Front-line Ukrainian soldiers say it seems like Russia has 'unlimited' artillery shells to throw at them while they're worried about running out

• Front-line Ukrainian soldiers say it feels like Russia has been firing "unlimited" artillery shells.
• Troops tell the BBC they worry about running out of ammunition by the end of year. 
• New weapons from the US and NATO allies, like the Abrams tank, could change the tide of the war.

Front-line Ukrainian soldiers in the Donbas region say it seems like Russia has "unlimited" artillery shells to throw at them — while they remain worried about running out by the end of the year.