@Ca_Varminter From my observations, during the hollow-ogive core formIng process a couple of things can happen. Cores can be be formed that are too light. For me this is a definite 0.5 grains less than the target weight. If this occurs from the core being too close to the finished weight when cut (this can result from being the first few cuts when setting the weight on the cutter or being the last cut from a cut strand of wire as opposed to cutting cores directly from the spool) or leaving a core in the hollow-ogive core forming die longer than others on the down stroke, more lead is bled off causing a slightly lighter core. An example would be if a 153 grain core is used to form a 150 slug and after forming the hollow ogive the formed hollow-ogive core is 151 grains or less, then the slug produced will likely be reduced to a 145 grain slug. Reason being, the hollow tip in the point forming die may not be uniform. It may be obviously wider than others because the core was too close to the finished weight. When I notice variance in the appearance of slugs I alter the weight to ensure that all slugs produced are uniform in not only weight, but appearance. When the weight is altered say 3-4 grains, I can hear the air escaping from the hollow in the projectile as I swage it down to the next target weight group. I've done it too fast and had a hollow point pop off of the point forming punch when I grabbed it before having a firm grip on the slug. Pulling it off made a "pop" sound. In the case where the core is heavier, say a 159 grains, this will become a 155 grain slug. Instead of me applying a lot more pressure to make it a 153 grain formed hollow-ogive core from a 159 grain cut core, I will stop applying pressure where I encounter the greatest amount of resistance in the down stroke, which can sometimes be well before the final portion of the cam turning over at the bottom of the stroke. This core will be weighed and set aside to make an different weight slug after the others within the target weight have been completed. In these cases when a new weight is set after the majority of the batch are made, the external punch holder will be adjusted to the new target weight. In this process 3 or 4 grains may be bled off via the point-forming die to achieve the target weight and a fully formed tip. This will require more than slight pressure applied to the ram handle. Existing literature suggests that shaving weight this way should collapse the hollow cavity, but this has not occurred. Also in this process air can be trapped behind the existing sprue within the bleed hole due to air being forced from within the hollow ogive until the tip is fully formed around the point-forming internal punch, as well as more lead will be extruded from the die because of the weight alteration.
I'm not saying this is the correct way, but as a beginner to swaging this is how I've been doing it. For me it's tough reading through the literature and extracting what is relevant to what I'm making as an airgunner from instructions written for centerfire bullet makers using copper jackets. Especially towards the end of a long day which is part of the reason this thread exists. This thread is for people who have not done much swaging, infrequent swaging, but mainly for those that are entirely new to swaging with the Corbin S Press only having read what the manufacturer has published (which is mainly for centerfire bullet makers from what I've encountered). I have yet to use the one-step process. If I am doing something detrimental to my dies, I'd like to get this straight now so that I don't mislead others into damaging their equipment or so that anyone else considering doing things this way can have access to better information before purchasing.
