FX FX Impact M2, M3, M4 POI shift when installing moderator

[Superpete]

Hi, wan to get your opinion how you deal with this issue.
When I go out shooting in the woods, I carry my M3 700mm barrel with no compensator, when I shoot on my backyard I put on DonnyFL YOKOZUNA, point of impact shifts with compensator on it due to barrel sagging, as you can imagine, shift is about 2MOA, my backyard shooting range is 40 yards.

Now, I would like to hold same POI at all times, so I can go back and forth without re-zeroing.

So I looked in to this, there are few solutions.

1. Bottle to barrel clamp - I got one, did not like it, just because if I need to switch bottle, it messes up POI pretty bad, big time re-zero, that clamp pulls barrel way off, so, this option is not an option.
2. Barrel tensioner - I keep watching videos about them, FX one seems to be best option, BUT people complain how loud it gets without shroud, AND will that keep barrel straight with or without compensator, no sagging? I did not come across any videos or posts confirming that.
3. SaborTactical TRS rail with barrel support - many reviews, some say it's working great, others saying that it's not, also I don't want to add lots of extra weight to my M3, walking the woods already heavy enough, don't know how much rail weight is, can't find that anywhere, but I imagine it's little bit extra, but the BIG questions, will it do for what I need it to do?

Any other options out there, or I just put that DonnyFL on and keep it on all the time, but again, go in the woods, that barrel gets little big longer, little bit heavier, I rather walk without it.

Any thoughts on this would be appreciate it, how do you deal with this?
Thank you very much!

 

[JaceSpace1369]

Hi, wan to get your opinion how you deal with this issue.
When I go out shooting in the woods, I carry my M3 700mm barrel with no compensator, when I shoot on my backyard I put on DonnyFL YOKOZUNA, point of impact shifts with compensator on it due to barrel sagging, as you can imagine, shift is about 2MOA, my backyard shooting range is 40 yards.

Now, I would like to hold same POI at all times, so I can go back and forth without re-zeroing.

So I looked in to this, there are few solutions.

1. Bottle to barrel clamp - I got one, did not like it, just because if I need to switch bottle, it messes up POI pretty bad, big time re-zero, that clamp pulls barrel way off, so, this option is not an option.
2. Barrel tensioner - I keep watching videos about them, FX one seems to be best option, BUT people complain how loud it gets without shroud, AND will that keep barrel straight with or without compensator, no sagging? I did not come across any videos or posts confirming that.
3. SaborTactical TRS rail with barrel support - many reviews, some say it's working great, others saying that it's not, also I don't want to add lots of extra weight to my M3, walking the woods already heavy enough, don't know how much rail weight is, can't find that anywhere, but I imagine it's little bit extra, but the BIG questions, will it do for what I need it to do?

Any other options out there, or I just put that DonnyFL on and keep it on all the time, but again, go in the woods, that barrel gets little big longer, little bit heavier, I rather walk without it.

Any thoughts on this would be appreciate it, how do you deal with this?
Thank you very much!

I don't think it matters what you do to the rifle.You will always have a point of impact shift. My Uragan 2 barrel is clamped on with eight screws, the moment I put a moderator at the end of the point of impact shifts. Even if it's by .5 - 1 moa

 

[nervoustrig]

For what it’s worth, my experience has been that even tensioned barrels and heavy walled barrels secured in the beefiest of receivers…they still exhibit an obvious POI shift when a moderator is attached. They help but if your goal is an imperceptible elevation change at 40 yards, the chase will probably drive you mad.

If God smiles upon you, it may work out that a barrel band located close to the muzzle will do the trick. But often times even this approach will still exhibit some shift, presumably because of the moderator’s effect on muzzle blast, or a walking POI shift will emerge as the reservoir pressure declines, or the approach is simply not viable for other reasons (like the practical reason you cited).

My advice? Well…nothing ventured, nothing gained so by all means try to improve upon the current 2 MoA shift but don’t get discouraged if it can’t be reduced to zero.

Another way of dealing with it is to simply make a second range card. I realize it’s not especially appealing to those of us who have the unrelenting drive to slay the dragon but it is perhaps the most pragmatic and expedient.

 

[Ries]

Honestly, the only real decision here is whether or not to keep the moderator attached.

I’ve seen mixed reviews about the Saber TRS rail as well. It’s a pricey upgrade, and if it doesn’t deliver, that’s a hard pill to swallow.

As for the FX tension kit — it’s far from perfect. It removes the shroud, and suddenly the Impact sounds like a .22LR. On top of that, some users have reported POI shifts, likely due to how the carbon fiber gets tensioned across various parts of the rifle. Temperature fluctuations seem to play a role in that as well. The tension kit is like a bandage on a wound.

 

[Superpete]

Honestly, the only real decision here is whether or not to keep the moderator attached.

I’ve seen mixed reviews about the Saber TRS rail as well. It’s a pricey upgrade, and if it doesn’t deliver, that’s a hard pill to swallow.

As for the FX tension kit — it’s far from perfect. It removes the shroud, and suddenly the Impact sounds like a .22LR. On top of that, some users have reported POI shifts, likely due to how the carbon fiber gets tensioned across various parts of the rifle. Temperature fluctuations seem to play a role in that as well. The tension kit is like a bandage on a wound.

I agree, TRS rail is expensive but if it did the job, I would say it's worth the money, but to get one to try and ended up not using it, that is hard pill to swallow. Thank you for your input.

 

[FXmaster]

Moderator causes turbulence in all baffle internal design or how tight the muzzle exit hole is, if you change moderator or remove , all of them will have a different / slight point of impact shift. Also, if you add a moderator, the baffles tightness will help propel the projectile that resulted in a slight feet per second increase. So don't borrow a moderator expecting it has the same point of impact. There is also thread tolerance, If you have a moderator that is fitted loosely side to side - when you tighten mod down the silencer center line will be off with the barrel and this affects the clearance of the ammo through the baffles that will cause POI shift. In 100 yard event i sometime take off the air stripper or moderator and see which condition handles the wind better in windy condition. I have to shoot at the sighter to re-zero or measure the point of impact shift. Moderator does affect accuracy, at times I test different silencers and they all different group size and yes, I select the one that has the tightest group. and prior to all the testing, I make sure the barrel and silencer turn truly on a lathe or v block to Make sure the two turn straight as one

 

[Superpete]

Ok, I got it. Thank you for explanation, looks like I will probably keep moderator on at all times. Thanks again