The Accurate Reloading Forums THE ACCURATE RELOADING.COM FORUMS Guns, Politics, Gunsmithing & Reloading Gunsmithing Question of barrel whip?Go | New | Find | Notify | Tools | Reply | |
| Question of barrel whip? | Login/Join |
One of Us |
Hello everyone, I have a win model 70 (1980's vintage) "lightweight". It essentially has a featherweight barrel in .270. Yesterday I did a little shooting, even though it was terribly hot outside (95). I was surprised to find that the rifle was shooting 5" lower than my last known point of aim - from Memorial day weekend of this year. Because it was so hot, I shot only 2 rounds before cooling. All the screws & mounts were tight. As I was cleaning the rifle this afternoon, I noticed the stock (HS precision) has a noticible amount of wear down the barrel chanel which is asymetrical. The wear is "centered" for the first 3 - 4 ", but then quickly moves "up" and "right" the further down the chanel you go. This seems odd as the barrel is floated all the way back to the receiver lug - with what I'd guess to be a 1/16" gap (the stock has a rather large chanel). Is the barrel "whiping" that much when its fired? Any suggestions as to what I might investigate with the changed point of aim? I was shooting the same loads, and while the gun has "bumped" around a little in the back of the car (cased), it's hard to think it got bumped that much. BTW, it has a Leupold VX II 2-7. I treat my stuff pretty carefully, so I'm scratchin' my head here.  Thanks for the help. friar Our liberties we prize, and our rights we will maintain. | ||
|
| One of Us |
Not to start a war here...wood vs synthetic..but it's not unknown for the synthetics to react petty significantly to high heat. Take it out on a cooler day and I;ll bet a Big Mac (with fries) that your zero will return to normal...let us know | |||
|
| One of Us |
that might just be the case! Memorial day shooting in Minnesota was picture perfect - maybe 70 degrees. Nebraska's been hot as hell last few days.  I'll keep you posted - and danke! friar Our liberties we prize, and our rights we will maintain. | |||
|
| One of Us |
Also, in order to be sure that the forearm is truly free-floated, you hafta check it while actually holding the rifle while sighting on a target in your usual sight-in position. That is, over sandbags or with military-type sling or whatever; your body position and resulting pressure on the forearm can easily cause it to contact the barrel. Regards, Joe __________________________ You can lead a human to logic but you can't make him think. NRA Life since 1976. God bless America! | |||
|
One of Us |
Keep the Mac and fries, I would settle for hearing the theory behind that.  FWIW, HS Precision stocks are pretty well known for their stability in extreme environments. Also, with the solid aluminum chassis running from the front sling stud back through and beyond the wrist, they are also one of the stiffest stocks as well. _______________________________________________________________________________ This is my rifle, there are many like it but this one is mine. My rifle is my best friend, it is my life. | |||
|
| One of Us |
Westpac: Any fool can figure out that I'm not a big fan of synthetics...but this is not theory..this is observation. In another life, I held down a real job as a gunsmith type with Gander Mountain in WI. We saw more guns in a week than most gunsmiths see in 10 years. We had a range where we test fired, sighted in, etc. On one of those 100 plus days, if you took some synthetic stocks out to shoot, you could actually see the fore end warp. Look, I don't care if you want to use a synthetic..that's your business. My personal observation is that while synthetics seem very stable in moderate temps...100 plus is another ball game. | |||
|
| One of Us |
Duane, today's high end synthetics, such as the HS Precision, that happens to be the subject of this thread, should not be confused with the cheap tupperware stuff or yester-year. And even if this were one of the cheap synthetic stocks, I would still like to know how the elevated temperature is going to cause the gun to shoot 5" lower. You brought it up. _______________________________________________________________________________ This is my rifle, there are many like it but this one is mine. My rifle is my best friend, it is my life. | |||
|
| One of Us |
Join the club. Here in Texas, we've had over 40 consecutive days of 100+ temps. I have been shooting three of my problem child rifles for the last three weekends, and they too have had their point of impact move any where from 2" to 5". They are all wood stocks and all are floated. Two of them have aluminum pillar bedding. The third one is a Tikka T3 with that stupid aluminum recoil lug.I have been wondering if maybe the aluminum is moving in and out and messing with me, since aluminum expands and contracts so much with the temperature. Any comments from you G-smiths out there. I shoot out of a shop and I have been taking the guns in the A/C in my office after each 2 or 3 round salvo to cool. Seems like it might help some - maybe(?). After three rounds the barrel is hot enough to cook on. Shoot 5 in a row and the barrel would make a good branding iron. "The right to bear arms" insures your right to freedom, free speech, religion, your choice of doctors, etc. ....etc. ....etc.... -----------------------------------one trillion seconds = 31,709 years------------------- | |||
|
| One of Us |
Take a full diameter barrel blank and tie a wire around each end and suspend it from the ceiling. Insert a snug fitting plug, with a small center hole drilled through, in one end of the barrel. Look through the other end while holding a lit BIC lighter beneath the barrel. The flame doesn't have to touch the barrel, just the heat from the flame. Watch as the diffraction rings bend and distort as the barrel heats. The more it heats, the more it bends. Remove the heat and watch how long it takes for the rings to regroup. It doesn't take much heat to pull a gun barrel out of alignment. And when a barrel begins to move, so goes the groups. Now take that full diameter barrel blank and cut it up in 5-6 inch sections and start measuring wall thickness. You won't have to go far to see that the barrels walls are not uniform around the bore. Anyone who's ever shortened a gun barrel has seen this. A hot barrel is likely going to move along the path of least resistance. And if your barrel is free floated, you need to take that additional movement into account and add more clearance. If you are going to free float a barrel, I suggest a hell of a lot more than a dollar bills width. In fact, I would double that to two hell's. _______________________________________________________________________________ This is my rifle, there are many like it but this one is mine. My rifle is my best friend, it is my life. | |||
|
| One of Us |
Westpac: Maybe you proved the point...barrel deflection...and you know the stock is also going to be affected..so combine the two....viola ...5 inches! Or...maybe my observation was the barrel warping??? Or why can you install wood siding on your house and butt the joints...try vinyl and you gotta overlap...or..install composite decking and directions say to allow 1/4" every 16 feet for expansion. My point is that sythetics seem to expand and contract far more than wood...again...in my observation...I just knew this would come down to synthetic vs wood!!! You won't change my mind and I won't change yours...use your plastic and I'll use wood...we both be HAPPY! | |||
|
| one of us |
Coefficient of thermal expansion - Al 13.1, Iron 6.5 .Don't know the the numbers for synthetics but vinyl siding is a good example as early siding had a problem .They learned to overlap and to not nail tightly so it can move. If it gets Texas hot - even RR tracks can buckle in extreme heat. | |||
|
| One of Us |
I have nothing against wood. It has it's place. But really, comparing vinyl siding to something made of Kevlar, fiberglass and carbon fiber? And when it comes to wood siding for my house, you guessed it, I prefer brick._______________________________________________________________________________ This is my rifle, there are many like it but this one is mine. My rifle is my best friend, it is my life. | |||
|
| One of Us |
It sounds like some of us shooters might be realizing that the old way still might be the best way. Usually history will repeat itself 3 to 4 times before the "stupid/not so good" ideas are weeded out on a more permenant bases. It is true that a good type of wood that has been cured "properly" AND "sealed" will have minumum warpage and can literally be hard as a rock. Personally, I will take wood over any synthetic on a hunting rifle, I am a traditionalist. Having said that, I do prefer a synthetic stock on my shotgun and self-defense weapons. Go figure? Still no responses on actual experience with aluminum pillar beddings? Please give input/output. "The right to bear arms" insures your right to freedom, free speech, religion, your choice of doctors, etc. ....etc. ....etc.... -----------------------------------one trillion seconds = 31,709 years------------------- | |||
|
One of Us |
My bet is on the scope. vari X II hold zero about as good as the cheapest scopes out their, you move it 4clicks and it does nothing you move it 4 more nothing moves, then 4 more and its close to dead on next time you go shoot its 16 clicks or more off zero. leopold target and tactical series seem to track ok the rest of the line up dont track worth a damn. I cant say for sure because i dont have the rifle in front of me but 5" of movement out of wood, synthetic, or metal movement is unlikely unless something is radicaly wrong | |||
|
| One of Us |
Were the action screws re-torqued at any point? | |||
|
| One of Us |
Hello everyone, Vinyl siding aside, the action screws were tight upon inspection and were not re-tightened anytime between the shooting sessions. I've never had a problem w/ this scope. In fact, it's given very good service to date. Again, while I haven't abused it by any means, it has bumped around in cars, boats, and airplanes. I'll keep you posted when I shoot again. On the bright side - just downloaded the trail cam, and there's a couple of nice bucks lookin' purty!!  friar Our liberties we prize, and our rights we will maintain. | |||
|
| One of Us |
I've had some of the same thing happen with a vari-x III and a Zeiss Conquest in the last three weeks. Could it be the heat again?? I know, it's "global warming". "The right to bear arms" insures your right to freedom, free speech, religion, your choice of doctors, etc. ....etc. ....etc.... -----------------------------------one trillion seconds = 31,709 years------------------- | |||
|
| One of Us |
A Benchrest shooter Al Mirdoch once told me why he left his rifle barrels covered with a towel while on the rests and not shooting. He noticed that when the sun shinned on just one side of the barrel that his point of impact moved over one inch horizontally at 100 yards. This was with a good 6 P.P.C. rifle . Even the good laid up stocks will move if you heat them past 200 degrees. i.e. in a truck window on a hot summer day . With that injection molded stuff all bets are off . Replace with a rifle stock before shooting. Float that barrel properly . Have stock bedding checked by a gunsmith and epoxy bedded if necessary . Use known good optics properly mounted stress free to test . Shoot off a proper rest with some windflags . Post the targets here. Glenn | |||
|
One of Us |
Not to mention the difference in ammo that is sitting in the sun or ammo out of a cooler environment. Just thought I would compound the problem. I can't say first hand but have a buddy that says hes had pressure problems with ammo shooting prarie dogs on hot days with his ammo sitting in the sun. God Bless, Louis | |||
|
| One of Us |
i am sure the heat had a lot to do with it and it was a combination of several things that cause that much movement of the groups i have also tried to take a rifle inside to cool faster in the a/c i dont do that anymore as i have found that unless you let the barrel cool completely then bring it back out side and let it warm back up completely to ambient temp wierd things start happening i suspect that it is cause by the barrel cooling and heating unevenly ie: the muzzel end cools and heat alot faster than the breach end that has been cooled in the a/c But the second part of the first post has been neglected i am also curious as to how much "whip" can be expected from the feather weight type barrel contours in the medium bores say .277 to .308 | |||
|
| One of Us |
"...Nebraska's been hot as hell last few days..." Hmmm, is this theory or proven fact? Maybe hell is cold "as hell" Jim Kobe 10841 Oxborough Ave So Bloomington MN 55437 952.884.6031 Professional member American Custom Gunmakers Guild | |||
|
One of Us |
Weird, I've shot several Vari XII's over the last 20 yrs & have never experienced this! Rod -------------------------------- "A hunter should not choose the cal, cartridge, and bullet that will kill an animal when everything is right; rather, he should choose ones that will kill the most efficiently when everything goes wrong" Bob Hagel | |||
|
| One of Us |
Excellent quote! | |||
|
| Powered by Social Strata |
 | Please Wait. Your request is being processed... |
|
Visit our on-line store for AR Memorabilia