Low power pesting solution..

If you have the budget for the HW30 as Intensity stated would be a very good choice and would do fine accuracy wise but if you are on a tight budget which I suspect with your wanting to shoot with BBs comment and don't intend to spend much then a Crosman 1377 pumper for $60 would do just fine out to 20 yards with open sights. Use white out or neon spray paint to make the sights more visible. You can vary the power with less pumping for your needs and plenty accurate inside of a tin building.

If it were me I would use my S&W 586 with 6" barrel 10 shot Co2 revolver that dispatched many pest birds and rats inside of a warehouse on many occasions.

CA
 
This might sound funny,but earier at the beginning of fall I picked up a Daisy 880 for around 35 bucks at Wal Mart. I performed a few tricks I viewed on line,cleaned the barrel 1st with Ballistol then a patch with a Light amount of Flitz metal past then followed by more lightly oiled patched w/ballistol followed by dry.

I sprayed the brown stock with truck bed liner,super glued the bb loadin gate w/superglue (No bb shootin out of this!. Did some easy trigger work and lube.

Got some pics here wearin a UTG 3-12X40AO. Trigger is not bad,power is@10+ ft lbs depending on the number of pumps. Quite a Fun,accurate,inexpensive pesting gun wit adjustable power! Hopt this helps You!!
1543811697_18256323435c04b2719bfa70.90265636_20180918_170107_HDR.jpg
1543811698_10624184295c04b272a35842.40359010_20180918_140905_HDR.jpg
1543811699_16329340535c04b273a11360.93193424_20180918_140845_HDR.jpg
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Damn... That is better shooting than what a 1377 would do at 25 yards! Much CHEAPER YET!

Is it the CURRENT WALMART Daisy 880? If so I am buying one next time I go to Walmart!

I have a Lothar Walther Daisy 753 10 meter match barrel laying around, wonder if it will fit?

Had to buy the replacement valve attached to the new LW barrel in order to get my 753 out of bed

having respiratory problems.

CA
 
This might sound funny,but earier at the beginning of fall I picked up a Daisy 880 for around 35 bucks at Wal Mart. I performed a few tricks I viewed on line,cleaned the barrel 1st with Ballistol then a patch with a Light amount of Flitz metal past then followed by more lightly oiled patched w/ballistol followed by dry.

I sprayed the brown stock with truck bed liner,super glued the bb loadin gate w/superglue (No bb shootin out of this!. Did some easy trigger work and lube.

Got some pics here wearin a UTG 3-12X40AO. Trigger is not bad,power is@10+ ft lbs depending on the number of pumps. Quite a Fun,accurate,inexpensive pesting gun wit adjustable power! Hopt this helps You!!
1543811697_18256323435c04b2719bfa70.90265636_20180918_170107_HDR.jpg
1543811698_10624184295c04b272a35842.40359010_20180918_140905_HDR.jpg
1543811699_16329340535c04b273a11360.93193424_20180918_140845_HDR.jpg
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I would add the 2100 crosman in this group as well....I have two of them and both are great at 25 yards.



Having had this issue myself...with barns, other animals, equipment, the ability to vary the power is pretty top on my list.....I would really rule out anything that I could not "dial down" one way or another. If you are doing birds, they are not built very tough and I have had through and through hits and dents in my steel sided barns. You will learn just what power you need.

My building that had the most issues is an 40x80....so distance is not that big of a deal....about any air rifle will do a quarter group at those distances.

I went with the 2100 for really a few reasons, it was cheap, I had a 766 as a kid, and I just like the looks of it. Later on for the rats and mice I got a 2200 and that has the oomph for thicker critters. You could also do the 397 or 392, those are a little more spendy then the 2100, and another reason I went 2100 was cost. I am really shocked just how accurate they are with good pellets.

On a side note, I have found a great many "cheap" air guns come alive with a pellet that works with it.....might start a thread on that.
 
I am not so sure Crosman pumpers are as durable as they used to be based on recent reviews and posted images of the receivers splitting in half with minimal use. I think the Daisy 880 can be upgraded to have a metal receiver ordering direct from Daisy rather inexpensively. I cringe at the thought of mounting scope rings onto plastic dovetails OUCH!!!

CA
 
I am not so sure Crosman pumpers are as durable as they used to be based on recent reviews and posted images of the receivers splitting in half with minimal use. I think the Daisy 880 can be upgraded to have a metal receiver ordering direct from Daisy rather inexpensively. I cringe at the thought of mounting scope rings onto plastic dovetails OUCH!!!

CA

My 2100's are metal, they are a few years old now....not sure if they have changed or not. I am very, as in VERY happy with them.
 
And now for something completely different... a Gamo G2 Recon in .177. This is actually a "youth rifle" shooting about 71/2 ft lbs with Crosman 7.9 CPHPs or AA Express 7.4s. It is fairly quiet, easy to cock as a break barrel, has fiber optic open sights, and with a little Red Tar lube added to the spring is very mild in its shot cycle. Well under a hundred bucks, I've found it to be a great around-the-yard shooter. Stick a red light on it and you should have no problems with over-penetration of the tin.