N50 with an Avenger

[igolfat8]

I hit the barrel lottery with my Avenger .22 so I figured I’d try a few N50 cards and I was pleasantly surprised by the results. It has now surpassed my best scores with a host of much higher priced rifles including RedWolf, Uragan, Cricket II, a few FX’s, Brocock Sniper XR, and my recent favorite a .22 Prophet. Granted the conditions were pretty calm to get these results and higher powered rifles fare better when the conditions worsen.

 

[thomasair]

Very good....that’s nice to see!

Mike

 

[Pistonjohn]

Wow that avenger can shoot!

 

[TonyG]

They are gonna sell a million of those things, I have two myself.

 

[Joef]

Wow really nice shooting.with that rifle,

Thanks for posting,

Joe

 

[queenks]

Pretty impressive. !!

 

[MikeBell]

It doesn't seem to be pellet fussy.

 

[igolfat8]

No it’s not fussy. It shoots AA, JSB 16’s and 18’s well. 18s have an advantage in the wind though.

 

[my87csx481]

Sorry for the off topic....



On mine, the surface finish on the chamber ID (where the probe o-rings seal) is rough looking. And then the rifling seems to be an abrupt 90° transition (if looking at a cross section of the barrel). Pushing a pellet through into the rifling with a wooden dowel....it just feels nasty. Pellets get gashed up pretty bad.



I assume yours is not like mine at all, or you did some work to it. Care to share any info?



I plan to do something, but I do not have access to a lathe. I'm working out how to use a drill press to spin the barrel, and polish the chamber a bit. Not sure how I will blend the transition into the rifling. Any ideas?

 

[igolfat8]

My Buddy has an Avenger and his barrel is not like mine. When pushing a patch through mine it twists the cleaning rod as normal. When pushing a patch through his it goes bump, bump, bump and so on like it’s skipping across ribs 90* to the axis of the bore which sounds more like yours. His will only shoot 2-3” groups at 50 yards so it’s evident that these barrels are certainly not all the same and consistent. Another buddy has one and he only cleaned his when new and it shoots great nearly out of the box.

When my barrel was new it took a LOT of effort and scrubbinging to get it clean, like 100+ patches. I used solvent and bronze brushes followed by solvent patches and kept repeating until it was clean. Both of ours would have unexplained fliers that seemed to happen out of no where so I did the full on barrel polishing and waxing process on both of ours. This alone was the biggest gain in accuracy but it’s a LOT of work, but we’ll worth it IME. 


I purchased Felt pellets from Brownells.

https://www.brownells.com/gun-cleaning-chemicals/patches-mops/cleaning-pellets/weapons-care-system-pellets-prod13839.aspx

And the brass adapter to fit on a cleaning rod. Thread two pellets on that adapter, using a drill and work in Kroil into the pellets. Coat the pellets with 400 grit lapping compound and vigorously scrub the barrel, from the breech to the muzzle in 6” increments using at least 50 strokes per 6”. Then 50 strokes from breech to 12” then 50 strokes from breech to 18” and so on until you reach the muzzle. I’ve done this process 4 times and the gun keeps getting more accurate every time I do it. Every 6” (after 50 strokes) I replaced the pellets and pushed the crud out with clean patches between pellet changes. You have to remove the barrel from the gun to do this process and I clamped the barrel in a wood jaw vise to hold it securely during the scrubbing. 


After I did the treatment with 400 grit then I repeated it with JB Bore paste then repeated using JB Bore Brite.

https://www.brownells.com/search/index.htm?k=Bore+paste&ksubmit=y

This is a boat load of work and not for the frail with low stamina. However the results speak for them selves. After 4 treatments and hundreds of strokes I am very happy with the way my Avenger is shooting and don’t plan any more work to it. The final step is a thorough cleaning with DeNatured alcohol, until patches come out perfectly clean. Then two more dry patches followed by a bore waxing using a cotton mop saturated with Johnson’s Paste Wax. Allow the wax to dry for at least 1/2 hour, then go shoot it and report back your results. You should see a noticeable improvement in accuracy and if it’s not where you want then repeat and try again. These barrels are REALLY filthy and rough inside and this process will smooth them out like they should be from the get-go.

 

[my87csx481]

Again, sorry for the off topic.



But wow. Thanks for all the info, and all the effort to post it. Very much appreciated.

I will be polishing at some point, but I suspect it's not as bad as I may have described it (not the land surface finish anyway). It's the transition that's crunchy/chunky. For the sake of clarity, a picture is worth a thousand words. As best I can tell by looking into the breech (with the barrel removed, through an eye loupe), this is what I believe the cross section would look like (see image). My plan is to soften the transition somehow, then polish the bore.

 

[igolfat8]

There’s probably a proper tool for that but it’s beyond my pay grade. Sorry I’m not any more help. Perhaps you could ask Mike N since he builds Thomas rifles and he would likely know how to answer your question best. I think the area you want to reshape is called the leade but I could be wrong???

 

[my87csx481]

Thanks again....and (I forgot to say) nice shooting.

 

[igolfat8]

Thank you. I just IM’d Brownells about this and they suggested calling their gun techs tomorrow between 8 and 4 PST. Perhaps they have a simple too that could bevel, throat or polish the leade. Please report back what you find out.

 

[my87csx481]

Sorry again for the off topic, thread hijack.

Thanks. I'll give them a call tomorrow. I know there is such a thing as a chamber reamer. But I was fairly certain those are specific to powder burners (and their cartridges) but, I have zero pb experience, so I could be completely wrong. And maybe there is something usable for air rifles.

I will report back what they say. I decided to start my own thread, in a more appropriate area (so I don't keep hijacking this one). https://www.airgunnation.com/topic/avenger-22-barrel-questions/

Thanks again for the help.



Edit: I opted to not contact Brownells. But I did do some googling and found several threads on other airgun forums, as well as information regarding chamber reamers, and throating reamers (and where they can be purchased, and also how to make them if I had access to a lathe and milling machine). I think I would be fine if I could just get a 45 degree chamfer on the lands, transitioning from the chamber to the bore. The pellet probe does push the pellet just past the 90 degree shoulder. If I were to use a 1 degree per side tapered reamer (the preferred angle, as I understand it), I suspect this would be way too shallow of an angle, and cause even more issues (because the area I keep calling the chamber is way larger than pellet diameter). Well, at least I think the chamber diameter is way larger....but looking at the schematic, and the o-ring spec for the pellet probe....it should be 5.5mm (.2165")....or .22 caliber. I guess I need to take it apart again and do some measuring before making a decision on how to proceed.

Anyway....hijacking again, sorry. Thanks again for the help.