Not Sure What To Do…Continued POI Shift
I recently posted a topic related to barrel fouling and after a good cleaning, things tightened up….Thought my troubles were solved…..but things started going south after a couple of targets. So, I switched scopes and sure ’nuff things tightened up for a couple of targets then POI started shifting and groups started spreading. So I tried changing lubricants on the pellets from Finish Line Krytech to FP-10…and you guessed it things improved only to fall apart.
I picked up a Mad Dog Ultima Long stock…which of course helped quite a bit. BTW, KnifeMaker has a very good idea to shim gap between bottle and stock to negate bottle flex. I used a rubber wine cork, cut lenght-wise and sanded til it fits snug…that also helped but then groups widened up.
I thought about changing shooters to get rid of the “me” variable…but right now none are around this area that I know, so, I got out the trusty Marauder .25. It shot very tight and consistent.
I did read on the Yellow where there is speculation about POI shift being related to the AF barrel bushings. Adam SoCal makes an interesting, low cost suggestion to shellac the barrel bushings with fingernail polish, let dry then press them in to over come the gap issue. I’ll try that. Doug (Dyotat100) makes larger bushings that improve accuracy he has helped Tofazfou and his .257 setup….that’s a thought.
The next move is to tear the gun completely apart and clean it thoroughly. I’ll coat the main tube/hammer/spring with Finish Line Teflon. Then I’ll reassemble and use Blue Loctite on all screws. Not sure if I’ll fingernail polish at this time but why not? Also I have one more scope/rings combo to try…. a Leapers tactical side focus scope.
I’ll roll the barrel on plate glass to check that it’s true…while it’s out of the gun.
After that….I’m out of ideas. I really like this gun but if it continues to shoot this bad, I might have to cut my losses and go for something else.
I hate being beaten so if anyone has ANY suggestions please let me know. I’m including yesterday’s target, (30 yards starting at top left at 3000 psi shooting off a bench with bag). It might speak for itself. Looks like things tightened up towards the last few groups but there still was a little shift also the last group was shot 54-60 so pressure was getting low.
Thanks for any suggestions and help.
Five shot groups starting top left, JSB EK’s/FP-10.
All Replies
Walk hit it right on the nose! You should have a light EVEN coating of lead dust but NO spattering. I’ll bet that when you take a close look, you’ll find clipping damage. If that’s the case, just open up the passage holes in the baffles a few thousandths of an inch!
Let us know how it works out!
Wildfire :5:
WalkonKing, excellent advice. I’ll be doing exactly as you said as soon as the weather cooperates. I totally forgot to mention that the inside of the end cap, along it’s edge is spattered and splotchy with silver. Looks like someone took a small paintbrush and flicked silver paint around the inner edge of the end cap. Not sure if that is normal or an indication of something not right. I’ll post when I get out and shoot.
KPinNC
If everything is snug, scope is good, orings lubed and barrel is good.
Clipping can be the problem.
What I do is shoot it without baffles and cap and see how the accuracy is. If it the same then probably not clipping.
If it is better, then you have clipping.
I color the ID of all baffles and cap with a sharpie and shoot several times.
Then I take a magnifying class and see if the sharpie has been disturbed….that is where the pellet it touching causing erratic behavior.
WalkonKing, I have done the Q-tip test and everything is smooth, I’ll get out and shoot some targets without the baffles and try that as soon as this rainy weather blows over. I might take a super closeup shot of the crown and post.
I talked with AirForce yesterday and they are gong to get their techs on it ASAP. A shout out to AirForce…they responded immediately and are genuinely very helpful.
Appreciate the continued effort from you guys on the Forum.
KPinNC
Take the end cap off and take out all the baffles and see how it shoots then.
Also take a magnifying glass and look at your crown and go over it with a q tip to see if there are any burrs on it
WalkonKing, thanks for the advice, I did figure the cocking knob thing early on in the game and I have found that it shoots best when pushed to the left (with me behind the gun).
Well, I shot this weekend and things were quite disappointing. Shot Friday night with calm conditions and had bad groups. Shot again Saturday with some wind (shooting into the wind) and compared with my Marauder. Here’s the one of many targets….they were all similar so I’m just posting one. I really don’t have much else to say. I have contacted Airforce at this point since it’s still under warrranty. Maybe they can help. Wish they could send me a “loner barrel” just to troubleshoot by process of elimination.
KPin NC
Also be sure to always push your cocking knob to the same side each time
Took everything apart and cleaned. Did the tape wrap on both bushing as there was a significant amount of slop between the bushing and frame. Bushing to barrel grubs weren’t loose but weren’t tight either. Now it’s more snug. Tefloned everything. Reassembled using VC-3 on all grub screws. So after this ice storm blows over I’ll try to get out this weekend and see if there’s any improvement.
I’ll post targets once I re-zero. and if it’s still throwing lead everywhere. I’ll start looking at another gun.
The reason I sold my Condor! one day dead on 10 minutes later 2 inches high and right. 2 hours later 3 inches left tight groups always but not same point of impact.
I can take my Datystate out of the closet 6 months later and hit the bullseye. Condor was sold!
Added info if you plan to go into the trigger.
Trigger on the AF guns aren’t hard to work on and access with only one hex screw and that plate holds all 3 trigger springs down.
There is another small spring and tiny ball bearing on the safety bar end, becareful not to let it fly off you could lost it.
This bar if slightly bent is often the cause of a hard to disengage safety.
I had to straighten mines and deburred the edges and it became easy and smooth to set.
I’d change the first stage one first and reassemble to test, this is the one closet to the trigger blade.
At this point the feel improves a lot and you may not need to change the middle one out.
The length/tension is up to you, you might want it harder or even softer.
If the feel of the break feels jerky you’d might want to add a little moly grease to the shear contact point.
No need to punch out the pins, just apply some with a tooth pick.
Also if you have notice spring creaking sounds when squeezing the trigger I’d roll the OEM springs in a bit of moly also.
The squeaking is from the springs rubbing up against the sides of.
You can always put the OEM one back anytime, so keep it somewhere safe.
~ GKU
Again, thanks for replies. Good points that I will follow up on. I had originally meant to mention trigger pull; I have not worked on the Condor trigger…I did with the Marauder, removing the lawyer spring, and it is wonderful. After some thought, this might be a big contributor to my problem. GKU I have read your procedure before on your link and have been dragging my feet on it only because I’m not comfortable with going into the Condor trigger assembly yet but I usually find things are easier once I delve in than when just thinking about it….
Lurker I haven’t deburred the frame but it sound like that’s something that’s a must.
Got lots to work on tonight and through the weekend.
Many thanks for the input from you guys…I’ll let you know if there are any improvements.
KPinNC
To cure the OEM top hat from moving I Blue Loctite the top hat tread also.
I use a tooth pick and feed a little not to much right into the top hat while in the gun.
Make sure it’s set where you what it and let it dry overnight.
To make adjustments you need to remove it from the bottle and insert something into the port hole while turning the top hat to readjust it.
Your speed looks right with Kings @ 920 fps.
From the looks of your target the shots have a vertical POI shift.
Causes could be the you are fighting with the rear bag or rest when aiming.
It could be that you’re trigger sensitive like myself and caused by a hard pull and jerky rough breaking second stage trigger.
My groups improved when I lighten the trigger pull using G-2 pilot pen springs.
Note that this will void your warranty and done at your own risk.
http://talonairgun.com/forum/viewtopic.php?f=1&t=31581#p319240
~ ATB ~ GKU
The tape definately snuged up the fit. After removing the barrel again i could see where a little tape was being scraped away but it held on well enough that there was very little play if any.aybe it is from years of tac tac training that I don’t shoot one hole groups but everyod gave me more confidence. I haven’t been to the range since Nov. but when my 257 gets here And the temperature gets in the warm 50s I’ll be there a lot.
Oh, have you de-burred the inside of the frame ❓ the breach knob had mine so bad that the burrs were scraping the plastic around the rear end of the hammer. I’m sure that is another thing that causes POI shift.
Sorry, I neglected to mention I was using the Talontunes one-piece top hat with the larger insert shooting at an average of 860 fps. I was using the OEM top hat at around 0.95″ for 920fps av. but the Loctite is starting to work loose. I might go back to it and use the TT wide open for Baracudas.
I glanced at the final pressure and at a glance it looked to be around 2000 but I have noticed that the AF gauge differs from both my scuba tank and CF tank (which are both about the same reading) and the AF gauge reads low. So a 2k reading might be as low as 1600psi. I used the scuba tank gauge reading of 3000.
I usually don’t fill to 3000…just did it to see if that made a difference and apparently by the target….it does. Normally I fill to about 2600.
Lurker, did you find that the tape improved accuracy or POI stability? I might try tape before nail polish. Easier to remove if it doesn’t work.
Thanks for the responses.
KP
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This is the test I use when designing LDC.
The pellet doesn’t need to actually make contact to the internals.
If it’s very close to one side compared to the other it can send the pellet of it’s coarse.
http://talonairgun.com/forum/viewtopic.php?f=33&t=31176#p316826
Added note after taping I place the muzzle directly against my corrugated cardboard rubber mulch pellet trap and fire, it makes of a cleaner hole.
If when you try it again and the hole is at a slightly different place I would suspect it’s clipping on the inside baffle.
It doesn’t need to be exactly on center but if it’s very close to one side I would suspect that it’s a problem.
~ ATB ~ GKU