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I suspect that this is a stupid question, but how can the action be damaged by over torque when setting headspace? I do have a reason for asking. | ||
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On a bolt action too much torque can crush(typically pre 98 mausers) or twist (tweak) the receiver or in extreme cases such as P14 and M1917 Enfields it can crack the receiver during original barrel removal. Most will agree that over torqueing may affect accuracy on ultra accurate offerings. It can also cause a gun to have short headspace or some with cone breeches to cause the bolt head to contact the cone. PA Bear Hunter, NRA Benefactor | |||
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Well...I think one way to look at this is a barrel is a screw and the chamber is a hole in the end of the screw. When you torque a barrel (screw) you stretch it and you make the whole (chamber) longer and smaller in diameter. All of the above is just a guess on my part and based on my experience of shearing off screws and bolts by over tightening Mike Legistine actu quod scripsi? Never under estimate the internet community's ability to reply to your post with their personal rant about their tangentially related, single occurrence issue.  What I have learned on AR, since 2001: 1. The proper answer to: Where is the best place in town to get a steak dinner? is…You should go to Mel's Diner and get the fried chicken. 2. Big game animals can tell the difference between .015 of an inch in diameter, 15 grains of bullet weight, and 150 fps. 3. There is a difference in the performance of two identical projectiles launched at the same velocity if they came from different cartridges. 4. While a double rifle is the perfect DGR, every 375HH bolt gun needs to be modified to carry at least 5 down. 5. While a floor plate and detachable box magazine both use a mechanical latch, only the floor plate latch is reliable. Disregard the fact that every modern military rifle uses a detachable box magazine. 6. The Remington 700 is unreliable regardless of the fact it is the basis of the USMC M40 sniper rifle for 40+ years with no changes to the receiver or extractor and is the choice of more military and law enforcement sniper units than any other rifle. 7. PF actions are not suitable for a DGR and it is irrelevant that the M1, M14, M16, & AK47 which were designed for hunting men that can shoot back are all PF actions. 8. 95 deg F in Africa is different than 95 deg F in TX or CA and that is why you must worry about ammunition temperature in Africa (even though most safaris take place in winter) but not in TX or in CA. 9. The size of a ding in a gun's finish doesn't matter, what matters is whether it’s a safe ding or not. 10. 1 in a row is a trend, 2 in a row is statistically significant, and 3 in a row is an irrefutable fact. 11. Never buy a WSM or RCM cartridge for a safari rifle or your go to rifle in the USA because if they lose your ammo you can't find replacement ammo but don't worry 280 Rem, 338-06, 35 Whelen, and all Weatherby cartridges abound in Africa and back country stores. 12. A well hit animal can run 75 yds. in the open and suddenly drop with no initial blood trail, but the one I shot from 200 yds. away that ran 10 yds. and disappeared into a thicket and was not found was lost because the bullet penciled thru. I am 100% certain of this even though I have no physical evidence. 13. A 300 Win Mag is a 500 yard elk cartridge but a 308 Win is not a 300 yard elk cartridge even though the same bullet is travelling at the same velocity at those respective distances. | |||
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Hah Mike, that's always a pain especially if it's a 4-40 screw! Little ones are the worst. Numerous things can occur from this. I'm going to list a few scenarios harder barrel / softer reciever - receiver may twist or tweak, the internal threads could become damaged, bulging the front portion of the receiver. Mainly twisting the action bars is the biggest concern. Softer barrel / harder receiver - threads on barrel could strip, potential (but not likely) cracking of the receiver, possible flow from the barrel and binding Relatively same hardness - cracked receivers, stripped threads, twisting of receiver, stretching and stressing at weak points You must remember, if you begin to force something, than something has to give. Plus there's the potential of stressing other parts you may have not intended to. If you have a correct jig that's tighter than anything and allows no slop, than you look at the areas directly being effected, the receiver ring and barrel. The receiver ring is getting twisted, pushed out and stretched over to conform to the barrel, and once you start over torquing it than those stresses are amplified as it tries to make room to what you're doing. That's when the bad things happen, such as bulging or cracking. The barrel is relatively safe, being the internal thread portion. It does stretch to a minute degree, but the shank is the intrusive part of the operation. However in the sense of forcing it, than it will stretch inwards and flowing into where it's being forced. You'll see stretching, squeezing and compression as the force increases, therefore distorting the internal diameter, or the chamber and throat area. "Molotov Cocktails don't leave fingerprints" -Dr. Ski | |||
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Acquaintance of mine fiddles with a lot of frog military rifles, and the factory workers seem to have taken to cranking the barrels in hard at times, which is why Century Arms had a guy figure out how to rechamber MAS rifles to 7.62NATO without removing the barrels from the actions when they were importing them and selling them, as such. If you try to unscrew one there is significant galling of the threads. "if you force things, something will give", as you said...A lot of those frog rifles, if you try and unscrew the barrel you'll destroy the receiver/barrel on the way out even if as originally built it functions fine. Nice to have the option of parts replacement in the future instead of having a receiver married to a barrel. Might want it to be something else someday or re-barrel it. The fact that somebody got it to screw in where they wanted it doesn't mean you'll ever be able to change it back if a lot of force was involved and it even worked... I severely screwed up a S&W revolver trying to get the front sight to line up where I wanted, instead of re-indexing everything properly about a decade ago. It was about 5 degrees off, but forcing it a few more degrees as part of the means of adjustment wasn't a very good idea. At least it was mine, right? | |||
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yes, the action, on most any rifle, can be damaged by over tightening what's the problem? opinions vary band of bubbas and STC hunting Club Information on Ammoguide about the416AR, 458AR, 470AR, 500AR What is an AR round? Case Drawings 416-458-470AR and 500AR. 476AR, http://www.weaponsmith.com | |||
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I bought a very nice 6mm Wisner 700 Mannlicher stocked, custom on Gunbroker, but was out of town when the rifle was delivered. When I examined the piece, it was obvious that the barrel (Douglas Featherweight) had been turned. A "go" headspace gauge is pretty snug, but will work. With new factory brass, neck sized with a lee collet, and trimmed, a good many will not chamber or are really tight. Accuracy was poor with several handloads, so I dropped the barreled action in a short action BDL stock with no improvement. I just sized 30 fired cases in Redding full lgt. dies and it was necessary to knuckle the press over in order to get the cases to chamber easily. Ordinarily, I would never do this for fear of pushing the shoulder back. Something really fishy here. the rifle is pristine, but obviously has had headspace issues. My guess is that someone, not James Wisner, tied to correct a excess headspace issue and over-torqued. The previous owner says that the barrel was removed to facilitate re-blueing of the barreled action! HuH! I'm going to load and shoot some of the full lgt sized brass. If that doesn't shoot, I'm at a loss for the next step. Chamber cast? Re-headspace? Rebore-I'd like to keep the tube as the inletting is superb. | |||
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It sounds to me like a slightly "tight" chamber. Easily fixed, but doesn't necessarily explain poor accuracy. How bad is the accuracy? John Farner If you haven't, please join the NRA! | |||
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John: Accuracy was 2.5-3" groups at 100 yards. Talley lightweights with a scope that is a proven performer. Bullets were Sierra 85 HPBT and Nosler 95bt, with IMR 4350 and IMR 4831sc. I'm going to try some hundred grain flatbase with the resized brass and Reloader next week. I really can't understand why this rifle had a headspace issue. The Wisner stock is beatifully checkered and truly pristine. I don't have a borescope, but my older 243 sako rifles went over 3K rounds before groups opened to 1.5" and it was obvious that they had been through the puckerbrush. | |||
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Sounds fishy to me but a tight chamber as John said is an easy fix. A go gauge should never be snug www.KLStottlemyer.com Deport the Homeless and Give the Illegals citizenship. AT LEAST THE ILLEGALS WILL WORK | |||
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A 6mm Remington should shoot better than that for sure. I'd start with the basics: bedding, throat errosion, crown, etc.; in my experience a slightly tight chamber doesn't hurt accuracy, it just makes operating the rifle a PITA. John Farner If you haven't, please join the NRA! | |||
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There is no law that says your dies and shell holder are anymore accurate than the rifle's headspace. As far as the accuracy goes the skinny barrel may need a litle more time than you have spent to find a good combination. First of all are you using a bullet appropriate for the twist? | |||
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Tell me how overtorquing a 700 barrel tightens headspace. you would have to make either the front ring give or the shoulder on a barrel. I tighten BR and 700 barrels to 150# and it changes nothing. Stoneybroke, you have another problem. Butch | |||
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The edit thingy disappeared. You might stretch the threads[highly unlikely] as they are 1.062 diameter. Butch | |||
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butch, I have to ask. Do you tighten your BR guns to 150 foot/pounds? I have seen 100 yd BR guys hand tighten there barrels with just a dab of Blue Loctite. I know a few gunsmiths who tighten barrels to probably 20 foot/pounds torque. I am no gunsmith, engineer, or similar. I fit barrels (hunting rifles) to .002" - .004" crush fit. I have switched pre fit barrels taking approx 5/16" past touching to line up sights. I haven't ever hurt anything by so doing. I am not saying which way is right, wrong or indifferent. I am just curious. PA Bear Hunter, NRA Benefactor | |||
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I do and have been to a great deal of BR matches in the last 25yrs and have yet to see anybody use anything other than some type of oil or grease on the threads. 95% of the barrels and receivers are stainless. This is done to keep the threads from gauling. When the torque wrench is handy, yes I do. Go to the Super Shoot at Kelbly's in Ohio. You will see approx 500 BR shooters. They have a barrel vise at the rangemasters station with a 2' tee handle receiver wrench. When I get out in the shop in a little bit I will post info on tightening barrels with references that you can look up. Butch | |||
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