Slug accuracy in .22 Avenger

I’m brand new to pcp’s and tuning. After watching all the reviews and tuning guides on YouTube on shooting slugs accurately I decided to buy my first pcp, the AV Avenger. While it seems to shoot every type of pellet with good accuracy, it has shot no slugs with any accuracy at all. I’ve tried several different tune settings and played with them further with similar results. Pellets shoot fine to good and slugs shoot awfully. I’m hesitant to keep buying different slug brands on the chance that I can find one that shoots well. I’ve tried FX hybrids, Nielsen 20.2 grain in .216, H&N 23 grain in .217. Groupings for all 3 types are so bad you can’t even call it a group. Does anyone have any suggestions for a good course of action? 
 
giv,

Research "how to slug a barrel". This will give you a good idea of the size(diameter) that will work best in your gun and save you a lot of trial-and-error time(and money) on slugs that are too big or too small for your barrel

Sorry if this is common knowledge but it’s not to me. Do I need to remove the barrel to push pellets through it, or can they be pushed through from the muzzle end?
 
gjv,

You should take off the barrel and slug it from the breach end toward the muzzle end. Most airgun barrels have choke(an area of tighter constriction thought to aid with accuracy with pellets) on the muzzle end. This choke usually has an adverse affect on accuracy of slugs(as slugs don't require any choke in the barrel to be accurate).

Push one slug thru until it starts to get tight near the muzzle end at the choke. Then stop and push it back out toward the breach and measure it. You will need calipers that measure to at least the thousanths(.001) of an inch. This will give you the diameter of your BORE. Then push another slug thru all the way out the muzzle end and measure it. This will give you the diameter of the CHOKE(good to know how much constriction the choke is putting on your slug). You want to size your slug .001 larger the measurement of the BORE(part of the barrel which extends from the breach to near the muzzle end of the barrel), not the CHOKE(last few inches of the barrel where the final constriction is). If you size the slug to the CHOKE, then the slug will be too small in the breach/bore part of the barrel and you will get "blow-by" as air escapes around the slug, being too small to seal the gap. I don't know how tight the choke is on your (Avenger)barrel, but it will be a tighter constriction than the bore. If it is a MUCH tighter diameter than the bore, you may not find a size of slug that is super accurate. I doubt that is the case as many people shoot slugs out of Avengers(I would have thought one of them might have already responded to your question with what works well in their guns by now).

I know this is a lot, but it's good info to have the process to finding the right size slug for your gun. All else is trial and error. But, I would advise you to ALWAYS trust YOUR results out of YOUR gun over anything anyone tells you should happen(everyone's individual situation is unique to them). I have learned from the many people on the forum know a lot more than me. Perhaps some of them with specific experience with the Avenger barrel can help.

Good luck
 
I will order some .218 slugs since I’ve tried the .216 and .217 already. Unfortunately the sample packs are sold out, so my desire to purchase different weights is currently a bit subdued. Thanks for the input.

https://www.ebay.com/itm/293614809601

These are cast slugs but high quality. Shop his website and then order the sample packs from the ebay link above.
 
Steve at AEAC Youtube channel reported good luck with most slugs using a 42-43 ft/lb tune:



https://youtu.be/2D_Zml_2wd4



He chose the FX Hybrids and .217 H&N slugs to shoot at 50 and 100 yards in his final review:



https://youtu.be/oUpBxCbi5o8


Ghostranger, 

I have watched both of those more than once. Those are the two slug varieties that I started with, and the groups were multiple inches apart at 50 yards using Steve’s power tune settings. I went through the tuning process outlined in his guide and never found any accuracy with the 3 kinds of slugs that I bought. However, 3 pellet varieties shot with good accuracy all through the process. So, I think your slugging the barrel idea might be the best option because my barrel must be different than his somehow. Thanks 
 
gjv,

It sounds like you've done your due diligence then. It is a good starting point, but not surprising to get different results than Youtubers(which is why I always recommend that people let THEIR OWN results be their guide, not what someone says). 

Slugging YOUR particular barrel will give you good, accurate, solid data about YOUR barrel to work with. With this info, you should start seeing some "commonality" in the sizes of ammo which perform well.