Folks,
Like many of you I have expanded many necks to a larger diameter in the past- which is why this time it's got me baffled and hopefully someone can shed some light on what has happened.
Rich Sherman the cartridge designer sells his ADG 338 SS head stamped brass with a .284 neck diameter and it's up to the reloader to expand the case neck to 338. In fact, Rich and I spoke and we cannot figure out how I am crushing necks?
Personally, I like to expand my case necks in a two step process but I do know many guys with the 338 SS that have expanded the neck in one step.
Step 1: Open the neck from .284 to .308
clean and set the Sinclair mandrel body die in the press, confirmed my case neck would not hit the top of the die as it went over the mandrel. Secondly, I chamfered and deburred the necks, applied proper lube to the ID of the neck and some on the Sinclair E30 (.308 dia.) mandrel ...opened all .284 necks to .308 without any issue.
Step 2 Open the neck from .308 to .338
lightly lubed the ID of necks and the Sinclair E33 ( .338 dia.) mandrel.
BOOM .... every few cases I would crush a neck? It happened enough for me to say ok that is not me inducing too much pressure on the ram handle what the hell is happening? I should add that the crushed neck diameter is expanding to the correct diameter that a non crushed case is measuring meaning I am not hitting the edge of the case mouth with the mandrel.. the 40º shoulder is simply failing and pushing into the case body
Die body is clean and set properly... CHECK
Lube applied properly...CHECK,
Previously opened all necks to .308 without issue.. CHECK
I first suspected the E33 mandrel is out of tolerance but I used it for my 338 EDGE never had in issue. Took out my caliper and pulled a few measurements off it no issue albeit the "taper" doesn't seem to be as much as it should be ( I ordered a mandrel and die body from a different manufacturer to compare)
In addition, I now suspect the brass is too soft (maybe over annealing occurred?) Not really a way to confirm that >> if the other mandrel crushes more necks then I am going with this theory ....
Hopefully someone here in the forum can shed light ?
thanks for reading !
Like many of you I have expanded many necks to a larger diameter in the past- which is why this time it's got me baffled and hopefully someone can shed some light on what has happened.
Rich Sherman the cartridge designer sells his ADG 338 SS head stamped brass with a .284 neck diameter and it's up to the reloader to expand the case neck to 338. In fact, Rich and I spoke and we cannot figure out how I am crushing necks?
Personally, I like to expand my case necks in a two step process but I do know many guys with the 338 SS that have expanded the neck in one step.
Step 1: Open the neck from .284 to .308
clean and set the Sinclair mandrel body die in the press, confirmed my case neck would not hit the top of the die as it went over the mandrel. Secondly, I chamfered and deburred the necks, applied proper lube to the ID of the neck and some on the Sinclair E30 (.308 dia.) mandrel ...opened all .284 necks to .308 without any issue.
Step 2 Open the neck from .308 to .338
lightly lubed the ID of necks and the Sinclair E33 ( .338 dia.) mandrel.
BOOM .... every few cases I would crush a neck? It happened enough for me to say ok that is not me inducing too much pressure on the ram handle what the hell is happening? I should add that the crushed neck diameter is expanding to the correct diameter that a non crushed case is measuring meaning I am not hitting the edge of the case mouth with the mandrel.. the 40º shoulder is simply failing and pushing into the case body
Die body is clean and set properly... CHECK
Lube applied properly...CHECK,
Previously opened all necks to .308 without issue.. CHECK
I first suspected the E33 mandrel is out of tolerance but I used it for my 338 EDGE never had in issue. Took out my caliper and pulled a few measurements off it no issue albeit the "taper" doesn't seem to be as much as it should be ( I ordered a mandrel and die body from a different manufacturer to compare)
In addition, I now suspect the brass is too soft (maybe over annealing occurred?) Not really a way to confirm that >> if the other mandrel crushes more necks then I am going with this theory ....
Hopefully someone here in the forum can shed light ?
thanks for reading !
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