The SRA is the Socialist Rifle Association. It started out as a group of all flavors of leftists (anarchists, MLs, demsocs and everything in between) working together to create a positive gun culture for leftism and to train people to defend their communities and themselves during the rise of the alt-right and Donald Trump-style fascism in the States.
However, many branches of the PSL (Party for Socialism and Liberation, a strongly ML political party in the States) decided that the SRA was the perfect vehicle for them and so instructed their members who were also members of the SRA to do everything they could to push out the anarchists and demsocs. Now it is just another branch of the PSL.