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Barrel Tester
- Thread starter AR-180
- Start date
- Joined
- Oct 8, 2010
- Messages
- 49
AR, this is how it was explained to me: a barrel tester doesn't matter... you can build something to put a barrel in that will hold the barrel absolutely still when what really matters is how it performs in the gun. If you machined a 100# block of steel to clamp the barrel in it would change the dynamics of the barrel function too much to matter what it does in the gun. All that matters is the three point contact between the bushing/barrel, barrel/slide lugs and barrel legs and slide stop pin. Just buy a Kart barrel and learn how to fit it. No need to reinvent the wheel 
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Kevin
)Kevin
I am a benchrest competitor and gun builder. There is only one way to test a barrel and that is at the range. If you should run across a way to accurately predict their performance without chambering and fitting, let me know and we can both get rich! In the bench game, guys change barrels more often than their underwear! The vibration pattern changes with each fraction of an ounce of metal removed. In most cases, pistol barrels and military barrels are not the accuracy limiting factor. In pistols it is the load and then the shooter. Military guns are purposely built to loose tolerances so they will function under adverse conditions and therefore are only as accurare as they can be for their intended purpose. I am tired of hearing "my gun will shoot .200 inch groups all day long as long as I do my part" That is the problem. "MY PART" includes properly preparing your brass, properly worked up loads, having good equipment, properly tuned, with close tolerances, the ability to read the wind (wind has no trouble moving a 200 ton airliner so a hundred grain bullet is easy) and knowing hos to compensate for changing conditions. So my bottom line here is that in most cases "it aint the arrows, it's the indian shooting them that is the problem." Dont worry so much about the barrels, most are good enough for our purposes. Fit and chamber the and get to the range and have fun with them.
Earl
Earl
A
Andre
Forum Guest
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I'm a competitive smallbore rifle, precision air rifle, sporter air rifle, and air pistol shooter, and the current American Legion national champion in Sporter class air rifle.
There is no point in testing a barrel in a vise. In a vise or fixture eliminates barrel harmonics, that is what your really testing for. When a shot is shot, the moment the bullet leaves the case the barrel starts to vibrate. Mostly up and down, and the point you want the bullet to leave the barrel is when the barrel is in the topmost or bottommost position of it's harmonic. Because there is a little pause at the top and bottom of the wave, that is the best place to have the bullet exit the barrel for utmost consistency. When you have a barrel/load combo that exits the barrel when the barrel is not at the top of bottom most position, it can hurt accuracy and in a competitive situation a barrel tuner should be used. Check out Beesting tuners if your interested.
All this happens in just a few miniseconds, faster than the eye can see. But it's there, and even less on airguns. But it's still there and has to be accounted for.
https://www.youtube.com/watch?v=AqgPu9gSmVc
There is no point in testing a barrel in a vise. In a vise or fixture eliminates barrel harmonics, that is what your really testing for. When a shot is shot, the moment the bullet leaves the case the barrel starts to vibrate. Mostly up and down, and the point you want the bullet to leave the barrel is when the barrel is in the topmost or bottommost position of it's harmonic. Because there is a little pause at the top and bottom of the wave, that is the best place to have the bullet exit the barrel for utmost consistency. When you have a barrel/load combo that exits the barrel when the barrel is not at the top of bottom most position, it can hurt accuracy and in a competitive situation a barrel tuner should be used. Check out Beesting tuners if your interested.
All this happens in just a few miniseconds, faster than the eye can see. But it's there, and even less on airguns. But it's still there and has to be accounted for.
https://www.youtube.com/watch?v=AqgPu9gSmVc
Many of the best pistol shooters and gun builders test pistol barrels before fitting.
Pistol barrels from fixtures shoot very similarly to how they shoot from a gun. The harmonics of the pistol barrel are actually quite similar. For rifles, this isn't true.
My my goal is to wind up with a pistol that will shoot hardball ammo into 2.5" or less at 50 yards. It takes a superior barrel from a fantastic maker to do this.
Just choosing a Kart, KKM, Bar-Sto, etc. doesn't guarantee these results.
If it were easy, any gunsmith would be capable of making the gun that can win at Perry. Clearly, that isn't the case.
I appreciate the enthusiasm, but much of what people think about barrels is very much unproven.
Pistol barrels from fixtures shoot very similarly to how they shoot from a gun. The harmonics of the pistol barrel are actually quite similar. For rifles, this isn't true.
My my goal is to wind up with a pistol that will shoot hardball ammo into 2.5" or less at 50 yards. It takes a superior barrel from a fantastic maker to do this.
Just choosing a Kart, KKM, Bar-Sto, etc. doesn't guarantee these results.
If it were easy, any gunsmith would be capable of making the gun that can win at Perry. Clearly, that isn't the case.
I appreciate the enthusiasm, but much of what people think about barrels is very much unproven.
- Joined
- Jul 30, 2012
- Messages
- 505
Just about every gun I own will shoot better than my capability, so I can offer no advice on the ability of a fixture to accurately replicate real world conditons. But, for what you want, sounds like you will have to build a fixture to hold the barrel as closely to the actual firearm but with a locked breech. I suspect the locked breech will have some impact on the barrel's behavior as well. I have actually built 1911s that would shoot 2-3 inch groups at 50 yards. The hard part isn't selecting a good barrel, it's getting everything else in the system to be consistent. I always stayed with quality aftermarket barrels from know manufacturers and never had a problem (with the barrel).
I will be interested in seeing what you come up with.
I will be interested in seeing what you come up with.
A
Andre
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I've been to the Perry outdoor range several times, pistol shooters shoot 25 yards not 50 as I have been told while I was there. I doubt your going to shoot 2.5" at 50 yards with factory ball. No way, maybe handloads, but I still doubt it.
Maybe gunsmiths test barrels before making the gun, but it's not the best way to test the gun for accuracy.
Andre,
I have competed in the Nationals at Perry. Pistol shooters do indeed shoot at 50 yards with just one hand. I've done so at Perry multiple times. On a good day with one of my better guns, I can be close to a perfect score at 50 yards.
You test the barrel first so that you don't waste time fitting a barrel that won't shoot to a gun. Then, you fit the barrel well. I can tell after shooting the gun if it'll meet my expectations. A barrel tester also helps a shooter know if it is a barrel or pistol build that's going south when accuracy falls off.
There are several factory loads that will meet my requirements. Federal Gold Medal Match is an example.
