Changing moderators and accuracy.

[Redgum]

Recently change moderators on several of my centrefires, I always zero whenever I change anything as a matter of course and expect the zero to change. When researching on the net for reviews I came across some interesting info on the fact that by changing the harmonics of the barrel with a different weight moderator, bullet grouping could also be altered, sometimes quite dramatically. Something worth knowing, especially for those that don't know much about barrel harmonics and ammo as last year I heard from a mate who had been out with someone shooting and missed a fallow three times, he had put a different moderator on the rifle without test zero, luckily it was three misses and not an injured deer.

[shootgun]

Gave up using moderators on my rifles for this very reason.

 

I belive the benefits of using a moderator are outweighted by the advantages of not using one.

Edited November 17, 2016 by shootgun

[Dead-Eyed Duck]

Gave up using moderators on my rifles for this very reason.

 

I belive the benefits of using a moderator are outweighted by the advantages of not using one.

I personally wouldn't be without a moderator, as the noise without one can be ridiculous, especially when lamping at night.

 

I can only say that 0.75" groups at 100 yards have been easily achieved on my 0.17Rem, 223 Remington 700, 22-250 Remi Varmint and 223 Sako, all fitted with moderators.

 

Perhaps it has something to do with the make of moderator?

[Dougy]

They should improve accuracy more often than not, reducing flinching, muzzle flip and less felt recoil. All 3 will improve accuracy.

[shootgun]

They should improve accuracy more often than not, reducing flinching, muzzle flip and less felt recoil. All 3 will improve accuracy.

 

Flinching is due to the man behind the butt, nothing to do with the rifle.

 

I do agree a moderator help in respect with the muzzle flip and recoil, however, those happens after the bullet leaves the barrel so nothing to do with accuracy.

[sako751sg]

Would say its common sense to re-zero after changing mods so its lesson learned hopefully.

Wouldnt be without a mod now on any rifle as great to see bullet strike combined with way less noise.

[Dunkield]

I does seems bit foolish to not check zero after trying a different mod, the POI can change dramatically.

When I had my PES t12 on my .223 mod off to mod on was about 5 or 6 inches different, going to an ASE on the same rifle it is just few clicks difference mod on/mod off.

[LeadWasp]

They should improve accuracy more often than not, reducing flinching, muzzle flip and less felt recoil. All 3 will improve accuracy.

as an integrated system of man, gun, and support you're dead right.

 

I'd debate the bit (not yours) about beneficial effects on recoil happening after the bullet has left. The air displaced by the bullet will impinge on the internals of the moderator with increasing effect AS the bullet travels down the barrel. So there will be some benefit during this time. Also the bullet is never going to outrun the gas expanding behind it so this gas will also impinge on at least the first section of the moderator whilst the bullet is still inside it.

 

I can see few real world advantages to not having a moderator - length, weight and carry mainly. A downside of a couple of hundred FPS aren't going to make a huge difference to sporting shots and you get to keep your hearing for longer. A well made moderator is a very useful thing.

Edited November 18, 2016 by LeadWasp

[bornfree]

I had a similar problem. I have two tikka t3 varmints one 243 one 223. The 243 will shoot groups with any mod on it. The 223 is perfect with a predator 8 on it but with a wildcat evo or an ase jet z it was like a shotgun pattern. Both those mods work fine on the 243.

[Redgum]

I had a similar problem. I have two tikka t3 varmints one 243 one 223. The 243 will shoot groups with any mod on it. The 223 is perfect with a predator 8 on it but with a wildcat evo or an ase jet z it was like a shotgun pattern. Both those mods work fine on the 243.

 

If you reload you should be able to custom a load to suit any moderator, in theory anyway.

[fortune]

I does seems bit foolish to not check zero after trying a different mod, the POI can change dramatically.

When I had my PES t12 on my .223 mod off to mod on was about 5 or 6 inches different, going to an ASE on the same rifle it is just few clicks difference mod on/mod off.

I find this very interesting because I have a pes 12 and I have used it on my fully bedded win mod 70 lightweight in 223 and I can't use it at all. The difference between on and off is in the next field. I can zero the gun off mod and it will shoot a tight group on the dot but fit the mod and it will shoot a tight group but in the next field. It is so different that the distance is greater than the adjustment of the scope. This can be compensated for by moving the bases but not the elevation. Still shooting without is just one shot per target usually so I'm not that fussed about not using the mod.

[fortune]

If you reload you should be able to custom a load to suit any moderator, in theory anyway.

I do agree that it could be done but I couldn't be bothered to have two completely different loads and the possibility of them getting muddled up.

[activeviii]

not only will it adjust the harmonic wave to the barrel but also the FPS will go up as well., i have known a titanium mod to shoot higher then a bare barrel.

 

you can, if using factory ammo, use a harmonic bung from limb saver to adjust the wave and tighten the group. you can also use them with home loads if your swapping between mod, brake and bare rifle to tune for the same POI.

[Bangbangman]

I am pro-moderator but have experienced extreme loss of accuracy on two occasions. One was .308 (.30 cal mod) and the other a .22LR. In both cases, bullets were clipping one side of the final "baffle"/end cap.

 

If you are experiencing dramatic loss of accuracy (rather than shift of POI) with a mod fitted, get a DECENT gunsmith to check your muzzle-threading and moderator. Not all threading jobs are done well...

 

I've also seen bullet-clipping with mod that has loosened during a string of shots (not me).

 

Bullets that haven't stabilised (twist too slow, heavy subs for e.g.) can hit the mod but would also show poor accuracy without mod.

 

not only will it adjust the harmonic wave to the barrel but also the FPS will go up as well., i have known a titanium mod to shoot higher then a bare barrel.

 

A change in barrel harmonics could certainly cause point of impact to be higher but how would fps be increased by a mod?

Edited November 19, 2016 by Bangbangman

[fortune]

The group position on my rifle with the mod on is WAY, WAY down and right. I put a rod up the barrel and it was central in the mod. When I've got the time to get back into it I will have to reload different bullets at different velocities to try to make some sense of it all. The problem is finding a mod that would work from all of the ones out there.

[Dekers]

I does seems bit foolish to not check zero after trying a different mod, the POI can change dramatically.

When I had my PES t12 on my .223 mod off to mod on was about 5 or 6 inches different, going to an ASE on the same rifle it is just few clicks difference mod on/mod off.

 

More than a bit I'd say!