In the
IPSC, open class is the category where there is virtually no restrictions on what you can or can not install on your
race gun to improve its shooting characteristics.
This has resulted in a flood of aftermarket performance enhancing products for Colt 1911 style pistols and more recently the CZ 75 style pistols. Some actually do something to help you shoot better and faster while some are debateably just magic feathers.
A very well built and well tuned race gun does have its appeal as it can fire full power ammunition and yet kick no harder than a mild load .380 and are extremely accurate. They cost a lot too, a high end open class pistol can easily reach over $5000 after buying all the parts and having a gunsmith install it and tune it.
This was one reason the IDPA was created, because some shooters felt that the IPSC had become an equipment pissing contest and was more about who could pour the most money in their guns rather than a real test of skill.In more ways than one the IPSC had become the exact opposite of what it wanted to be, a competition for practical shooting.