FOURBUX 22 Posted June 14, 2012 Report Share Posted June 14, 2012 I received my Chaos Titan rail a little less than a month ago, and I have had nothing but trouble with the main screw that bolts the handguard/lower rail on. The screw that was included with the rail didn't sit all the way in due to a small burr between the gas block and the rail and it stripped the last 1/8" of threads off of the screw (the only part that was actually screwed in). To replace that I went to Lowes and picked up a screw and installed it, but it quickly broke at the next trip to the range. After removing the broken shaft, I picked up a grade 10.9 from Ace Hardware (it was the hardest they sold) and added a washer to help bridge the gap between the rail and the gas block. After ~300 rounds that screw broke last night at the range. What screw do I need!? I've seen grade 12.9 online...is that little extra hardness what I need or is there something beyond that made especially for guns/recoil? Quote Link to post Share on other sites
lbsrdi 1,078 Posted June 14, 2012 Report Share Posted June 14, 2012 Maybe try contacting Cam. Quote Link to post Share on other sites
FOURBUX 22 Posted June 14, 2012 Author Report Share Posted June 14, 2012 Maybe try contacting Cam. Unfortunately I didn't order my rail directly from Chaos. He still might be willing to help though, possibly sell me a screw at least. Quote Link to post Share on other sites
The_Caged_Bird 474 Posted June 14, 2012 Report Share Posted June 14, 2012 If the screw won't go all the way in, it doesn't matter what screw you install. Think of it like wheels on a car, if your lug nuts (or lug bolts for the VeeDubs) are loose, that takes all of the force off of the spindle and bolt head/nut and puts it on on the shaft of the screw causing a sheared stud or bolt in no time. With the screw all the way in, that puts the pressure on the head of the screw and the gas block which doesn't allow anything to move since there are enough threads of the screw into the gas block to actually get it tight. If it were me, I'd get a tap of the correct size and thread-pitch and run it in and out of the gas block a few times with some oil to get rid of the burr and have proper thread engagement. I realize that with Russian threads, this is sometimes easier said than done, but that's what I would try first. Quote Link to post Share on other sites
FOURBUX 22 Posted June 14, 2012 Author Report Share Posted June 14, 2012 (edited) If the screw won't go all the way in, it doesn't matter what screw you install. Think of it like wheels on a car, if your lug nuts (or lug bolts for the VeeDubs) are loose, that takes all of the force off of the spindle and bolt head/nut and puts it on on the shaft of the screw causing a sheared stud or bolt in no time. With the screw all the way in, that puts the pressure on the head of the screw and the gas block which doesn't allow anything to move since there are enough threads of the screw into the gas block to actually get it tight. If it were me, I'd get a tap of the correct size and thread-pitch and run it in and out of the gas block a few times with some oil to get rid of the burr and have proper thread engagement. I realize that with Russian threads, this is sometimes easier said than done, but that's what I would try first. The screw will go all the way in until snug, it just seems that especially with the length that was provided by Chaos, there is still more thread in the hole that isn't being used. The burr also isn't in the hole, it's on the rail just behind the hole, and I have filed it down so the rail will sit flush with the gas block. There is still a gap that has been milled into the Chaos rail, and I had a washer in there to try to help the screw bridge the gap. Here's a quick visualization to demonstrate what I'm talking about: Edited June 14, 2012 by FOURBUX Quote Link to post Share on other sites
The_Caged_Bird 474 Posted June 14, 2012 Report Share Posted June 14, 2012 Ahh, I guess I misunderstood. I assume the original screw is too short. When you finally get a screw, you could try trimming the end until it fits perfectly, just remember to round the starting threads a little so that you can get the screw started straight. Quote Link to post Share on other sites
Bizarro 9 Posted June 14, 2012 Report Share Posted June 14, 2012 (edited) I am assuming you are using a verticle foregrip then the shift when fired would be shearing off the screw from continued recoil force. My worry would be if you go with a higher grade screw you might cause the lug to elongate and no longer hold the screw. Check with some of the bolt specialty stores that deal with metal fabricators. Look under fastners in the phone book. Fastenal is a dealer in my area. The size of the bolt is a metric M5-.8 x what length you need. Here is a grade chart that shows the different strengths of fastners made to ASTM specs and stay away from imported fastners if at all possible. http://www.americanf...kings_steel.asp Edited June 14, 2012 by Bizarro Quote Link to post Share on other sites
IndyArms 10,186 Posted June 14, 2012 Report Share Posted June 14, 2012 And also dont forget that HARDER = BRITTLE Just because it is harder doesnt necessarily mean its the proper tool for the job... you MAY need a slightly SOFTER steel that will allow itself to "flex" just enough that it wont shear off because its TOO brittle... Does that make any sense?!?! Quote Link to post Share on other sites
FOURBUX 22 Posted June 14, 2012 Author Report Share Posted June 14, 2012 (edited) I am assuming you are using a verticle foregrip then the shift when fired would be shearing off the screw from continued recoil force. My worry would be if you go with a higher grade screw you might cause the lug to elongate and no longer hold the screw. Check with some of the bolt specialty stores that deal with metal fabricators. Look under fastners in the phone book. Fastenal is a dealer in my area. The size of the bolt is a metric M5-.8 x what length you need. Here is a grade chart that shows the different strengths of fastners made to ASE specs and stay away from imported fastners if at all possible. http://www.americanf...kings_steel.asp You guessed correctly - I am using a vertical foregrip. I suspected that this was causing some of my issues, but the gun handles nicely with it, and I'm much more accurate with it than without, so I've got to find a workaround. With the rail being made of steel billet, I'm not necessarily worried about it elongating. Since you seem to be familiar with various grades/hardness of these, do you have a recommendation? And also dont forget that HARDER = BRITTLE Just because it is harder doesnt necessarily mean its the proper tool for the job... you MAY need a slightly SOFTER steel that will allow itself to "flex" just enough that it wont shear off because its TOO brittle... Does that make any sense?!?! That makes sense, but I think especially with the vertical foregrip my goal would be to get the rail and the gun to act as one unit and deliver the recoil to the stock/my shoulder as opposed to absorbing some of it through the body of the rail on that screw...right? Also, if the screw flexes, wouldn't it eventually break? Edited June 14, 2012 by FOURBUX Quote Link to post Share on other sites
The_Caged_Bird 474 Posted June 14, 2012 Report Share Posted June 14, 2012 I'm with Indy... Also, does the forearm tab fit snugly into the receiver? I'm running a DPH, and I had to tap it in with a hammer to get it to fit, with a recess in it for the gas block to sit in, and a snug fit between the rear tab and the receiver, the screw is only there to keep you from pulling the fore-arm off if you pull down on it. All the rest of the forces are on the gas block and receiver. Quote Link to post Share on other sites
FOURBUX 22 Posted June 14, 2012 Author Report Share Posted June 14, 2012 I'm with Indy... Also, does the forearm tab fit snugly into the receiver? I'm running a DPH, and I had to tap it in with a hammer to get it to fit, with a recess in it for the gas block to sit in, and a snug fit between the rear tab and the receiver, the screw is only there to keep you from pulling the fore-arm off if you pull down on it. All the rest of the forces are on the gas block and receiver. I haven't 100% checked for this, but the rear tab fit just fine into the receiver without any kind of force. If it were moved in any direction, the screw wouldn't line up properly. (Also...are you an mc chris fan?) Quote Link to post Share on other sites
The_Caged_Bird 474 Posted June 14, 2012 Report Share Posted June 14, 2012 I wouldn't say fan, but I am familiar with his work and I DO enjoy a few of his songs/skits... Quote Link to post Share on other sites
FOURBUX 22 Posted June 14, 2012 Author Report Share Posted June 14, 2012 I wouldn't say fan, but I am familiar with his work and I DO enjoy a few of his songs/skits... I've been meaning to ask you that since I saw your sig. Quote Link to post Share on other sites
Bizarro 9 Posted June 14, 2012 Report Share Posted June 14, 2012 (edited) I was thinking the same as Indy, that if you do go with a harder grade of bolt you might still be shearing it off due to it being more brittle. Don't know if it is do-able but you might have to increase the diamater of the screw by drilling and re-tapping the lug on the barrel to give you more "meat" to absorb the recoil. This wouldn't be a simple job either. Just wondering if something else is causing extra pressure on the screw that is more than it was designed to support? What you shooting Super Magnums? Edited June 14, 2012 by Bizarro Quote Link to post Share on other sites
FOURBUX 22 Posted June 14, 2012 Author Report Share Posted June 14, 2012 That's the sad part...I'm shooting 7 1/2 Federal. Quote Link to post Share on other sites
FOURBUX 22 Posted June 14, 2012 Author Report Share Posted June 14, 2012 I think one of the major issues is that the recoil of the gun is putting a shear force on the screw, which it is only able to handle if the screw is completely clamped down. Given that I have not used loctite on any of the screws, I wonder if the screw starts to back out and then is unable to handle the shear force of the shotgun/gas block recoiling inside of the rail. Quote Link to post Share on other sites
The_Caged_Bird 474 Posted June 14, 2012 Report Share Posted June 14, 2012 I wouldn't say fan, but I am familiar with his work and I DO enjoy a few of his songs/skits... I've been meaning to ask you that since I saw your sig. "No, you're way too mean and therefore you deserve to get capped!" Quote Link to post Share on other sites
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