velocity and grouping questions
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velocity and grouping questions
It seems that if I up the velocity of my LP1, the tightness of groupings suffer. So my question is really whether there is an ultimate advantage to higher velocities (and therefore suffer through the adjustment period) or if one should find the velocity which yields best results...at least for now. I am trying to keep most of the variables under scrutiny and control so that any changes are isolated for the most part. Thanks for any thoughts on the matter. Craig
Hi Craig, although the ultimate goal will be how the combo performs when you are shooting the pistol but to establish some benchmark comparisons and results you may want to vise or otherwise lock down the pistol. It may be an easier way to see how different pellets group at different velocities with your pistol of choice (the Steyr?). I am currently running my LP-1 fairly hot, 520-530 fps depending on pellet. I haven't benched it in any way myself but it is currently grouping very well (I've been practicing again). Then again my FAS 604 does a great job at 400 fps. Good luck, hope to see ya soon, Joe G.
I have put my pistols in a vice and tested many different pellets (mfg and size) across the same velocity range.
First I had to find a velocity that was going to give me a good group. When I first did this I had Scott dial my pistol in at 550 fps since this it what I had heard was a good starting point for the LP1. I played around with the selection of pellets I had and found a setting that gave me a good tight group for what I had a good supply of pellets.
Since then I have moved on to the LP10 and did the same thing. I had a larger supply of pellets to choose from but the result was the same. I keep the target I shot for referance and use the "knot lot" for matches and all other pelets for practice.
I found it best with the pistol in the vice to move around the target that I attached to a home made trap that has a cardboard front to it.
This set up is also a good way to determine after how many shots you will start to see a loss in accuracy depending on where you started from. I do not remember what the results were but I do know that above 2000 psi I can shoot more than 80 shots which is plenty for me in a match.
First I had to find a velocity that was going to give me a good group. When I first did this I had Scott dial my pistol in at 550 fps since this it what I had heard was a good starting point for the LP1. I played around with the selection of pellets I had and found a setting that gave me a good tight group for what I had a good supply of pellets.
Since then I have moved on to the LP10 and did the same thing. I had a larger supply of pellets to choose from but the result was the same. I keep the target I shot for referance and use the "knot lot" for matches and all other pelets for practice.
I found it best with the pistol in the vice to move around the target that I attached to a home made trap that has a cardboard front to it.
This set up is also a good way to determine after how many shots you will start to see a loss in accuracy depending on where you started from. I do not remember what the results were but I do know that above 2000 psi I can shoot more than 80 shots which is plenty for me in a match.
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Mark Briggs
- Posts: 583
- Joined: Mon Mar 01, 2004 8:35 am
- Location: The Frigid North - Ottawa, Canada
My limited testing has shown that velocity may not be the king, nor is extreme velocity spread or standard deviation the best measure of ability of a certain pellet to group well. It seems to be some magical mix of exactly the right pellet size/shape and weight that hits the sweet spot for the barrel of a particular pistol. Just as an example, my LP10 shoots inexpensive JSB Schak's very, very well, and the SD value is at least twice that of the next best pellet. By comparison, the pellet this pisol "likes" best produces only marginally tighter groups than the Schak's, but has only a mediocre SD value. Go figure...
Some of the best groups I've shot have produced relatively poor SD numbers. I've also found that, of the four air pistols I've tested, only one really likes high velocity settings, while the other three seem much more content to loaf along in the 460 - 490 fps range. I still have a bit more tuning to do, but the results so far are very good.
I sold the "fast" pistol and kept the other three so now I buy my pellets by the case lot so I'll have good consistancy that I can count on for a couple of years or more (well, I hope it'll take at least a couple of years to consume that many pellets!). And as it turns out, these three pistols all seem to prefer heavy pellets, so the H&N Finale Match Glatt (rifle) pellet is the projectile of choice.
Mark.
Some of the best groups I've shot have produced relatively poor SD numbers. I've also found that, of the four air pistols I've tested, only one really likes high velocity settings, while the other three seem much more content to loaf along in the 460 - 490 fps range. I still have a bit more tuning to do, but the results so far are very good.
I sold the "fast" pistol and kept the other three so now I buy my pellets by the case lot so I'll have good consistancy that I can count on for a couple of years or more (well, I hope it'll take at least a couple of years to consume that many pellets!). And as it turns out, these three pistols all seem to prefer heavy pellets, so the H&N Finale Match Glatt (rifle) pellet is the projectile of choice.
Mark.
The results I've seen posted, from a high end APs, show "bad" groups still fitting inside the inner 10 ring. My take on this is to get pellets from a reliable souce (brand) and just work on the truely limiting variable, me. I buy Vogel pellets and just train. I really don't see the pellet, speed and/or combination of the 2 as relevant to my scores. When I'm that good, well.... I can dream, can't I.
However, the scientist is me loves to tinker with all the settings and to see what other folks are doing. :-)
However, the scientist is me loves to tinker with all the settings and to see what other folks are doing. :-)