Thread: Length of a rifle with welded on suppressor?

Originally Posted by gadgetman

Burnt powder attracts water vapour and acts as a great electrolyte for electrolysis. It has been the demise of many crowns and threads where an aluminium can has been left on. Not sure how stainless would go. If the suppressor is fixed and you cannot clean well enough it could be an issue.

You're of course correct regarding the burnt powder/water vapour creating an electrolyte and corrosion risk. In my opinion though the corrosion would predominantly not be due to dissimilar metal galvanic action - I would expect very nearly the same corrosion between a carbon steel suppressor & carbon steel barrel as between a stainless steel suppressor and a carbon steel barrel.

Re. aluminium suppressors, normally the aluminium would come off worst (be the anode) in a steel:aluminium pairing. So in your example I'm sure there can be corrosion, I just don't think it would be galvanically driven to attack the steel.

ADDED: Anyway, I like Gundoc's idea of high strength loctite. Apart from avoiding some of the potential issues with welding, done properly it would also be a sealant at the suppressor/barrel interface and prevent corrosion in these joints.

Originally Posted by PaulNZ

You're of course correct regarding the burnt powder/water vapour creating an electrolyte and corrosion risk. In my opinion though the corrosion would predominantly not be due to dissimilar metal galvanic action - I would expect very nearly the same corrosion between a carbon steel suppressor & carbon steel barrel as between a stainless steel suppressor and a carbon steel barrel.

Re. aluminium suppressors, normally the aluminium would come off worst (be the anode) in a steel:aluminium pairing. So in your example I'm sure there can be corrosion, I just don't think it would be galvanically driven to attack the steel.

ADDED: Anyway, I like Gundoc's idea of high strength loctite. Apart from avoiding some of the potential issues with welding, done properly it would also be a sealant at the suppressor/barrel interface and prevent corrosion in these joints.

https://www.nzhuntingandshooting.co....88/#post885024

https://thebloke.co.nz/suppressor-storage/

Originally Posted by gadgetman

https://www.nzhuntingandshooting.co....88/#post885024

https://thebloke.co.nz/suppressor-storage/

I probably didn't explain myself clearly. With a suppressor left on and uncleaned, absolutely the muzzle will corrode - no argument here. It's just that the suppressor being aluminium is not the cause - google a galvanic series chart and take a look. Aluminium is anodic (sacrificial) to carbon steel - perhaps there's a particular corrosion environment where this reverses but I haven't heard of it. The barrel corrodes, but dissimilar metal corrosion is not the mechanism in this case.

Now with a stainless suppressor rather than aluminium, suddenly a carbon steel barrel is on the wrong side of the material pairing. Galvanic corrosion between the suppressor and barrel could accelerate corrosion of the barrel in this case, but in my opinion the effect would be minor compared to the other corrosion mechanisms.

Will a blast of CRC (or similar ) after shooting prevent the corrosion?

Just curious.

from my experience crc is crap for corrosion resistance . wd40 would be a better option in my opinion but I would think just an aerosol gun oil such as rem oil would be best .
I assume the OP wants to use subs for stealthy shots.... so just how short can the barrel go and still shoot subs at a worthwhile velocity ?

Originally Posted by Ftx325

from my experience crc is crap for corrosion resistance . wd40 would be a better option in my opinion but I would think just an aerosol gun oil such as rem oil would be best .
I assume the OP wants to use subs for stealthy shots.... so just how short can the barrel go and still shoot subs at a worthwhile velocity ?

The Lithgow model 1B that I plan on shortening currently has a 24" barrel. If I shorten the barrel to let us say 8 inches, I would expect to lose 100fps firing subsonic .22LR.
I have read that the optimum length of a .22 barrel for velocity is about 16 to 18 inches, so 24" is too long. An example with subsonic .22LR in an 18" barrel is 1114fps, but when 10" is cut off to 8 inches the velocity reads about 1048fps so a reduction of 66fps (nothing really). Please see link: BBTI - Ballistics by the Inch :: .22 Results

Update so far:
Yesterday, I sent an e-mail to the Tauranga Arms Officer Paul McLennan, regarding rifle overall length with a fixed suppressor.
Attached to my email was a written statement signed by lawyer Nickolas Taylor who gave his interpretation of the Police Policy on overall length but suggesting it be taken from the end of the butt to a fixed suppressor or fixed muzzle device.

This email and statement were then forwarded to the Head Arms Officier in Auckland and Paul McLennan expects a written reply next week.

22lr optimum length is around 14"? Your subs may end up super with the short barrel and defeat the purpose. Maybe easier to buy a bigger gituar case

Originally Posted by Jimmynostars

22lr optimum length is around 14"? Your subs may end up super with the short barrel and defeat the purpose. Maybe easier to buy a bigger gituar case

@Jimmynostars do you read the link I included?

If you go with a factory length barrel It will be quieter
shorter 22s are definitly louder than longer ones with subsonics
the other consideration is ricochets which 22 subbies are very fond of on flat ground/grass

Originally Posted by Hermitage

@Jimmynostars do you read the link I included?

Just had a quick look now, nothing but the 60gr is a subsonic round these rarely stabilize in a 22lr standard twist. Have a hunt round for subs going super with a shorter barrel

Originally Posted by Hermitage

@Jimmynostars do you read the link I included?

That was almost all Std Velocity, not subs.

Originally Posted by Hermitage

Update so far:
Yesterday, I sent an e-mail to the Tauranga Arms Officer Paul McLennan, regarding rifle overall length with a fixed suppressor.
Attached to my email was a written statement signed by lawyer Nickolas Taylor who gave his interpretation of the Police Policy on overall length but suggesting it be taken from the end of the butt to a fixed suppressor or fixed muzzle device.

This email and statement were then forwarded to the Head Arms Officier in Auckland and Paul McLennan expects a written reply next week.

Finally got a reply from Police Arms Officer Head Office about the legality of a shortened barrel with a fixed suppressor:

“If the modification of adapting a suppressor is permanent and from the butt of the rifle to the end of the permanently fixed suppressor exceeds the overall length of a pistol, I don’t see an issue. I would suggest you (arms officer) inspect it upon completion to ensure that the modification is indeed permanent and complies with legislative correctness".

Note. Arms Act 1983 defines pistol - means a firearm (other than a prohibited firearm or restricted weapon) that is designed or adapted to be held and fired with 1 hand, and includes any firearm (other than a prohibited firearm or restricted weapon) that is less than 762 millimetres in length

Regards

Paul McLennan
District Arms Officer | Tauranga & Whakatane | New Zealand Police
Phone +64 7 5774300 Extn: 77112 | Direct Dial 07 5774412
Tauranga Police Station, 11 Monmouth Street, P O Box 144, Tauranga 3140

That is so reasonable, I'm blown away

Originally Posted by Hermitage

I'll wait to see if anyone on this forum knows. If not I'll phone the local arms officer tomorrow (has finished from work today).

I'm not phoning a lawyer....he might charge me for the info

Na, he is usually happy to give a bit of advice. (from myexperience)

Andif heis going to charge, then surely he has to say what his rates etc are before you consent to employinghim.

Give him a call.