Can I claim futures trading losses on federal taxes

yes.

Use Form 6781 to report:
• Any capital gain or loss on section 1256 contracts (see below for definition) under the mark-to-market rules, and
• Gains and losses under section 1092 from straddle positions.

https://www.law.cornell.edu/uscode/text/26/1092 
For details on section 1256 contracts and straddles, see Pub. 550, Investment Income and Expenses.

https://www.irs.gov/pub/irs-pdf/p550.pdf 

A section 1256 contract is any:
• Regulated futures contract,
• Foreign currency contract,
• Nonequity option,
• Dealer equity option, or
• Dealer securities futures contract.
For definitions of these terms and more details, see section 1256(g) and Pub. 550.
A section 1256 contract doesn’t include any securities future contract, option on a securities future contract, interest rate swap, currency swap, basis swap, commodity swap, equity swap, equity index swap, credit default swap, interest rate cap, interest rate floor, or similar agreement.
Special rules apply to certain foreign currency contracts. See section 988 and Regulations sections 1.988-1(a)(7) and 1.988-3. If an election is made under section 988(a)(1)(B) or 988(c)(1)(D), attach to your return a list of the contracts covered by the election(s). On the attachment, show the net gain or loss reported from those contracts and identify where the gain or loss is reported on the return. If an election is made under section 988(a)(1)(B), report on Form 6781 the gains and losses from section 1256 contracts that are also section 988 transactions.