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Gunsmithing What is the advantage of an integral lug and rail

Tony1320

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Minuteman
Feb 13, 2017
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I've always read and heard that integral lug and rail was important or a benefit but why? What exactly is the advantage over a properly pinned lug and rail?
 
I don't know the benefits of an integral lug. As for the rail, it isnt' going to move under recoil. I would think a lugged rail would have the same benefit, but I don't have any information to back that up.
 
More ridgid. Less parts.

What does that really do for you? Will a pinned lug action headspace the same everytime like an integral lug action so you can order barrels without sending the action in?
 
Yes. A separate lug (assuming it's flat) will headspace the same every time with the same torque just like an integral action.

An argument can be made for the rigidity of the system... but you're really starting to split hairs at that point. I think the biggest thing is that you don't have to worry about screws coming loose and you don't have to worry about lining your lug up @ 6 o'clock.
 
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The benifit is to the gunsmith working on the rifle. No need to turn an area on the tenon for the lug. No need to setup for indexing the recoil lug, or drill into the receiver for a pin. Less risk of making a mistake.

Theoretically, it should cost a little less and have a faster turnaround. But its moot on Winchesters and FNs. Cutting the ectractor clearance is more time consuming than dealing with the recoil lug.
 
The benifit is to the gunsmith working on the rifle. No need to turn an area on the tenon for the lug. No need to setup for indexing the recoil lug, or drill into the receiver for a pin. Less risk of making a mistake.

Theoretically, it should cost a little less and have a faster turnaround. But its moot on Winchesters and FNs. Cutting the ectractor clearance is more time consuming than dealing with the recoil lug.

It’s a mixed bag. The gunsmith doesn’t get paid to do all those operations then he’s just hanging barrels.
 
Food for thought after a 25 year stretch of doing this stuff:


Integral lugs are nice because you don't have to clock the darn things when you bed a rifle.

Typical scenario: Blueprint, barrel, fit to stock. Tear down, clean up, finish work, coating, now reassemble the B/A. The real fun now starts.... All the Badger wiz banger clocking tools in the world don't work for shit 99.9% of the time on a bedded rifle. You end up being ever so slightly off and then you spend a half day dinking around to get that lug snugged back up exactly where it was when you did the receiver casting in the stock. If you tape the sides of the lug, the clearance gives you a teeny weeny bit of room for margin, but its not much.

I speculate this could be why so many folks bed a gun after coating the action. They may say its all about the most obsessive fit possible, I say it avoids the desire to slit your wrists while meditating in the middle of a busy street. :)

So, pinned lugs and integral lugs are the shizzle from a GS perspective. The shooter at home should really care less. The gun is no more accurate with or without one. That is fact and Remington M700's have proven it over and over again.

Integral bases:

Nice if you make a habit of pitching your rifle off cliffs. The issue I have with them is you are stuck. Lets be real, OPTICS are a big, big deal to shooters. If I suddenly have an epiphany tonight and tomorrow I begin offering the absolute bestest, greatest, wiz bangy optic ever, folks will come running. Now, say my optic requires a 0 moa optic cause I have Jedi powers that bend light and a 30moa base is advised against. Well, all you guys with one piece 30moa based actions are now excluded from the opportunity.

Interchangeable bases give options, that is my only point here. Scopes change with more frequency that one might think. x10 in the "Gamer Gun" crowd cause guys are always looking for the edge.

Rifles have worked extremely well with little screws holding bases for over a century now.

Just a thought...
 
A pinned lug should headspace the same as a integral lug. But as said a integral lug gets you a few more threads and will never ever come off. Same with the rail. Pinned beats just screws, integral beats pinned unless for some reason as Chad said you need to change it. I've been running 20 MOA rails for a while and never had a reason to change.
Chad, when is the release on the Jedi scope and how many internal organs will it cost?
 
Food for thought after a 25 year stretch of doing this stuff:


Integral lugs are nice because you don't have to clock the darn things when you bed a rifle.

Typical scenario: Blueprint, barrel, fit to stock. Tear down, clean up, finish work, coating, now reassemble the B/A. The real fun now starts.... All the Badger wiz banger clocking tools in the world don't work for shit 99.9% of the time on a bedded rifle. You end up being ever so slightly off and then you spend a half day dinking around to get that lug snugged back up exactly where it was when you did the receiver casting in the stock. If you tape the sides of the lug, the clearance gives you a teeny weeny bit of room for margin, but its not much.

I speculate this could be why so many folks bed a gun after coating the action. They may say its all about the most obsessive fit possible, I say it avoids the desire to slit your wrists while meditating in the middle of a busy street. :)

So, pinned lugs and integral lugs are the shizzle from a GS perspective. The shooter at home should really care less. The gun is no more accurate with or without one. That is fact and Remington M700's have proven it over and over again.

Integral bases:

Nice if you make a habit of pitching your rifle off cliffs. The issue I have with them is you are stuck. Lets be real, OPTICS are a big, big deal to shooters. If I suddenly have an epiphany tonight and tomorrow I begin offering the absolute bestest, greatest, wiz bangy optic ever, folks will come running. Now, say my optic requires a 0 moa optic cause I have Jedi powers that bend light and a 30moa base is advised against. Well, all you guys with one piece 30moa based actions are now excluded from the opportunity.

Interchangeable bases give options, that is my only point here. Scopes change with more frequency that one might think. x10 in the "Gamer Gun" crowd cause guys are always looking for the edge.

Rifles have worked extremely well with little screws holding bases for over a century now.

Just a thought...

Thanks for chiming in, that cleared things up
 
I thought I would bump this thread up with a question I've been wondering: If I buy a custom action with a pinned rail and pinned lug will there ever be a situation where I think to myself: "Damn I wish my action had an integral rail and lug!"
 
I thought I would bump this thread up with a question I've been wondering: If I buy a custom action with a pinned rail and pinned lug will there ever be a situation where I think to myself: "Damn I wish my action had an integral rail and lug!"

Only time would be if the rail works itself loose at the wrong time. Even pinned, it can cause POI shifts.
 
I thought I would bump this thread up with a question I've been wondering: If I buy a custom action with a pinned rail and pinned lug will there ever be a situation where I think to myself: "Damn I wish my action had an integral rail and lug!"
Both are not important to me.
I’m actually happy my Nuke has a separate rail as I was able to put one on it with more inclination.
 
In a recent podcast, Phil Cashin proposed that actions able to be turned as a cylinder (non integral lug or rail) inherently fit better into chassis. His assertion was its much more probable of that action having as close to perfectly turned surface as possible.

He says they see less movement and less need to bed those types of actions into a chassis.

The logic makes sense to me.
 
A round action typically sits on only a small part of the chassis. A flat bottomed action makes more sense.
 
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A round action typically it’s on only a small part of the chassis. A flat bottomed action makes more sense.

The context was comparing non flat bottom actions with and without integral rails or lugs.
 
If you don’t want to mount a round action in a chassis without bedding, it’s a moot point.

Also I’m not a machinist but impatience or poor capitalization strikes me as the only reason a round action made on a mill would be out of round.
 
If you don’t want to mount a round action in a chassis without bedding, it’s a moot point.

Also I’m not a machinist but impatience or poor capitalization strikes me as the only reason a round action made on a mill would be out of round.

Take it up with the dude who has been putting all types of actions in chassis for the past 10yrs or so.
 
If you don’t want to mount a round action in a chassis without bedding, it’s a moot point.

Also I’m not a machinist but impatience or poor capitalization strikes me as the only reason a round action made on a mill would be out of round.

Remington: Challenge accepted!
 
Remington is both impatient and poorly capitalized.

I don’t know if it’s applicable to an integral lugged action but fixturing a receiver and surface grinding it is the way to make the roundest, most true exterior in small numbers.
 
But its moot on Winchesters and FNs. Cutting the ectractor clearance is more time consuming than dealing with the recoil lug.
Unless you're dealing with a Winchester Model 70 push feed or a Howa 1500. Then you're saving some time and money.
 
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If you don’t want to mount a round action in a chassis without bedding, it’s a moot point.

Also I’m not a machinist but impatience or poor capitalization strikes me as the only reason a round action made on a mill would be out of round.



If only it was that simple. An action, any action that is cylindrical in shape has some particular behaviors one has to be aware of during manufacturing. First, a review of the process in basic form:

1. You buy some round stock. If it's getting an integral lug you get it oversize.
2. Turn the OD to a diameter larger than finishing for the roughing portion
3. Poke a hole down the center of where the bolt runs.
4. EDM or broach your raceways. If its a fat bolt, you likely won't have to do this.

5. #5 is the crossroads. You can keep chewing on this thing and eventually finish it and send it off to heat treatment. There is a very, very high probability that it will come back with a form of mild curvature disorder and erectile dysfunction. When you go windowing out a receiver in the pre-heat treat condition, it likes to move around a bit. The heat treat process aggravates this behavior. You may very well discover than your bolt won't even go inside the action because of it. The tang area is especially sensitive to this. Likely why you see more and more aftermarket action companies bulking this part of the receiver up. It distorts less and is easier to machine.

The other option:

5.1 The blank is sent out for heat treat before any of the finishing operations with the understanding there's more to do afterward. It'll be in the low to mid 40's C scale most likely. Still very machinable but it is going to be a little harder on tooling. If the material is of good quality (multi arc vac furnace processed stuff where it runs through the ovens a few times before shaped into whatever so that the dirty crap gets purged out of it) and predictable, it should come back in very good condition that doesn't create any weird conditions that drive you crazy.

6. Now you can finish the thing. Grind it, turn it, whatever. There's no real reason to grind a receiver on its OD. It just adds time. A well tooled turning center will land well inside of any tolerance required. Cut your ports, poke your pin holes, thread mill some threaded holes, etc. . . Your done with the heavy lifting at this point.

7. Off to finishing. Usually anymore its a chemical/tumbler media process. Then it can go out to service for any coatings that might be wanted.


There are likely a few things I'm leaving off here and I may have a couple of the steps out of the exact sequence. It's more about the point of operation orders than a step by step. The heat treatment process is one that can/does frustrate people. This whole game of "custom action" is very price point driven. It doesn't take "unobtanium" to make a bolt action receiver. More affordable materials can and are used because it makes a price point that is attractive to more potential customers.

Companies like ARC (American Rifle Company) really don't give 2 shits about what they spend on materials and they prove it by committing an absurd amount of capital buying stuff that typically only gets used in airplanes and defense items. Does it matter to a guy shooting? Prolly not. He just needs it to work. However, to one very particular mechanical engineer, it does. He uses the best stuff available because it makes him sleep very well at night.

Hope this helps.

C.
 
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Who is Phil Cashin?
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I recently bought a Defiance Deviant Tactical. Integral lug, integral scope base.

It is my belief that the action is more rigid, the scope stays zeroed better, and I don't have to deal with a separate lug.

Since I've had that action, I haven't had to rezero it more than the initial one, whereas I had to do it occasionally on my Rem700. The Rem700 has a Nightforce base on it.

Defiance actions are also heat treated before machining.
 
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Also I’m not a machinist but impatience or poor capitalization strikes me as the only reason a round action made on a mill would be out of round.
Jeez, there you go again talking out of your ass

Round actions are made in lathes, with side trips to a broach or EDM to cut the raceways. If you're poor and have no live tooling on your lathes, another side trip to a VMC happens to do any cross features like the sear window, action screw holes, gas relief, etc.
 
Thanks @LongRifles Inc. That's a lot to think about. Someone like me who won't do anything more complicated than spinning prefits on and off. With that in mind do you think I will ever have a reason to care weather or not my lug is part of the action or just pinned?
 
5. #5 is the crossroads. You can keep chewing on this thing and eventually finish it and send it off to heat treatment. There is a very, very high probability that it will come back with a form of mild curvature disorder and erectile dysfunction. When you go windowing out a receiver in the pre-heat treat condition, it likes to move around a bit. The heat treat process aggravates this behavior. You may very well discover than your bolt won't even go inside the action because of it. The tang area is especially sensitive to this. Likely why you see more and more aftermarket action companies bulking this part of the receiver up. It distorts less and is easier to machine.

When there's a high possibility of heat treatment distortion, I'm a fan of doing most of the work in steels like 4140, 8320, and 9310 when through hardened to mid to high 30s HRc, with possibly a well placed stress relief operation before the final tool passes, and ending with a trip through gas nitriding for the final case hardness.

That's how I do several shafts for aerospace components and for an extremely demanding yellow construction equipment manufacturer.

As you pointed out, the exact specifications that the alloy is purchased to makes a difference

Does anyone making actions follow that path or something similar?
 
I recently bought a Defiance Deviant Tactical. Integral lug, integral scope base.

It is my belief that the action is more rigid, the scope stays zeroed better, and I don't have to deal with a separate lug.

Since I've had that action, I haven't had to rezero it more than the initial one, whereas I had to do it occasionally on my Rem700. The Rem700 has a Nightforce base on it.

Defiance actions are also heat treated before machining.
I haven't had to re-zero my remy since I put locktite on my 419 base screws. Before that I had problems too. I will spend the money if I need to for a one price but I think there is probably some middle ground between your deviant and a 700 that is perfectly adequate for me.
 
I'm getting quoted and replies to something from years ago.

Oddly, I have my notifications turned off, but am still getting them. Is it because I had them turned on when I replied in this thread back in 2018?
 
I'm getting quoted and replies to something from years ago.

Oddly, I have my notifications turned off, but am still getting them. Is it because I had them turned on when I replied in this thread back in 2018?

You sir have thread herpes!
 
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ANYTHING other then integral lug, rail, flat bottom and a one piece bolt etc etc etc are JUST cost cutting measures!!!

With modern machinery (anything made after 1970s) everything should be made as one piece!

Winchester M70 was made properly in the 60s ( except the obvious blunder on no integral bases on top) while Remington 700 action was made as cheaply as they possibly could... a round tube with drilled holes into it. Which made it possible for Americans to own more cheap rifles instead of quality made ones!
(Tikka has even pushed it further... but they at least did it properly.)

Need a different MOA rail?... Use a different mount/rings, with positive or negative MOA built into.



.
 
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