One moderator for two different rifles

Erik Hamburger

Well-Known Member
I have looked in some detail into moderators, in particular the weight and length (I am looking for a light-weight and short moderator) considering the materials used and the price asked. As the amount of Posts on this site indicate, a confusing subject, as there is no industry benchmark test and the amount of moderation also depends on the type of round/load. However the majority of manufacturers claim a moderation of between 25-28 Db - no manufacturer seems to be able to improve on that range or falls below it.
Having decided on the manufacturer I wonder if the moderator for the .308W rifle can be used on a .243W rifle without any significant reduction in moderation. (The barrel screw threads are, btw, the same on both rifles, yes I did check!). Obviously, one would expect a .308W moderator on a .243W rifle to be slightly less effective than a .243W moderator on a .243W rifle.

But...by how much????
Noticeably?
Negligible?


Thank you for sharing your views and experience.
 
I use an ase utra northstar on my .243 and .308 (a .30 cal one) and tbh the noise reduction is perfectly acceptable on both.
 
i use my old hardy g4 that was on the .243 17x1 now its on my 6.5 . my other t8 fits any 14x1 up to .308
 
I've recently been using my .308 roedale on my .223 and it isn't as quiet but it still saves my ears so it's good enough.
 
I'm glad you posted this thread, I could only get a .308 one for my .243 and was worried it'd be a bit baggy!

I'll rest easier knowing other folk are ok with it.
 
I bought a second Wildcat Predator off here, was sold to him and listed on his ticket as .30 cal, turned out it was a .338!. Sounds exactly the same as my other Predator (which is a .30) shooting on both a 308win and a 300aac Blackout :)
 
I use the same 6.5mm bore PES on 6 calibres from .243, .222, .22, .17

it is a high quality high attenuation moderator to start with
really don't think it matters for the lower calibres
closer is better but unless the moderator is already poor on the sound reduction level am not sure your average shooter would notice the difference
 
Excellent replies, thank you. The consensus appears to be that it will be perfectly fine. It wil require two different rear bushes as the two barrels are of a different outside profile, but they are easily changed.

Obviously, when I asked someone who makes and sells moderators, the answer was that it would really be better to have two! Yes, hmm. ;)
 
Does anyone know how much larger the moderator hole diameter is to the actual calibre its designed for?

Might be interesting to measure this difference-maybe a cf .22 mod has a hole of .35 diameter. Any reloaders out there with calipers like to check?
 
I have a copy of a scandinavian shooting mag where the journo tested 22, 6mm, 6.5, 308 and 35 or 375 moderators.
Using a moderator for the right size of cartridge will always give the best results.
In the test the author tested 223 with the above mods and measured results, and then 6mm with all of them etc.
I don't have the said mag to hand but I believe it was somewhere in the region of a 2db reduction of moderation with each calibre group, more so I think using a 22 or 6mm on a mod for a 375.
I dont think it will make any noticable difference using a 30 cal mod on a 6mm rifle, just don't do it the other way round:doh:
 
Hi all,

I've got an ATEC CMM 4 marked <6.5 that I use on my 22.250.

Does anyone have any thoughts on getting it reamed out to 7mm so I can use it on a .270 By my maths .270 is 6.86mm. How much bigger does the bore of the moderator have to be than the round?

it would be nice to be able to use one Mod for both rifles but I don't want to kill myself for the sake of a couple of hundred quid.

Cheers,

Jim
 
I use the same Aurora on my .308 .223 and .243............no problems but seriously considering going without when woodland stalking for more ease of shooting offhand...........
 
This interests me since I am about to buy a Browning A Bolt in .223 flavour with a T8 mod.

I liked my .270 Browning A Bolt so much I pretty much narrowed the field to another one :)

I had been wondering whether the mod could be switched between the two guns - the barrel diameter won't be an issue but I imagine I will have to measure the bore to ensure sufficient clearance for the .270 round.

Don't want to turn my biggest cannon into a bomb...
 
It's not simply a case of the size of the hole because the bullet may yaw on exiting the barrel. This is more likely with long, boat tail bullets, worse if marginal for your twist rate. I would never try and use a .223 mod for a .270, even if the bullet "theoretically" fits through the measured bore. The exit bore of the mod is not always the narrowest section (as I found when I stripped my Predator.

I use an Ase Utra .30cal mod for my .308, .243 and .223 rifles, with good effect for all manner of stalking/foxing loads. However, during preparation for a comp requiring mods, I was using my .308 and my standard target homeload. The latter uses a Lapua Scenar 155gr bullet which I'd never fired through the mod. To my surprise the groups were erratic because the bullet was clipping the edge of the mod. I contacted the shop who sold it (and threaded the barrel). They were happy to take it back and have the rifle in to inspect the threading job. They did suggest (at my discretion) that I open-up the bore in the area of the clipping (they would still uphold their offer to replace and inspect irrespective of my tinkering.)

Due to the hassle of getting the mod and rifle back to them, I chose to tinker first. Happily it worked and the groups were back to unmoderated normality. I had not had the same problem with stalking bullets before this. My assumption is that the increased yaw of the longer bullet (in comparison to hunting designs) was enough to clip the mod.
 
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