Page 1 of 1
Barrel diameter
Posted: Thu Apr 22, 2004 1:29 am
by TPE
Hi, what is the acceptable tolerance in barrel diameter for air pistol? We were testing different pellets and did not find one which would have produced a decent group. With the same pellets three other APs had nice groups.
Next the pistol was taken to a gunsmith who measured the inner diameter of the barrel. Is the result 4.54mm within acceptable tolerance or could this be the cause of bad grouping? The velocity of the pellets has been also measured and the dispersion in velocities is ok.
The pistol is two years old and is manufactured by one of the major brands in the industry.
Cheers,
-TPE
Barrel diameter
Posted: Sun Apr 25, 2004 9:37 am
by Tigress
Paivä, TPE.
Your homepage indicates that you are an arms dealer.
Then it is probably not surprising to you that most barrels of match AP or C02 pistols (and rifles) in Europe are made by the well known Lothar Walther company. (Not Walther Sportwaffenfabrik). They have a reputation for reasonable quality, I think.
About 2 years ago the release of new model af a match AP istol from an european manufacturer was delayed . This was blamed on a less than perfect production lot of barrels from one manufacturer.
When tooling up for a new production run, some changes in tolerances are introduced.
I do not know if your barrel diameter (groove diameter) is within accepted standards. You could probably ask Lothar Walther for information.
Shooting Tigress.
Re: Barrel diameter
Posted: Sun Apr 25, 2004 2:08 pm
by TPE
Tigress wrote:
Your homepage indicates that you are an arms dealer.
G'day.
in this case unfortunately not. If I were, I might have accurate equipment to measure more of the AP regarding this "loose groups" problem. However, I'm just an average shooter hitting 560s on a good day. The page links to my club's home page...
-T
"loose groops" / testtarget
Posted: Mon Apr 26, 2004 3:13 am
by Tyger
Just out of curiosity:
You experience less than satisfying groops from your AP, when shot from a fixture? Regardless of match pellet brand?
But tell us: the test target shows off a very tight groop, does it not ?
Re: "loose groops" / testtarget
Posted: Mon Apr 26, 2004 4:51 am
by TPE
Hi,
Tyger wrote:
You experience less than satisfying groops from your AP, when shot from a fixture? Regardless of match pellet brand?
yes, the AP is clamped tight and we have shot nice groups with other guns from the same bench, so I do not think the bench is a problem. We have tested RWS and different variatoins of H&N. 4.49 and 4.50 sizes were tested from different bullets.
Tyger wrote:
But tell us: the test target shows off a very tight groop, does it not ?
Unfortunately no test target was delivered with the gun :-(
-T