mystery eBay barrel

I took a chance and I think it paid off.

9mm conversions for the XD-40

The Springfield Armory original¹ XD 9mm, .357 SIG, and .40 S&W use the same frame. The latter two can be converted to 9mm with either

• a conversion barrel
• a complete 9mm barrel and slide assembly

The slide assembly route is about the same cost as a whole 9mm so the conversion barrel is preferable. No one except one high-end shop still make barrels for the original model. There are a few on the used market, and still fewer in the 5”² flavor.

the listing

I saw this listing for a barrel: Storm Lake Springfield XD Tactical 9mm Pistol 5 3/8" Barrel, so I investigated.

The label on the barrel’s packing sleeve reference a custom order for a customer – I have blurred his name for privacy. It gives various internal data like inventory location (don’t care) and model (I care a lot).

The model was listed as XDT9 Conv DI. This seemed to suggest a 9mm conversion barrel for the tactical (5 inch) line. The 9mm has no conversion options because the larger caliber barrels won’t fit in the 9mm slide. So if conv really meant conversion it had mean converter to 9mm. DI might mean drop-in which was common language when the conversion barrel was new.³

OAL is given as 5.51”. I think this was so barrels for the 5” guns could have porting or a thread adapter on the end. Or have the last half-inch lopped off if desired. Looking at the pics the barrel’s diameter seemed to be greater than that of the stock 9mm, which would make sense for a conversion barrel to fit a .40 slide. The sleeve label notes No Ports.

With the label out of the way we can see some clues on the barrel itself. It’s stamped STORM LAKE XD 9MM but lacks the Storm Lake logo I’ve seen on others. Maybe no logo on the custom jobs? The overall shape of the breech end in the listing pics matches the shape of my stock .40 barrel.

All these clues suggested this was a conversion barrel that might fit my XD. I was the only bidder at the starting price (~$130) and won it.

the fitment

I received the barrel and it was in great shape. I dropped a 9mm round in and it plunked as it should. So far so good. I removed the round and cleaned and lightly re-oiled the new-to-me barrel. Patches run through were barely smudged.

I field stripped the XD and cleaned it up too before dropping in the new barrel. It fit nicely. The recoil spring installed as expected so I reassembled the XD and did a function check; seems to work. 9mm mags are recommended for reliability but I just ordered a used one so it’ll be a week until it gets here. So I loaded the 9mm round in the .40 mag – it fed and extracted correctly when I cycled the slide. Obviously I won’t know for sure until I fire it but it looks promising.

If it works with the 9mm barrel I’ll pick up another 9mm mag or two. If it doesn’t work I’ll relist on eBay and someone more clueful can try it in their XD. Will update this space after a range test.

effect on velocity

I’d given my full-frame 9mm to my daughter earlier so the only 9mm sidearms I had were subcompacts with 3.1” and 3.2” barrels. Plinking rounds (Berry’s plated RN 124gr) are ~952fps through the sub guns and should be ~1075fps out of the 5.5” barrel.⁴ 124gr Gold Dots are moving 1013fps out of the mouseguns and should be ~1125fps out of the 5.5”.

1. there was XD, then XD mods 2-4. But we can call the original one mod 1 for clarity. ↩

2. the so-called tactical model ↩

3. the other option would have been something like partially fitted, requiring final fitting by a gunsmith to the specific sidearm. ↩

4. these are loaded so they do not exceed the 1250fps limit out of the 16.5” carbine. ↩