Someone asked about this the other day. Gageshop.com sources their pins from meyer, and you can buy sets or individual pins for $4 or less. Here is how I use them as a final step in brass prep.
Gage pins...
- Thread starter David Christian
- Start date
Variation of Sinclair mandrel die?
He's using the gauge pin as a precise version of a sizing mandrel. The type of die it is installed in is a little less relevant than the end result, provided that everything is reasonably straight.
The 'business end' doesn't HAVE to be tapered, particularly if he's only moving the dimension a tenth or so. Would it be advisable? Yeppers.
Biggest thing is to make sure you have the entire case neck being "hit" by the entire diameter of the mandrel, at the same time, and don't run the GD thing into the top of the die.
No. The Sinclair, 21st, PMA, etc. mandrels and dies are sorta proprietary to this industry, with the enlarged shank.
The way he's using this is as a little more crude version of what a dude from Texas makes with an elegant collet setup. Probably works just as well.
butchlambert
Site $$ Sponsor
I buy my Deltronic pins and other measuring devices from Crescent Gage. They are a longtime customer of mine and are 1 block from one of my shops.
https://crescentgage.com/
https://crescentgage.com/
I can't speak for the Lee Collet bullet puller pictured, but I would not have confidence that my RCBS Collet bullet puller would hold the pin gauge in a nearly perfect concentric position. I just doubt a bullet puller is properly machined for this purpose.
How is your neck concentricity afterwards?
How is your neck concentricity afterwards?
No to collet sizing die. It is a Hornady bullet puller. Very simple and easy to swap out collets and pin sizes whether it is .264, .284, or .308.
Business end of pin has been rounded over with sand paper then steel wool. Flip the pin over and opposite end can be used to shear off a donut inside the case.
For less than $20 you can buy 5 different pin sizes in 1/2 thousands increments (i.e. .2840, .2835, .2830, .2825, .2820) and really fine tune your neck tension process.
Works like a charm. I don’t worry about concentricity, nor do my results suggest concentricity matters to a point. One more step in my reloading process that I was able to eliminate.
David, are those minus gauges?
I have mostly purchased minus gages, but am thinking about switching to plus sizes to partially offset a bit of brass spring back.
Brians356
Gold $$ Contributor
Thanks for clarifications. I had thought maybe you were using the sharp edge to scrape a mild donut. If the neck is already very close to size (and at least minimally chamfered) then just rounding the edges makes sense now. I have hundreds of gages, all "minus" which suits my purposes. These things become indispensable once you have them to hand for a time, I'm always finding new uses for them.
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Dave, I just blew up your pic and realized that is a plus gauge pictured. I assume you short stroke by sight so as not to obscure the gauge size markings or is it etched deep enough to not be a problem.
pat fulghum
( ͡° ͜ʖ ͡°)
I bought these a while ago from 21st Century...
http://www.xxicsi.com/expander-mandrels.html
You can buy a whole set and they are laser marked for easy identification.
http://www.xxicsi.com/expander-mandrels.html
You can buy a whole set and they are laser marked for easy identification.
pat fulghum
( ͡° ͜ʖ ͡°)
@David Christian ,
Does this really shear it off (physically remove it) or does it just roll it over and make a burr facing toward the primer pocket.
I tend to use specifically sized end mills that will actually cut them out without any damage to the neck walls.
- pat
Dusty Stevens
Shiner
I always ask what problem does the donut cause? With a properly designed chamber your bullet will never contact the donut and it does not affect accuracy.
yes with a bit of stroke technique the entire donut shears off. Now, I did not mention this in the prior message, as I never have to do this, I neck turn and use the pin to expand any donut to the outside, but if for some reason you wanted to shear one off, you could use the sharp end of the gage pin inserted into a chamfered neck.
Brians356
Gold $$ Contributor
I've long held reservations about this notion. The limitation of that, as I see it, is that a donut cannot be pushed completely to the outside (rendering the inside a virtual cylinder) while on the mandrel, at least not with brass walls on the order of .010" thick (and brass not nearly dead soft.) One could verify this by inspecting closely the outside of the neck while on the turning mandrel. The donut will hold a tighter grip on the mandrel while outside turning, and inevitable spring-back will leave a (possibly) reduced inside donut after removing the mandrel. For our purposes one might reduce a donut sufficiently this way, but reaming (in a proper tight-fitting reamer die, or on a machine lathe) is the only practical way I can think of to completely remove a donut. Your idea of shearing it with one stroke of a pin gage is intriguing, but I wonder if a harder (carbide?) pin with a carefully dressed corner wouldn't better meet the requirement.
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I went this route. 21st had a good Black Friday Sale and I purchased a few sets.
dgeesaman
Gold $$ Contributor
I did the gage pin set with Hornady collet puller for a little while. It works but you have to be careful to not ram the brass mouth into the die plus the donut question. On mine, the shellholder has enough looseness to make up for the fixed gage pin.
I'm not sure if I've got donuts. Per Dusty's point, it shouldn't matter. But pushing the gage pin expander past it, you can definitely feel where it reaches the donut point and pushes back.
The Sinclair and 21st century expanders are very well made, slide in smoothly, and the die is set up so you can't ruin brass. 1/2 thou increments is truly more resolution than I can use.
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