Lug Setback/Galling Trued Actions

M

mk4500

Guest
Hi All,

I'm having a trued 700 action rebarreled, cerakoted and headspaced with a PTG bolt.

Does setback and or galling of the lug recesses/bolt become more of an issue on trued actions with tighter tolerances?

How common would these issues be with a standard chromoly action and PTG bolt? I'm trying to decide if I would be a good idea to cerakote the inside of the receiver as well to reduce the likelihood of said problems arising.


Thanks,

-Mark
 
mk4500 said:
Hi All,

I'm having a trued 700 action rebarreled, cerakoted and headspaced with a PTG bolt.

Does setback and or galling of the lug recesses/bolt become more of an issue on trued actions with tighter tolerances?

How common would these issues be with a standard chromoly action and PTG bolt? I'm trying to decide if I would be a good idea to cerakote the inside of the receiver as well to reduce the likelihood of said problems arising.


Thanks,

-Mark
Click to expand...

I'll try these




Does setback and or galling of the lug recesses/bolt become more of an issue on trued actions with tighter tolerances?
Click to expand...

No. Or if it does it has nothing to do with "tighter tolerances" and all to do with scrubbing the case-hardening off the lugs and seats.

How common would these issues be with a standard chromoly action and PTG bolt? I'm trying to decide if I would be a good idea to cerakote the inside of the receiver as well to reduce the likelihood of said problems arising.
Click to expand...

I don't see the connection here......PTG to factory is 'good' (better than factory/factory) and cerakote is just paint. It does nothing to strengthen the substrate.
 
[QUOTE
No. Or if it does it has nothing to do with "tighter tolerances" and all to do with scrubbing the case-hardening off the lugs and seats.

.[/QUOTE]

Al, the only custome action I know of that is actually "case hardened" in the truest sense are the McMillan. That was their big selling point, extremely hard surface with a softer core to insure ductility.

Remingtons, and most customs, are simply 4140 or some other Chrome Moly Steel, tempered to the mid 30 RC range. The surface is no harder, or softer, than the core.
 
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jackie schmidt said:
[QUOTE
No. Or if it does it has nothing to do with "tighter tolerances" and all to do with scrubbing the case-hardening off the lugs and seats.

.
Click to expand...
Al, the only custome action I know of that is actually "case hardened" in the truest sense are the McMillan. That was their big selling point, extremely hard surface with a softer core to insure ductility.

Remingtons, and most customs, are simply 4140 or some other Chrome Moly Steel, tempered to the mid 30 RC range. The surface is no harder, or softer, than the core.
Click to expand...
[/QUOTE]

Thanks Jackie. In any case truing won't affect lug setback on a modern firearm..... The only cases I've known of where truing caused setback issues were many years ago when guys were converting Mausers and Springfields and such. I was unclear.
 
Any action that has full contact or near full contact on the lugs, naturally, by the fuller contact, wipes the mating surface cleaner and DOES need to be kept lubed. Just a light coat of a good HP grease, wiped on the bolt lugs and then with the bolt closed with the trigger pilled ON AN EMPTY CHAMBER is best.

I've seen shooters squirt a ridge of grease on the bolt lugs before inserting the bolt. This much grease builds up a mess inside the action lug area and can cause trouble by catching any powder residue or grit.


.
 
Thanks for the info guys. It looks like I'll be picking up some HP grease and maybe one of those lug cleaning kits.


I was just curious on the prevalence of setback and galling as this is my first foray into customizing/truing a rifle .....and as you might imagine, I'm running into a ton of new information (and questions) online.
 
Just a question. Why would anyone machine the lugs either on the bolt or the action abutments.

If you check them, and even lap them, and have good contact, just leave them be and re-cut the threads and action face true with the bolt raceway.

When you remove metal from the back of the lugs and the action abutments, you screw with the timing of the action in the cocking and extraction cycle.
 
The lugs were machined as part of an action truing "package". I wasn't aware that this was not advisable.

In any case, I believe the PTG bolts have slightly thicker lugs which gives some additional material to play with in terms of timing. At least that's how I understand it.
 
Stan Ware

has posted several good YouTube Videos on this subject in which he fits a new bolt up to a botched up trueing job. In his videos he has to re-cut the surfaces and replace the bolt handle, re-timing the action in the process. He does a great job of explaining the process as well.

Pete
 
Pete Wass said:
has posted several good YouTube Videos on this subject in which he fits a new bolt up to a botched up trueing job. In his videos he has to re-cut the surfaces and replace the bolt handle, re-timing the action in the process. He does a great job of explaining the process as well.

Pete
Click to expand...

SOOO freakin true!!!

BTW mk4500 if you read any posts on this forum by Stan Ware, or Dans40X or Al Nyhus or Randy Robinette or Greg Walley pay close attention, these guys understand action/trigger/bolt timing like few in this world....and some of them know something about making bullets too.....and barreling,

and bedding,

and tuning,


but I digress :)

LOL

al
 
I cut my internal lugs as i have seen as much as .004 difference between the two. usually .002 or less but i have seen .004 im not sure you could lap that much? When i do an action truing i always let my customers know that there is a possibility that the bolt handle will need to be re-timed . Lee
 
skeetlee said:
I cut my internal lugs as i have seen as much as .004 difference between the two. usually .002 or less but i have seen .004 im not sure you could lap that much? When i do an action truing i always let my customers know that there is a possibility that the bolt handle will need to be re-timed . Lee
Click to expand...


How do you establish a centerline or base measurement from which to measure this?
 
Of all the actions I have worked I have never found any action body lugs or bolt lugs to be case hardened, So, the metal left and the metal removed is the same hardness. But, the greater contact surface the more the need for proper lubrication.

A factory hunting action may only be cycles 200 or so times in its lifetime, a custom competition action will be cycled more than 200 times in a weekend tournament.


.
 
In Stan's video

skeetlee said:
I cut my internal lugs as i have seen as much as .004 difference between the two. usually .002 or less but i have seen .004 im not sure you could lap that much? When i do an action truing i always let my customers know that there is a possibility that the bolt handle will need to be re-timed . Lee
Click to expand...

the action he worked on had been "Lapped". It was out by something like .012, noticeably lop sided and the same was true on the internals, of course. He had to set the whole thing back quite a bit, Fortunately, with a Rem type bolt the back of the bolt can be cut off easily, if necessary.

Pete
 
mk4500 said:
The lugs were machined as part of an action truing "package". I wasn't aware that this was not advisable.

In any case, I believe the PTG bolts have slightly thicker lugs which gives some additional material to play with in terms of timing. At least that's how I understand it.
Click to expand...

Gents,

If PTG leaves their lugs a little thick to facilitate timing, that certainly is an interesting way of dealing with the timing issue, specifically fore and aft. But if I'm understanding bolt timing correctly, the placement of the bolt handle must be clocked as well to be truly timed. No?

Thick lugs aside, I would expect that a PTG bolt would be nuts upon delivery, and not need truing.

In re: lap vs. cut, where does one draw the line, measurement wise, when deciding to lap, or cut lug abutments that aren't square with each other?

Justin
 
Zebra13 said:
Gents,

If PTG leaves their lugs a little thick to facilitate timing, that certainly is an interesting way of dealing with the timing issue, specifically fore and aft. But if I'm understanding bolt timing correctly, the placement of the bolt handle must be clocked as well to be truly timed. No?

Thick lugs aside, I would expect that a PTG bolt would be nuts upon delivery, and not need truing.

In re: lap vs. cut, where does one draw the line, measurement wise, when deciding to lap, or cut lug abutments that aren't square with each other?

Justin
Click to expand...

How could PTG know the internal measurments of your Rem 700 action. Long ways from a custom action. No way of knowing who has touched it with a tool bit. You need a smith that knows bolt timing to get one right.
 
True

sdean said:
How could PTG know the internal measurments of your Rem 700 action. Long ways from a custom action. No way of knowing who has touched it with a tool bit. You need a smith that knows bolt timing to get one right.
Click to expand...

but with a little extrey material, the process might go smoother. Apparently, from watching Stan's video, not all Smiths know much about either bolt timing or lapping. How does one know who knows, is the real question. A couple of years ago I asked for someone to explain bolt timing on one of these forums. The silence was deafening. A few days later, a gentleman from Alaska called me, on his dime and explained to me, in detail, bolt timing and how simple it was, in reality.

There are more than one series of Bolt timing on YouTube. Those sharing this information can only help everyone. I can't imagine how keeping this kind of information shrouded is productive to the Smithing Business. Who can't or has the desire to make a jig and learn to silver solder, want to DIY? I had a my 700 Bolt handle replaced by a Smith who knows his business.

Pete
 
Pete, you made me laff :)

Pete Wass said:
but with a little extrey material, the process might go smoother. Apparently, from watching Stan's video, not all Smiths know much about either bolt timing or lapping. How does one know who knows, is the real question. A couple of years ago I asked for someone to explain bolt timing on one of these forums. The silence was deafening. A few days later, a gentleman from Alaska called me, on his dime and explained to me, in detail, bolt timing and how simple it was, in reality.

There are more than one series of Bolt timing on YouTube. Those sharing this information can only help everyone. I can't imagine how keeping this kind of information shrouded is productive to the Smithing Business. Who can't or has the desire to make a jig and learn to silver solder, want to DIY? I had a my 700 Bolt handle replaced by a Smith who knows his business.

Pete
Click to expand...

At this I laffed.........."YUP!"

Apparently, from watching Stan's video, not all Smiths know much about either bolt timing or lapping...............
Click to expand...

And at this I chuckled too.....

A few days later, a gentleman from Alaska called me, on his dime and explained to me, in detail, bolt timing and how simple it was, in reality.
Click to expand...

Bethcha' a cawffee that the gentleman in question offen sees the fellow who posts as "Dans40X"
 
sdean said:
How could PTG know the internal measurments of your Rem 700 action. Long ways from a custom action. No way of knowing who has touched it with a tool bit. You need a smith that knows bolt timing to get one right.
Click to expand...

sdean,

What Pete said. Leave them thick, and cut them into proper timing. I agree that you would still need this done by a smith who knows timing. And like I said, that only takes care of fore and aft. I think clocking the handle is a component of timing also.

Dan at Dan's 40X did a bolt for me a couple of months ago. It came out nuts.

Justin
 
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