Does sizes matter? Lengh

[Shinyknight]

This topic will focus on the fx liners. There are 500mm 600mm 700mm 800mm. We all know the longer the barrel the more power you get from it. The real question is, does size matter when it's about accuracy? Accuracy or precision, whatever you want to call it. I am talking about being able to hit your target (aim point) over and over constantly. If your group is all over the place that isn't accuracy. So, the question is will longer barrel be more accurate than a shorter barrel? If power isn't something I want, but accuracy is, should I get a longer barrel or shorter? If I want to hit a dove size bird at 100 yards plus, can a shorter 500mmbarrel do just as good as a 700mm or 800mm?

 

[GeneT]

There's actually a good argument to be made for a shorter, stiffer, barrel for accuracy at the expense of power. There are a huge number of variables though - just as two "identical" barrels seldom shoot identically. I wouldn't hesitate to play with the shorter barrels, but recognize that some of it is luck of the draw. A good long barrel will out-shoot a lousy short barrel every day, but all else being equal, the short barrel should have some advantage.

GsT

 

[Airgun-hobbyist]

I was told of an experiment with a known accurate barrel, where they cut it down incrementally and tested accuracy each time. The results were the accuracy stayed with the barrel, but power/speed declined with the shortening length.

 

[EPG]

This topic will focus on the fx liners. There are 500mm 600mm 700mm 800mm. We all know the longer the barrel the more power you get from it. The real question is, does size matter when it's about accuracy? Accuracy or precision, whatever you want to call it. I am talking about being able to hit your target (aim point) over and over constantly. If your group is all over the place that isn't accuracy. So, the question is will longer barrel be more accurate than a shorter barrel? If power isn't something I want, but accuracy is, should I get a longer barrel or shorter? If I want to hit a dove size bird at 100 yards plus, can a shorter 500mmbarrel do just as good as a 700mm or 800mm?

Hi Shinyknight,

Regarding FX liner length and how it effects accuracy… A few points to consider (there are many variables)

Shorter barrels/liners are stiffer than longer barrels.

FX liners are thin and flexible compared to a traditional steel barrel.

Those first two points mean that a long FX liner may be more prone to harmonic flex. Harmonic flex may impact accuracy, but it can also be managed/reduced via barrel tuners, weights, carbon fiber tubes, etc.

A longer barrel requires less air to achieve a target velocity. (The longer barrel gives more time for the air charge to accelerate it).

Less air means a longer barrel can be used with a milder, more air efficient tune (less hard hammer strike on valve). This mellower tune may help the shooter achieve accuracy as the rifle is less jumpy.

A longer barrel may increase the overall time till the pellet leaves the muzzle (lock time). This longer lock time will require the rifle to remain still longer to achieve accuracy.

All these points are simplified, and there are many experts on AGN who will drill into great details if you want to know more.

My personal experience- based on currently owning 3 FX PCPs (and 15 PCPs overall):

I target shoot so accuracy is top priority. I prefer longer barrels for the milder tunes.

I prefer bullpups so that even though the barrel may be 600 or 700mm, the overall length of the rifle is reasonable.

I have had great results with 600mm (600 is somewhat long) FX liner barrels, and harmonics have not been a problem.

I’ve used FX barrels of 380, 500, 600 and 700mm both with and without the FX carbon fiber sleeves - and have not noticed a significant difference in accuracy - so barrel harmonics with the thin FX liners has not been a big issue for me.

I hope this helps,

-Ed

 

[Shinyknight]

Ok guys thanks I was thinking going to 500mm. I own an fx impact 600mm and it's kinda long. Wanted to know if going to 500mm I will lose accuracy or not. I'm not trying to follow all those high power tune you see on youtube. I plan to shoot .22 15gr and 18gr jsb at about 800 fps. And also plan to shoot up to 100 yards on pest. So if 500mm barrel can still be accurate to hunt up to 100 yards, I'll order a 500mm barrel

 

[Outbrdman]

From my experience the shorter barrels tend to be more accurate. The projectile spends less time in the barrel, less chance for the gun to move before it leaves the muzzle. My 800mm impact m3 in 35 cal is very sensitive to this.

 

[bigHUN]

From my experience... and I have couple liners with same TR's in 25x500 and 25x600 and 25x700. (TR 1:27 and TR 1:18)
If I want to get a 888 fps for my projectile - a number is just for example - a longer barrel is easier to tune the Dwell.
Now, the next... I am still using orings to float my liners, tried the CF tube but naaah, tried the barrel tensioner and naaah, I am back to original design but stiffer orings.
The shorter liners are stiffer and need to find the nodes with speed and Dwell....plus or minus 10 fps can ruin a game, more tinkering. And next day is humid and hot - you start all over again.
The longer liners not soo sensitive for +/-20 fps and easier to manage the harmonics with a barrel tunner.
And again, I am shooting rings only 50 and 100 BR, large volume shooting, and these are my findings ....

 

[woogie_man]

No.

As long as you have a QUALITY barrel you will be fine. Like bigHUN said above.... shorter barrels are stiffer. You will lose velocity but accuracy should still be just as good as the long barrel. Do an expriement and see what happens. Typically, when people say that short barrels are just as accurate as long barrels people will get pissed, because long LONG ago a longer barrel was needed as the barrels sucked.

 

[DonC]

My Anshutz 2002 has a 14 1/2" barrel. It is tuned for 19 ft.lbs. I get excellent results in Field Target.
A famous UK competitor and writer, Nick Jenkinson used a pistol barrel on a TX200 when ever he competed in piston class.

 

[Firewalker]

In most cases, harmonics can be tuned, wether it's due to liner rotation, jam-nut torque, barrel weights or even incremental trimming.

There is a lot of half-right stuff shared online such as a 700mm barrel will move throwing the pellet!

That may be true at 300fps and exasperated with a springer sporting a 700mm barrel but high speed photography shows that the timing of the pellet leaving the gun and the reaction of the barrel/gun mass, lags behind at modern speeds.

Ballistic High-Speed did a few shots of slower speeds where 700fps & 800fps rounds were well gone from barrels 30" long before the gas energy acted upon the gun mass.