Reply With QuoteI'm no Savage expert, but I've never seen a "Benchrest" shooter share an advantage! And I'd be real suspicious unless you've actually seen them do it.Originally Posted by memilanuk
This is not rocket science, people.
It is more important than rocket science.
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I'm no Savage expert, but I've never seen a "Benchrest" shooter share an advantage! And I'd be real suspicious unless you've actually seen them do it.
This can be analyzed as a 'bolted joint' situation. One nut is the receiver, the other is the nut, and the clamped item is the lug, and the barrel is the bolt or stud. The load is the force applied by the blast psi exerted over the area of the bolt head (less the force resisting brass extraction due to brass friction on the walls of the chamber). It's the opposite force as what is applied on the lugs. Each material, barrel, nut, lug, and receiver, will all have a different level of 'springiness' (spring constant). It's related to the effective area of the part, the modulus of elasticity of the part, and the length of the part. The same is said of the bolt or barrel. The preload needed to resist joint separation is all you're looking for. That preload or fastener torque is related to the applied force (the blast), and the effective spring constants of each of the components in the joint. The math is all algebra, but the particulars of the loading and the calculation of the spring constants of each component are pretty hard to get accurately in this case due to unknowns. What's more, the surface finish of the mating parts and the level of lubrication and thread engagement make a big impact on the wrench torque. It's a 25% guess at best since you're measuring indirectly. Fastener preload is best measured by fastener stretch, which in this case would be barrel stretch between the chamber end and the nut. It's not practical to measure such, so we all use wrench torque as a 'best guess'.
As for the comment about engineers; I have full faith in a good engineer. I have little in that of an hourly worker carrying out the directions accurately for a number of reasons. Most of this is to the fault of the worker, due to a lack of knowledge or a lack of care. A lot of it is due to the fact that most engineers have a tough time dumbing down the message enough to get any old Joe to grasp it and believe in it 100%. We're not the best communicators.
A good read in "Machinery's Handbook" or in a decent machine design textbook from a reputable author will go along way into understanding the dynamics of a simple bolted joint. But as you can probably gather from the junk above, the input variables are not easily gotten in this case. I figure the big boys (Savage) have enough time and engineering resources to know what is the best fastening torque. Of course a manufacturer has other motivations, but to err on the best side, I'd go w the 800lb roided out Gorilla tight...
Having toured the factory recently... their torque wrench is, as has been mentioned elsewhere, set for something like 87 ft-lbs of torque. There is a short extension on it, but the person giving that part of the tour (Chris Bezzina) said the torque value had been calculated to *include* the extension. He had no explanation for why the barrel nuts are so bloody tight and hard to get off; I don't think it's a problem the factory is all too worried about - their barrels definitely ain't coming off on their own. They did put some thread sealant on the barrel shank (brand = Loctite) to keep some of the finishing solutions from creeping their way in later, but unless that thread sealant is acting as a thread *locker*, or the finishing solutions are getting past it (I have had much less problem getting 'bare' stainless barrels off stainless actions than I have getting 'coated' barrels off coated actions...), dunno.
i have decided that the only time i need to get a nut tighter is when the barrel has a muzzle brake on it.
it seems when i remove the brake( hand tightened but a real good fit ) to clean the barrel i have broke the barrel loose on two different barrels
robert
100 foot pounds is not a whole lot of torque, actually. I've recently begun using a tool that makes unscrewing a Savage barrel nut --child's play-- I used to soak them in Kroil over night and then grunt and hammer and etc.. but with the new tool--piece of cake-- as a bonus, this tool also can be used to anneal brass with a precision you never imagined-- and it anneals the brass all the way through--No I do not own stock in the company --Induction Innovations-- but I wish I did.
Using a new portable induction heater (mini ductor II) that I bought from tooltopia.com for less than I paid for my complete Ken Light annealing machine, I can now heat up the barrel nut with a directly applied flameless heat, which frees up the nut and makes disassembling a Savage barrel easy as pie. Of course I never have any trouble with barrels I installed because I use anti freeze compound, but that's a different thread.............
Hammer on your "non savage" switch barrel rifles are they set up like the savage with a nut, if not what kind of a switch barrel are they?
I have used a Torqe wrench on mine and a friends , But we usually use a resized case , screw the barrel till it stops then turn the nut down . Then I open and close the bolt on a couple of resized pieces of brass . Soon as I get it where the bolt is just barly felt on closing , I peck it with a piece of brass drift a time or 2 . Can change in the stock without taking the scope off this way. It is my way and I am sticking to it. ;D
On the Belnap sight I typed in Savage nut wrench, Nothing found. anyone ordered one from them to fit thier Savage nut? Lou
A great civilization is not conqured from without,until it has destroyed itself from within. In God We Trust
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Hammer on your "non savage" switch barrel rifles are they set up like the savage with a nut, if not what kind of a switch barrel are they?
Some of my non-Savage rifles use Savage-type barrel nuts -- Remington 700, Weatherby Mark V for 460 and smaller, etc.
The Sakos use something that looks externally like the Savage barrel nut but has two different thread patterns on the barrel - coarse and fine. These barrels can be changed with a lightweight shirt-pocket size spanner wrench without removing the barreled action from the stock. Can change the barrel in the field in under two minutes without removing anything but the barrel itself. Have one Sako with barrels ranging from 264 Win Mag to 470 Capstick and another Sako with 22-250 up through 375-06 Improved.
The Rugers, the Weatherby Mark V in larger than 460, and some others do not lend themselves to the barrel nut approach -- mostly from an aesthetics point of view. These use no barrel nut and use a regular shouldered barrel. Several barrel makers have my particular actions blueprinted and have CNC computer programs made for these specific actions so that I can order additional barrels without sending them my actions for final fit. New barrels fit perfectly when delivered.
McMillan and some others keep custom CNC programs for their fiberglass or other synthetic stocks to match my barreled actions and their idiosyncrasies. Again, that way I can order additional stocks without sending barreled actions for fitting and the stocks fit perfect when they arrive.
The majority of my guns have free-floated barrels, but some do not. With swap barrel guns free-floated is the easiest way to go.
Scope base and mount systems need to be standardized across lots of actions and be quick-detachable (what quick-detach means can be a fun debate). On a single action may have half-dozen different scopes to use in a single day depending on the use, the specific shot, the rifle barrel being used, etc. But the same scope may be switched between multiple rifle actions too.
It can get tricky if you're using one specific barrel on multiple actions. Don't recommend that for most people. Too much cost involved in initial setup of the actions.
Swap barrels on calibers like the 500 A-Square, 550 Magnum, and 585 Nyati get tricky due to the need for barrel mounted additional recoil lugs and the perfect matching of them to stocks. Some might argue that on a particular trip to Africa you shouldn't be switching from the 550 to the 585 in the middle of a cape buffalo charge, but others will suggest it is important to have exactly the right gun for the specific charge.
One wouldn't use a 222 Remington Magnum with a 13-inch twist on a bull prairie dog when the situation called for a 222-1/2 Remington with a 12-7/8 - inch twist -- would they ?
These are the most common types of switch barrel methods that I use.
Life can be fun.
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Thanks for that Hammer ;D
this guy has a neat approach for switch barrel rifles
http://www.lprgunsmith.com/lpr_switch_rifle.htm
hey, optics panet has nut wrenches on sale for $27. order a pack of $2.99 targets and get the free shipping on $30 or more orders
when i was putting my barrel back on, i had the headspace set, put the barrel in the blocks and went to tighten the nut. the nut, lug and receiver spun all at the same time. i had to reset the HS and im wondering if i should put the receiver in blocks and clamp that with the vise instead of the barrel? anyone using any lube on a stainless barrel going into a non stainless reveiver? thanks
i put the receiver in the blocks and set the nut to 50 ft lbs. it all went smooth after i had the right tools. i made a vise from stuff i had laying around.
[img width=600 height=400]http://farm3.static.flickr.com/2788/4425422377_7ca5007b81_b.jpg[/img]
the blocks from SSS had two sets, one for heavy barrels and one for smaller contours. i used a rasp to hog out the blocks to fit the receiver. drilled a hole in one block and used a bolt in the action to anchor the receiver... im sure this is old hat for most, but its my first bolt, first barrel swap, so its all been a learning experience for me.
[img width=600 height=400]http://farm3.static.flickr.com/2792/4426195268_192a46faf6_b.jpg[/img]
anyway, 50 ft lbs its all good.
Factory tight is my choice. There is more to the question than just making it easy to remove the barrel next time. The barrel/receiver threads need to be preloaded enough to prevent movement in the joint under the loads of firing. May mean choosing the right thread lub and different torque values for different calibers.
Anyone have 'official' instructions from Savage?
I've changed/re-barreled about 25 Savage rifles and use the same technique every time. You're on your own with setting/turning for HS/FB but once you found and locked your position, use (BLUE ONLY) loc-tight with 75 LBS of torque. Apply about 8 drops of loc-tight and torque the barrel ring using the CORRECT Savage barrel/ring tool. The barrel will NEVER come loose, it has proven to provide the best accuracy and it can be removed with less effort than a factory barrel!
I've built many, many Savage bolt guns.
If you just give it a good snug, it will come loose sooner or later, and it does not matter if it's a stock gun or one that has had the face of the action and barrel nut trued or not.
Do tighten them up pretty good. I never measured torque. They don't need to be as tight as some of the factory barrel nuts that I have had to beat on with a BFH, but they should be fairly tight.
Mine were usually always faced as I did accuracy jobs, but either way, do make them more than snug for safety reasons.
Just think if the nut comes loose and you don't know it, all of a sudden you have way excessive headspace because the barrel has unscrewed a little and a possible blow up of the rifle. It's just not worth it to not get them pretty darn tight.
I retired from the gunsmithing business about 5 years ago, but the barrel nuts have not changed since then except for the smooth one's.
For those, figure where the bottom of the nut will be and drill a hole, almost but not all the way through and use a spanner wrench to loosen and tighten the nut.
John K
Anti Freeze compound ? Is that Prestone or store brand???
Sorry, I couldn't resist your typing error (I never make typing errrrrors)
I think you meant Anti Sieze compound
My Best, John K
explain "all the way through".
not for the budget minded ::), the poster is looking for a cheap way to do the job.
http://www.cornwelltools.com/webcat/...dDuctor-II-Kit
.223 Rem AI, .22-250 AI, .220 Swift AI .243 Win AI, .6mm Rem AI, .257 Rob AI, .25-06 AI, 6.5x300wsm .30-06 AI, .270 STW, 7mm STW, 28 nosler, .416 Taylor
In the end, tighten them pretty darn tight, but I see no reason to tighten them as tight as the facory does except perhaps liability.
I've had to beat the living snot out of some factory tightned barrel nuts, no reason for that, but they should for sure be more than hand tight.
I think this is the part where good common sence comes in, as un common as it may be anymore.
John K
Could it be that the torque required to break a factory tightened nut is greater than the torque Savage used to tighten it?
The word 'stiction' comes to mind. Some of the bolts and nuts I have tightened in various applications took more effort to break loose than the effort put into tightening them. Not rusted or galled. Makes a little snap or crack sound before starting to turn. For me, putting the nut back to factory tightness does not mean using as much muscle as it took to remove it. The 70 to 100 ft-lb range sounds good for tightening but it might take more to remove it again especially if it has had time to 'set'.
I put mine on hand tight with a good whackwith a steel hammer. She is a shooter
I let my wife tighten up my last one. ;D
Just to satisfy myself, (having a bit of difficulty taking one loose) it is righty tighty correct? Not a left hand thread, just checkin. ???
yep,you got it
drybean
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