Is it worth re-crowning this barrel?

[Green_Yamo]

Would this skyhawk barrel benefit from re-crowning it, or does it look good enough? The gun will produce 1/4" groups at 20 yards (I haven't had a chance, or the weather to shoot it at longer distances), but I'm thinking that it might shoot a little better if it was re-crowned. I have already removed the burrs from the TP and internal o-ring slot, and lapped/polished the barrel using VFG pellets/rod and J-B Bore paste followed by Mother's polish. I'm thinking the only other way to eek out some accuracy would be to try to improve the crown. I would probably just try the brass screw method first, and if this doesn't have any effect, maybe get a crowning tool and give that a shot. Any thoughts?

 

[addertooth]

How many pellets have you put through it. I have seen a lot of air rifles which do not strut their stuff until you are north of 1000 pellets.

When determining accuracy, 20 yards is mighty short. You will have a better feel for accuracy when you have stretched it out to 40 to 50 yards. Then you will want to post your resulting target here. Some inaccuracies are based entirely upon the rifle, others have human-contributed errors.

Your crown does not look horrible, but like all things, there may be room for small improvement.... but wait for longer range results... so you have something to compare any potential changes with.

 

[TNT19]

Looks ok from what can be gleaned from the pic. I would check to see if there are any burrs, imperfections internally with the grooves that may have an impact on the accuracy. I did my kral barrel, my gauntlet barrel and my priest barrel and all 3 were lights out afterwards. 

 

[Vetmx]

That is a crazy good SPA crown. Probably the best I ever seen. But something we can’t see is if it’s square to the bore. That takes a lathe. Your gun seems to be shooting good at 20. I do all my initial accuracy testing at 30-35yrds. That’s where a problem generally starts to show.

 

[Xbowsniper]

Green_Yamo,

That looks like an absolutely excellent quality crown, I would not touch it at all.

Tom Holland 

Field Target Tech 

 

[nervoustrig]

I agree with vetmx, I have several SPA rifles and they all had poor crowns from the factory. The earliest was from March 2017 and the latest was Dec 2019. The crown on your Skyhawk looks better than all of them.

The biggest issue though has been damaged rifling at the muzzle from where they haphazardly ran a piloted crowning tool into it. For example, I had to cut a small portion from the end of a CP2 recently (Diana Chaser).

Before and after:





Having said that, I doubt yours has these problems based on how it's grouping but they are easy things to check if you want to put your mind at ease. The rifling damage is easy to identify visually. For the crown, the best way is to push a couple of pellets through. One of the more common recommendations is to use a cotton swab and see if it snags fibers, but in my experience that is not sufficiently discriminant. A pellet makes it super easy to tell. For an unchoked barrel, you should feel no increase in resistance as the head is emerging from the muzzle (a couple of user reports say it's unchoked but I'm not 100% sure). I will just say it is extremely rare for an inexpensive barrel to be completely absent of at least a subtle wire edge pushed into the bore.

 

[Green_Yamo]

Thanks for the help guys! I only have a little more than a tin through the gun so far. I don't think there were any internal burrs on the rifling. When I pushed a pellet through the bore (after all of the polishing and barrel cleanup), it pushed smoothly through, with even pressure until the choke. The pellet came out with smooth, even rifling marks. Unfortunately, I don't have the tools to be able to tell if the muzzle was cut square. If it's a bit off, it's definitely not obvious. There ARE some very minor chatter marks on the rifling just before the crown. The marks are very subtle. I definitely couldn't feel them when I pushed the pellet through.

I had a little bit of time and clear weather to stretch it out a bit. I shot four 5-shot groups at 40 yards, with little to no wind. Groups were pretty consistently around 1/2" - 5/8". I did have one flier, but that was it. Although I wish the groups were 1/2" or less (WITHOUT the flier), I'm thinking that I can live with this. (Although I sure wish my crown looks like NervousTrigger's - WOW THAT'S NICE!!!

Thanks for all the advice!

 

[Guest]

I'd be happy with those groups. My best 5 shot group at 50yd is .317 from an air arms using jsb 10.3g pellets. The same gun will consistently give 5/8-3/4" groups with 15.5g NSA slugs at the same distance.

 

[Guest]

Forgot which group I was in... =) Quarter inch groups are pretty good at 20 yards, even in a PCP. Sure some guns will shoot smaller than that, others wont. That crown looks good. If you are wanting to improve your groups start sizing pellets before you start working on that crown. Just my two and your mileage will likely vary.