Question about barrel thickness, heat, and accuracy.

greg11

greg11

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So, I'm just wondering something about barrels. With respect to barrels heating up and diminishing accuracy, just how much of an impact are we talking about?

I have a Stevens 200 on the way, which I'm told is a decent platform for a beginner (cheap and capable). This is my first precision rifle of any sort, and it has a sporter barrel. It's in .223, which I also understand is a barrel burner, of sorts; leading to a hot barrel quickly.

How much can I expect my groups to open up as my barrel heats up? Lets say for argument's sake, the rifle groups at 1 MOA. Do hot barrel groups open up by 1 MOA? 2? 3?

The most I'll be shooting at first is 200 yards, as that's my range's max. But when I go out into the woods, I'll be setting up longer shots. Just wondering what to expect.

I think down the road I'll look into a stainless Shelin Barrel, but I'm trying to build it as cheap as possible to start with...

Also, concerning changing calibers, which I hear is easy on a savage, could I move from .223 to say, .308 (or anything in between), with a simple barrel change?
 
Factory barrels are a crap shoot wrt barrel heat induced warping.

I have seen most barrels sporter or heavy warp at some point as the barrel warms up. Every now and then you find one that can take a whole whack of heat and not loose much accuracy.

I would say the sporter 223 barrels I have owned and/or shot started to open up after 5 to 8 rds depending on ambient temps.

The only way to find out is to test and see what your barrels quirks are.

Quality match barrels that are stressed relieved, like the Shilen, can get pretty darn hot and still keep putting them bullets into the same hole.

But excessive heat will quickly increase bore wear so unless you have to due to the needs of a competition or to stop the hordes of attacking zombies, keeping ANY barrel as cool as possible is a good thing.

Jerry
 
First of all, the term "Barrel Burner" generally refers to a cartridge that wears out barrels (actually wear out the throat) very fast. The 223 is not a barrel burner, but all barrels wear exponentially faster is used to the point of excessive heating.

Barrel warping occurs because of homogenous inconsitencies in steel, which is a common issue with factor barrels, and because of latent stresses that occur as a byproduct of the manufacturing process - another common problem in factor barrels. Hammer forged and button rifled barrels are created by pushing or beating steel out of the way to make the rifling. This does not mean these manufacturing processes cannot or do not result in superb barrels, because many button riflers such as shilen end up making terrific barrels, but the process does create less than desirable results in a significant percentage of barrels, which is why many button riflers offer different grades of barrels.

Both of these processes can make extremely accurate barrels (Tikka for instance) but to hedge your bets against heat-induced dimensional changes, you would want to look at stress-relieved, cut rifling, heavy contour barrels, and professional installations.
 
Thanks guys. I never thought of the homogeneity of the barrel's composition. Makes sense.

I'll have to put mine through the paces to discover it's quirks, as Mystic put it.

I'l make sure to abide by the 5 second rule mentioned here. I think I'll shoot a 4 shot string, then shoot the SKS or a pistol for a while, then resume with the Stevens... This should give the factory barrel some time to cool between strings.

Down the road, I'll look at an aftermarket barrel for sure...
 
If you can find them, the stick on therometer strips like the ones used on aquariums would make a nice way to monitor barrel heat. But you will need one that goes to 50C. Some welding shops sell this stuff.

Otherwise, just shoot and see when the barrel warps. Feel the barrel and that will give you an idea of when to let it rest.

Jerry
 
That's a good idea...

Another question:

Can you paint/duracoat SS barrels? Or does that act to insulate the barrel and reduce it's ability to radiate heat?
 
I have an infra-red thermometer that I use to keep tabs on wheel hub temperature. My wife took it from me because she uses it to evaluate hoof temperature (on her horses... careful.) It works very well to measure barrel and action heat too.

I just haven't figured out what temperature is too much
 
Not to veer off the barrel topic too much, but, in reality, it is a Stevens 200. Not bashing it, just want to point out some things that you might consider before you start blaiming the barrel for all of your groups.

One thing that could definately have an effect on your accuracy is the stock. It is light and flexible. It can flex to the point where it will make contact with your barrel. That will affect accuracy. Also, the stock is not bedded (from factory) and that will affect groups.

The stock trigger is quite heavy on that gun and will make shooting ragged holes tougher than with a good aftermarket trigger.

Everything these guys said about barrels is great information. They have forgotten more about tuning rifles than I will ever know. The Stevens 200 is a great platform to build on. Just don't don't overlook some of the more obvious culprits before you start thinkning a hot barrel is opening up your groups.
 
Oh, I know, the stock is terrible. I don't have it yet, but I've heard plenty about the tupperwware. I'm going to dremel out the stock for some steel inserts, which I'll bed into the stock with fiberglass. From what I've read it helps the stock 100%. It's then getting krylon'd with a tasteful color to get rid of that ugly gray.

The trigger can also be adjusted to 2.5lbs. I've bookmarked a bunch of how to threads.

I'm going to try the gun in it's factory state for a long while first, as I want to see, feel and notice the changes I make.
 
Obtunded said:
I have an infra-red thermometer that I use to keep tabs on wheel hub temperature. My wife took it from me because she uses it to evaluate hoof temperature (on her horses... careful.) It works very well to measure barrel and action heat too.

I just haven't figured out what temperature is too much
Click to expand...

Apparently, even when patches of cleaner sizzle when they are pushed down the barrel, it is not hot enough to create detrimental damage to the barrel. cp:
 
greg11 said:
Oh, I know, the stock is terrible. I don't have it yet, but I've heard plenty about the tupperwware. I'm going to dremel out the stock for some steel inserts, which I'll bed into the stock with fiberglass.
Click to expand...

Might I suggest using carbon fibre arrow shafts rather than steel? It is something someone mentioned on here. I got mine from a Wholesale Sports shop. The guy on the archery counter used to throw the offcuts away. I am sure you could find similar. Very light and amazingly stiff it seems a better option than steel.
 
Even if you have to buy a couple of carbon fibre crossbow bolts (generally stiffer than arrows for regular bows), youre looking at an investment of what? $20, max?
 
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