NOTE: Keep in mind that sample stepped "M" style powder through expander (PTX) I am beta testing is an early "rough" research & development (R&D) version that may not be same as final production version. Remember the
beta testing of 3D printed white colored rotary magazine for Lee Precision's new inline bullet feed die that had "rough" edges that I needed to scrape smooth? Now the production rotary magazines are made of durable polymer in red/black colors that even look different (Yes, Calvin and I even exchanged emails about red vs black color for final production and we both agreed that instead of all black or red, having "Lee Precision" red with black would set the rotary magazine apart from other all black products) -
https://leeprecision.com/inline-bullet-magazines/
What THR members are allowed to see and participate in is rare manufacturer-consumer collaboration where full transparency of new product research and development is exposed for examination out in the open. Early R&D product samples are reviewed and tested under the watchful eyes of collective membership of THR with, and believe me when I say, comprehensive detailed examination of decades of reloading and shooting experience by those who have used, broke and even fabricated their own products to "make things work". This is "Open Source" IT concept applied in "real time" to reloading and handloading.
Of course, as a beta tester, my role is to push the R&D samples to the limits, even to the breaking point, from the end-user perspective to not only validate the original intent of the product but to test the aspects of the sample beyond the original intent to make the product better for final production. And I welcome the "what if/will this ..." feedback from THR members as they help me better focus to beta test like the "myth busting" I conducted below.
Original product intent - When I suggested to Calvin that Lee Precision consider offering stepped "M" style powder through expander, it was done when I was asked to beta test the new inline bullet feed die/rotary magazine, so as to prevent bullet tipping during shellplate indexing and allow square seating of bullet without tilting, the original product intent of "M" style expander.
On our numerous email exchanges, we discussed different aspects of "M" style PTX to not only produce "square seated" dropped bullets from the bullet feed die that won't tip with shellplate indexing but also other aspects like being able to work with larger sized lead/coated bullets instead of customers having to buy different sized "M" style PTXs to whether to incorporate additional "flare" to the step to help with bullet feed die use.
Calvin's comments mentioned in post #17 reflect the original product intent of keeping the dropped/hand set bullet square for bullet seating without tilting and asking me to beta test affects of "scraping" of brass as keeping the bullet square was the intent of this product -
https://www.thehighroad.org/index.p...powder-through-expander.916523/#post-12573158
"... scraping of the brass. That is one of our primary concerns too. Are you finding that is actually brass or just 'cleans' the inside of the case ...
It was also found that the squarer the bottom of the expanded portion of the case was, the more consistent the starting of the projectile. This is the reason for keeping the corner as abrupt as possible. Without that abrupt corner we felt that there was not much difference or advantage over the existing tapered expander.
Let me know what you think and what you are finding for yourself."
With the feedback from THR members, I devised the following "myth busting" to verify whether "scraping" of brass from inside of case neck was significant. Based on the measurements, I believe the concern/myth of case wall thinning is busted and I will be forwarding the results to Calvin for further product consideration.
I will be beta testing next whether this "scrape" mark affects jacketing/plating/coating of bullets, so stay tuned.
Remember, we are in R&D phase of this product, happening in "real time" with THR members involved and providing "real time" feedback.
I will keep testing with expanded sample size and report back.
UPDATE: This is mini "myth busting" done for concern regarding R&D sample of "M" style PTX scraping brass from inside of case mouth (Not case neck).
Myth Busting - So to check longer-term effect of brass being resized and expanded repeatedly as to whether brass is getting scraped significantly, I marked the base of sample cases by headstamp and measured the case wall thickness at the mark .050" below case mouth. Then I resized/expanded the cases ten (10) times and resized again to straighten out the case mouth and measured the case wall thickness at the same mark .050" below case mouth.
Blazer, FC, .FC., WIN, R-P, R-P "." and G.F.L. headstamp cases were tested (Black marks on base indicate where case wall thickness measurements were made)
New 2023 Pro 1000 was used with case ejector removed to continuously cycle the cases for resizing/expanding ten (10) times
Picture of test cases after being resized/expanded ten (10) times
And here are the results (Case wall thickness measured .050" below case mouth - Before - After):
- Blazer - .010" - .010"
- FC - .010" - .010"
- .FC. - .010" - .010"
- WIN - .011" - .011"
- R-P - .011" - .011"
- R-P "." - .011" - .011"
- GFL - .011" - .011"
Comments: I did not repeat the bullet setback testing of these cases because taper crimp applied with brass .100" below case mouth as to neck tension is significantly overshadowed by neck tension from thicker case neck .200" below case mouth and we "myth busted" case wall scraping .050" below case mouth.
FYI, case wall thickness measurements .100" below case mouth (Where taper crimp is applied) -
https://www.thehighroad.org/index.p...nd-bullet-setback.830072/page-3#post-10712225
And case wall thickness measurements .200" below case mouth (Where most neck tension to hold bullet base comes from for 115 gr FMJ/RN bullet) -
https://www.thehighroad.org/index.p...nd-bullet-setback.830072/page-3#post-10712225
