Moderator weight affecting accuracy?I

The weight of the moderator will change the POI, but not the accuracy in my experience.

So..... how do I approach this? You've got about a dozen potential factors all colliding to (probably) generate your observations, and it is kind of a lot to explain. Let me try and hit you with the sparknotes. 

If you don't shoot PBs, particularly higher power PBs, you might not be aware of why/how your form can affect your POI. In short how you place your ass behind the gun will affect your POI on groups. If you drop your shoulder under recoil or place your weight directly behind etc you can certainly walk your groups around. Some people deny this, but it is pretty trivial to demonstrate if you and your gun are good enough. Barrel length, muzzle brakes/moderators, gun weight, etc can all affect this equation. 

I also agree that it shouldn’t affect accuracy unless it was having a baffle strike.

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This though is completely untrue, in fact the complete opposite is true. Both firearm suppressor and airgun moderator design is a compromise between sound suppression and acceptable accuracy loss, among other factors. You can make a design which is very quiet and uses aggressive cross-jetting to accomplish it. You rarely see such designs though, because nobody is willing to tolerate the associated accuracy loss. Even in designs which don't generate cross-jetting like that, minor changes in how close the pellet travels to solid objects inside the moderator can open up groups without a physical baffle strike. It is a weird phenomenon to observe, but it is a thing. It is almost certainly more of a thing with airguns than firearms I should add, because airgun pellets are incredibly easy to destabilize. They have so little mass in their skirts (by design) but a great deal of surface area and it is right at the perimeter of the round. 



As far as doing diagnostics to try and split what factors are causing what, you might want to start with just having someone else shoot the gun. Changing form and printing some good groups might be very informative. None of this BTW is meant as a shot at Donny.



This whole stacking tolerances thing of attaching moderators is a giant mess, and I'm more than a little surprised we don't hear about its consequences more often. Either way I hope something in there is helpful. If you have any other questions, I'll do my best to try and answer them. 

My experience indicates that the more efficient the moderator, the better the accuracy. Maybe not a hard fast rule, but have seen it more than once.

I have noticed that a .30 does take more concentration to shoot more consistent. But once you get the hang of it man the results are awesome!! Interesting about the difference in the moderators though. I haven't had an issue though with one causing inaccuracies.

I think a key here is the weight difference.



My son shot an ar-15 on a national level. the rifle had to be within limits, even to the testing of the trigger which could not be below 3 lbs.

When looking at the rifle it appeared normal but both butt and forearm were stuffed with lead. There are companies which make form fitting

weights just for this. Anyway, the rifle ended up at 18, yes 18 pounds. This developed some strong arms and bodies, but most importantly,

it kept the rifle and sight picture from as much movement, therefor better accuracy.

I,ve seen more than one one inch group at 100 yards with open sights.

@pjdurand

yes you are correct in adding more weight to the gun will stabilize it. I used to shoot in competition matches (Aloha State Games) with a Caspian 45acp, anyways I used to have weights on the end of my barrel to keep the muzzle flip to a minimum and stay on the target.

Aloha

Aloha braddah Mark,

I tried to see if my moderator would change the poi on my impactX 700mm barrel because it's the longest barrel I have. Anyway i wen put the donny emperor v3 and brah the poi was like an inch lower at 50 yards, the group was tight just lower. My impactsX is tuned to shoot jsb 34gr @ 920 fps. I might rezero for this moderator because my wife said she couldn't hear me shooting, normally she does. I usually have my hugget magna on it.

Aloha