Springer Precision P320 & P320 X5 Guide Rod - TUNGSTENPrecision ground from solid durable tungsten, these Springer Precision guide rods allow you to use common 1911 springs in your Sig Sauer P320. This allows you to easily tune your gun to your loads and preferred recoil impulse, while getting the added weight of tungsten. Works with the ISMI X5 recoil springs we offer, which provide better lock up over 1911 length springs. P320 Full Size (NON X5): ONLY compatible with the P320s with 4. 7" barrel.