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P320 Slide weights between calibers

503 Views 5 Replies 4 Participants Last post by  Tgg
I just bought a full size 9mm upper with a Romeo 1 for my P320 and it is noticeably lighter than the .357 Sig assembly that I have. I’m wondering if it’s normal or did I end up receiving a counterfeit slide?
I broke everything down and put them on a digital scale, the breakdown is as follows:

Complete .357 upper - 19.7 oz
Complete 9mm upper - 17.55 oz

.357 barrel - 4.5 oz
9 mm barrel- 4.2 oz

.357 RSA - 1.25 oz
9mm RSA - 1.2 oz

.357 slide - 14.0 oz
9mm slide - 12.15 oz

I was expecting the Romeo to add weight but that doesn’t seem to be the case, the .357 slide has night sights and the 9 has suppressor height irons in addition to the Romeo. Appreciate any input you can offer!
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I don't have a 320, but am not surprised the .357/.40 slide assy. is heavier. SIG and Glock .357 and .40 slides I am familiar with, have less steel machined away during manufacture than slides intended for 9mm. The FN/Browning Hi Powers were another that used a heavier slide with the .40s, etc. The heavier .357/.40 slides compensate for the heavier recoil impulse of these calibers...
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Thanks Rock, I never planned to get into 9mm but I couldn’t resist a P210 Legend. After that I figured I’d make at least one more pistol capable of shooting 9, I just wasn’t expecting a noticeable weight difference between the two.
Yeah the hotter .40S&W and .357SIG need more mass in the slides. It is rather noticeable in the P229 too.
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I have a 3.6” barrel caliber exchange kit for a P320. The 40/357 slide is 2 ounces heavier than the 9mm slide. Slight difference in barrel weights between 3.3 oz and 3.6 oz.

Even though the weights are different I think the dimensions are similar and I am able to use the same holster regardless of what slide I have mounted.
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Thanks guys, you put my mind at ease !!
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