177 M-rod POI shift may be gone....

[Doc]

You would need to make a new style stripper with threads and either thread the barrel or the shroud or both. The idea is to pull on the end of the barrel with the shroud pushing against the breach. The stock configuration pushes on the barrel and probably one of the reasons you get POI shift especially with a sticky oring. Tension will make the set up much more rigid and should eliminate that one weak area but I am a huge fan of pillar bedding and free floating the airtube. All my powder burners are pillar bedded and so is my Mrod.

[RayK]

All my powder burners are pillar bedded and so is my Mrod.

Did you do it yourself?

I want to do all my Marauder rifles, but it is such a messy job. I had to disassemble the trigger assy to get it clean and that is even with a release agent covering it all.

Ray

[jhm757]

You would need to make a new style stripper with threads and either thread the barrel or the shroud or both. The idea is to pull on the end of the barrel with the shroud pushing against the breach. The stock configuration pushes on the barrel and probably one of the reasons you get POI shift especially with a sticky oring. Tension will make the set up much more rigid and should eliminate that one weak area but I am a huge fan of pillar bedding and free floating the airtube. All my powder burners are pillar bedded and so is my Mrod.

I am not a Machinist and don't have access to a machine shop, or the funds to pay someone else to do the work.

So I guess I will have to stick with the easy stuff like lubing the air stripper o-ring.

Jim - jhm757

[RayK]

Jim, I know you're talking to Doc, but bedding the action cost very little if you do it yourself and that you're interested in accurate bench rest shooting, it would be worthwhile to do on your gun.

I spent about $10 on a pipe the diameter of the Marauder air tube to use as a sanding form to add tolerance to the stock inlet and to get it flat, then another $10 to $15 for the JB Weld. You need a mold release agent, but natural color shoe polish is supposed to work well.

Ray

[jhm757]

Ray

What I am wondering is how will this work with the synthetic stock?

It seems the air tube has contact with the synthetic stock only back close to the trigger assembly and then just above where the sling stud is. My concern is that without that contact point above the sling stud will the synthetic stock be rigid enough to not flex and make contact with the air tube anyway?

So would there be some way to stiffen up the synthetic stock without adding a ton of weight? Or do I need to go to a wood stock?

I think I would prefer a wood stock, except for the extra weight, but I got my rifle before the wood stock version was available.

The weight might be good if it was just a bench rest rifle, but I hunt with this rifle also.

Thanks!!!

Jim - jhm757

[SHOOTINIT]

Once you got a good barrel and pellet it likes and are not getting "fliers", the POI shifting will look like this. You shoot 3 pellets into a single hole, then the 4th, 5th, 6th, pellet go into a single hole away from the first hole, then it will shift back to the first hole for pellets 7, 8, 9, and 10.


Ray

SOUNDS LIKE A SCOPE ISSUE

OR LEAVE YOUR GLASSES ON FOR 4-5-6

[Doc]

Yes Ray. I was taught how by Mobe Renolds who tested barrels for Ed Shilen. I use a dial indicator attached to the barrel and read the end of the stock when tightening the action screws on a Remington 700. Its best to stuff modeling clay everywhere you dont want epoxy.

All my powder burners are pillar bedded and so is my Mrod.

Did you do it yourself?

I want to do all my Marauder rifles, but it is such a messy job. I had to disassemble the trigger assy to get it clean and that is even with a release agent covering it all.

Ray

[jimmyk]

When you screw down the shrould end cap does it put any pressure or compression on the air stripper? I know there's a ridge that keeps the baffles in place but I don't know if the air stripper mates up to the first baffle. If so I guess that might be an issue. I'd take one of mine off but there both shooting too well to be jacking around with it. . I like to see one of you guys that has the equipment and the know how to put together a tension system. DOC has mentioned it several times. I think DR650 could design one also .
JImmy

[RayK]

Its best to stuff modeling clay everywhere you don't want epoxy.

Excellent idea. I'll do that next round.... It would be easier to clean out clay than epoxy.

Doc's barrel-in-tension idea is a good one, but requires some serious changes to the basic design.

Ray

[Doc]

Yes it does. If you have the earlier o-ring version or the spring version it pushes against the stripper and barrel. Hold a long piece of thin wire between your two index fingers and put a little pressure on it. See how it flexes? I think this is happening on our Mrods and each time the gun is fired the harmonics make the barrel wiggle and if it has pressure against it who knows where it will settle in place for the next shot. Thats why the POI mods like the solid air stripper and SSBB have helped but have not eliminated it. I removed the oring behind the cap and taped the stock baffles so they are a pretty snug fit in the shroud. My stripper is tight on the barrel and the baffles are against the end cap with the o-ring removed so the first baffle does not contact the stripper and there is no pressure on the barrel.

When you screw down the shrould end cap does it put any pressure or compression on the air stripper? I know there's a ridge that keeps the baffles in place but I don't know if the air stripper mates up to the first baffle. If so I guess that might be an issue. I'd take one of mine off but there both shooting too well to be jacking around with it. . I like to see one of you guys that has the equipment and the know how to put together a tension system. DOC has mentioned it several times. I think DR650 could design one also .
JImmy