Flintknapper
Member
Have you had any problems with the gas check coming loose inside the case?
No.
They are crimped on very tightly. When seating the bullet the pressure is against the Gas Check, so as long as it is properly crimped you should have no problem.
Of course, once the powder ignites, the expanding gas contacts the Gas Check pressing it firmly against the bullet base (several thousand pounds of pressure while still in the case). So....not much chance anything will go awry.