I'm SBR'ing a doublestar lower, and their lowers have the engravings "Cal. Multi"  I have no problem specifying a caliber, but since the receiver is engraved as "Multi", I'm not sure if I should put "5.56", "Multi (5.56)" or "Multi" down as the caliber.

I may ask them when I call to ask about the "cert of trust" thing today.

Anyone have any info on what to do if your receiver is marked multi?

Just put the caliber you are building.

On each of mine I have listed what it said on the receiver, including "MULTI" and I have been approved.  However, I have heard that it depends on who is reviewing your paperwork and there are some who may reject it.

Gotcha, I will just list 5.56.  For some reason I thought they wanted you to specify what it said on the lower receiver.  After re-reading the Form1, it seems they just want the caliber.  5.56 it is  Thanks guys

If you put multi you will get a nice chain letter from the examiner telling you to fix your error and send the corrected copy back to them and then you get a form one with corrections on it so if your paperwork ever gets looked at I am sure a few eyebrows will go up. I just went thru a something of the same thing with my schedual A for my trust the ATF wants that now. Why you say no clue but my examiner held up my form 4 for three weeks till I called and spoke to her. Great lady and she said that I could e-mail it to her. Had I not called she was getting ready to send me and my dealer one of the dreaded ATF form letter.
Luke

I've done three lowers in the past year that had CAL. MULTI on the receiver. I put the actual caliber in box 4c (e.g. 5.56) and in box 4h (additional information) I put "CAL MULTI". All forms have come back approved w/o any issues.

"Multi" approved here.

You can also put all claibers that you plan to use.  

For example my M16 is registered in .22, 9mm and .223.  

Most HK sears are reg'd in 9mm, .223, and .308.

I wrote mine as: .22lr 9mm and 5.56mm. We'll see how it go's..

double tap