I saved enough money and want to know what you would buy. My choice is an Air arms s510 carbine but in.22 or .25 Cal. Please tell me why you would get either Cal. Thankyou.Frank.
When selecting rifles from the UK, be sure to inspect the fine details ( power, shot count, regulator). Because of the power restrictions, the .25 caliber tends to be underpowered and has a low shot count. It seems that their platform works better for the .22 and .177 caliber. although AA have very cool looking rifles, I personally believe other brands are better suited for the US market, especially if you are considering the .25 caliber. They have made some attempts to satisfy the US market with the Galahad but again the .25 is underpowered."Mick-VA"If your specific rifle choice is the AA S510 Carbine (very nice) I think it's important to focus on that model and it's capabilities as a platform vs generic discussion of calibers.
A google search using "S510 and Carbine and String" will yield many hits for various forum discussions and the image tab will show screenshots of many people's shot strings.
When I review the information and shot string data available on the Carbine version of the S510, (OEM box stock), I would opine that the platform is better suited to .177 and .22 for optimal levels of power and shot count given the carbine's smaller air capacity and state of OEM tune. Information for the .25 reveals it's underpowered for that caliber compared to most .25s available and has a fairly low shot count given the smaller cylinder and higher air consumption necessary to propel the .25, and has the most volatile, unregulated power curve among the 3 calibers.
I have 2 S510s in XTRA version (.177 and .22) but no Carbine.