Back in december I submitted a Form 1 for an SBR, but now with the SBtactical SB3 it really doesn't seem to make sense to have an SBR, and deal with the admin (crossing state lines ect..)

so can you cancel a Form 1 and get you $$ back?

Yes. Instructions for doing so are on the form.

Thanks!

§ 479.172 Refunds.
As indicated in this part, the transfer tax or tax on the making of a firearm is ordinarily paid by the purchase and affixing of stamps, while special tax stamps are issued in payment of special (occupational) taxes. However, in exceptional cases, transfer tax, tax on the making of firearms, and/or special (occupational) tax may be paid pursuant to assessment. Claims for refunds of such taxes, paid pursuant to assessment, shall be filed on ATF Form 2635 (5620.8) within 3 years next after payment of the taxes. Such claims shall be filed with the Chief, National Firearms Act Branch serving the region in which the tax was paid. (For provisions relating to hand-carried documents and manner of filing, see 26 CFR 301.6091-1(b) and 301.6402-2(a).) When an applicant to make or transfer a firearm wishes a refund of the tax paid on an approved application where the firearm was not made pursuant to an approved Form 1 (Firearms) or transfer of the firearm did not take place pursuant to an approved Form 4 (Firearms), the applicant shall file a claim for refund of the tax on ATF Form 2635 (5620.8) with the Director. The claim shall be accompanied by the approved application bearing the stamp and an explanation why the tax liability was not incurred. Such claim shall be filed within 3 years next after payment of the tax.