Back strap size?

[ParaGunner]

I have a friend who just got a deal on a xdm compact 45acp. He wants to get more full size mags with the spacer on the mags. I see 3 different sizes of spacers available. How do I tell what size back strap is on the gun to order the same size spacer to match on the full size mags?

[dave33]

Punch the retaining pin out and slide the current backstrap off, it will have a S, M, or L stamped on the inside. Or if he got the case with the other backstraps use them to determine which one it is.

[ParaGunner]

Thanks Dave. So #1=small #2=medium and #3 =large? The mags with the spacers list #1-#3 on the descriptions of them.

[dave33]

Yes, that's correct. Been so long since I looked at mine I forgot if there were letters or numbers in there, I just remembered it was labeled.

[ParaGunner]

Thanks again Dave.

[TSiWRX]

New here. Sorry to be visiting this one so late.

If your friend has not yet purchased the spacers (Springfield Armory calls them "X-Tensions"), ask him to please perform a few day's worth of reload drills before he finalizes his backstrap as well as X-Tensions sizing decision.

For some shooters, spacers such as these can cause the mag to hang in the magwell after the release has been punched, mainly due to the meat at the heel of their dominant hand (or, if they're using a padded-palm shooting glove, the same) "locking" to the texturing or other physical features on the spacer.

Cutting or otherwise modifying the spacer at that area to allow for clearance can be the definitive fix, but for XDm-owners, if this is found to be an issue, sometimes, the simple substitution of a smaller spacer can serve as cure.

It may look funny, but it's a functional fix for some, and should not affect one's grip.