Point of impact with LDC

Point of impact with LDC

Joined: November 27th, 2011, 8:07 pm

March 5th, 2012, 5:40 pm #1

Has anybody experienced this . My rifle is shooting dead bulls eye with out the moderator. When I shoot it with the moderator it's down about 1 1/2 at the 5 o'clock position. Let me know if this is normal or is there something going on inside. Thanks guy's Jim
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Joined: April 1st, 2005, 4:58 am

March 5th, 2012, 5:52 pm #2

Clipping from an internal of the moderator or the final exit cap, and or whatever you have inside as a baffle or baffle material.



OR

The change in the gas vortexes caused by the LDC.


I have a POI change too, so I just leave it on all the time and shoot to the POI of the moderated gun.
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Joined: May 12th, 2001, 1:29 pm

March 5th, 2012, 5:58 pm #3

Has anybody experienced this . My rifle is shooting dead bulls eye with out the moderator. When I shoot it with the moderator it's down about 1 1/2 at the 5 o'clock position. Let me know if this is normal or is there something going on inside. Thanks guy's Jim
Steve
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Joined: November 27th, 2011, 12:01 am

March 5th, 2012, 5:59 pm #4

Has anybody experienced this . My rifle is shooting dead bulls eye with out the moderator. When I shoot it with the moderator it's down about 1 1/2 at the 5 o'clock position. Let me know if this is normal or is there something going on inside. Thanks guy's Jim
It always happens, same thing on my rifle
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Joined: July 24th, 2009, 4:33 pm

March 5th, 2012, 6:00 pm #5

Has anybody experienced this . My rifle is shooting dead bulls eye with out the moderator. When I shoot it with the moderator it's down about 1 1/2 at the 5 o'clock position. Let me know if this is normal or is there something going on inside. Thanks guy's Jim
I bought a Neil Clague LDC for a Hammerli Pneuma, and never saw a POI change when I put it on. But when I put that LDC on another rifle, I had to lightly "sand" the base of the LDC in the opposite direction of the POI shift. I taped off the half of the base that did not need sanding. This worked just fine. Neil would tell you to use a fine file, but I didn't have one at the time. I did have 200 grit paper.
Now here's the kicker. I put a shroud on that same rifle. The shroud came with a threaded adaptor that allowed an LDC to be screwed on to the end of it. Well, it needed the LDC. Not all shrouds are created equal. Wouldn't you know it? I now had to sand the LDC's base again. This time i gratefully only had to sand it true across the base. So, the POI is now the same with or without the LDC. Pretty simple, really. It turn out the "face" on the rifle(before the shroud installation) was not true, and I was sanding the base of the LDC to meet it.
hope that helps.
darryl
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Joined: November 4th, 2003, 11:39 pm

March 5th, 2012, 6:05 pm #6

Has anybody experienced this . My rifle is shooting dead bulls eye with out the moderator. When I shoot it with the moderator it's down about 1 1/2 at the 5 o'clock position. Let me know if this is normal or is there something going on inside. Thanks guy's Jim
<p>if your group is still very good at most outdoor distances (say 15 + yards) I would say clipping  is highly unlikely. Think about a pellet being clipped but still holding a tight group...I do not think its very probable- shot after shot. The way I read your post I would take it your group is still good? Correct me if I'm wrong. If the group is all over the place IE "no group" And the attachment is securely mounted then yes I agree clipping sounds like the problem.</p><p>Now as for the group moving. Well when you attach something on the end of a barrel or shroud obviously harmonics and the balance of the gun are going to change or at least can. Thus changing where the group falls or "zeros" to. I am very suprised that attachments do not change poi more than they do. And yes I have had it to where it does not change at all that I noticed anyway.</p><p>Without me going back to the post I am not sure ...is it a  shrouded model of airgun? Does the piece screw directly to the barrel or attach via set screws? There is another can of worms opened if its a shrouded model even without clipping.</p><p>Anthony Storey</p><p>PS and yes some of the ones I have built have "clipped" no doubt about it</p>
Last edited by FTAnthony on March 5th, 2012, 6:09 pm, edited 1 time in total.
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Joined: October 31st, 2003, 3:37 am

March 5th, 2012, 7:57 pm #7

Has anybody experienced this . My rifle is shooting dead bulls eye with out the moderator. When I shoot it with the moderator it's down about 1 1/2 at the 5 o'clock position. Let me know if this is normal or is there something going on inside. Thanks guy's Jim
<p>Often attaching any muzzle brake will affect the POI. I've seen it after installing a RWS, a Beeman, a Rich from Mich and  JM Apex muzzle brake on different guns. If your groups are acceptable then you can just adjust your scope for the change in POI. Under certain circumstances the change in the barrel harmionics caused by the direct attachment of the LDC or brake, could cause the most accurate pellet to no longer be that. You may have to check to see if another pellet shoots better with the LDC attached.</p><p> </p><p>Nathan</p>
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Joined: October 11th, 2006, 11:32 pm

March 5th, 2012, 8:16 pm #8

Has anybody experienced this . My rifle is shooting dead bulls eye with out the moderator. When I shoot it with the moderator it's down about 1 1/2 at the 5 o'clock position. Let me know if this is normal or is there something going on inside. Thanks guy's Jim
does not change POI and any distance. Then i have a shroud that does. Remember with these things (ldc's/shrouds) there are chambers/baffles that not only does a pellet slip through multiple small orifices but so does the air. And the air follows the pellet out of the barrel. The air and pellet coming out of a LDC is different than when the LDC/shroud is not in use. So POI will and can happen
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Joined: July 24th, 2010, 1:44 am

March 5th, 2012, 8:42 pm #9

Has anybody experienced this . My rifle is shooting dead bulls eye with out the moderator. When I shoot it with the moderator it's down about 1 1/2 at the 5 o'clock position. Let me know if this is normal or is there something going on inside. Thanks guy's Jim
to the barrel of a R9 will considerably change the point of impact at only 30 yards. Not a biggie for me, I simply readjusted the poi and the gun shot as accurate as before. Years ago I added a Beeman muzzle break to my R9s simply because cocking the gun was wearing the bluing off the barrel, and the "break" made a neat cocking handle.

Anywhoo......for me what you observed was commonplace.
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Joined: September 2nd, 2010, 1:00 pm

March 5th, 2012, 9:29 pm #10

Has anybody experienced this . My rifle is shooting dead bulls eye with out the moderator. When I shoot it with the moderator it's down about 1 1/2 at the 5 o'clock position. Let me know if this is normal or is there something going on inside. Thanks guy's Jim
the only thing it seemed to change at all was that groups over 50+ yards seems to tighten up a bit.
Could be my imagination but sure seemed to get tighter 75 & 100 yard groups with the Moderator installed.
Might just be the weight on the barrel.
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