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Converting P226 .40 to 9mm

6K views 44 replies 21 participants last post by  jkallner 
#1 ·
I bought a P365 for EDC and love it. Also just ordered a P365XL.
So most of my pistols are chambered in .40, but I’m thinking of switching all to 9mm.
First I thought of selling off all the .40s, but I decided to convert my home defense pistol to 9mm and see if it’s reliable and still shoots well.
It’s a 2007 Sig P226 SRT .40 that I’ve already put a SRT kit and solid rod into.
So I ordered a Barstow 9mm threaded barrel and lighter slide spring and a 9mm magazine.
The barrel seems to fit well without any custom fitting.
I’ve also ordered a Gray Guns flat trigger kit to install later.
I’ll check back in once I get it to the range for testing.
 

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#7 ·
...
It’s a 2007 Sig P226 SRT .40 that I’ve already put a SRT kit and solid rod into.
So I ordered a Barstow 9mm threaded barrel and lighter slide spring and a 9mm magazine.
The barrel seems to fit well without any custom fitting.
I’ve also ordered a Gray Guns flat trigger kit to install later.
I’ll check back in once I get it to the range for testing.
So how did it shoot?

For a 40 to a 9 conversion, don't you also need a lighter recoil spring and mags for the 9mm?
 
#8 ·
If he installed the BowMar barrel like mine, he is in for the most pleasant surprise of his life.
Their 9MM barrels are micro nail drivers. I have a photo of one that a friend of mine (35 years younger and much better shape) fired at the range where the single hole in the middle of the target at 12 yds is the pass through of 5 rounds. I think the kid was a ringer.
 
#11 · (Edited)
Thank you for your post - I went this route and the barrel didn't drop in (although 3 other BarSto barrels did in other guns). In shop having it fitted. I thought that as heavy as the walls were that this would be a fun project. Hope it gets out of the hospital soon.

-dec

Oh - you might see some folks just tossing a 9mm barrel into a 40/357 sig frame on Youtube and claiming success. Please do NOT consider doing this. It will be an accident just waiting to happen. What works on Tuesday may just hurt you on Wednesday.
 
#14 ·
I have the P226 in 40. Bought a Barsto conversion barrel for it.It did not "drop in." I was new to firearms at that time and didn't want to mess anything up. I took mine to a gunsmith. Cost me $170 and a little over a week. I bought the 9mm recoil spring too.
I shoot the Barsto more accurately and consistent than the 40. I have since purchased a second slide and a 357 sig barrel too.1 grip, 1 trigger, 1 set of controls, 3 calibers, how can it get better then that?
I can't express this point enough though. Pay ATTENTION. When changing calibers, put away unused caliber including ammo! I say out loud 40 barrel, 40 ammo and 40 magazine while I double check barrel marking, mag marking and ammo. Swap to 9mm, all the 40 stuff goes into the range bag and 9mm stuff comes out. Swap barrel and spring, verify 9mm barrel, mags and ammo are the only ones out. Its more important when going from 9mm to 40 as a 40 wont chamber in a 9mm barrel but the 9mm round slides right into the 40 barrel. Be careful and enjoy!
 
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#21 ·
That's because this is a "barrel" list to fit a pre-existing slide, to change calibers, while a Caliber X-Change Kit, is just that... a kit including the barrel and appropriate slide.
 
#25 ·
I saw a NIB 9mm caliber x-change kit on ebay for cheap for cheap so I bought it. I needed new sights anyway, the SIGLITEs on the original slide had dimmed.

Yesterday I installed a GG curved double adjustable trigger, also on my P229. Easy peasy. I also replaced the slide catch because the original would not lock back with the 9mm magazines I have. I haven't shot them yet, my range is in the same place I hunt deer.
 
#26 ·
Sorry a little older thread but just joined. I recently got a Barsto 9 conversion barrel too and totally agree with Newbie. What I did to keep things straight for me is got a a stainless guide rod and 3 nickel mec gar mags so when i am shooting the 9 it all matches visually. Just the way my mind works to keep it all sorted out and not use wrong ammo. Barrel was tighter than the standard 40 barrel (sig seems to have more tolerances built in than you would think) but did not have to file it down any to this point. I may have to eventually shave a little off of bottom of feed ramp as when I disassemble the slide wants to hang up from coming off. Think the bottom of the ramp is just a milimeter or so too much and hits the block but with a little push it comes out..
 
#27 ·
You should look at allowing the barrel to tilt up a little higher in the ejection port. A couple of strokes with a stone would likely be all you need... not so much to the "rear", but "downward" where shown, this is a .357 Sig barrel which had the same "drag" you are describing. Look for burnishing marks on your barrel in this location, that will show you where contact is made. A couple of passes with a stone, and recheck for fit, remember, a little at a time!

Metal Parallel Steel Household hardware Handle
 
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#30 ·
Don’t do that. The feed ramp is NOT too long. The barrel just needs to sit higher in the slide. An incorrectly fitted barrel affects POA/POI. Take the material off of the top, not the bottom. Look at Willards photo, and follow his advice. Ignore good advice at your own peril.
 
#35 · (Edited)
#36 ·
When removing the slide I've got give a little arm push to get the slide to come off since. It's definitely the bottom of the feed ramp contacting the block. When the 40 barrel is in it slides off freely and yes there is intential friction on the bottom of the feed ramp on that barrel too but not like the 9.
 
#39 ·
Thanks TF

Please see attached pic of the Barsto Barrel. The collar on the barrel has a flat spot on top as I circled on top. This is what I am thinking would need to be filed down based on recommendation. The barrel chamber portion that fits in the ejection port is almost the exactly same dimension (within .003") of my 40 factory barrel front to back.

381513
 
#40 ·
Yep, that's it, and please don't use a file! If nothing else, get a small India (Aluminum Oxide) sharpening stone, as stainless is tough to machine with cutters, which a file actually is, plus leaves a smoother surface.
 
#41 ·
Do a couple of passes with the stone, then check the fit. It takes a little longer, but it's difficult to add metal back!😉
 
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