Springers: is a shorter barrel better for accuracy?

[MikeSSS]

Example would be  R7 vs HW-30s. 

Because the pellet transit time is less, in the shorter barrel, the pellet may exit the barrel during a calmer moment in the rifles shot cycle.  On the other hand, a little velocity is lost and so there will be more pellet drift in the wind.  And, the opposite may happen, the rifle may be in a calmer period when the pellet exits the longer barrel. 

  R7 is 13.5" with a barrel brake weight, HW-30s is 15.5" with no barrel brake weight.  The R7 in question is the one on PA's site, the one that comes with no sights. 

Any opinions on this? 

Anybody know if barrel length makes any difference? 

Anybody know if a barrel brake weight makes a difference?

Thanks,

Mike

[Hanabata808]

You just don't want the barrel to be so short that the piston slams at the end of the chamber. I think the designers probably already did their homework on proper barrel length. There are some folks here that do in fact trim down the barrel a bit with good success.  Just need to mindful of keeping enough back pressure for the piston. If the pellet leaves the barrel before the piston is finished doing its thing, it'll be an unpleasant slam at the end of the chamber and will probably cause damage to your rifle's internals.
Barrel brake weight helps to keep your rifle steady. More steady will help with accuracy.

[breakfastchef]

The R7 is a tack driver. I would say the quality of the barrel is a better determinant of accuracy, not length.

[ac12]

The barrel/muzzle weight helps to dampen the barrel movement ocilations. 
It helps more when shooting from a non-rested position, especially the standing position.

[MikeSSS]

The barrel/muzzle weight helps to dampen the barrel movement ocilations. 
It helps more when shooting from a non-rested position, especially the standing position.

That is exactly what I want, a steadier hold. 

Thanks,

Mike

[Blue]

I just finished turning a springer into a carbine.  In the process I chopped 5" off the barrel bringing it down to 13.75".

It actually shoots faster (picked up almost 10 FPS), and it's more accurate now.

The increase in speed I'm attributing to (and I'm only guessing here) less velocity lost to friction as the pellet travels through a shorter barrel.  The increase in accuracy I think is more from putting a nice crown on after the chop.  Theoretically I think the longer a pellet takes to leave the barrel, the more time there is in the shot cycle for outside influences to effect POI.

Blue

[triggerfest]

With a longer barrel, after the shot, you still can hold aim (because of the longer barrel it is easier to correct the recoil) - according to the specialists..., this would give more accuracy...

[QVTom]

With a longer barrel, after the shot, you still can hold aim (because of the longer barrel it is easier to correct the recoil) - according to the specialists..., this would give more accuracy...

I think you are confusing length with mass, a heavy barrel will be less influenced by recoil from the action.  A short bull barrel is the way to go unless the extra length is need for cocking leverage on a break barrel.

Tom

[gard72977]

Would the longer barrel give the mass at the end more leverage to hold the barrel still?

[Bullit]

The 14" mark with higher powered air rifles *springers), give good pellet engagement to the rifling.  A good crown tops it all off.   The compression chamber volume/piston travel, has to be taken into account, to avoid damage if the pellet is loosely exiting the barrel,   before the piston has settled to it's "home" position.

[GunnerAl]

Barrel length and accuracy are a fancy mix. Ever see a target rifle with a short barrel..??

But there's so much more to it than just length. Harmonics plays maybe the biggest role in how and where a projectile leaves the muzzle each shot. Barrels whiplash back and forth when fired, yes, even an air rifle's barrel too. Most air rifle barrels are mild steel but even if they were hardened, vibrations would still plague the shooting cycle, just a slightly different frequency of vibration. Poor manufacturing, sloppy fit, poor seals, poor rifling and internal specs can all affect your shot to shot consistency. Then comes the ammo, don't forget these little pieces of lead because they are the actual busines end of it all and where they go is generally where you point the gun. If they are poorly made then even the most expensive best made barrels can seemingly turn to custard, real quick...

Until you start paying for purpose made equipment, the general day to day stuff (which most of us use), comes with no guarantee of success...

[Duckfish]

Quack

A better quality barrel is a more a accurate barrel

Duck

[MDriskill]

The classic Cardew book "The Airgun from Trigger to Target" extensively explored the question of barrel length, and determined that even in a fairly powerful springer (they were of course testing Brit-market guns of around 10 to 12 fpe power), the pellet only accelerates for about the first 7 inches!  Beyond that, drag is reducing velocity, though the effect is really rather minor. 

Springers work at very high pressures, but with a very small volume of air.  I've read other testing that indicates optimum barrel length even for a .22 rimfire is just about 18 inches, so it all makes sense.  It's not like a centerfire gun where the volume of propelling gas is many times greater, and a longer barrel always means more speed.

As already mentioned though, when shooting a spring rifle in the real world, the effect of barrel length on cocking effort and handling/balance, are vastly more important!  It's interesting to debate things like velocity variation and barrel harmonics under recoil, but IMHO those are microscopic variables in comparison.

[Bullit]

Well...
You are compressing a pretty good ratio of air volume, from the chamber, into a tiny breech port, and then, out thru the barrel. Volume is a big part in getting more power from the same spring, in 2 identical rifles.    If you wanna know for sure, you can take the time to calculate the pressure at points down the barrel, and see how it becomes lower at those points.

Barrel Harmonics are not small potatoes to me.
Look up air rifle barrel movement. There's a video (maybe Youtube?),  that shows that They DO move a lot more than you think.  Eye opening stuff.

[Benny]

Barrel length and accuracy are a fancy mix. Ever see a target rifle with a short barrel..??[/quote]

Actually a lot of match guns have rather short barrels. For example my Steyr LG-1 and my friend's FWB 602 appear to have 25" barrels but the last 9" or so is actually just a hollow tube. 

[Bryan Heimann]

Ithink it depends on how you like to shoot.  With open sights, I think a longer barrel helps you to aim with greater precision.  With a scope, I think the reduced lock time of a shorter barrel may help.

[GarthThomas]

Barrel length and accuracy are a fancy mix. Ever see a target rifle with a short barrel..??

Actually a lot of match guns have rather short barrels. For example my Steyr LG-1 and my friend's FWB 602 appear to have 25" barrels but the last 9" or so is actually just a hollow tube. 
[/quote]
Those are single stroke pneumatic rifles and like any compressed gas rifle they need the barrel length to achieve velocity, a springer works on a different principle but don't ask me to explain it. I have cut 4" off a barrel on one of my QB57s and added choke, it shoots better than when I got it and it's much less pellet fussy unfortunately I got into the habit of taking it apart and messing with the internals so often that I lost track of improvements and set backs long ago.