Mod coming loose

[gmart122]

If the o ring is sandwiched between mod and shoulder of thread, then not a good idea. The shoulder is what aligns the mod with the bore of the barrel on most guns, although there are other methods. Most mods/threads are cut loose enough for the shoulder of the mod to fully engage the shoulder of the barrel. Putting a rubber ring between the two faces does not guarantee alignment anymore.

It may work ok for one person, the next may get bullet strikes in the mod.

Of course the way to fix it once and for all is to recut the thread on barrel & mod to a left hand thread.

 

[Brithunter]

If the o ring is sandwiched between mod and shoulder of thread, then not a good idea. The shoulder is what aligns the mod with the bore of the barrel on most guns, although there are other methods. Most mods/threads are cut loose enough for the shoulder of the mod to fully engage the shoulder of the barrel. Putting a rubber ring between the two faces does not guarantee alignment anymore.

It may work ok for one person, the next may get bullet strikes in the mod.

Of course the way to fix it once and for all is to recut the thread on barrel & mod to a left hand thread.

Why would a Left Hand Thread help?

 

[ejg]

Why would a Left Hand Thread help?

Depending on direction of twist in barrel the mod could either be tightened or loosened because of the torque direction when firing.
The sudden torque impulse can be very sharp especially with a heavy calibre and light rifle.
edi

 

[pinkfoot1]

If the o ring is sandwiched between mod and shoulder of thread, then not a good idea. The shoulder is what aligns the mod with the bore of the barrel on most guns, although there are other methods. Most mods/threads are cut loose enough for the shoulder of the mod to fully engage the shoulder of the barrel. Putting a rubber ring between the two faces does not guarantee alignment anymore.

It may work ok for one person, the next may get bullet strikes in the mod.



Of course the way to fix it once and for all is to recut the thread on barrel & mod to a left hand thread.

In my original post I did say to use a tight fitting, thin, 'O' ring and to tighten it down hard a number of times to cause it to bed in on the shoulder. This tightening action actually cuts away some of the outer periphery of the 'O' ring, leaving a thin annulus matching the diameter of the threads, sufficient to grip the male and female threads without preventing the metal face of the moderator bush seating onto the barrel shoulder. This can be verified by using lamp black or engineers blue.

 

[Crosshair243]

Just searched and found this thread. My Roedale on my factory cut Steyr Pro-Varmint is doing the same. It screws on lovely, tightens up nicely with no play what so ever then sure enough, 10 or so shots later, it comes loose.
I'm going to try ptfe tape for now but might try another make of mod as that seems to be the problem.

 

[Hornet 6]

A mod coming lose probably has more to do with the shoulder being out of square to the thread, than it has to do with thread size.
If the shoulder is out of true the moderator will not lock cleanly against the shoulder, also steel barrel and alloy threaded section will
expand at different rates so will work lose.

Neil.

 

[bewsher500]

Is it just me or do a lot of these threads start with
"my Roedale mod is coming loose"!?!

 

[AN DU RU FOX]

its not just you,

 

[Crosshair243]

Is it just me or do a lot of these threads start with
"my Roedale mod is coming loose"!?!

In the interest of balance, the one on my .308 doesn't come loose

 

[AN DU RU FOX]

Let us hope for everyones safety that no ones mod comes loose,