Smaller cal

Forums General Discussion Smaller cal

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    Crusher
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    Just wondering if anyone else has experienced this. I'm wondering if there is a difference of the rifling and its effects in the smaller caliber ?? I have a couple of FX guns in 25 and they are lights out accurate. Then I have another of the same make in .177 and I just can't get the accuracy I'm looking for. It is sad that my Marauder 177 shoots better.

    To be more specific, my wildcat 25 is stable as can be. But my wildcat 177 just isn't as accurate. I was excited thinking I was going to get a 177 for pesting that would be as accurate as the rest of the guns. Don't get me wrong, it isn't missing by a mile or anything. In fact, it is pretty accurate. It just isn't as tight as the rest in larger calibers.

    So, could it be the grooves pressed into the ST barrel aren't deep enough? Or maybe the laws of physics just effect the 177 so much more?  I see more fliers from the smaller calibers. Does it just take so much less to disturb the pellet flight? And if so, why then would my less than $500 Marauder be so accurate and throw less than half as many fliers?

    Just wondering if there is something I can do to make this WC 177 shoot a little better. It has a HUMA reg and the ES is stupid low. I've adjusted the speed up and down along with the reg pressure until I have it shooting about as good as it's going to get. Maybe I'm just expecting too much?

     

    Crusher

     

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    John_in_Ma
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    What speed are the pellets going and what type/weight are they?

     

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    Skillet
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    Sometimes an individual gun just isn’t as accurate as others of the same make/model /caliber. Barrels machined on different days, even as the tooling wears, can show disparate ammo preferences and potential.

    Could be that barrel could use some bore polishing, even at the crown.

    I’d slug it and feel for rough spots

    A factor with smaller pells can be weight disparity; a .177 pell off by 1/2 gn is a larger percentage than a .25 off by the same .5 gn

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    Crusher
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    Currently getting the best accuracy with the JSB 10's. Huma set to 120 bar and shooting about 905. And they shoot hole in hole for maybe 5 or 6 shots. Then a flier. I have checked the pellets looking for anything different. I washed, sorted and weighed them. The 10.2 grains shoot the most consistent groups.  I have tried from 820 fps all the way up to 955. But I still get a flier at least every 8 shots or so. I've cleaned the barrel, checked everything for tight. Checked probe depth. Checked for clipping. Tried with and without mod. So far, nothing keeps the fliers away.

    And again, I'm not talking about missing an inch or something. I'm talking one hole in the other for several shots, then one high and right about 1/8-1/4". When I'm shooting at a target that is only 2mm, missing by 10mm is a mile.

    Sometimes it shoots like this. These are 2 shots each hole.

     

    And then it shoots like this. And this is 4 shots in a row.

     

    So, something weird is happening. I'm going to try some AA pellets I have. Also have some .177 predators. Problem is they don't fit in the mag. I think I have one or two other brands to try as well. 

    Maybe I should contact FX and see if they think something is wrong with the barrel?  Maybe have them send me a new one?

     

    Crusher

     

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    sonny
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    maybe something in the hammer spring or valve causing a harmonics problem? vibration? almost looks like scope or cant problem.

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    Stefanjan
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    Skillet is correct.  The slightest variation in pellet weight make a larger difference as does skirt size head diameter etc.  You have a regulator which should help with speed destabilization.  I just added an air stripper to my hatsan and after tuning it noticed a large improvement 

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    BigTinBoat
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    Crusher

    Currently getting the best accuracy with the JSB 10's. Huma set to 120 bar and shooting about 905. And they shoot hole in hole for maybe 5 or 6 shots. Then a flier. I have checked the pellets looking for anything different. I washed, sorted and weighed them. The 10.2 grains shoot the most consistent groups.  I have tried from 820 fps all the way up to 955. But I still get a flier at least every 8 shots or so. I've cleaned the barrel, checked everything for tight. Checked probe depth. Checked for clipping. Tried with and without mod. So far, nothing keeps the fliers away.

    And again, I'm not talking about missing an inch or something. I'm talking one hole in the other for several shots, then one high and right about 1/8-1/4". When I'm shooting at a target that is only 2mm, missing by 10mm is a mile.

    Sometimes it shoots like this. These are 2 shots each hole.

     

    And then it shoots like this. And this is 4 shots in a row.

     

    So, something weird is happening. I'm going to try some AA pellets I have. Also have some .177 predators. Problem is they don't fit in the mag. I think I have one or two other brands to try as well. 

    Maybe I should contact FX and see if they think something is wrong with the barrel?  Maybe have them send me a new one?

     

    Crusher

     

    Personally I think you have the reg set too high, especially to be tuned at 905 with the 10.3's. When I originally had my reg at 120bar I could turn the HS in and get 1025 fps with the 10.3's. I backed it all the way down to 90bar and now i get no fliers with the 10.3's at 865fps avg.

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    Crusher
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    sonny

    maybe something in the hammer spring or valve causing a harmonics problem? vibration? almost looks like scope or cant problem.

     

    I see why you could think that.  I have leveled the gun, then the scope and made sure the reticle is straight with the old "string" trick. Then I have a bubble level on my rest and on the scope. I used to fight cant because the other rest I had just seemed more natural like that. but this thing is straight up and down. I'm starting to think it has to be the barrel. Either the groves are wearing out somehow or the crown is jacked up.

    Here is a group of 10 shots I did back when I first got it.

     

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    0akhonor
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    I'm going to follow this thread- I have an Impact with .177, 22, .25 barrels- the original smooth twist.

    I've a chrony, big mix o' pellets, and an inclination to experiment.

    My .22 will do .5" groups @ 100  on a calm day. The .25, about .75 to 1". The .177- with 13.4 JSB'S only., @ 820 fps, maybe .75" @ 50.

    These are typical groups, the ones with a magazine, not taking to much time, just shooting at paper groups.

    Reg is set @ 115-ish for .177, 130 -ish for larger pellets. I've gone up and down with it, experimented with hammer and valve opening. If I shoot 10.3's in the .177, I've the reg set to110, and try to keep pellet speed below 850.

    Slugged the bores, bore pasted them- my gun shoots the .22 best within reasonable distances.

    Other members in my club swear by their .25's.

    I want to use my .177 kit for field Target, and it's ok, but I've another gun in .177 that shoots tighter groups, with less effort, and 10.3's at 900, so less arc and wind deflection. I'm not calling it quits, it's the journey, not the winning that is interesting. Hoping to get the impact shooting like a laser in .177, but haven't found the magic bullet yet,, so to speak..

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    Crusher
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    BigTinBoat

    Personally I think you have the reg set too high, especially to be tuned at 905 with the 10.3's. When I originally had my reg at 120bar I could turn the HS in and get 1025 fps with the 10.3's. I backed it all the way down to 90bar and now i get no fliers with the 10.3's at 865fps avg.

    That is possible. I found with the reg lower than 120, I couldn't get what I call "harmony" out of it. So yes if I crank the HS in with it at 120, I'd get 1000+. but by backing out from the knee of the curve with the HS, I get a much smoother shot. And it isn't followed by a blast of air that isn't pushing the pellet.

    I walked this think around for days, going down the reg by 5 all the way to 85. I did get it shooting around 850 with the hs cranked in to the knee. But it still had fliers. 

    I guess after the match tomorrow I'll start easing the reg back down and see if I can make anything happen. Thanks for the input guys.

    Crusher

    ps. When I got the gun it was shooting the 10's at 955 and that is the group of 10 I showed in the group above.

     

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    sonny
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    best of luck crusher at the match im sure you will do well.

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    Skillet
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    “…or the crown is jacked-up.”

    A light polish on the crown is easy to effect. I use a sharpened pencil, chucked in a cordless drill with lapping paste on the end.

    The #2 pencil is soft pine and just a carrier for the polish. Just a quick spin, clean and shoot for groups. Never made a gun less accurate for me, and improves, more often than not. You prolly already know that a Qtip  can reveal larger burrs, but not always ‘micro’ burrs

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    Element
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    Gamo coyote whisper .177 stacks pellets 10.5 boxed preimers…no reg, just the best .177 pcp i have ever shot! Fill pressure from 2200 down to 1500 lights out.

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    sharkman
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    https://m.youtube.com/watch?v=puF3EryiQ4c

    This video was done by UA and John from FX talks about the original smooth twist barrel with .177 pellets. Time stamp approx: 5:13 into the video. He claims the original smooth twist shot the .177 “meh” and that the new X barrel system would solve that issue.

    If the accuracy for you was never quite there then maybe this helps… if the accuracy was there and has slipped then ignore this completely. 

    -Sharkman

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    airgunmike56
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    I jumped in on the 177 PCP guns . I have and own 22, and 25 caliber guns , But no FX guns , I just bought a Vulcan #2 in 177, Shot count is amazing from a single fill. I have a CZ barrel so it may be apples to oranges , But my gun seem to like the 13.43 gr JSB pellets at around 815 FPS. I was shooting the 10gr JSB at around 940 FPS. Seems like everyone is going bigger to the 30 caliber and all. But I like filling once and shooting a lot . In your case you might have to shop around and find the right pellet your gun likes . Maybe some other shooters can jump in here with a 177 FX and tell you what pellet there gun likes , It may get you a little closer to the right pellet. 

    Mike

     

     

     

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    Crusher
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    Skillet

    “…or the crown is jacked-up.”

    A light polish on the crown is easy to effect. I use a sharpened pencil, chucked in a cordless drill with lapping paste on the end.

    The #2 pencil is soft pine and just a carrier for the polish. Just a quick spin, clean and shoot for groups. Never made a gun less accurate for me, and improves, more often than not. You prolly already know that a Qtip  can reveal larger burrs, but not always ‘micro’ burrs

    I may give this a try later this week.

    Thanks everyone for the input. I appreciate it.

    Crusher

     

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    Springrrrr
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    I was going to mention the smooth twist barrel is just not that great for 177 pellets but the video said it for me.

    I have a similar dilemma with my Wolverine R.  I get these flyers also but most of them go to the right.  I determined that maybe, just maybe, it could have something to do with trigger lock time.  The time it takes from the trigger to break to the time the pellet starts moving in the barrel.

    If I squeeze the trigger with the very tip of my bent finger, the problem subsides tremendously and any wind has a large affect on the pellet too.

    177 used to be pretty much a standard for air guns, now we are looking at 22 and above.

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    Kitplanenut
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    I jumped on the 177 just for the 25 yard competition. Plus just like screwing around with these guns. Have a FX smooth twist and out of the box it was, not so good. Took it down and did the old port and polish on everything. Now if the air flows over it the corners are rounded and polished to a mirror finish. Everything that moves was cleaned of any heavy lube that might cause inconsistency. Reg was changed to a Huma and is set using Huma's reg tester. Started with the reg at 90 bar and worked up to 120 bar. Have tried the hammer spring maxed out to almost backed out. Shooting the JSB 10.2 grain. At 50 yards on a clam day it will do the same as what Crusher has described. I would say 80% one hole and 20% fliers out maybe a half inch. Always high right or left. As far as everyday accuracy this gun is damned accurate. At 50 yards a sparrow doesn't have a chance. To compete with, not so much. I have no answers and am at a loss as what to try other then maybe a barrel change. sylvan

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    BigTinBoat
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    Are you guys shooting with the gun in a vise? Are you using a trigger aid?

    Are you weighing and sizing pellets to within 5% of each other?

    Are you shooting indoor?

    If the answers are no to any of the above questions then I would honestly say it's the shooter/pellets/conditions, not the gun causing the differences.

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    addertooth
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    When a good gun shoots great one day, and poorly the next there is often a search for a "cause".  If you have good pellets, good shooter and good gun, there is often another cause.  I used to struggle with this, one session I would shoot the lights out, the next week, not so much amazing accuracy.  I realized the problems was non-optic Optics problem.  Or in other words, my parallax was adjusted wrong for that day.  Keep in mind that things like temperature affect your scope, even good ones.  I had gotten into the bad habit of setting my parallax to a known value and shooting.  My best shooting days were always the ones where I was calibrating a new scope.  Why?  When calibrating the scope, I always did the "head bob" test to determine if parallax was correct.  The best parallax adjustment may not be at the peak of sharpest focus.  With a head bob test, you have your air rifle secured to a bench or a sold bench rest bags position.  While looking through the scope, bob your head around, if the crosshairs move away from the center of the target, then parallax is NOT correct.  This means that small changes in your head position (frequently happens when cocking your air gun) changes where the crosshairs align with the target.  This can cause the crosshairs to "look" like you are exactly on the center of the target, but point of impact will actually be off the bullseye.  

    Always do the head bob test before you do serious shooting.  Your ideal parallax knob position may change due to temperature.  Every wonder why so many top shooters use a camera mount on their rifle scopes?  It is because the camera is ALWAYS held in the exact same position each time, this helps reduce the risk of changing point of impact versus what the reticle shows.  

    I hope this helps some of you, who have awesome airguns, but get variations in your results.

                         Addertooth

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