Fastbolt
Member
The standard recoil spring for the 645/4506/745 (I don't have the 945 listed), when standard ball loads are being used, is S&W part#20161.
However, the 645/4506 & 745 also have a wadcutter (target) load light recoil spring, part#20071.
If you're using 230gr standard ball powered loads, you can get feeding and extraction problems if the recoil spring is too light.
S&W used to publish a handy reference for both .45 recoil springs (for their 5" guns).
If the use of a standard factory recoil spring doesn't resolve your issues (meaning one that never measures less than 7" free length, out of the gun), then I'd look at the extractor spring. A light powered/weakened extractor spring can cause some headaches when you're running full power (standard) loads in the big S&W .45's.
Just a thought.
However, the 645/4506 & 745 also have a wadcutter (target) load light recoil spring, part#20071.
If you're using 230gr standard ball powered loads, you can get feeding and extraction problems if the recoil spring is too light.
S&W used to publish a handy reference for both .45 recoil springs (for their 5" guns).

If the use of a standard factory recoil spring doesn't resolve your issues (meaning one that never measures less than 7" free length, out of the gun), then I'd look at the extractor spring. A light powered/weakened extractor spring can cause some headaches when you're running full power (standard) loads in the big S&W .45's.
Just a thought.