Hi all, Jack (of all trades) here. I’m a long-range shooter, a mechanic and a hobby electrician. In long-range shooting it’s all about getting consistent loads, which some of us develop ourselves. We prepare the brass, insert a primer, pour in powder and seat a bullet on top. Then we shoot and repeat. Consistency is key, and one of the best way to get accurate loads is to make sure the seating pressure is consistent from cartridge to cartridge. The only way to measure this is to make sure that every case has the same tension in the neck. This is usually done with a hydraulic pressure gauge on the reloading press itself.
Me, on the other hand, is planning to make a bullet seater die that can measure the force it takes to seat the bullet into the brass case. I’m an experienced lathe user.
The normal pressure to seat a bullet relates to approx. 30 kg of force. Scaling, not sure, but 250 gram scaling will be more than enough.
I’m planning on using the TAS606 as my load cell, and this is sadly where it stops for me. I’d like to have a display on the wall which states the pressure in kilograms, preferably with a hold function that display the highest force used to seat the bullet, and a reset function.
Could anyone help me with a parts list? I wouldn’t mind if it looks a bit high tech when fellow shooters come to visit
Thanks in advance!
Picture below is of a seating die that is used to seat a bullet into a case. I will modify the part marked with red on a lathe and install a load cell in between.
Thank you. The load cell you are referring to is the one I have been looking at. I will make a new micrometre top on the bullet seating die which will fit on the existing die, but the transmission of the force will go through the load cell. I haven’t done the due diligence nor any construction plan yet, but now the mechanics seems like the least of the problem.
Is there a chance of just using the load cell and do a direct mV/V scaling inside a display unit – like one power supply (10V) connected to the load cell and one display unit with a mV/V converter, without anything else. So just the converted number appears in the display? Or will the amplifier be mandatory in such a application?
Do you want a project or a product?
A commercial scale indicator will effortlessly knock out the electronics so you can concentrate on the difficult task of force-measuring-press-design. Many controllers have a peak display that works exactly as you describe. Here’s one listing Peak Hold in the features:
There’s a slight nomenclature distinction to be aware of. Scales measure weight which is a force due to gravity & masses. This force is also assumed to be in the down direction, normal to our surface. The measurement you are performing is also a force but is not dependent on gravity or mass or direction. Some people and devices get very hung up on how the force is generated and raise a stink if you mix them up, even though the equipment (or the finger getting pinched) can’t tell the difference. So get in the habit of calling it pounds-force, kilograms-force, Newtons.
Similarly, some instruments that perform your desired measurement might not be called scales. Here’s a force indicator that performs all the functions of a scale plus some other non-weight, force measurement stuff like a tension/compression button. Note the unit of measure icons: lbf, kgf, N. Force Indicator - Dillon
I’ve done some informal consulting with a few distance shooters. Semi-automated, precision weighing of the powder charge was the new hotness about 5 years ago but there are advancements still being made in the hobbyist field. I haven’t heard of anyone using a precision press but it sound interesting and achievable.
To DIY you’d need the amplifier too. You can hook it up like so, perform a calibration and then after you’ve got that going simply add in a screen like YellowDog mentioned…something with at least 2 rows would be better for your case, so you can display both current force and peak-hold force.
