Thinking of drilling and doweling the breech to the upper
I have done a good bit of wrenching on my guns already and one area of design that bothers me is as follows. I have continually noticed that the breeches and the uppers have room to be manipulated as to their exact alignment and are only limited to the I.D. clearance in the upper and the O.D. diameter of the barrel. None have been perfectly aligned when initially disassembled but I do put them back as close to aligned as possible when I put them together. This alignment is just two flat faces kept in alignment by compressive forces when the moderator is tightened on the barrel. As an example my R3M/R3 .25 have .020″ clearance between the two components. Math would have me believe that .003″ of slippage or movement back there could be compounded to effect POI by almost .500″ at 50 yards with 3 times that much available in extreme shift.
#1: What do the people here think about this modification, It is very reversible with just removing the dowels. ??
#2: Would it be better to make matching counter bores in both components and make a disc that fits and fills both voids for the locator. ??
Doug…
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I would not choose a shroud fastened with only grub screw for the reason you mentioned. It will move. If the frame moves with the barrel, then there might not be dramatic changes in poi. With my gun I experienced shift because the barrel is smaller in od than the holes in the frame. Hence the need for shims. Also, my shroud screws on like the oem unit. However, I can only hand tighten it will never be as tight as the oem unit. My shroud is tight, but not enough to benefit from the “stretching effect”.
Ideally, I would like to keep the oem shroud if I could attach an LDC to make it as quiet as I need it be. For now, my current set up does the job.
Gabe
Yes. I need to email NC and ask him if he can make a Moderator that will go into place of OEM shroud Cover.
I have talk to NC years ago about this issue. He doesn’t have the tools or tube size, so I ended on bonding a FX 6″ shroud extension then screw on a Ldc adapter. Call him he may have the tools and tube now.
Unscrew OEM shroud cover (they are all the same for .22 or .25 R3) . It will expose the baffles. Then screw in replacement cover that is integrated to additional 5-7 inches of bigger in diameter moderator.
With This design there is no need to mess with Barrel mounting. It will retain OEM baffles, retain OEM barrel nut/stretching.
Here is a quick hand drawing LOL
Does it makes sense?
Hat this idea been tossed? -just curious
I also noticed that if the barrel nut isn’t pretty tight the gap between the cylinder and the shroud isn’t as distinguished as it is when it’s torqued with the Russian torque wrench;)
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My gun was down for a week, while I was doing a r3m for r3 swap with another forum member here. Back together now, hope to shoot a little tomorrow. I am wanting a good base Line, grooping on this 25 before turning it into a cast bullet shooter, gotta order a big tank Monday, I run out of air when I go somewhere away from home to shoot if using the 25 and or 30 with my little 90ci. tank. Im hoping to shoot 75 indoor tomorrow on the 25 and 30. I got everything in to start casting .257’s and a TJ’s custom hammer forged barrel on order for the 25 long.
Hey ride…any updates on your project? I didn’t know until after reading this post that the tension on the barrel nut is what’s keeping the breech snug. So I applied some anti seize compound to the nut and breech screws….lined up the breech and snugged the barrel nut down pretty good. Left side is aligned perfect….right side is a little off…but that’s due to the parts not being matched in production. Even with dowels it will never match up perfectly. But I have no issues with accuracy or leaks from the breech.
I also noticed that if the barrel nut isn’t pretty tight the gap between the cylinder and the shroud isn’t as distinguished as it is when it’s torqued with the Russian torque wrench;)
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What will this gain, just curious what you are working on here…
what it will gain is not accuracy but if I forget or someone does not know that it will come off in your hand and the gun end up on the floor,,and be in need of some serious work…..piece of mind
Thanks
I am doing the dowel mod to all of mine…
I do not see how a baffle system that does not use significant compression on the barrel as original does to tighten and clamp all these components together could ever hold a zero on the upper and scope mounting base. ?? This system uses compression from that nut to hold the front scope mounting base,shroud adapter,rear shroud,and front shroud adapter all with only squeeze. Pop you barrel nut off and judge for your self for the answer.
ride I did notice that after about a hundred shots or so that the two flats were not lined up like they were after the last time I torqued the barrel nut on my 30 cal they did move because I checked them with a straight edge when I had torqued them and after 100 shots or so I checked them again that’s how I figured it out,,,they wont move again..
What will this gain, just curious what you are working on here…
Thanks
I am doing the dowel mod to all of mine…
I do not see how a baffle system that does not use significant compression on the barrel as original does to tighten and clamp all these components together could ever hold a zero on the upper and scope mounting base. ?? This system uses compression from that nut to hold the front scope mounting base,shroud adapter,rear shroud,and front shroud adapter all with only squeeze. Pop you barrel nut off and judge for your self for the answer.
o and I forgot to mention the muffler cover on the gun will get put up and I will turn a new one with a collar on the end that will house the set screws to secure it to the baffle housing,,still working that one out where it looks good and functions well without doing any damage to the housing
Since there’s a lot of ldc talk o this thread I have some questions. I’m suppose to send my gun to NC for a screw on shroud. He assures me even tho it can only be hand tightened there wont be a problem. He said he has never had a problem with them and cant make one like the factory. I’m suppose to send gun out in a couple of days and don’t know what to do. Will the dowling mod make up for the new ldc and will anyone on here do that for others?
Thanks
After tuning and correcting all of the minor issues like muffler and orings I get regular 1/2″ groups at 50 yards. All I did was to select out bad pellets visually and there were only a few. I shot an entire tin in 30 5 shot groups and my best group was 3/8″. Most were about 5/8″ but plenty were 1/2″.
secoda what kind of groups are you getting at that speed,,,,i need data im all ears right now,,,
secoda what kind of groups are you getting at that speed,,,,i need data im all ears right now,,,
I don’t know what this gun is capable of doing accuracy wise yet, im still waiting on scope to come back from hawke so that will give me time to complete the mods and dream of this thing hitting its mark when I need it too,even if that means 700 fps to 800 fps or more I will study it till I find all its secrets.
Wow. Nice work. I am running 875 fps on my Standard 30 and I suspect it is still a bit hot for the barrel length.
I had to use a ream on the muffler so I figured why stop there,next will be the upgraded hst with lock nut and I will prolly do the hand grip on the stock and have it sprayed with bed liner,next im thinking I may turn the heat down some on fps to help save the valve and give me a few more shots,hell when you got a 44 grn 30 cal pellet coming out I don’t think a small drop in foot lbs of energy is gonna be a big thing,,,
Nice work all ! Although these “mods” should´ve done at the Factory, IMO. Maybe on the next run of EG´s ??
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This is what I was referring to and done to mine.