Caliber Conversion Kits and Zero

[C. Stockwell]

I've never used a caliber conversion kit in a handgun (think having a drop-in 9x25 Dillon barrel for your 1911 or Glock or a .22 conversion kit). How do these work with zeroes on sights? How "off" are the sights? Do you re-zero for each time you change calibers?

 

[Shawnyc]

I use a 22 conversion for a Glock 19. Basically it replaces the entire upper, sights and all so that doesn’t apply. Once had a Glock 27 with a 9mm barrel, didn’t notice a difference. Also use a 22 bolt conversion for AR’s. Haven’t tested it more than 15 yards or so but I do not rezero.

 

[TrashcanDan]

Most of the .22 conversions include a slide, so theres no re-zeroing.

Are you asking about a complete conversion or going from like .40 to 9mm and its just a barrel?

 

[C. Stockwell]

Most of the .22 conversions include a slide, so theres no re-zeroing.

Are you asking about a complete conversion or going from like .40 to 9mm and its just a barrel?

Let's say just a drop in barrel.

 

[TrashcanDan]

Let's say just a drop in barrel.

I did have to re-zero, but I had put in adjustable rear sights at the same time and purchased the appropriate amount of magazines for that caliber and just stuck with that (.357 sig to .40)
Obviously if your going from something like .45 to 9mm or 9x25/ .38 super comp, you may have to do more like an extractor, firing pin. May run into an issue going from a large pin to small, but most are small these days. You may have to re-spring it (main and recoil)
Breechface might be another issue.
A complete slide is a popular option because you can build it to that specific caliber and change it out quicker as a complete package than individual components and still retain a lower assy that can accommodate both.

Going from centerfire to .22 is always a complete package. I have a Marvel and Kimber conversion and they were both drop in with one mag.

 

[mac1911]

I've never used a caliber conversion kit in a handgun (think having a drop-in 9x25 Dillon barrel for your 1911 or Glock or a .22 conversion kit). How do these work with zeroes on sights? How "off" are the sights? Do you re-zero for each time you change calibers?

Im going to say the zero wont be terribly off between pistol cals until you start to reach out.

With the cost of some conversion kits might as well by a new pistol.

 

[KMM696]

I had a conversion barrel from Storm Lake to take a Glock 21 to Glock 20. The zero didn't change on that one, and it shot very well. It would eject reliably, but all over the place. My theory was that the larger slot cut in the slide to fit the 45ACP case head was allowing the 10mm case to move a bit and hitting the ejector in slightly different spots. After trying several different extractors, I gave up on it. It never failed to eject, but I got tired of chasing 10mm brass all over the landscape, sold the conversion barrel and bought a G20.