Gunsmithing Lug Lapping question---
Re: Lug Lapping question---
Remove the firing pin. If the rifle is a Ruger, Remington, Savage, etc., it is not difficult to take out.
For a low-budget lapping tool, take a case that fits your rifle(.223, 22-250, whatever you are lapping). Cut the case in half and get a spring from the hardware/building supply store. Put the spring in between the two halves and use it to provide the pressure on your lugs while you lap'em.
The spring I used to use was bought from a hardware store and looked like a little version of what would go on a screen door.
david
Remove the firing pin. If the rifle is a Ruger, Remington, Savage, etc., it is not difficult to take out.
For a low-budget lapping tool, take a case that fits your rifle(.223, 22-250, whatever you are lapping). Cut the case in half and get a spring from the hardware/building supply store. Put the spring in between the two halves and use it to provide the pressure on your lugs while you lap'em.
The spring I used to use was bought from a hardware store and looked like a little version of what would go on a screen door.
david
Re: Lug Lapping question---
We have a rod thats threaded with a alum handle on it. Anythin along that line will work. If you leave the firing pin in there is no advantage per say. Its just way easier to do it without and use something to put back pressure on it. Always make sure you go all the way on the down stroke.
We have a rod thats threaded with a alum handle on it. Anythin along that line will work. If you leave the firing pin in there is no advantage per say. Its just way easier to do it without and use something to put back pressure on it. Always make sure you go all the way on the down stroke.
Re: Lug Lapping question---
If the bolt body isn't sleeved or the raceway bored with an over sized bolt body,the sear & f/pin's striker will exert upward pressure on the bolt body undercutting the RH bolt lug/buttress.
If the action/bolt are properly trued,lapping the bolt lugs is not required.
If the bolt body isn't sleeved or the raceway bored with an over sized bolt body,the sear & f/pin's striker will exert upward pressure on the bolt body undercutting the RH bolt lug/buttress.
If the action/bolt are properly trued,lapping the bolt lugs is not required.
Re: Lug Lapping question---
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: DANS40X</div><div class="ubbcode-body">
If the action/bolt are properly trued,lapping the bolt lugs is not required. </div></div>
I disagree. I think it should be done no matter what.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: DANS40X</div><div class="ubbcode-body">
If the action/bolt are properly trued,lapping the bolt lugs is not required. </div></div>
I disagree. I think it should be done no matter what.
Re: Lug Lapping question---
If you are trying to lap the lugs with the barrel attached and no other work done is a waste of time and can lead you to other problems that you may or may not be aware of.
Lapping lugs with a barrel attached, especially a factory barrel with an off center chamber is asking for trouble.
If you are not sure of the outcome or are not sure of just exactly what you are doing don't even mess with it.
Dans40x is correct, leaving the pin assemble in can also cause you other problems. You need even rearward pressure, preferably from the front to lap the lugs.
If you are trying to lap the lugs with the barrel attached and no other work done is a waste of time and can lead you to other problems that you may or may not be aware of.
Lapping lugs with a barrel attached, especially a factory barrel with an off center chamber is asking for trouble.
If you are not sure of the outcome or are not sure of just exactly what you are doing don't even mess with it.
Dans40x is correct, leaving the pin assemble in can also cause you other problems. You need even rearward pressure, preferably from the front to lap the lugs.
Re: Lug Lapping question---
Think about it this way. When you lock the bolt down by rotating the bolt handle clockwise you change the position of the lugs from the 3 and 9 o'clock postion to the 12 and 6 o'clock position. When the cocking piece/striker connects with the sear it pushes the back of the bolt up into the top of the receiver. So when the back of the bolt raises, even if its a few thousands, it will raise the lug in the 12 o'clock position off the receiver lug area.
Think about it this way. When you lock the bolt down by rotating the bolt handle clockwise you change the position of the lugs from the 3 and 9 o'clock postion to the 12 and 6 o'clock position. When the cocking piece/striker connects with the sear it pushes the back of the bolt up into the top of the receiver. So when the back of the bolt raises, even if its a few thousands, it will raise the lug in the 12 o'clock position off the receiver lug area.
Re: Lug Lapping question---
The idea is that even if it is pushed back in the lug area, you are still getting movement each time the rifle is fired. Going back to the whole plan of having the same exact thing happen each pull of the trigger. Plus, having the bolt lug get pushed back on to the lug abbutment area each time could put stress on the bolt lug.
With all of this being said, we could be just splitting hairs.
The idea is that even if it is pushed back in the lug area, you are still getting movement each time the rifle is fired. Going back to the whole plan of having the same exact thing happen each pull of the trigger. Plus, having the bolt lug get pushed back on to the lug abbutment area each time could put stress on the bolt lug.
With all of this being said, we could be just splitting hairs.
Re: Lug Lapping question---
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: tunacan</div><div class="ubbcode-body">so do you not agree with dans40x that it puts upward pressure leaving the firing pin in? I lapped my lugs with the pin in and I have great contact but I am a little concerned after Dans comments </div></div>
No sir i agree with him on that. If you dont take the barrel off you can look at the surface inside the action to see if the lugs are making full contact at all. The barrel will need to be removed to do this as hateca points out.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: tunacan</div><div class="ubbcode-body">so do you not agree with dans40x that it puts upward pressure leaving the firing pin in? I lapped my lugs with the pin in and I have great contact but I am a little concerned after Dans comments </div></div>
No sir i agree with him on that. If you dont take the barrel off you can look at the surface inside the action to see if the lugs are making full contact at all. The barrel will need to be removed to do this as hateca points out.
Re: Lug Lapping question---
My barrel is off and I can see where I am getting good contact on the locking lugs.. I used a sharpie and colored the bolt lugs, 1/2 cycled in a couple times and ALL of the sharpie is gone.
Am I ok or am I getting some sort of false reading based on the fact that I'm not getting the reward pressure that is talked about in previous threads.
My barrel is off and I can see where I am getting good contact on the locking lugs.. I used a sharpie and colored the bolt lugs, 1/2 cycled in a couple times and ALL of the sharpie is gone.
Am I ok or am I getting some sort of false reading based on the fact that I'm not getting the reward pressure that is talked about in previous threads.
Re: Lug Lapping question---
It doesn’t take a lot of pressure, it just takes even pressure. If you are not putting even pressure to the rear then you could be fooling yourself.
I use a spring loaded plunger set-up that screws into the action to push on the bolt face so all I need to do is concentrate on the bolt lapping, instead of trying to hold pressure to the rear and lap at the same time. Bolt lug lapping is the last thing that is done in a truing operation, if at all. If the receiver face, lugs, and receiver threads are not true you are gaining nothing by lapping the lugs, and you could in fact make things worse.
Again why worry about lug lapping if you are going to do nothing else to the action?
Do you also know lapping the lugs can change headspace, especially on a factory barrel that has long headspace to begin with?
It doesn’t take a lot of pressure, it just takes even pressure. If you are not putting even pressure to the rear then you could be fooling yourself.
I use a spring loaded plunger set-up that screws into the action to push on the bolt face so all I need to do is concentrate on the bolt lapping, instead of trying to hold pressure to the rear and lap at the same time. Bolt lug lapping is the last thing that is done in a truing operation, if at all. If the receiver face, lugs, and receiver threads are not true you are gaining nothing by lapping the lugs, and you could in fact make things worse.
Again why worry about lug lapping if you are going to do nothing else to the action?
Do you also know lapping the lugs can change headspace, especially on a factory barrel that has long headspace to begin with?
Re: Lug Lapping question---
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: HateCA</div><div class="ubbcode-body">
Do you also know lapping the lugs can change headspace, especially on a factory barrel that has long headspace to begin with?
</div></div>
Great point. Better check the headspace. It could change it alot. Maybe even up to .005" or more if you really worked at it? What grit compound you use?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: HateCA</div><div class="ubbcode-body">
Do you also know lapping the lugs can change headspace, especially on a factory barrel that has long headspace to begin with?
</div></div>
Great point. Better check the headspace. It could change it alot. Maybe even up to .005" or more if you really worked at it? What grit compound you use?
Re: Lug Lapping question---
I used 600 grit. It took awhile but it got there. My barrel is being chambered and threaded tomorrow so head space will not be an issue.
Can you see anything alarming from the pictures. Any words of comfort.
I have read that will prperly recut lugs that there is no need to lap them in. I have also read that lugs should always be lapped in.
Being that I didn't use any sort of fixture for reward pressure and just the pressure of the firing pin is making me a little nervous.
Hopefully there is no damage done
I used 600 grit. It took awhile but it got there. My barrel is being chambered and threaded tomorrow so head space will not be an issue.
Can you see anything alarming from the pictures. Any words of comfort.
I have read that will prperly recut lugs that there is no need to lap them in. I have also read that lugs should always be lapped in.
Being that I didn't use any sort of fixture for reward pressure and just the pressure of the firing pin is making me a little nervous.
Hopefully there is no damage done
Re: Lug Lapping question---
There has also been other work done to the receiver. I was just under the impression that lapping the lugs was just one more variable to eliminate in order to acheive consistant accuracy.
This is my first go-round with a semi-custom rifle. The receiver is a Reminton 700 that has had the
face squared
bolt face squared
firing pin hole bushed
new firing pin/ extractor
scope mount holes aligned and redrilled to accept 8/40 screw
Scope base Bedded
Threads cleaned up
Holland Lug
RB ERV3 K trigger
HS Stock
I have a Benchmark barrel that I am having installed tomorrow.
Like I said before. I just want to ensure that the gun is going to shoot by eliminating any variables that I can.
There has also been other work done to the receiver. I was just under the impression that lapping the lugs was just one more variable to eliminate in order to acheive consistant accuracy.
This is my first go-round with a semi-custom rifle. The receiver is a Reminton 700 that has had the
face squared
bolt face squared
firing pin hole bushed
new firing pin/ extractor
scope mount holes aligned and redrilled to accept 8/40 screw
Scope base Bedded
Threads cleaned up
Holland Lug
RB ERV3 K trigger
HS Stock
I have a Benchmark barrel that I am having installed tomorrow.
Like I said before. I just want to ensure that the gun is going to shoot by eliminating any variables that I can.
Re: Lug Lapping question---
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: tunacan</div><div class="ubbcode-body">There has also been other work done to the receiver. I was just under the impression that lapping the lugs was just one more variable to eliminate in order to acheive consistant accuracy.
This is my first go-round with a semi-custom rifle. The receiver is a Reminton 700 that has had the
face squared
bolt face squared
firing pin hole bushed
new firing pin/ extractor
scope mount holes aligned and redrilled to accept 8/40 screw
Scope base Bedded
Threads cleaned up
Holland Lug
RB ERV3 K trigger
HS Stock
I have a Benchmark barrel that I am having installed tomorrow.
Like I said before. I just want to ensure that the gun is going to shoot by eliminating any variables that I can.
</div></div>
Then why are you trying to lap the lugs? If all that work was done as you indicate then you shouldn't have needed to do anything lapping wise, unless you don't trust they guy who did the work in the first place.
If you want to remove all the variables then leave that up to the guy building the rifle. Don't do anything that you are not sure of.
The problem I can see happening in this scenario is that the action was trued by one person, you are lapping the lugs, (not really sure how it's done or what the outcome should be), and another is chambering the barrel. Who are you going to go to if the rifle has problems? This is why most builders will not barrel an action that was trued by someone else without checking it first, and charging you for it as well.
I see nothing in the pics that would cause alarm but I wouldn’t touch it any more. Let the guy putting on the barrel do that.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: tunacan</div><div class="ubbcode-body">There has also been other work done to the receiver. I was just under the impression that lapping the lugs was just one more variable to eliminate in order to acheive consistant accuracy.
This is my first go-round with a semi-custom rifle. The receiver is a Reminton 700 that has had the
face squared
bolt face squared
firing pin hole bushed
new firing pin/ extractor
scope mount holes aligned and redrilled to accept 8/40 screw
Scope base Bedded
Threads cleaned up
Holland Lug
RB ERV3 K trigger
HS Stock
I have a Benchmark barrel that I am having installed tomorrow.
Like I said before. I just want to ensure that the gun is going to shoot by eliminating any variables that I can.
</div></div>
Then why are you trying to lap the lugs? If all that work was done as you indicate then you shouldn't have needed to do anything lapping wise, unless you don't trust they guy who did the work in the first place.
If you want to remove all the variables then leave that up to the guy building the rifle. Don't do anything that you are not sure of.
The problem I can see happening in this scenario is that the action was trued by one person, you are lapping the lugs, (not really sure how it's done or what the outcome should be), and another is chambering the barrel. Who are you going to go to if the rifle has problems? This is why most builders will not barrel an action that was trued by someone else without checking it first, and charging you for it as well.
I see nothing in the pics that would cause alarm but I wouldn’t touch it any more. Let the guy putting on the barrel do that.
