How tightly should a sound moderator be screwed on?

Q: How tightly should a sound moderator be screwed onto my rifle?

CHRIS PARKIN replies: Generally, tight! It’s hard to specify an exact torque setting as it is nigh on impossible to attach a torque wrench to a sound moderator. Realistically, around about 5 to 6Nm of torque is about as tight as the average hand can apply to a fitting like a 50mm-diameter sound moderator.

I would always recommend removing a moderator after use to avoid corrosion issues, and if removal and refitting causes your zero to shift, look at the bedding on the rifle – is something moving?

I hold the rifle/scope/mounts between my knees and use both hands to nip up a moderator, and similarly to remove one, so if anything is likely to move, this will encourage it. I like to know of possible issues here before they occur.

When you shoot, resonant oscillation in the barrel can encourage mods to loosen off so I always tend to subconsciously check they are nipped up any time my hand passes by them, just as it will always automatically check ‘safe’ status, I suppose. Finer metric threads do seem to remain tight more than coarse imperial ones but any will do the job perfectly well, with correctly specified threads and tolerances.

It’s best to tighten a mod when hot as the expansion, and later contraction, of the metals, no matter how minimal, will assist you here to get it even tighter. Don’t be tempted to shoot a mod downrange off the end of your barrel and accuse others of manufacturing errors, when in fact you have not put the mod on tightly enough!

Lastly, a rubber glove in your gun cabinet will assist mod removal when you get home if it needs extra grip to get it off. Do not be tempted to leave it until the following day as corrosion sets in quickly, and it never hurts to wipe gunshot residue off the barrel’s crown with an oily cloth to keep it sparkly clean too.