Service Rifle Float Tube

[ks_shooter]

I have a buddy who is a CNC Machinist and has offered to help me construct a Service Rifle Float tube. I can purchase a standard barrel nut for about $5. He has scrap tubing of about any gauge I would want. All I need is a drawing, or a description of how to make one of these things. I have read that the better float tubes are three-piece assemblies that allow for the proper indexing of the sling swivel. All of the float tubes that I have seen pictures of are completely assembled so I don't really understand how it all goes together and what the different pieces look like. Besides being hopelessly cheap, the other reason I want to make this myself is because I am thinking of making the float tube out of aluminum instead of steel, to keep the weight down. Can anybody offer some info or pictures? Thanks.

 

[Steve Smith]

I'll take some pics for you tonight, cool?

Forget aluminum. That tube should be strong, strong, strong. The old style steel DPMS tubes are even too weak. Put a seasoned HP shooter on it and he'll break it off in a weekend.


Actually, I really don't need to take pics. Take a look here and you'll see that CLE has a lot of pics AND some engineering notes from trial and error re: gas tube slots and float tube thickness. FWIW, the RRA tube is built like this as well. A bend in the gas tube is necessary.

http://www.compasslake.com/float_tube.htm

 

[ks_shooter]

Steve,

Thanks for the reply. I have seen the pictures on the CLE website, but I need more detail on how the float tube attaches to the barrel nut and how the indexing of the float tube for the sling swivel is accomplished.

I don't have any practical experience with these float tubes. Why and where do they fail? Do they just bend over in the middle? Does the sling swivel prong pull off? I know that most match rifle tubes are made of aluminum, are they just much thicker? Any idea what gauge and type of steel tubing is used on the CLE or RRA tubes?

I noticed that some of the tubes have the sling swivel hanging directly down off the end cap (like the CLE) while others (RRA) have the sling swivel cantilevered off the end so that it appears to be in the same position as the original swivel. The second approach looks like it would be much weaker than the first in terms of bending the swivel prong. With the first design, the "ear" on the bottom end of the lower handguard would have to be removed, correct? With both approaches, it looks like the old swivel prong on the front sight base should be removed.

 

[Steve Smith]

I can't give you a great answer because I haven't had to do it for myself, either. I know where you can get the answer, though. BTW, It is my understanding that John Holliger uses a strap wrench to turn the tube so that it is timed correctly and then to hold it as he tightens the nut.

Right here: http://forums.delphiforums.com/gunsmithing/start

As far as where they fail, mainly where the exit the receiver, or the front swivel breaks, or they bend along their length. I think the MR guys' aluminum tubes are pretty thick...they look it.

The RRA method does look more fragile, I technically it would be, but it is very strong, I assure you. That's what I use on two guns (have a CLE on the third) and I have put tremendous pressure on both RRAs and they have never moved. I don't know of anyone who has make a RRA or CLE tube fail, but I know several who have ruined lighter grade tubes. The front sight swivel will need to be removed for either tube. I think the RRA method looks nicer.

 

[Jon Coppenbarger]

warning:
the rock river tube is the best out there for production piece.
i believe to do it right as on my rifle the gas hole in the barrel is set back slightly as are the front sight assy. but my service rifle barrels are done this way from the start and are not standard barrels from rock river. might not make any difference but it gets everthing tighter with no space.
if you check steve i do believe you will find that on your wilson the front sight assy is set foward just slightly more than your pac-nor.
my advice is to send it to someone who knows what they are doing or buy one from rock river and put it on.

steve really puts pressure on his and he does not have any problems.

also you need to keep them a standard size as if you go to cuff weights on the front you only have two sizes to chose from.

otherwise you get stuck with wheel weights and believe me its alot easier working with weights that fall off when you take the handgaurd off.
with the proper set up I can change the front weight of my rifle between positions like real fast.
I can have it weight alot on off hand or if I'am shooting alot of matches like perry I can slowly reduce my weight to keep me from getting tired after a few days.
also it lets me add alot of weight in my rapid prone like lets say I shoot a 14# rifle in off hand and sitting and then go to a 18# rifle in rapid prone and back to 14# in slow prone.
you can mix it up any way you want if you want or need to.
you would not believe how fast your rifle recovers after recoil on your rapid prone with a little extra weight up front.
also on a calm day I like a little lighter rifle but when its real windy alot of weight in off hand or even the other positions can make a big difference.

I would advise to send your rifle to some one like j.h. and get it done right the first time and you will never ever have to worry about anything again on it and you get all the advantages I get .

dang steve I keep letting these little secretes out all the time.
please do not try anything I have said it will not help.

lol jon

 

[Steve Smith]

KS, I see that you posted your query in several places, including that Comp Gunsmithing forum. I think you'll get a fine answer there. FWIW, there is a drop-down window at the top of the screen that has several HP boards on it. the Fl, Tx, and Ga sites are very popular. The Fl site is perhaps the most technically inclined shooting site I know of. It is a very valuable resource. We have a Sunday night chat as well.

BTW, I agree with Jon, stick to a standard size tube, so you can get cuff weights that match. I tried using mag wheel weights and found that they will sometimes fall off and rattle around. Could cause accuracy problems if it rested against the gas tube.

Jon, stop letting those secretions out. They make the house smell bad. LOL!