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Posted: 3/12/2006 12:05:24 PM EDT
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I've never understood it... You pay $300 for a 4-railed aluminum free-floating forend, and what you get is an unsightly gap between the end of the rail and the start of your front sight base. LaRue, Daniel Defense, Samson, Troy... they all seem to have that "gap".    My first time out with my Daniel Defense forend, I thought maybe the handguard cap was supposed to go there... but nope, it didn't fit. Now I would just say to myself that it was allowing for manufacturing tolerances or something... BUT then there's PRI, Armalite, and Yankee Hill... From the ones I've seen, those do NOT have any gap. Anybody have any good input as to why "the gap"? |
You know, I thought that too, but I tried to put a cap on two different Daniel Defense forends, and it wouldn't fit. Also, if you'll notice the Samson pic I added, it has the cap and still has a gap. It doesn't bother me that it's there, but I do wonder why it's there. |
very interesting, have you thought about asking mark larue himself
Well no, but since I started thinking about this late Saturday, I doubt I'd have had any luck anyway. Besides, the extent of effort it took to post this question is about equal to the level of curiousity I have on the subject. |
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maybe it has something to do with the rail slots, if its any longer then it would be a problem with the rail slots? there are rails that extend past the front sight if it bothers you that much. the rifle in the second picture is good looking!  oh and from a side view the gap is barely noticeable between the rail and the rearmost of the pri flip up |
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WOAH! I thought you were talking about the small gap between the upper and the rail- not the rail and handguard cap. I would get rid of that cap- it exentuates the obvious. Is that where you tightened it? can you loosen it, set it back and retighten? I would guess that the manufacturer wants it to fit on rifles with different upper reciever specs and different barrel nut and barrel nut shoulder specs. It would be nice though to see the gap eliminated. Get out your dremel tool  If you opened the channel cut for the barrel nut teeth slightly to the front you would probably find that it allowed you to get rid of the gap. I'm not familiar with the rail system; but I would also assume you could take a few thousandths off either the teeth or front face of the barrel nut and that would probably help you achieve it also. (If it needed too much material removed you might possibly be able to get rid of the teeth weld a few spots, lathe them to create a new lip for the channel, and notch cut the barrel nut for installation with a CAR stock wrench. ) The point is that if anyone really cared it would be possible to get rid of that. I do think it should't exist- isnt that half the point of those systems? |
Well, the third one is a Lilja barrel (not Giffman).
Where was it hanging up? I always assumed the gap was for the handguard cap. I know on the third one (my rifle) that the FSB is not all the way against the shoulder of the gas block step in order to leave room for a handguard cap. I don't run one though so I can't say with 100% certainty that one would fit. |
I guess I should have mentioned... NONE of the rifles pictured are mine  They were just posted hither and yon and were a good representation of what I was talking about.
The handguard cap would touch the end of the tube before the FSB was in place to be pinned in. I'm going to go with eklikwhoa's suggestion... a little longer and you'd have a groove... a little more and it's half-a land. It would probably look chopped off. Hey thanks for all the input. |
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The handguard retainer (cap) is only used to retain a standard type handguard. It serves no useful purpose when running a FF tube. It's not there for esthetics. It's there to hold the front of the handguard in place. Why hang sheet metal parts off the barrel if they have no real purpose? |
Why does YHM sell a threaded end cap for their FF tubes then? Looks maybe? I leave the stock end caps on to close that giant opening that's at the end of the FF tube... It might not be useful, but for me it serves a purpose, it looks better... 
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Correct. The tan mid length posted by the thread starter belongs to me.....it is indeed a Giffman barrel. The picture is also deceiving due to lens barrel distortion from my crappy camera. Honestly though.....I couldn't care less about some gap. It works.....that's all that matters. |
Well, we can look at JosephR's 12.0FSPM since it shows both the cut in the top rail and the rails along the side for comparison. Based on that I'd say you are correct - at most you could get one more notch in before the FSB and even then it would be a tight fit, so it would probably be a 1/2 notch or 3/4 notch. Of course then we would all be upset that they manufactured it with that sloppy looking half notch that was useless for any practical purpose
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Is it a carbine length or a midlength rail? I'd guess carbine since it seems it would be impossible for all these rails to follow the 1913 spec, which is pretty detailed, and come up with different numbers of slots between the front sight base. |
Your guess is correct... Another thing that could be a factor is that the YHM is Weaver spec... |
Just so there is no mistake- I cut my 12.0FSPM short so the side rails don't end 'right' Didn't know if you caught that or not. |
What kind of stock is that in the 2nd pic?I really like it. |
Yep, I know... I've seen your picture several times. It's the only FSP I've ever seen that I actually liked. It looks GREAT. If I was that adept with the power-tool thingies, I'd want one of those too
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I didn't catch that actually; but for our purposes we only need the side rails to go to the back of the front sight base so we can make a direct comparison between where the top rail ends and the next notch of the side rail ends up in comparison to the FSB - and yours has that. |
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Yes. A midlength FF rail is 2.0 inches longer- 2.0 even. The notches and raised portion are just over 1/8" long each I believe and that just doesn't work out evenly. That's where the gap comes in (and why.) Who said you need powertools to cut aluminum? You just need huge balls to cut a $275 piece of aluminum with a $5 hacksaw!! I used a $2 file to clean it up and a few dollars in Duracoat and voila!!   I'm such an attention whore today.  Detail up front along siderails. The second time I cut a little more off and wanted to make the ends a little more unique. People were thinking the 12.0FSPM came the way I had it and I just had to give it that H&K angled leading edge:  |
While reading page 1, I was trying to remember where I saw one customized and sure enough, it was yours The "Gap issue" bothers me as well, not just aesthetically, but it also represents a risk of gas tube damage by contact in extreme use environments I am equally bothered by the gap at the rear, and am looking hard for the 'right' continuous rail for one of mine right now. the Vltor and Samson look good so far |
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