 |  | | | |  |  |  |  | what makes a great field target rifle a great field target? |  | |  |  |  |
Posted: Sun Jan 31, 2010 6:52 pm |
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| donec |
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I am wondering what is needed to have a great or at least a good field target rifle. It seems to me that a field target rifle should be 1 inch accurate out to and past 75m but doesn't really need to have that much energy at the target.
I looked at Pyramidair at the field target rifles and was surprised to not see the discovery listed. All I see is springers and high end pcp's. |
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Posted: Mon Feb 01, 2010 6:34 am |
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| Alstone |
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I shoot FT using an AA tx200hc and the most I have shot is 45m and getting the pellet within a 1” group at that range is a problem, but I think doing it at 75m is pushing the limit’s a bit, especially on a FT range when you take into account any slight breeze there maybe.
The thing about springers and high end pcp is that the output is constant for every shot, where as on a Disco it drops off with each shot requiring adjustments for the changing fps, which makes things difficult.
Al |
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Posted: Mon Feb 01, 2010 11:12 am |
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| rsterne |
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| Quote: |
| on a Disco it drops off with each shot |
I have done extensive testing with my Disco.... Dead stock it is capable of 25 shots within plus or minus 2% of 810 fps with 15.9 gr. Exacts or 840 fps with 14.3 gr Express.... It has a very nice bell curve starting at 1900 psi through 1200 psi.... That gives a vertical dispersion of just 0.2" at 50 yards.... certainly plenty good enough for FT.... and a heck of a lot better than I can shoot....
If you find 5% tolerance acceptable, you get 30 shots from 2000 down to 1000 psi.... That increases the vertical dispersion to 1/2" at 50 yards.... but at 30 yards it is still only 0.2".... good enough for most uses, if not FT....
Bob |
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_________________ Dominion Marksman Silver Shield - 5890 x 6000 in 1976, and downhill ever since!
Airsonal: Too many to count! |
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Posted: Mon Feb 01, 2010 12:16 pm |
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| broommaster2000 |
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That being said, the noize of the Disco will scare the field targets of.  |
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Posted: Mon Feb 01, 2010 3:10 pm |
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| donec |
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| Alstone wrote: |
The thing about springers and high end pcp is that the output is constant for every shot, where as on a Disco it drops off with each shot requiring adjustments for the changing fps, which makes things difficult.
Al |
Why would the disco be dropping off like that? Could it have to do with the base pressure of 2000psi vice 3000psi? Would the output drop off if you were using co2? |
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Posted: Mon Feb 01, 2010 3:12 pm |
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| donec |
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| rsterne wrote: |
| Quote: |
| on a Disco it drops off with each shot |
I have done extensive testing with my Disco.... Dead stock it is capable of 25 shots within plus or minus 2% of 810 fps with 15.9 gr. Exacts or 840 fps with 14.3 gr Express.... It has a very nice bell curve starting at 1900 psi through 1200 psi.... That gives a vertical dispersion of just 0.2" at 50 yards.... certainly plenty good enough for FT.... and a heck of a lot better than I can shoot....
If you find 5% tolerance acceptable, you get 30 shots from 2000 down to 1000 psi.... That increases the vertical dispersion to 1/2" at 50 yards.... but at 30 yards it is still only 0.2".... good enough for most uses, if not FT....
Bob |
Have you done any testing using co2? |
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Posted: Mon Feb 01, 2010 5:13 pm |
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| rsterne |
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No CO2 testing.... doesn't interest me.... too cold here during hunting season and the loss in power compared with HPA isn't worth the increased shot count and cost....
Bob |
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_________________ Dominion Marksman Silver Shield - 5890 x 6000 in 1976, and downhill ever since!
Airsonal: Too many to count! |
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Posted: Mon Feb 01, 2010 7:13 pm |
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| scroller99 |
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I've shot FT with my 2250 and did alright and now that I have a better scope I can't wait to go back and try it again  |
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Posted: Tue Feb 02, 2010 9:57 am |
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| Alstone |
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I've never seen anyone using a Co2 rifle for FT, but I have used a qb for rough shooting and find that the fps changes depending whether you are in sun or shade, i.e. inside a wood or out, and not capable of the accuracy required for long shots even at 40mm targets.
Firing from a fixed position is better as the temperature is more constant.
Al |
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Posted: Tue Feb 02, 2010 2:37 pm |
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| donec |
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| Alstone wrote: |
I've never seen anyone using a Co2 rifle for FT, but I have used a qb for rough shooting and find that the fps changes depending whether you are in sun or shade, i.e. inside a wood or out, and not capable of the accuracy required for long shots even at 40mm targets.
Firing from a fixed position is better as the temperature is more constant.
Al |
Sorry for my ignorance but what is qb? |
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Posted: Tue Feb 02, 2010 3:15 pm |
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| fritz |
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| He's talking about a kind of rather cheap chinese airgun. Probably a QB-78, with HPA mod since it's too cold for Co2. |
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_________________ "I never set out to be wierd, it was always everyone else who called me it" -Frank Zappa
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Posted: Tue Feb 02, 2010 3:19 pm |
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| rsterne |
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CO2 is also affected drastically by the rate of fire, particularly if using powerlets.... they chill as you shoot, causing a falling velocity string.... About the only way around it is to detune the gun to get it in the "self-regulating" range like the way a PCP works....
Some CO2 rifles could probably be tuned up to 12 FPE for Int'l FT, at least in .22.... but I don't know of any that would produce 20 FPE for the North American rules.... Under the 12 FPE rules, in particular, .177 would be king.... and 12 FPE is ~ 800 fps with 8.4 gr. pellets.... probably a bit of a stretch for most CO2 rifles.... although you could probably get there with a modified 850.... I don't know about a Disco on CO2....
Bob |
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_________________ Dominion Marksman Silver Shield - 5890 x 6000 in 1976, and downhill ever since!
Airsonal: Too many to count! |
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Posted: Tue Feb 02, 2010 6:02 pm |
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| Alstone |
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I was talking about a QB 78 running on Co2 capsules, the maximum output from it is around 10.6 flb which =755fps with 8.4 g .177 pellets, and this is with a tune up.
As Bob says trying to get near the UK 12flb for FT would be difficult, and as for your North American rules 20flb would be very difficult, plus I should think that when working at the maximum output it would drop off very quickly to a rate it can sustain, because some courses are very busy and your shooting anything up to 50 targets a round, which would require a capsule change unless your using a bulk tank.
Al |
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