Gunsmithing Consensus on recutting remington 700 threads

[Clark]

Re: Consensus on recutting remington 700 threads

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: AJ300MAG</div><div class="ubbcode-body">Your going to assemble custom rifles, but don't have a clue how the fire control system works.


PRICELESS... </div></div>

From Wikipedia, the free encyclopedia
<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">A fire-control system is a number of components working together, usually a gun data computer, a director, and radar, which is designed to assist a weapon system in hitting its target. It performs the same task as a human gunner firing a weapon, but attempts to do so faster and more accurately.</div></div>

My father sub contracted millions of $ out to Hughes for fire control of some of my father's gun designs.

What does it all mean?
I would have thought "fire control system" meant sprinklers, but it is aiming.

 

[AJ300MAG]

Re: Consensus on recutting remington 700 threads

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">What does it all mean?
I would have thought "fire control system" meant sprinklers, but it is aiming.</div></div>

The trigger along with the associated parts are also refered to a rifles "fire control system".

Knowing how it functions is a start, a GOOD gunsmith should know the issues that cause trouble with a fire control system and their effects on accuracy.

 

[Clark]

Re: Consensus on recutting remington 700 threads

I am a grammar Nazi:
a) "comprised of" when they mean "composed of"
b) "differential" when they mean "difference"
c) "fire control system" when they mean "trigger"

Pap to Huckleberry Finn: "..Why, there ain’t no end to your airs.."

What does it all mean?
It is correct to say "utilize" when you mean "use". There is nothing I can do about it.

 

[Wild_Bill]

Re: Consensus on recutting remington 700 threads

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Clark</div><div class="ubbcode-body">I am a grammar Nazi:
a) "comprised of" when they mean "composed of"
b) "differential" when they mean "difference"
c) "fire control system" when they mean "trigger"

Pap to Huckleberry Finn: "..Why, there ain’t no end to your airs.."

What does it all mean?
It is correct to say "utilize" when you mean "use". There is nothing I can do about it. </div></div>

Sorry the fire controll on a remington includes the trigger, cocking piece and firing pin not just the trigger and it also is incorperated in a properly timed bolt if the bolt is not timed correctly then none of it will work so the bolt is also part of the fire controll system.

if we are getting picky get it correct

 

[AUJohn]

Re: Consensus on recutting remington 700 threads

It's always seemed to me that GOOD gunsmiths have some mental health issues. Things MUST be as perfect as they can, it HAS to be double and triple checked. Then checked again. "Let's just do this one more thing", "That's not quite right I need to...". They don't try to "get by" or make do. Find the cheapest way to do something or not bother on something else as it's not that important. It's easy to pick the attitude when you speak to them and I've always thought these guys "went bad" like this quite fast after starting.

I don't think it's something that can be learned or forced. Normal guys tend to be run of the mill, push the jobs out smiths who do just that, like many others.

It might fit in and be useful for those replying to talk about how they were when they started out. Did they always want to do everything they could and learn everything, try as much as they could? Or were they "forced" by issues to start doing this and found an interest. I know some of the guys here still do this, seek ANY information out where they can and use it if it worked.

 

[Clark]

Re: Consensus on recutting remington 700 threads

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Wild_Bill</div><div class="ubbcode-body">

Sorry the fire controll on a remington includes the trigger, cocking piece and firing pin not just the trigger and it also is incorperated in a properly timed bolt if the bolt is not timed correctly then none of it will work so the bolt is also part of the fire controll system.


</div></div>

I can't believe that there are engineers at Remington that would allow the word "control" in a name of a group of trigger parts that have no control loop, to be in any Remington parts list or publication.
Often an engineer will find errors like that introduced by drafters or technical publications, but they should red line the error. It should then be fixed before sign off.
I don't know anyone at Remington, but I know they do have an engineering organization. I heard that Steven Perniciaro was chief engineer at Ruger in 2000, but later moved to Remington.

I am no control engineer. The only purely control gig I ever got was consulting for stabilizing a power distribution system, with feed back, in cell phone towers being built in China. I am not very good at it, but I know what it is.
http://en.wikipedia.org/wiki/Control_theory

When one designs and develops a battle tank with fire control, the fire control engineers do a sweep on the barrel elevation with a phase gain analyzer [very handy for verifying the loop compensation].
That sweep's purpose is to measure the gain magnitude and phase shift incrementally through the frequency domain.
That test means something to engineers with some control background.
To the layman watching; the test makes the tank look like an elephant trying to hump something faster and faster.

 

[Twisted300Win MAG]

Re: Consensus on recutting remington 700 threads

I personally am not a gunsmith. That being said, I understand stress pressure and tolerances, due to the type it work I do. The main point I would like to make is, the main goal of any trade that demands "precision fit" is achieving a tight stress free fit concenric to a datum plain. How can you accomplish this when you are trying to screw two parts that are not concentric to the same plain? The recover face recoil lug and barrel may meet evenly but your creating uneven pressure on the threads. That means the flanks wouldn't have even tension.
Just my point of view.

 

[300sniper]

Re: Consensus on recutting remington 700 threads

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Twisted300Win MAG</div><div class="ubbcode-body">I personally am not a gunsmith. That being said, I understand stress pressure and tolerances, due to the type it work I do. The main point I would like to make is, the main goal of any trade that demands "precision fit" is achieving a tight stress free fit concenric to a datum plain. How can you accomplish this when you are trying to screw two parts that are not concentric to the same plain? The recover face recoil lug and barrel may meet evenly but your creating uneven pressure on the threads. That means the flanks wouldn't have even tension.
Just my point of view. </div></div>

I have to agree with your point of view.




And a couple years later and now in the business, has AZ's opinion changed on this topic?

 

[hero's machine]

Re: Consensus on recutting remington 700 threads

I ended up reading this thread last night....the whole thing. It was painful. One thing it reinforces is that adaptation and ability to evolve is what its all about. A strong mind is good, bit an open mind is more prosperous.

 

[E. Bryant]

Re: Consensus on recutting remington 700 threads

I read this thread during lunch today. The question I have is quite simple - why are we relying on the threads to center the barrel relative to the receiver? Would it not be advantageous to use a cylindrical feature on the barrel tenon (located between the shoulder and the threads) and the appropriate mating surface inside the receiver to provide radial alignment?

Keep in mind that I'm just some dumbass electrical engineer, but I've seen a fair number of mechanical systems in my (relatively) few years, and damn few of them attempt to use a threaded fastener as a means of radial location. For example, look at the main or rod bearing caps on an IC engine - they often use dowels to align the caps, instead of relying on the clamping fasteners. And although it's been a while since I've read through the numerous Carroll Smith books, I seem to recall that he often states that threaded fasteners are for clamping, not for alignment.

Just a thought. It's obvious that the present method works pretty well, so this is more a hypothetical question than any serious suggestion that anyone should change their ways.

 

[300sniper]

Re: Consensus on recutting remington 700 threads

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Eric Bryant</div><div class="ubbcode-body"> And although it's been a while since I've read through the numerous Carroll Smith books, I seem to recall that he often states that threaded fasteners are for clamping, not for alignment.

</div></div>


i'm pretty sure smith's point was that threaded fasteners shouldn't be relied on to align a part in a shear load. i see no reason that a quality threaded barel tenon wouldn't absolutely center in a quality threaded receiver. the 360 degrees of opposing 60 degree threads pretty much give it no choice. now if the shoulder joint isn't absolutely perpendicular to either of the threaded surfaces and you compensate by making the thread fit loose, all bets are off.



...off to dig up my copy of carroll smith's "engineer to win" and "nuts, bolts, fasteners and plumbing handbook"

 

[E. Bryant]

Re: Consensus on recutting remington 700 threads

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 300sniper</div><div class="ubbcode-body">...off to dig up my copy of carroll smith's "engineer to win" and "nuts, bolts, fasteners and plumbing handbook"

</div></div>

... AKA "Screw To Win"

 

[LRI]

Re: Consensus on recutting remington 700 threads

. . .yet in spite of all of this, rifles continue to shoot very small, impressive shot plots. Custom builds, factory directs, etc. . .

It begs the question, just how relative is it to accuracy?

A month ago a customer from Gillette came in with a Lawton receiver and a barrel fitted up by someone else. Upon tear down I discovered the threads were -.025" on the major tennon diameter. The receiver literally rattled off the barrel tennon once we popped it loose.

He reported that the gun shot very well for him for its entire life.

I realize this is just one example and its hardly conclusive. Just using laws of averages I'd be willing to speculate this isn't the only gun out there like this.

So again, just how relevant is it from a strict performance perspective? Ignore anal retentiveness for the moment.

It would stand to reason that the "perfect" barrel tennon would use a taper to locate center. Similar to a CAT40 or Morse taper.

Put a cross pin in it to maintain location and let it roll. Essentially, this is how Anschutz does it on their M54 actions. That being said they don't really shoot any better than a properly fitted up 40x or Stolle Swindlehurst.

 

[Mike Casselton]

Re: Consensus on recutting remington 700 threads

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Keith at PCR</div><div class="ubbcode-body">Its good for business to preach holding tolerances to a tenth, and to say you true everything possible to be trued. In the real world, you might be supprissed who actually does and how important it is.

I'm still in school and can only pass on what I'm being taught. I will say my instructor trues an action in 1/4 the time most guys on here do, and his rifles shoot. He just brought groups in yesterday of one he just made in school... smallest was .177", largest was around half MOA. and it was a 300WM.

Now, I'm not saying what my method will be after school. I may decide to recut the threads, I may not. I will do what I must to build rifles that shoot great. And I will be succesful in doing it. </div></div>

To be honest with you, I'd be happier with a rifle that shoots a more consistent .350 than one that shoots a .177 then a .500 for the next group. Think about that for a minute.

 

[Mgordon]

Re: Consensus on recutting remington 700 threads

I bet some people wish this thread would just go away...lol

 

[300sniper]

Re: Consensus on recutting remington 700 threads

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Eric Bryant</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 300sniper</div><div class="ubbcode-body">...off to dig up my copy of carroll smith's "engineer to win" and "nuts, bolts, fasteners and plumbing handbook"

</div></div>

... AKA "Screw To Win"

</div></div>

i always do.



oh wait. what?

 

[redirt78]

Re: Consensus on recutting remington 700 threads

Tagging this for tomorrow, only made it to the end of page two.

 

[E. Bryant]

Re: Consensus on recutting remington 700 threads

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 300sniper</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Eric Bryant</div><div class="ubbcode-body">... AKA "Screw To Win"

</div></div>

i always do.

oh wait. what?

</div></div>

Awesome

I broke out my copy of Smith's handbook over lunch, and found a couple interesting passages:

Page 71 - "... never depend upon bolts to locate the part. Always bear in mind that clamping is the function of bolts and that location is the function of dowels."

Page 88 - "Location should be by means of dowels or by locating or piloting diameters on the clamped parts."

Obviously, this stuff is way more critical on flywheel bolts and two-piece brake rotor hats.

The subject of alternative and asymmetric thread forms (starting on page 210) is also very interesting with regards to barrel fitting. In particular, the ability of the Spiralock form to distribute stress over the entire length of the female thread (as opposed to just the first few threads) is intriguing. It would seem that such a thread form could not be relied upon to radially locate the barrel relative to the receiver, and would thus require some sort of tapered or cylindrical centering feature.

Anyways, that was a fun way to spend lunch hour. Back to the grind!

 

[LRI]

Re: Consensus on recutting remington 700 threads

Spiralock is great. . .

Till you go to buy inserts. Way, way, way overpriced as its a proprietary setup. For the guys using HSS it's not too hard to figure out how to grind your own.

Next is the challenge of getting the barrel back off. Chromoly isn't so bad on a carbon steel action. I shudder at the thought of doing this on a SS receiver/barrel. It will certainly make for a solid joint!

Have your bandsaw/boring bar standing buy during a rebarrel. You'll need them.


From my experience:

You can in fact locate a part to center with a thread. Keep in mind that a mass produced part (meaning, clutch hat, flexplate, rotors, etc) have to go together lickity split on the assembly line.

A single barrel onto a receiver isn't in the same category.

Case in point. Next time someone is barreling up a custom action or one that's been tuned up, take a moment to stick an indicator on the rear bridge portion of the bore. It's very possible to see under .001". Go right off the bore and ignore the interrupt from the raceways or (if you have them) stuff a gauge pin in there. Rotate slowly. Most Nesika actions checked this way run half of that (.001") when we do them.

Don't sweat it!

C.

 

[300sniper]

Re: Consensus on recutting remington 700 threads

Screws/bolts shouldn't be used to locate parts but a tenon thread is not locating parts. It is only locating the fastener itself. It should not see a shear load either.