I knew there'd be a moderator POI shift but WOW!

[TG59]

This is my first add-on moderator experience: a Weihrauch slide-on model for the 16mm barrel on an .177 caliber HW95 springer. The is the type that is held on with grub screws and fits around the front sight. This gun has been tuned and has a smooth shot cycle at 14 fpe.

I have read that moderator benefits for springers are debatable, but qualitatively the gun seems to have a much quieter report during first trials when shooting inside my garage at 10 yards.

I anticipated a POI shift but was very surprised when groups at 10 yards were nearly 2 inches lower when using the factory iron sights attached to the barrel. The vertical POI change was very similar for the three pellet types tried. There was no noticeable horizontal POI change.

The unit fits snugly to the barrel with very little clearance. The smallest hole through the moderator is at least 0.265" which gives some clearance for the 0.177" pellet.

Groups at 10 yards are still within my margin of error with iron sights and show no signs of irregularity As soon as the weather allows I will put the scope back on and check groups at longer distances.

 

[Gerry52]

When I put my Donny FL Ronin on my FX Royale or Boss I have to compensate 2 mildots for "droop". Accuracy is superb while using it, actually a hair MORE accurate but, I too, was surprised at the amount POI changed that 1st time. As long as horizontal is not affected it's easy to deal with.

 

[Sqwirl57]

Moderators on springers absolutely make a difference down range from the gun although it may not seem like it from the shooters standpoint thanks to all the noise from the piston slamming home. Setup a camera down range and record a few shots with the moderator on and off. The audio will tell you all you need to know.

 

[Rawroots]

This is my first add-on moderator experience: a Weihrauch slide-on model for the 16mm barrel on an .177 caliber HW95 springer. The is the type that is held on with grub screws and fits around the front sight. This gun has been tuned and has a smooth shot cycle at 14 fpe.

I have read that moderator benefits for springers are debatable, but qualitatively the gun seems to have a much quieter report during first trials when shooting inside my garage at 10 yards.

I anticipated a POI shift but was very surprised when groups at 10 yards were nearly 2 inches lower when using the factory iron sights attached to the barrel. The vertical POI change was very similar for the three pellet types tried. There was no noticeable horizontal POI change.

The unit fits snugly to the barrel with very little clearance. The smallest hole through the moderator is at least 0.265" which gives some clearance for the 0.177" pellet.

Groups at 10 yards are still within my margin of error with iron sights and show no signs of irregularity As soon as the weather allows I will put the scope back on and check groups at longer distances.

Let us know if fps also suffers, thanks.

 

[Sqwirl57]

Let us know if fps also suffers, thanks.

If there is any change in velocity it will probably bump it up a hair but realistically there will be next to no difference on a springer. That whole "silencers reduce power" thing is just video game nonsense. Silencers and moderators give a little more room for the air to push the pellets before the baffles strip the air out.

 

[Rawroots]

If there is any change in velocity it will probably bump it up a hair but realistically there will be next to no difference on a springer. That whole "silencers reduce power" thing is just video game nonsense. Silencers and moderators give a little more room for the air to push the pellets before the baffles strip the air out.

The reason i asked was i tried a small moderator on a pcp, and it suffered fps along with accuracy, when i put a larger moderator on, my fps returned along with original accuracy, quite sure caused a restriction on air leaving barrel. Back pressure.

 

[Sqwirl57]

The reason i asked was i tried a small moderator on a pcp, and it suffered fps along with accuracy, when i put a larger moderator on, my fps returned along with original accuracy, quite sure caused a restriction on air leaving barrel. Back pressure.

Sounds like there was some slight clipping on the smaller moderator

 

[Rickrick]

I agree with Sqwirlgugger on clipping.

That much change is more likely clipping. I had to change from a frame attached moderator on my condor to a barrel screw on moderator.
I have beat my gun up pretty bad and I wouldn't guarantee my barrel is lined up with my frame perfectly but the donnyfl changed accuracy greatly with it being attached to the barrel and not the frame.

Then one day poi began going 4" off at 50yds. I finally realized the slugs were clipping again right as the slugs were leaving the moderator.
I had to start filing the end cap more and more, the end cap is close to a .4 opening in my .25 moderator.