military guns versa civilian guns

What type of gun is it and what is it chambered in?

If you have a "civilian gun" you simply don't use it like a "military gun".

Carlos Hathcock did just fine with a Winchester Model 70 with no modifications.

You don't have to wait for the barrel to cool unless your goal is the smallest possible groups. If it's just hitting a 12 X 18 target, that won't matter so much.

Sounds like you need to float the barrel. The pressure of the stock against the barrel is probably causing deflection as it heats up.

Had that problem decades ago with a Winchester 670, the low-grade model of the 70, in .243.

First shots were dead nuts on, it would then walk up and left as it heated up.

Tried this, tried that, tried the other thing, nothing helped.

Found out that most barrels don't come out with straight bores after the gundrilling operation and they usually have to straighten them before rifling and turning the contour, so I assumed this was a straightened barrel. It was OK for its design purpose, deer hunting, where you take one (sometimes two) shots and that's it for the day.

I suspect that modern hammer-rifled barrels no longer have this problem of built-in stresses changing POI as they heated, simply because the process requires exacting stress-relieving ater production.

I was going to try cryogenic stress relieving on the barrel, which was reported to give good results on this kind of problem. But I gave the rifle to someone with an explanation as to its behavior before I could try cryo-annealing.

Cryogenic stress-relieving might work for your barrel.

Terry

REFs:
http://www.unisig.com/information-and-resources/what-is-deep-hole-drilling/what-is-gun-drilling/

http://firearmshistory.blogspot.com/2010/05/rifling-manufacturing-hammer-forged.html

http://www.cryotron.com/cryogenic-stress-relief.htm

Welcome to the forum.....................




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Benchrest shooters shoot more rounds than you think at a rate more rapid than you might think and very accurately.

You problem might be the rifle or even the design of the rifle but really doesn't have anything to do with a civilian owning it.

These gun shoot tiny groups and the only time they stop shooting a group is to wait for the wind to be right, not let the barrel cool.

https://www.youtube.com/watch?v=Yv274JUfSOg

Hathcock did just fine with .50 BMG he civilianised with a scoped too. snicker.
"...need to float the barrel..." Guarantees nothing.
Hunting rifles are not made for rapid fire shooting. Battle rifles had wooden stocks that went close to the muzzle for a reason. Part of it was to prevent burns to the user. MG crews were usually issued gloves to handle extremely hot (red hot on occasion) barrels.
However, a hot hunting rifle barrel doesn't move around. It does expand and contract though. That can change the POI.

First of all the problems you have have nothing to do with the gun being for civilian use or military use. Lets take a modern sporting rifle in semi-auto and compare it to an M4. Do you really think there are major differences between the two? There is but there isn't. One is fully auto capable and one is semi-auto. Beyond that they are virtually built to the same specs and have the same basic operation. Yes, I could go into a lot more detail here but this will suffice.

Now in regards to your problem, we need more info. What rifle are you shooting, what ammunition, etc. Is this a bolt gun or a semi-auto? If its a bolt gun, is it in a chassis, is the barrel free floated, etc.? What contour is the barrel etc.? Lets say for example that you have a competition built bolt gun that is in a chassis and the barrel is free floated, there are still a number of things that could be causing your problem. You need to check your scope, make sure the rings are tight and not moving, make sure the action screws are tightened down to the correct torque, etc. if you check all of that and you still have problems make sure the barrel is absolutely not touching anything when it is heated up after a string of shooting. Then you have to look at ammo loading inconsistencies, even though I am 99% sure this is not your problem. In regards to the contour of the barrel, bigger/thicker contours will be less effected by heat and therefore allow you to shoot longer strings without cooling. The downside is that they take longer to cool off. If you have a pencil barrel the opposite is true. it will be effected by heat much sooner but it will also cool off faster so there is advantages and disadvantages to both. trust me there is no magical process to create a barrel on a military weapon, the civilian barrels as you refer to them are made using the same materials and processes as any barrel the military uses. In many cases, the same companies will produce them. Please don't get into this comparison that the military stuff is better than the civvie stuff. In fact, join the military and you will quickly find out that often times equipment sold in the civvie world is much better than any standard issue item big brother will provide you.

Moving POI typically is a function of heat, but usually is not tied solely to the barrel. Often it is an issue that happens when there are external forces on the barrel. It could be stock touching the barrel and flexing the barrel ever so slightly as the barrel warms, or internal stress in the barrel/receiver lockup pulling it in one direction or the other as it heats up. Pull the stock off and make sure that it's not putting pressure on the barrel anywhere. If it does have to put pressure somewhere (bolts, studs, etc) they need to be bedded so that they are very consistent at any temperature.

The OP has not answered what gun he has but this is the reason my pencil-barrel mini-14 I bought in the early '90s never leaves the safe.

Mike

Little of this applies to the AR 15 and the like but reflect my experience with bolt actions.

As noted above, a lot of problems come from improper inletting, under or over torqued action screws, and things like that.

To see if you have a bedding problem, try getting either inletting fluid (midway or brownells), cheap lipstick, lampblack (very messy), or something like that to determine where your barrel and receiver are touching the stock. There are threads that will guide you to correcting barrel and receiver bedding problems here and elsewhere.

A few other issues--sometimes barrels, particularly thin ones, can be bent--quick visual check resolves that, action screws either under or over torqued--find the recommended torque for your model's action screws and apply that, magazine issues--some want separation from receiver (Mauser types) while others don't.--check forums for your model and its peculiarities, barrel bands if present can lead to inconsistency if too tight or too loose --forums are your friend here, stock warpage--determine through visual if bad or through inletting, and some barrels need downward pressure at the tip while others like to be free floated--trial and error with temp shims or free float the barrel.

BTW, a tip, pick one type of factory ammunition and bullet profile and stick with it throughout your troubleshooting. Switching factory ammo or using handloads when troubleshooting just adds more variables to the accuracy equation.

FWIW, regarding bolt actions--there is a significant difference between military and civilian rifles. Military rifles are generally overbuilt and aim for good enough accuracy rather than perfect. Militaries generally dislike parts that break easily and complicated designs. Thus, they are generally heavier than civilian rifles and can stand a lot of abuse that a factory model simply will not take. The downside is that you often have to spend a lot of time with military rifles to even get accuracy approaching a cheap off the shelf hunting rifle at Wally World and if left in military garb are much heavier than most civilian rifles (apart from benchrest).

Originally posted by: boom boomFWIW, regarding bolt actions--there is a significant difference between military and civilian rifles. Military rifles are generally overbuilt and aim for good enough accuracy rather than perfect. Militaries generally dislike parts that break easily and complicated designs. Thus, they are generally heavier than civilian rifles and can stand a lot of abuse that a factory model simply will not take. The downside is that you often have to spend a lot of time with military rifles to even get accuracy approaching a cheap off the shelf hunting rifle at Wally World and if left in military garb are much heavier than most civilian rifles (apart from benchrest).

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I could kind of agree with this, but none of my bolt actions are off the shelf walk-mart R700's either. Most of mine are custom built but plenty of rifles that can be bought by a civvie that are made to take abuse, the Sako TRG and Accuracy International are two I can think of right off the top of my head that are plenty overbuilt. So, while yes you could argue this, for the most part a bolt gun is a bolt gun and you should not be getting wildly inaccurate shots out of them. if you are then there is something wrong as stated above, barrel slightly bent, crown problems. shooter issues, ammo inconsistencies, wrong torque specs, all kinds of things.

So..... Another disappeared OP?

khegglie said:

So..... Another disappeared OP?

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Well, he posted in the middle of the night (my time) so maybe he is taking a nap.

I have both military and civilian rifles and none require an hour to cool down after 2-3 shots before they will group MOA or less. Yah, my Mini 14 would not shoot to POA after 12-15 shots and the barrel heated up.

Lightweight hunting rifles have this problem as they really are not made to take many shots over and over again. As an example my old Savage 99 in 300 Savage is dead accurate for the first couple shots. But if I run a string of shots over and over again accuracy goes out the window as the bbl heats up.

The real answer has to do with measuring deviation vs killing a human. The barrel heating up and changing the point of impact an inch or so at 100 yards would not cause a problem in combat.....

To help with the correct history. Most every civilian firearm came from miilitary application first. a few examples
Colt SAA
1911 45 ACP
30-06 rifle
the repenting rifle
every Mauser
S & W M/P

YAAH...........OP gone

Sounds like the OP has a gross conceptual error on the assumed differences between "civilian" guns and "military" guns. Especially with respect to use and accuracy.

If you're in competition shooting where high accuracy and consistency is the name of the game, then you're talking about an entirely different class of rifle, ammunition, and shooting practices.

"Military" rifles aren't magical rifles designed to shoot the 1/4" center of a bullseye out of a target at 100 yards with every round fired.

kitsapshooter said:

To help with the correct history. Most every civilian firearm came from miilitary application first. a few examples
Colt SAA
1911 45 ACP
30-06 rifle
the repenting rifle
every Mauser
S & W M/P

Click to expand...

I never once heard or was made aware of a rifle that was sorry for anything ..... I suspect you meant "repeating."

Actually the military had rather a disdain for repeating rifles, the Spenser and Henry Rifles notwithstanding. Yes, they saw good use in the Civil War, but only because President Lincoln became a fan and pressed the issue. Many top brass thought soldiers would be wasteful of ammo with them and didn't care for them.
However, they were used .... so in the end I cede your point.