overall handguard itself is, etc., so a cheese grater isn't going to necessarily help much, despite all the extra material. I've also been told that a big issue was that there was relatively loose fit between the barrel nut and the handguard itself on the MK16s (at least for that batch back then), and when combined with the relatively soft aluminum barrel nut, impacts would permanently deform the barrel nut and cause shift; the fact that the legendary MK1s were made with 7075 barrel nuts, and so are the MK4s and MK8s, makes me think that 7075 barrel nuts are fine, as long as tolerances are properly held.

If you're so worried about all this shit, just get a monolithic upper and call it a day.

They're literally called Super Modular Rails though.

[Default.mp3]

They're literally called Super Modular Rails though.

Sure, and DD also calls them rails, etc. Doesn't mean they're right. I know, I know, prescriptivism is a lost cause, everyone knows what it means in context, and I'm just going to look like a pedantic asshole if I keep up this fight, but dammit, words have meaning.

[Eyesquared]

None that I'm aware of.



I hadn't heard Rangers picked them up, where did you get that info?



They're literally called Super Modular Rails though.

You can see the 75th Ranger Regiment URGIs in recent videos on their Facebook page. If you follow Pat Mac on Instagram you can also see them in the videos earlier this year when he was training 3/75.

[M2CattleCo]

Geissele rails are so easy to change that I would just enjoy the MK16 as hard as you want and if you bend it unscrew 4 little bolts and pop a new one on.

I love Geissele rails, the MK14 is my favorite.

[pastaslinger]

I stopped buying Geissele products but more related to their quality level relative to their price point (imagine buying a colored but otherwise normal buffer tube for $80) and my very poor experience with their Black Friday sale when I was quoted a ship date of by 8 weeks, soared past 8 weeks, had my credit card charged up front, then got to see them give away the same uppers as I had bought at shot show to free. I was so upset by their poor business practice that I refunded through my credit card company, as did many others, rather than waiting even longer and getting a coupon that would've required me to buy more Geissele products to benefit from.

[theJanitor]

I’d be more worried about rail deflection when loading up pressure on the rail while using a laser. You can deflect a laser while loading up a vfg on a barricade, or loading up a bipod. Chuck had mentioned this in a recent Q&A session. Like I said, just look at the ribbing and construction of the mk4/8 compared to the mk16, which is just a tube.

I have a mk16 and a laser is going on that, so I’m not that worried. Just do some testing on your own, and know your own gun. My mk8 shows very little deflection under load. I haven’t tried the mk16

[theJanitor]

@Sanch , looking back at your original post, I think you'd be much better off finding a factory assembled upper. If we're simultaneously talking about MAWL's, NV, bent rails, overgassing, and adjusting gas via depth of gas tube insertion, I think it's more critical that you just buy factory.

BCM has been very good at releasing various uppers, from 12.5-16" in all varieties. SOLGW has put out a ton of stuff, including the 13.7's. There are lots of ways to get a suitable upper for your needs. You obviously have the budget, buy a factory upper and get to actually using it, instead of worrying about it.

[JRB]

Perfect example of what I explain to folks as 'too much religion in equipment choice'.

Handguards and rail systems in particular seem to generate entirely too much excitement and 'religion' around a piece of fucking aluminum. Does it mount well? Does it hold all my shit? Are all the holes the correct shape for my preferred geardo theology? Is it reasonably priced? Is it actually available?
There's a LOT of rails on the market from a lot of good companies that check all those blocks, from brands that don't start with 'G'.

A name or brand is only as good as the customer service, otherwise it's just a piece of metal. If you're spending more money on it than a 'just the metal' price for it, you ought to get some good QC/QA and customer service to back that up. Otherwise just buy a cheap Brownells Wrenchman or MI free float and put more money in the barrel where it matters.

On that note, if your free float rail costs more than your barrel, you're building a stupid rifle.

@Sanch , looking back at your original post, I think you'd be much better off finding a factory assembled upper. If we're simultaneously talking about MAWL's, NV, bent rails, overgassing, and adjusting gas via depth of gas tube insertion, I think it's more critical that you just buy factory.

BCM has been very good at releasing various uppers, from 12.5-16" in all varieties. SOLGW has put out a ton of stuff, including the 13.7's. There are lots of ways to get a suitable upper for your needs. You obviously have the budget, buy a factory upper and get to actually using it, instead of worrying about it.

^Wholeheartedly agreed. Buy a quality upper from a vetted, duty grade manufacturer like BCM, Sionics, Daniel Defense, etc and stop sniffing the proverbial corks on all this stuff.

[Calvin118]

I got a 16" super duty with a 15" mk 16 rail with the receiver integrated anti rotation tab in their Black Friday sale. This one came with the reduced size gas block. In order to test it's trustworthiness I dropped it 3x from six feet onto an old wood floor. It was dropped directly onto a scout 300 mini attached via arisaka inline mlok at the end of the rail. This would give the rail as much of a torque insult as it would ever see in my hands. It hit so hard that the pad on the end of the stock popped off all three times.

The result? No appreciable loss of rail mounted zero and no rail damage. Maybe the new smaller gas block made a difference? Maybe it was the receiver tab? No damage to the mlok slots either.

I still prefer the Mk 8. In side by side comparison it flexes less than any of the popular tube rails at a given length and the plus shape works with my big hands. But I would have enough confidence in the mk 16 they sent me.

[RAM Engineer]

I asked Ken Elmore to build me an upper a few years ago, and he stated that he would not use Geissele rails, and the only rails he currently (at the time) would use were Larue or rails that attach to a USGI OEM barrel nut. At the time, Larue didn't offer an MLok rail, but they have since rectified that, as long as you don't want an uninterrupted top rail.