PDA

View Full Version : Tips for Designing Boolits?


Daekar
03-29-2021, 11:46 AM
I am interested in purchasing a 155gr to 160gr, 0.359 diameter NLG RF mould with a meplat in the 0.250 area for use in 357mag revolver and break actions. I have seen other weights with this kind of design, but none quite what I am after.

I am comfortable with CAD software so producing a drawing is not a problem, but I am pretty sure there are factors governing the ideal shape of a boolit nose that I am not aware of. Are there any general principles which I should keep in mind when considering how to shape things?

Alternatively, I am totally willing to just buy an existing design if one is out there...
475AR
03-29-2021, 12:12 PM
Go to accurate molds, and look @ 36-159H or 36-160T (smaller meplat but if you ask Tom he can adjust it to the .250 you want)
His catalog is a treasure trove of designs.
Daekar
03-29-2021, 12:21 PM
Go to accurate molds, and look @ 36-159H or 36-160T (smaller meplat but if you ask Tom he can adjust it to the .250 you want)
His catalog is a treasure trove of designs.

Yes, I love that website! Do you think he would be willing to make a NLG version of an existing design? That might be the easiest thing instead of reinventing a well-tested wheel.
475AR
03-29-2021, 12:25 PM
See below post (darn cell phone..)
475AR
03-29-2021, 12:27 PM
Yes, he will. Also depending on the guns you plan to use them in an LFN like the 36-159H may be a better choice?
Daekar
03-29-2021, 12:39 PM
Yes, he will. Also depending on the guns you plan to use them in an LFN like the 36-159H may be a better choice?

As long as it will chamber properly in a S&W Model 60 cylinder, it will work. I have to confess, I am only guessing the difference between a RF and LFN: They both have a curved contour leading to the nose, but the LFN carries more of its mass outside the case thanks to a more eccentric elliptical profile, yes? Or... looking at the drawing, maybe not even elliptical...

I do like the look of the 36-159H better than the 36-160T.
475AR
03-29-2021, 07:49 PM
You are correct, the lfn does carry most of its weight in the nose, and also frees up some case capacity.
I don't know what the max overall cartridge length is for a model 60, but the 357 case is about 1.27" and the crimp to nose of the 36-159H is .385" would make 1.655" col so if that fits you are good to go otherwise use 38spl brass and it should be fine.
Daekar
03-30-2021, 04:41 PM
You are correct, the lfn does carry most of its weight in the nose, and also frees up some case capacity.
I don't know what the max overall cartridge length is for a model 60, but the 357 case is about 1.27" and the crimp to nose of the 36-159H is .385" would make 1.655" col so if that fits you are good to go otherwise use 38spl brass and it should be fine.

Hmmm... just did a little measuring on my model 60, and it looks like the max OAL is going to be REALLY close, down to the thousandth. Might consider something else with a slightly shorter nose. Thanks for the advice!!