minimal AP velocity?

[yana]

I'm testing with my Tau 7 at the mo. It doesnt tear out its holes really nice and round. So I figured, míght be the velocity being too low.
I tested it yrs ago, and than it was around 100m/sec which is quite low. Bút its the factory setting.
Would upping to about 125m/sec solve the problem?
Does it mean less accuracy when its holes arent as neat as they should be? Or not necessarily? Only longer locktime?
The holes arent ovales just not cleanly cut round.
I shoot the official 10m paper targets and ofcourse, flathead match pellets.

[joker]

I have my Tau 7 shooting at 480 feet/second (146 meters/second) and use Kruger 10M AP targets. I also use H&N or Bisley (which are made by H&N) flat nosed pellets. All these conditions result in very clean holes in the targets. The pistol returns 90 useful shots per 12 gram CO2 cartridge with an additional 5 shots falling off quickly.

Your 100 m/s velocity is far to slow to start with - chrono it upwards.

[Spencer]

for CO2 pistol, 390 to 400 fps (118 to 122 mps) should do the trick

[joker]

for CO2 pistol, 390 to 400 fps (118 to 122 mps) should do the trick

But not for PCP or spring??? Why for CO2 - its the velocity - not how it is derived that matters for target penetration - below 400 fps is too slow with some target brands at 10 M.

[Spencer]

for CO2 pistol, 390 to 400 fps (118 to 122 mps) should do the trick

But not for PCP or spring??? Why for CO2 - its the velocity - not how it is derived that matters for target penetration - below 400 fps is too slow with some target brands at 10 M.

Most CO2 target pistols were designed for, and deliver 10M accuracy at, 390-400fps velocity; whereas the PCP target pistols seem to be designed for a slightly higher velocity and 'springers' for a slightly lower velocity... be it barrel twist or whatever...

350fps or higher pellet velocity for target pellets should give a clean hole in a quality target material - poor quality target material is poor quality target material.

[Rover]

Crank that sucker up to 500+fps and you'll be in the vicinity of most current APs. I wouldn't like much below 450, which is slower than the FWB65 or Pardini K58.

[R.M.]

My Tau came out of the box at 390 f/s, and is as accurate as anybody needs. It also gives well over 100 shots per powerlette. The downside is the poor cutting on cheap targets. The solution, use better targets.

[yana]

I use good, official, targets.
I tested it a lot today, and found out this probably ís its correct setting.
Cracking up velocity half a turn instantly gave larger groups.
Now it easily shoots 7 shots within 6.5ctc. Thats rested, not clamped, open sights, 10m. As I always struggle with the Tau's opens, with scope I should do better and I'd expect around 5 mm ctc.
According to factory specs it shóuld do 3 mm ctc clamped 5 shots, not 7 so I'm very confident it wíll do that.
So there's nothing wrong with it. Apperantly. It just likes this velocity best.
:)
And a great many shots, I believe 120/130!? :)
Must add my Tau is a Match. These have selected barrels with better accuracy expectations than the Sport or Standard.
My Silhouette Tau 7 shoots at quite low velocity too(about 120m/sec), but it can keep 10 shots under our smallest eurocent coin, rested, 10m. Also, even freehanded, its capable of ragged holes of 5/10 shots! So it must be the correct setting..

[Tolkach]

I guess it depends on what you want, clean holes or accuracy. You can search the threads for pellet velocity vs. accuracy and read several articles. One place to look is http://www.tenrings.co.uk/11603.html. Scroll to the bottom of the page to get an idea of velocity vs. accuracy. I'm not familiar with your pistol, so I don't know how much of an adjustment you can make.

[OzzieM]

I guess it depends on what you want, clean holes or accuracy.

I disagree that you have to compromise accuracy for clean holes or vice versa. Using good quality paper targets you will get clean holes at muzzle velocities around 450 ft/s (air humidity plays a bit of a role here).

Muzzle velocity on the TAU 7 is easy to adjust. I suggest that you slowly dial up the power screw until you get clean holes in your targets. You will not lose accuracy.

OzzieM

[deadeyedick]

I'd like to know how you gauge shots for an accurate score without clean holes ?

[Tolkach]

I'd like to know how you gauge shots for an accurate score without clean holes ?

Template or plug.

[Misny]

If you are using NRA targets, then your problem is with your targets. I've experimented with them and can't get air pistols to cut clean holes no matter what I do. The same air pistol and pellets will cut clean holes in Edelmann targets which I get from our host (www.pilkguns.com). The Edelmann targets cost about 38% more than the NRA targets.

[R.M.]

Misny, you say 38% more, and you can score 10 shots per target without any difficulty, so the math says, use good quality targets. It's cost efficient.

[yana]

I tried screwing up its velocity, but that immediately resulted in larger groupsizes.
So I'll leave it as is. I dont shoot official matches anyway..
Could try other targets too. I'm our official targets though, recognised by our shooting association.

[Rover]

Turn the power up even more. There are "nodes" of accuracy caused by barrel vibration harmonics.

If you're not testing from a vice you're wasting your time.

Try different pellets. I like RWS Hobby or Diabalo Basic because they're light (higher velocity), cheap, and accurate.

[frog5215]

Just because your targets are "official" or "approved" or whatever doesn't mean they're good quality paper (which I feel means lousy quality as paper, but great as targets) I agree, Edlmann targets and some others I've tried punch nice clean holes. Others don't, even with higher velocity rifles.

The Walther LP-2 I used to shoot silhouette with ran about 280 fps. Even Edlmanns didn't cut cleanly.

Having too many old targets backing the one you're shooting can contribute to ragged holes, too.

[Misny]

Misny, you say 38% more, and you can score 10 shots per target without any difficulty, so the math says, use good quality targets. It's cost efficient.

We'll probably go to the Edelmann targets next season. Shooting 5 shots per target seems the best for matches. 10 shots would be too hard to score for the better shooters, who group many shots close together.