Lead rifled round?

[asterix]

Hi everyone,i found this today,i've searched all over the net to try and ID it but not having much luck.If anyone can help identify it i would be very grateful.It measures 13mm long by 10mm and is slightly concave at the base.
Thanks in advance,Dave

PS,this is my first post so i hope pics upload ok!

 

[peashooter]

It could be a bullet from a muzzle loading rifle I have quite a few as my mate shoots a .45 & a .50 muzzle loading rifle and casts his own bullets and balls they look very similar. where was it found

Richard.

 

[asterix]

Hi Richard,i found it in Dorset while metal detecting.The nearest i can find is a Whitworth gun but the size isn't quite right.I'm not sure how accurately they were made,i believe Whitworths were about .45 cal,this appears to be just under 40 cal.
I always find loads of musket balls but this is an unusual one for me,the only similar round i've found was 17mm across and was a Minie ball used by the British army for 3 years from 1851 to 1853.I can only think this is later as they reduced calibre for more accuracy.
Cheers,Dave

 

[hicky1300]

Rifled slug for a shotgun possibly??