Press Stroke effect on Headspace

[Suasponte]

I have a buddy that is new to reloading and is always fast stroking his press. I went thru the motion of setting up his FL die to bump the shoulder properly for his rifle. The other day I get a call from him saying that half of his ammo that he loaded would not chamber. He went on about how he had everything screwed down and had not F'd with the dies that I had set up for him. So, why would the ammo not chamber if I had set the die up properly?? Well, the reason is and this goes for most new reloaders is the press stroke itself. I went over to his house and watched him reload 50 shells. He hammered this brass in and out of the die at light speed and acted like it was a race to get done. After he had loaded all the shells I pulled out the Mo-gage and told him to check all 50. His gun was setup to be at 2 on the gage, and out of the 50 only 22 was in that range. This was all due to running the brass in and out of the sizing die to fast not allowing the brass to normalize at the dimensions you want. The others was out of spec and we went out back in his yard and he tried to chamber those one he set aside that was not at 2 our under. None of the rounds would close and the ones that did measure in spec closed with no resistance. I made this video to prove to him that a slow press stroke would net better results and that a fast stroke would actually make the brass grow.

Slow down that Sizing die press stroke and you will not have these issues as long as your die is set up properly.



Terry

 

[Fuzzball]

Press technique will do nothing to 'headspace', that's in the rifle, but it sure will affect sized case shoulder location. Sloppy work makes for sloppy ammo. ??

 

[RTH1800]

It is the same with bullet seating. Need to let the bullet hold it's position for a second to get consistent depth.
More of an issue to these kids who grew up slamming around video games.

 

[ZiaHunter]

Letting the ram dwell in the raised position for a few seconds will result in more consistent sizing. IMHO variances in sized brass is generally the result of varying degrees of hardness or when the expander is drawn through the neck causing the case to stretch. Hardness can be dealt through annealing. Stretching of the case by the expander requires that cases be properly lubricated and having consistent neck wall thicknesses. Neck wall thickness will vary between manufacturers and bushing die are best suited for dealing with it.

 

[lightman]

Fast operation often results in a short stroke. Do that and all of your careful measurements and adjustments are wasted. Lightman