Friends,
I tested my rifle with a Combro Cronograph and got the speeds below, after 5 shots with 4.49 N&N Finale Math pellets.
The rifle has a little more than one year of usage and 12 thousand shots.
Is it necessary to make some adjustament/manteinence beyond greasing ?
The speeds:
170,3
170,4
170,7
169,2
168,2
Thank you, Bruno Almeida.
Fein 700 Alu - Cronoghap - Are those speeds correct ?
Moderators: pilkguns, Marcus, m1963, David Levene, Spencer
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Bruno Almeida
- Posts: 39
- Joined: Wed Dec 19, 2012 1:36 pm
Well if those velocities are in m/s then they are pretty ok really, roughly 570 fps, it's a match rifle after all so that is about average. How's it shooting? if the groups are ok I would not worry much about it.
If that result is really in fps, then there is something wrong, because I cannot see a gun that is shooting that low being that consistent.
Alan
If that result is really in fps, then there is something wrong, because I cannot see a gun that is shooting that low being that consistent.
Alan
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Bruno Almeida
- Posts: 39
- Joined: Wed Dec 19, 2012 1:36 pm
Thank you for aswering,
The results are in fps,
What motivated me to run this cronograph test was the last competition i participated, for the first time i carried the rifle in a Pelican Case, using the weels of the case, i felt a lot vibration from the ground in the case but thrusted that the case would absorve it, when i thook the first shots i hit the 3 and 4, had to click a lot the diopter to rise the point of impact.
The diopter was mounted in the rifle when i carried it in the case and took all that vibration, so i wondered if the shots hitted so low because of this vibration or weackening of the fps of the rifle.
Thank you, Bruno Almeida.
The results are in fps,
What motivated me to run this cronograph test was the last competition i participated, for the first time i carried the rifle in a Pelican Case, using the weels of the case, i felt a lot vibration from the ground in the case but thrusted that the case would absorve it, when i thook the first shots i hit the 3 and 4, had to click a lot the diopter to rise the point of impact.
The diopter was mounted in the rifle when i carried it in the case and took all that vibration, so i wondered if the shots hitted so low because of this vibration or weackening of the fps of the rifle.
Thank you, Bruno Almeida.
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bpscCheney
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- Location: Wisconsin
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Bruno Almeida
- Posts: 39
- Joined: Wed Dec 19, 2012 1:36 pm
I really do not think that you would have less than 2fps spread on five shots at 170 fps. At those velocities they would not be shooting a bit low, they would be off the bottom of the target. Also they would not be grouping at all well. 170 fps is going to be barely enough to stabilize the pellet, so one would expect a big group, and oval (at least) shot holes.
Have you checked that the sight's are correctly assembled, both with the attachment to the rifle and also the iris? If the rifle is otherwise shooting OK it is much more likely that you will find the problem either in the sighting system, or (less likely) the fit of the action to the stock.
Alan
Have you checked that the sight's are correctly assembled, both with the attachment to the rifle and also the iris? If the rifle is otherwise shooting OK it is much more likely that you will find the problem either in the sighting system, or (less likely) the fit of the action to the stock.
Alan
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Bruno Almeida
- Posts: 39
- Joined: Wed Dec 19, 2012 1:36 pm
Friends,
Here is a picture of the chronograph and one of the groups of shoots, i tested a second rifle, also Fien 700, with similar results, maybe i am reading wrongly ;-(
http://imageshack.us/photo/my-images/841/u5p9.jpg/
http://imageshack.us/photo/my-images/515/0vsy.jpg/
By the way, if necessary, how can i adjust the speed in the mechanism of the rifle ?
Thank you, Bruno Almeida.
Here is a picture of the chronograph and one of the groups of shoots, i tested a second rifle, also Fien 700, with similar results, maybe i am reading wrongly ;-(
http://imageshack.us/photo/my-images/841/u5p9.jpg/
http://imageshack.us/photo/my-images/515/0vsy.jpg/
By the way, if necessary, how can i adjust the speed in the mechanism of the rifle ?
Thank you, Bruno Almeida.
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David Levene
- Posts: 5617
- Joined: Mon Mar 01, 2004 12:49 pm
- Location: Ruislip, UK
Unless the "FPS" is printed on the protective film (which it looks like you haven't removed) then you might have a problem with the crono.
I see that it's claiming the shot warrants as needing an FAC. Even if it is reading in m/s, which I suspect, unless you've set it for a ridiculously high pellet weight then there is no way I would expect an FAC requirement at that velocity.
Test your rifle through another crono to confirm.
For those who don't know, this type of crono has the ability to tell you when a firearm certificate is required in the UK, IF you enter the parameters correctly.
I see that it's claiming the shot warrants as needing an FAC. Even if it is reading in m/s, which I suspect, unless you've set it for a ridiculously high pellet weight then there is no way I would expect an FAC requirement at that velocity.
Test your rifle through another crono to confirm.
For those who don't know, this type of crono has the ability to tell you when a firearm certificate is required in the UK, IF you enter the parameters correctly.
I definitely would not trust that chrono. It does appear that it is saying that it is recording in FPS, That is the correct place to see that on the LCD. 170.9 m/s is 560.7 fps which with a nominal 7.9 grain pellet is 5.5 fpe which I expect would shoot just fine. To have a velocity reading of 170.9fps, and make over 16J (12fpe) would require a pellet weight 184.9 grains or more. If I remember correctly the default pellet weight for a Combro is either 14 or 16 grains, matching the average .22 pellet weight.
Looking at your shoot on the Suis Ascor display I don't think there is anything wrong with your rifle anyway. If it were really doing 170 fps it would not be correctly read by the system, as I do not think the pellet would penetrate the band. I know some cheap nasty CO2 pistols I tried (Umarex CP99's) were doing around 300 fps in .177, and struggled to fully penetrate through target card at 10m.
Unless you really know a lot about the workings of PCP regulators then I would not try to adjust anything in the rifle power wise. There is not as far as I know an adjuster that allows fine adjustment of velocity.
Alan
Looking at your shoot on the Suis Ascor display I don't think there is anything wrong with your rifle anyway. If it were really doing 170 fps it would not be correctly read by the system, as I do not think the pellet would penetrate the band. I know some cheap nasty CO2 pistols I tried (Umarex CP99's) were doing around 300 fps in .177, and struggled to fully penetrate through target card at 10m.
Unless you really know a lot about the workings of PCP regulators then I would not try to adjust anything in the rifle power wise. There is not as far as I know an adjuster that allows fine adjustment of velocity.
Alan
Some vibration in a pelicase isn't going to affect a rifle's speed, or pretty much anything else unless you've taken all the foam out. We use them for international shoots and they get wheeled across car parks, thrown into the back of planes, slung down luggage conveyor belts, wheeled through car parks again, stuffed into backs of cars and are still zeroed for 50m targets after 24 hours of that.
Check it on another chrono.
Check it on another chrono.
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Bruno Almeida
- Posts: 39
- Joined: Wed Dec 19, 2012 1:36 pm
Feinwerkbau say 170-175 mps is where the velocity should be and a 5 mps variation is acceptable and will make no difference to accuracy or grouping.
However, falling below 170 mps for several shots puts the gun out of spec so the rifle needs to be tested on an 'accurate' chrono to establish its true velocity. and if it performs several times below 170 then it should be checked out by a qualified FWB technician.
Testing conditions must be the same for all shots. Its important that the barrel is cleaned before testing and the same batch of pellets is used.
Air cylinder should be at least half full. The test range must have 'still' air.
Above all have the rifle tested on a chrono that has an accuracy certificate as issued to forensic labs. Its this level of chrono accuracy the gun manufacturers use when they issue test figures in their brochures and hand books, 170-175 mps in the case of FWB air rifles.
However, falling below 170 mps for several shots puts the gun out of spec so the rifle needs to be tested on an 'accurate' chrono to establish its true velocity. and if it performs several times below 170 then it should be checked out by a qualified FWB technician.
Testing conditions must be the same for all shots. Its important that the barrel is cleaned before testing and the same batch of pellets is used.
Air cylinder should be at least half full. The test range must have 'still' air.
Above all have the rifle tested on a chrono that has an accuracy certificate as issued to forensic labs. Its this level of chrono accuracy the gun manufacturers use when they issue test figures in their brochures and hand books, 170-175 mps in the case of FWB air rifles.
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Ulrich Eichstädt
- Posts: 187
- Joined: Sat Mar 20, 2004 11:06 am
- Location: Dortmund
I'm also pretty sure that the measurement was done in metric data, 170 is quite usual to FWB 700 and also 800 - Feinwerkbau tries to stay safe below the legal limt, which would be 174 m/s with an average 0.5 gram pellet.
And that would be my next assumption: If the H & N pellets are not pretty new (made within the last 2-3 months) it could also be possible that these are heavy 0.53 g pellets - you can't count on the info on the label for H & N production in the last year. When I was editor at VISIER (til february) we had to weight each pellet lot, because the weights didn't correspond often with the label. These times are (I'm happy about that) gone, but you have to check the weight of these pellets to be sure (with 0.50 g pellets I assume 173 to 176 m/s will be the average velocity - even the restrictive german gun law allows a tolerance of up to 1 Joule (= 8,5 J) with 1-2 out of 10 test pellets)
And 3rd, the Combro is just a "raw" tool to check the velocity - to be sure if it's 2-3 m/s up or down you might try a better chrono.
And that would be my next assumption: If the H & N pellets are not pretty new (made within the last 2-3 months) it could also be possible that these are heavy 0.53 g pellets - you can't count on the info on the label for H & N production in the last year. When I was editor at VISIER (til february) we had to weight each pellet lot, because the weights didn't correspond often with the label. These times are (I'm happy about that) gone, but you have to check the weight of these pellets to be sure (with 0.50 g pellets I assume 173 to 176 m/s will be the average velocity - even the restrictive german gun law allows a tolerance of up to 1 Joule (= 8,5 J) with 1-2 out of 10 test pellets)
And 3rd, the Combro is just a "raw" tool to check the velocity - to be sure if it's 2-3 m/s up or down you might try a better chrono.
Hi Ulrich
You may have some information on H+N Finale match pellets.
I have heard one or two shooters say they are not as good since they moved to a new factory.
I carried out a bench rest test with a FWB 700 and a tin of Finale match, it had the latest logo on the lid so I presume they are not that old.
Any way, I got a one hole group from 5 shots. I repeated the test and it was the same. I'm unclear which factory my new pellets came from so I assume the new factory.
Thanks
JSB
You may have some information on H+N Finale match pellets.
I have heard one or two shooters say they are not as good since they moved to a new factory.
I carried out a bench rest test with a FWB 700 and a tin of Finale match, it had the latest logo on the lid so I presume they are not that old.
Any way, I got a one hole group from 5 shots. I repeated the test and it was the same. I'm unclear which factory my new pellets came from so I assume the new factory.
Thanks
JSB