<SLV>
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I'm looking at getting a DSA short Steyr-pattern flashider. According to DSA it is 1" overall length with 9/16-24" LH threads. I know what left-hand threads are, but what does the 9/16-24" mean?
Need help parsing flashider lingo
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Owen
Moderator Emeritus
its the size and TPI of the thread.
The barrel needs to have the same size in order to screw the FH on.
The barrel needs to have the same size in order to screw the FH on.
<SLV>
Member
9/16 = ? ... how far the threads go into the 1" length of the flashider? Inside diameter of the threaded side of the fh?
24" = ? ... thread pitch?
OK... so I'm planning on having my barrel threaded to accept this flashider. These numbers don't tell me anything regarding the necessary barrel diameter, do they? My gunsmith said I have to make sure I have at least .040" more barrel than the I/D of the flashider. But when I contacted DSA tech-support these are the only numbers they provided to me.
24" = ? ... thread pitch?
OK... so I'm planning on having my barrel threaded to accept this flashider. These numbers don't tell me anything regarding the necessary barrel diameter, do they? My gunsmith said I have to make sure I have at least .040" more barrel than the I/D of the flashider. But when I contacted DSA tech-support these are the only numbers they provided to me.
rbernie
Contributing Member
The goal is to make sure that you don't cut the barrel too thin around the flashhider.
If the barrel bore is .308 groove-to-groove and the flashhider threads are .5625 (9/16"), you have .127" of metal around the bore (assuming the bore is centered in the barrel). Does this math make sense?
If the barrel bore is .308 groove-to-groove and the flashhider threads are .5625 (9/16"), you have .127" of metal around the bore (assuming the bore is centered in the barrel). Does this math make sense?
rcmodel
Member in memoriam
Tap drill size for 9/16"-24 is 33/64" or .515".
If you add the tap drill size + the .040" necessary for threads you would need at least a barrel O.D. of .565" to cut threads on it.
Nominal 9/16"-24 threads are .562" O.D.
I can't tell you how long the threaded section would need to be. That would have to be determined after you get the flash hider if DSA can't tell you.
rc
If you add the tap drill size + the .040" necessary for threads you would need at least a barrel O.D. of .565" to cut threads on it.
Nominal 9/16"-24 threads are .562" O.D.
I can't tell you how long the threaded section would need to be. That would have to be determined after you get the flash hider if DSA can't tell you.
rc
<SLV>
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Great! I'm actually installing this on a .312 barrel (7.62x39). I have plenty of "meat" for cutting threads -- 0.625 at the flashider location. However it is going to have to be permanently installed because my barrel length would only be 15.5" at that point.
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