Moderator damage - is this normal?

[Reloader708]

I only have moderators on my hornet and .22-250, they are all alloy construction but have a heavy stainless baffle which the hot gasses hit first after exiting the muzzle. I've had a fair number of rounds through both and when I strip them down you can see the baffles are slowly eroding. Obviously the .22-250 is eating the baffles much quicker than the hornet. You basically have an oxy cutting torch coming out of the muzzle. I did managed to get a set of spare baffles so I can replace as needed.
Have you a short barrel on your 708? If you are running full power loads through a short tube you'll have a big muzzle flash contained inside the moderator which will only make things worse. You could make life easier for your moderator with a bit of careful reloading without losing much in the way of velocity.

 

[Woodsy]

I only have moderators on my hornet and .22-250, they are all alloy construction but have a heavy stainless baffle which the hot gasses hit first after exiting the muzzle. I've had a fair number of rounds through both and when I strip them down you can see the baffles are slowly eroding. Obviously the .22-250 is eating the baffles much quicker than the hornet. You basically have an oxy cutting torch coming out of the muzzle. I did managed to get a set of spare baffles so I can replace as needed.
Have you a short barrel on your 708? If you are running full power loads through a short tube you'll have a big muzzle flash contained inside the moderator which will only make things worse. You could make life easier for your moderator with a bit of careful reloading without losing much in the way of velocity.

Interesting observations, thanks for sharing those. Yes it’s a short barrel, so what you say makes sense to me.
I use cheap factory ammo, PPU, which my rifle is very happy with. I’m sure you are right in saying that I could reload and make ammo which isn’t so hard on the moderator, but I’d rather buy a new moderator every couple of years than spend all the time and money I’d need to invest with another hobby!

I do appreciate the points you make though. Cheers,

 

[ejg]

We used to sell modular moderators and we sometimes added a baffle etc. Often fitting a stainless first baffle followed by alu baffles. The funny thing was... it was not always the first baffle that had the most damage. Sometimes second or third were worse.
Recon if one would look closely at what happens one would find the reason. Often loads of little bits are part of the payload going through the mod. Bits at supersonic speeds are also very abrasive. Maybe the "bits" need a bit of time to open the pattern.

This is a great video of what it looks like inside a mod when a shot is fired.


edi

 

[Odders]

I’ve had a Shultz and Larsen superdome moderator on my 7mm08 for about two years. I only shoot PPU 140 grain ammo.I don’t do any target shooting, only deer stalking and occasional practice/checking zero during which I fire maybe ten or fifteen rounds, (maybe one session like this every couple of months).

Every time I shoot the rifle, even if just one shot while stalking, I take the mod apart and clean it well with wd40 and kitchen towel until there’s no trace of any muck on the kitchen towel.

The end section of the moderator has started to erode - see pics. Is this normal/expected for such light use over two years? Anyone else with one of these mods notice the same?

Will this affect accuracy?

Get in touch with S&L or Alan Rhone, as I'm sure they'll want to see this.

ETA
Superdome moderators are from the "Hardcore" range & thus every baffle has a high chrome, stainless steel insert in the centre.

I'll admit to being surprised the front chamber doesn't include such an insert - will look at mine in the morning.

ETA 2
I see you've been in touch with Alan Rhone - best path forward IMO.

 

[G4ZZ]

I once had a Stalon that lost accuracy and after opening it up the inside was very much like the pictured mod, I was told it was from gas cutting.

 

[Jelen]

You may well be right and I intend to e-mail AES and get confirmation from them. If I get a response - one way or the other - I will post it on here.

OK. I e-mailed ASE Utra and got the following reply from their Sales Director
QUOTE: WD-40 or gun oil can be useful with aluminium suppressors where the corrosion is a bigger issue. To sum it all up: If I had a Jet-Z, I wouldn’t use any oil and it would still last 10 years. UNQUOTE.
Make of that what you will, but I will now follow his advice. I am keeping his e-mail in case my Jet Z falls apart in 4,995 shots

 

[Edinburgh Rifles]

"but the manufacturer does not recommend that is cleaned "

Finally.....

It is gas cutting though
very obvious difference between gas cutting/burning and clipping
"Gas cutting" leaves a porous but relatively smooth surface with a relatively uniform surface on the inside edge perpendicular to the bore
clipping shows physical witness marks, fractures and broken edges at the extreme, deformed edges, "lips" to the bore, deformity on the opposite side to the muzzle of any plane surface