Caliber change?

ibfestus · March 17, 2007, 05:33 PM

My local SOT tells me I should NOT mount a 9MM upper on my form 4 registered lower because on the form at box 4c "CALIBER, GAUGE OR SIZE (specify)" says .223.

At the same time he tells me it is OK to go to a 14.5" barrel or collapsible stock even though block 4e/f lists the barrel length of 20" and OAL as 38".

I live in KC MO and my dealer is ------'s Guns. IIRCC, Seems to me I have read an opinion by Lawyer James Bardwell (sp?) that once the piece is lawfully registered the caliber/OAL/and other features are a moot question.

Question: Where should I look for the true skinny?

VUPDblue · March 17, 2007, 06:59 PM

It is common practice to mount various uppers on registered SBR's or MG's regardless of their description on F1 or F4's. As long as you are in posession of the upper that was originally registered with the gun, you are probably good to go. I have a .22, .223, and 9mm upper that I run on my SBR. A little bird at the ATF told me that it was a non-issue. I wouldn't have any concerns over mounting a different caliber upper to my SBR or MG. Seems like you question is in regard to a MG. The way I have seen it interpreted is that MG trumps SBR or caliber. If it is a MG, the caliber or barrel or OAL matters little/none. If you really want to get an answer, call your local BATFE field office or their Firearms Technology Branch. These folks have always been very friendly to me and are very willing to help answer your questions.

Legion2600 · March 19, 2007, 12:57 PM

I wouldn't worry about it either. I have multi caliber uppers. Don't know anybody that's ever been hassled for doing so either.

Dave Haven · March 19, 2007, 10:13 PM

I made a .22LR conversion for a 9mm SMG that I made on a Form 1. From what I've heard from ATF agents and Class 3 dealers, it's a non-issue unless the registered receiver is modified, in which case ATF should be notified of a change of caliber or addition of a caliber.
IMBFOS, but that's what I've heard.

CleverNickname · March 20, 2007, 02:54 PM

The caliber, barrel length and OAL as listed in the form 1/form 4 are just used to help identify the gun, they don't place any legal restrictions on the gun.

This is why the BATF is rejecting most forms with entries like "<16" for barrel length. They know it's going to have a <16" barrel, otherwise it'd be pointless to register it as an SBR. They want to have a description of the gun that's as accurate as possible. So if it's a permanent change, then you should let them know. For example, if you have an SBR with a barrel that's permanently attached to the receiver, and you later cut down the barrel so it's even shorter, send the BATF a letter and let them know. It's not legally required, but it won't hurt. If you just swap on a different upper onto your SBR'ed AR15, it's not a permanent modification and they don't care.

mxwelch · March 22, 2007, 08:27 AM

I was told to transport my MG in the original caliber and use the conversion when I arrived at my destination. Don't know if that's accurate and I tend to agree with VUPDBlue. I can't see it being an issue if I didn't.

Wild Horse · April 2, 2007, 07:25 AM

I have several different caliber bbls for my '08 Maxim. I work things backwords, I check Shotgun News for cheap ammo and then get a bbl to fit.

My smith makes a feed block spacer for each caliber and marks them.

My form 4 shows 8mm but I have taken my guns to California which requires a tad of paperwork. Neither ATF or CA DOJ has ever questioned caliber issues.

p99guy · April 2, 2007, 11:32 AM

with a registered machinegun,change of barrel lenth is a non issue period.

as far as having to list that you will be using .22LR/6mm-223/6.8SPC/6.5Grendal/9mm/.40S&W/.45acp/.10mm/.30M1 Carbine/.50Beowolf uppers on your AR15 SBR or M16...One can simply sit down and write a letter to NFA branch and explain to them that you will be using these other calibers with your SBR registered receiver or Machine gun....they will note your file and that will be the end of that issue. forever and ever

you can even include this letter with your Form 1 or form 4 when you pay your 200.00 to have it registered to you.
like was said earlier, its just for ID of the gun, (its not for use in smacking you on the back of the hand with a ruler/ or prosecution)

March 17, 2007, 05:33 PM	#1
ibfestus Senior Member Join Date: October 21, 2006 Location: Smack dab in the middle of it... The good ol' USA that is. Posts: 126	Caliber change? My local SOT tells me I should NOT mount a 9MM upper on my form 4 registered lower because on the form at box 4c "CALIBER, GAUGE OR SIZE (specify)" says .223. At the same time he tells me it is OK to go to a 14.5" barrel or collapsible stock even though block 4e/f lists the barrel length of 20" and OAL as 38". I live in KC MO and my dealer is ------'s Guns. IIRCC, Seems to me I have read an opinion by Lawyer James Bardwell (sp?) that once the piece is lawfully registered the caliber/OAL/and other features are a moot question. Question: Where should I look for the true skinny?

March 17, 2007, 06:59 PM	#2
VUPDblue Senior Member Join Date: December 18, 2005 Location: Central Indiana Posts: 1,981	It is common practice to mount various uppers on registered SBR's or MG's regardless of their description on F1 or F4's. As long as you are in posession of the upper that was originally registered with the gun, you are probably good to go. I have a .22, .223, and 9mm upper that I run on my SBR. A little bird at the ATF told me that it was a non-issue. I wouldn't have any concerns over mounting a different caliber upper to my SBR or MG. Seems like you question is in regard to a MG. The way I have seen it interpreted is that MG trumps SBR or caliber. If it is a MG, the caliber or barrel or OAL matters little/none. If you really want to get an answer, call your local BATFE field office or their Firearms Technology Branch. These folks have always been very friendly to me and are very willing to help answer your questions. __________________ Silencers have NEVER been illegal !

April 2, 2007, 11:32 AM	#8
p99guy Senior Member Join Date: November 4, 2004 Location: Haslet,Texas(DFW area) Posts: 1,506	with a registered machinegun,change of barrel lenth is a non issue period. as far as having to list that you will be using .22LR/6mm-223/6.8SPC/6.5Grendal/9mm/.40S&W/.45acp/.10mm/.30M1 Carbine/.50Beowolf uppers on your AR15 SBR or M16...One can simply sit down and write a letter to NFA branch and explain to them that you will be using these other calibers with your SBR registered receiver or Machine gun....they will note your file and that will be the end of that issue. forever and ever you can even include this letter with your Form 1 or form 4 when you pay your 200.00 to have it registered to you. like was said earlier, its just for ID of the gun, (its not for use in smacking you on the back of the hand with a ruler/ or prosecution) __________________ Lighten up Francis!.....;Actor Warren Oats, in the movie "Stripes"

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March 19, 2007, 12:57 PM	#3
Legion2600 Senior Member Join Date: June 11, 2005 Location: DFW Posts: 108	I wouldn't worry about it either. I have multi caliber uppers. Don't know anybody that's ever been hassled for doing so either.

March 19, 2007, 10:13 PM	#4
Dave Haven Senior Member Join Date: February 1, 2000 Location: near Flagstaff, AZ Posts: 790	I made a .22LR conversion for a 9mm SMG that I made on a Form 1. From what I've heard from ATF agents and Class 3 dealers, it's a non-issue unless the registered receiver is modified, in which case ATF should be notified of a change of caliber or addition of a caliber. IMBFOS, but that's what I've heard.

March 20, 2007, 02:54 PM	#5
CleverNickname Member Join Date: August 3, 2002 Posts: 69	The caliber, barrel length and OAL as listed in the form 1/form 4 are just used to help identify the gun, they don't place any legal restrictions on the gun. This is why the BATF is rejecting most forms with entries like "<16" for barrel length. They know it's going to have a <16" barrel, otherwise it'd be pointless to register it as an SBR. They want to have a description of the gun that's as accurate as possible. So if it's a permanent change, then you should let them know. For example, if you have an SBR with a barrel that's permanently attached to the receiver, and you later cut down the barrel so it's even shorter, send the BATF a letter and let them know. It's not legally required, but it won't hurt. If you just swap on a different upper onto your SBR'ed AR15, it's not a permanent modification and they don't care.

March 22, 2007, 08:27 AM	#6
mxwelch Senior Member Join Date: January 17, 2006 Posts: 379	I was told to transport my MG in the original caliber and use the conversion when I arrived at my destination. Don't know if that's accurate and I tend to agree with VUPDBlue. I can't see it being an issue if I didn't.

April 2, 2007, 07:25 AM	#7
Wild Horse Member Join Date: December 20, 2004 Location: Nevada Posts: 66	I have several different caliber bbls for my '08 Maxim. I work things backwords, I check Shotgun News for cheap ammo and then get a bbl to fit. My smith makes a feed block spacer for each caliber and marks them. My form 4 shows 8mm but I have taken my guns to California which requires a tad of paperwork. Neither ATF or CA DOJ has ever questioned caliber issues.