Tuning Possible reason for flyers...what is the best fix?

[Dave]

After sighting in Taipan Veteran Long .25, I noticed a flyer in about every group. After recommendation from members I have gone through different areas of the mags, screws, and other possible things that one can easily check. 

I found that the mags did have a tiny burr inside the hole in both mags, and cleaned them carefully. As for the screws, everything seems to proper tightness. 

However, tonight I pushed a few pellets and slugs into the breech using the single shot tray and back out for inspection. It appears that the pellets are being pushed across some kind of burr in the breech, while the more pointed slugs don't exhibit this same effect. It is most noticeable on the H&N Barracuda hunter, while the JSB look like good crisp rifling marks on one side, and light marks on the other. I would think that the choke would eliminate this as it exists the barrel, but without removing my barrel completely to put a pellet all the way through I don't know for sure.

Any thoughts or advice would be appreciated. 

 

[vinny]

Following this one!

 

[Richmeister]

I would be I interested in hearing the recommendations you have as well.

Any way to push a slug safely through your barrel...?

 

[UCChris]

Likewise. I'd pull the barrel and see what you can see/feel with a q-tip

 

[shambozzie]

Dave, you can degas it to 100/150 psi and shoot a pellet into a thick folded towel to capture and recover pellet for inspection.

 

[Dave]

I removed the barrel and found the culprit causing slight shaving of pellet during chambering, and took some 2000 grit and cleaned up the burr that was causing it.

Pellet after removing burr.

I pushed a few pellets and slugs through the barrel while it was off as well.

Rifling looks good on the pellets, but the slug shows that lead is being pushed back, with the slug that was tapped through the choke a little quicker showing the most deformation. Prior testing had already shown this barrels choke didn't prefer any of the slugs, which this damage from the tight choke appears to answer the reason why.

At least this is one more variable that is taken out of the equation. I will have to make sure everything zeroed and adjusted for my determined optimal accuracy prior to taking it out again for long range testing. 

I will be installing the Huma regulator when I put the power plenum on, so if it is being caused by the reg, that will soon be fixed.

 

[qball]

Great detective work, sounds like you need a bore scope. That slug is pretty badly damaged, curious on the cause.

 

[Dave]

Great detective work, sounds like you need a bore scope. That slug is pretty badly damaged, curious on the cause.

I looked down the bore the best I could and there doesn't seem to be anything that is blatantly obvious that could cause it. My best guess from all the lead fouling and dust that the slugs were causing from shooting, that it's just due to the tight choke and the amount of engagement between slug and rifling. Since all the lead has to go somewhere that is displaced by the lands, the faster it is moving the more friction causes a galling effect on the lead. 

I definitely tapped that one through pretty quickly, which might not allowed it to turn on the rifling as well, as it was pretty adhered to the dowel rod I used... with the next slug I tapped it through very slowly to see what the cause of the first condition was, which was the better looking of the two. With pellets there is much less contact area, and more room for lead to be squished to where it needs to go. I believe this is why most slug barrels are unchoked, or a slug sized appropriately must be available to shoot as intended. 

We will see if anyone else can shed some light on this.

 

[JungleShooter]

Very helpful post! Thank you, Dave, for taking the time to write this up and do the photography. Excellent quality!

Matthias

 

[Franklink]

I feel like a broken record posting this again, but.......Taipan puts too aggressive of a choke on their barrels for slugs, and in many cases, even for mostly filled skirt pellets like the .22 MRDs. The tight choke usually shoots pellets very well though. 

 

[Guest]

Leave the factory regulator in it (they are quite excellent) then test for fliers at a reasonable range that isn't wind-affected.

I missed your first post about this so I don't know what what constitutes a 'flyer.'

 

[elh0102]

Looks like your problem was a TP burr, which you have fixed. I don't shoot slugs, and have no knowledge of the difference in the barrel design compared to pellet barrels. I would guess that the twist rate, chamber leade, and choke construction might all be different. Most precision rimfire barrels are choked, but the dimensions might be different. I would second the recommendation of keeping the Taipan regulator, unless chrono testing indicates a problem. On average, they may be better than the Huma. I expect you will get excellent results with your Vet using pellets. 

 

[Dave]

Leave the factory regulator in it (they are quite excellent) then test for fliers at a reasonable range that isn't wind-affected.

I missed your first post about this so I don't know what what constitutes a 'flyer.'

Sorry, this is continuation of a post where I took the gun out and shot at longer ranges. This target is one example, but this seemed pretty typical of each group having a flyer. The wind was still, so even at 100 yards crosshairs could be held dead on, with only adjusting for drop. Pellets sorted and all weighed 34.20-34.29 by my scale for this group at 48 yards.

 

[elh0102]

Was this group before or after you removed the burr? Have you done a chrono test? If not, you will be doing yourself a favor to keep the Taipan reg unless chrono testing indicates an issue. I seriously doubt that it is a problem. To cause that kind of flyer at 48 yards, the velocity variation would be extreme. 

 

[triggertreat]

Good job on the find/fix! It looks to me like your choke is a bit aggressive regardless of the fix. The peeling back of lead on the tails and the extra deep grooves gives it away.

I also weight sort all of my .25 cal and up projectiles. I also size them all using a NOE bushing and Lee press. I also lube those projectiles for even tighter groups and ES than without. It would be a really rare thing for me to see a flyer. I also polish my barrels. Give these extra steps a try if you wish and see if flyers are still a thing for you.

 

[Dave]

Was this group before or after you removed the burr? Have you done a chrono test? If not, you will be doing yourself a favor to keep the Taipan reg unless chrono testing indicates an issue. I seriously doubt that it is a problem. To cause that kind of flyer at 48 yards, the velocity variation would be extreme.

This was a group before finding TP burr.

Good job on the find/fix! It looks to me like your choke is a bit aggressive regardless of the fix. The peeling back of lead on the tails and the extra deep grooves gives it away.

I also weight sort all of my .25 cal and up projectiles. I also size them all using a NOE bushing and Lee press. I also lube those projectiles for even tighter groups and ES than without. It would be a really rare thing for me to see a flyer. I also polish my barrels. Give these extra steps a try if you wish and see if flyers are still a thing for you.

I think barrel polishing will be my next stop.

 

[qball]

Maybe some extra aggressive polishing for the choke to open it up just a tiny bit. Traditionally pellet barrels always have very tight choke, great for pellets but not so much for slugs.

 

[elh0102]

Polishing won't hurt, worth a try. In order to relieve the choke, you need to lap it. Unless you really know what you're doing (not to imply you don't), that is tricky task. What you have is a good pellet barrel, and I'd be hesitant to do anything to it more than cleaning and polishing. Whether you can make it a good slug barrel is questionable, whether you can diminish it as a good pellet barrel is not. 

 

[qball]

Polishing won't hurt, worth a try. In order to relieve the choke, you need to lap it. Unless you really know what you're doing (not to imply you don't), that is tricky task. What you have is a good pellet barrel, and I'd be hesitant to do anything to it more than cleaning and polishing. Whether you can make it a good slug barrel is questionable, whether you can diminish it as a good pellet barrel is not. 

excellent point! That’s why I suggested aggressive polish but lapping is a whole different story. I certainly will not attempt to lap the barrel and destroy it as a good pellet barrel while it’s all but certain it won’t make it a good slug barrel. 

 

[Dave]

Polishing won't hurt, worth a try. In order to relieve the choke, you need to lap it. Unless you really know what you're doing (not to imply you don't), that is tricky task. What you have is a good pellet barrel, and I'd be hesitant to do anything to it more than cleaning and polishing. Whether you can make it a good slug barrel is questionable, whether you can diminish it as a good pellet barrel is not.

Polishing won't hurt, worth a try. In order to relieve the choke, you need to lap it. Unless you really know what you're doing (not to imply you don't), that is tricky task. What you have is a good pellet barrel, and I'd be hesitant to do anything to it more than cleaning and polishing. Whether you can make it a good slug barrel is questionable, whether you can diminish it as a good pellet barrel is not. 

excellent point! That’s why I suggested aggressive polish but lapping is a whole different story. I certainly will not attempt to lap the barrel and destroy it as a good pellet barrel while it’s all but certain it won’t make it a good slug barrel.

I just ordered all the things I will need to polish the bore. Unfortunately, the J-b compound only seemed available as kit with kroil, making it a little more expensive, as I already have kroil. Also go a Montana x-treme cleaning rod.