Yes, brass was annealed .Have you annealed the brass first?
I get a crush fit with the brass I loaded hot with H 4895 . The milder loads,no crush fit.
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Yes, brass was annealed .Have you annealed the brass first?
That sounds like a great option . I would for sure be able to obtain my crush fit right from the start. ThanksAnother option would be to neck down 7X57 cases (PPU, cheap) to .25 using a .257 R F/L set back for a crush fit without an expander ball in the die and FF with COW. I make 6mm AI's that way but use a .243 W die, no expander. backed off, the .243 die with it's 20* shoulder makes for an easier neck down. New brass, anneal after neck down.
+1I prefer to run my fire forming loads on the hot side with a little faster powder than I'll end up using..
Really want them formed the 1st time out..
Thank you for the step by step instructions,I appreciate you taking the time . Your process sounds like a winner to me . This is new territory for me,I wish I would have waited and learned about the COW method before using hot loads with bullet jammed .Upon a neckdown from .28 to .25 the neck brass will thicken meaning neck turning might be needed. How much depends on your chamber neck dimensions as measured by a FF neck, allowing for .001 brass spring back.
Not to go into a big production, bullets should easily slip fit into a fired case. If not, the sized necks need to be turned down until an easy slip fit can be obtained. Excessive turning will result in inadequate neck tension. While not as accurate as a micrometer, a high quality caliper will suffice for measuring neck diameters. Like load up 5 rounds with successive .001 neck diameter reductions fire each, then test for slip fit for each. Go for the one with the biggest diameter yet allowing a slip fit. Seating bullets should require some force.
Just about every wildcat loader/shooter needs a neck turner.
Ideally the neck walls should be from .0125 to .015 thick and there has to be enough neck tension to hold the bullet. My 6mm AI loaded rounds = .268 - .028 - .243 = -.003, or .003 neck tension. .014 neck wall thickness. Upon resetting the neck turner cutting blade just barely contacts a sized previously fired and sized neck. This will allow for +- .001 duplication. Ideally, numerous neck turners could be used for a variety of ammo leaving each in a fixed setting but that would be spendy.
Upon FF by COW, a guess would be that 20 thou psi is sufficient to give sharp shoulder angles. I use pistol powder and any ole primer. Start by measuring the entire weight capacity of the case then only use 10% of that charge to start. Be real cautious. After fire forming be sure to remove any COW debris inside of the case as it will affect capacity for future loadings. I use a piece of rebar binding wire fashioned into a 100* or so angle on one end and straight on the other. Probe and scrape just under the shoulder and then poke the wire thru the spit hole and probe and scrape again. I FF in my garage using a 5 foot long piece of 4" diameter PVC pipe capped at one end. I insert about 18"inches of barrel into the pipe then fire. I clean the chamber after each 10 rounds. A dull thud can be heard outside the garage. I use 9 grains of HP38 to FF the 6mm AI.
I shot 85 grain Nosler BT bullets out of my .257 AI with H4350 @ over 3400.
That .5 grain of pistol powder makes a huge difference . Looks like I will buy some new brass and start over . I loaded up the brass that grew enough for a crush fit,they were the Hot H4895 rounds . Hope to shoot them today,I am hoping they survive the second firing OK .Here are some pics - on the left a 90% or so fireformed case needing just .5 grain more HP38 pistol powder - on the right a completed 6mm AI round with nice sharp shoulders and the neck turned down to .268. The bullet is a 87 VMax. Not intended for FYNE bench rest shooting but does ok. I turn my necks with a RCBS neck turner and periodically sharpen the cutter blade on a diamond knife hone. The cases are chucked into my DeWalt cordless and turned at some slow speed. I don't remove more than .004 at one session. I like to anneal after neck turning. View attachment 1125433
Ackley said to use snappy loads. I've also used coffee with a snappy load of IMR Red to form them. Worked wellThank you,my gut was telling me just what you say . I had my doubts about slow powder and light charges .
The IMR Red/coffee sounds interesting . Can you give some info on your method and powder charge please ?Ackley said to use snappy loads. I've also used coffee with a snappy load of IMR Red to form them. Worked well
The IMR Red/coffee sounds interesting . Can you give some info on your method and powder charge please ?
Dale, I simply used 15 gr Imr red, coffe, topped with tissue, 257 brass, load and shoot. 95-98% formed. Clean and load them for load tests. I like simpleThe IMR Red/coffee sounds interesting . Can you give some info on your method and powder charge please ?
Thanks Ken, I will have to give that a try . I have some cheap coffee that's perfect for something besides drinking. Thanks for the info .Dale, I simply used 15 gr Imr red, coffe, topped with tissue, 257 brass, load and shoot. 95-98% formed. Clean and load them for load tests. I like simple