New to Expander Die and mandrels
- Thread starter Schw15
- Start date
Are
like they bushings measure my loaded case with bullet and pick a mandrel 2 thousands under? And I have a full length sizer die then would u use the mandrel die to set the neck tension I want?
I just go by bullet size and brass behavior.
1-2 thou under bullet diameter is a safe start.
I actually use a full bullet diameter mandrel to fix up most brand new brass
You get spring back so you have to see what your brass does.
you can use a full length die then set neck with mandrel.
Yes.
I don’t get a full thou of spring back so I don’t consider it in my selections but you can. That’s why it’s tough to give definitive answers.
The 21st Century and Sinclair die bodies and mandrels are interchangeable with each other and are basically the same things made at the same places... except when it comes to die bodies 21st Century makes a fancier one with a "window" hole in the side (but I have one and do not recommend it because it's made of paper-thin aluminum and over time and after a couple of drops I wouldn't trust it, stick to the cheaper steel ones, you don't need the "window").
With their nomenclature the "Turning" mandrels are -.002 under bullet OD, while the "Expander" mandrels are -.001 under.
I also don't experience a full thou of spring-back (I anneal every firing) so I use the Turning mandrel .002 under. YMMV.
With their nomenclature the "Turning" mandrels are -.002 under bullet OD, while the "Expander" mandrels are -.001 under.
I also don't experience a full thou of spring-back (I anneal every firing) so I use the Turning mandrel .002 under. YMMV.
I use a Sinclair since it's what dad had handy. Anybody got a way to keep the mandrel from pulling out when I'm using it
go for the full kit it should have everything you need expanding mandrill and die not too bad cost wise I have enjoyed using them just not having to increase the things I have to do but it is what it is . If you go 21 century best of luck oh in case you didn't already know careful not to press then in much further than the neck it could crush neck into case and lube the inside of your case neck .
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Guys bashing the Sinclair question don't know what you are talking about.
The old Sinclair die is a stupid design, the "shoulder" in the die prevents you from pushing the mandrel through the top.
It seats from the bottom of the die and is retained by a set screw against a flat machined on the top of the mandrel body.
The "fix" is drill a hole or cut a notch in the mandrel where the set screw contacts it.
ETA:
"Our Generation II Expander Dies completely capture the mandrel within the die so the mandrel cannot pull out."
Even Sinclair realized it was dumb and redesigned their dies.
The old Sinclair die is a stupid design, the "shoulder" in the die prevents you from pushing the mandrel through the top.
It seats from the bottom of the die and is retained by a set screw against a flat machined on the top of the mandrel body.
The "fix" is drill a hole or cut a notch in the mandrel where the set screw contacts it.
ETA:
"Our Generation II Expander Dies completely capture the mandrel within the die so the mandrel cannot pull out."
Even Sinclair realized it was dumb and redesigned their dies.
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I don't know. I didn't check if Sinclair sold them years ago when their first iteration of mandrel die was sold.
I have their mandrel die from 20 years ago and it’s not a collet die. I don’t think they ever made one.
Sinclair carbide mandrels for me. FL size with the expander ball out then run the mandrel down the neck. Check for concentricity afterwords.
So guys I never ordered my expander Die been very busy and no service where I'm working at the moment. I believe I have to tight and some inconsistent neck tension on my 300 win mag. Great groups at 100 but at 1 mile opens up and sd at best maybe 15 to 18. I have spreads 2707 to 2770. My other barrel I have sd of 4 to 7 any where from 5 to 30 shots. I haven't ran into this issues this bad before..So would the expander Die or bushing die work best on controlling my neck tension? I use a forester full length Die and 230 a-tips. I've used bushing dies before. Also it is lapua 300 win mag brass they are very tight in neck
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If you aren't annealing, its going to be hard to predict how much spring-back you'll get and thus which methods should be used. I'd recommend annealing if you want greater consistency.
I measure and my brass when it'd fired will not allow bullet to fall in so looks like thick brass lapua. It measures .337 fired and loaded .336 to .3065. I have other brass gunwerks and sig I'm going to test them tomorrow. Neck tension is way better on the other brass than the laupa. I have 7mm-300 win mags and the laupa brass will work great necked down with the measurement I took. I guess tighter neck and the thicker brass caused me some issues on my SD.
Thanks for the heads up. Just ordered one for 30 cal... Reasonable price and actually in stock!
Mike
I anneal every time. Checked the expander ball on my FLS die and it mic'd at .3063-.3064
Neck ID on cases (checked with calipers) was about .3055... So I figure about .0009 or so spring back.
So a .307 mandrel should put me about .306 neck ID... Hopefully.
Mike
Neck ID on cases (checked with calipers) was about .3055... So I figure about .0009 or so spring back.
So a .307 mandrel should put me about .306 neck ID... Hopefully.
Mike
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