Red and Blue, Quiet a bit of difference, reddish - bluish,, color of your finger when smashed,, will be red , then in a few days, blue , then a slow transition to black before it falls off. I could not resist that one. )
one is an international spring (I think the blue one but I don't recall for sure), more throwing power. You can throw regular skeet targets with an international spring, but not vice versa, and i believe the international springs were a little more durable.
I stand by what I said. We just bought the coils, took the assembly apart and replaced the coil and rebushed as needed. About 6 years ago was the last time we bought coils and they alone were almost $60 dollars , Now we have Laporte's and Super stars. I personally opened the crate on a new 1574 Skeet machine years ago and it had the small spring and standard arm. Jeff