Cortina Precision Mandrel Dies

[TheOfficeT-Rex]

I didn’t see a topic specific to the Cortina Precision mandrel dies, and now that I’ve gotten to use it a bit (350 rounds-ish), I thought I’d share a couple observations and open the discussion for anyone that may be considering these dies.

My primary interest was in the mandrels/armoloy coating, however one of the selling points of this die is that it also acts as a base sizer die. In the product video, it is described as “the same as your sizing die” and “not a small base die.” Supposedly it will help with “clickers,” which has been an issue with some chamberings. I’ve never had a clicker that wasn’t a snipershide level pissing hot handload (with no pressure signs, of course), but I figured there may be some merit to holding the base of the case during the mandrel operation so I ordered a 308 win family die as well.

Fit/finish on the dies and mandrels are very nice. The inside is smooth, and sizes smoothly. I like the wrench flats and wrench holes on the lockring. The lockring has two sides, one rounded, and one squared that is allegedly machined true to the threads and perfectly square. I have no way to test it, but it sounds good. There are two set screws on the lockring. Mine came so loaded with yellow threadlocker that I couldn’t screw them in far enough to engage the die and stop it from spinning using a standard allen key. I cleaned most of the threadlocker off so that I could use the set screws.

I’m using this die to resize Lapua 6mm Creedmoor brass. It has been fired 10x in a standard PVA chamber and has never been annealed. There is a Mighty Armory FL sizer in station 1 (mandrel/decapper removed), and the Cortina die in station 3 of a 550. I measured several pieces of brass from fired, resized, and after the mandrel operation using Mitutoyo calipers.

Body diameter at the .200 line (ish)
Fired - .471
Resized MA - .470
Resized + Cortina - .469
For comparison, CIP/SAAMI maximum cartridge drawings put the base diameter at .4708” and .4703”.

With it squeezing an extra thousandth after I set the shoulder back, I did see headspace grow .0005” after the mandrel die. I did not think to measure overall lengths while I was reloading. I may next time just for giggles. Visually, there is a good amount of additional body sizing going on compared to the Mighty Armory die. The sizing appears very consistent within my small sample size.

Here’s an example of the base sizing, although it is a 6.5CM not from my rifle and received a little less of a squeeze, it conveys the idea/results...

Overall – It does what it says on the tin. I like the armoloy mandrels. I’m interested in hearing other’s experiences and if the extra base sizing is helping anyone outside of the PRC calibers.
Link to the Product video.

 

[AllenOne1]

I have one on the way, should see it in the next couple of days. I'm not interested in any additional sizing but the idea of holding the case in better alignment during the mandrel process seems like a plus.

I have felt one case mandrel real easy and another that seems to grab a little and have wondered if I'm really feeling a case that is cocked a little bit as the mandrel is pushed through. I know, sizing, neck lube, etc. could be the cause as easy as misalignment but this will eliminate that variable. I anneal every firing, sizing seems consistent with a Whidden bushing die and have tried with and without neck lube. Could be different thickness of the brass in the neck, unturned Lapua brass, or it could just be in my head.

 

[CK1.0]

The armoloy coating is interesting... I haven't seen that before in the gun market (though I'm skeptical as to what it has over something like TiNi)...

IDK if he's reinventing the wheel here, I actually tend to view the extra sizing pass on the base of the cases as undesirable and am skeptical of whether holding the case at the bottom matters, as a mandrel already self-centers cases without any help.

That said, another mandrel die in the marketplace isn't a bad thing for those who want to go there.

@AllenOne1, I've experienced what you're describing with the mandrel where it seems to barely kiss some cases and then there's obvious engagement with other cases... for me, it led to some experimentation with tighter bushings, and I've ended up purposely squashing my necks a little more than previously in order to get a more even engagement with the mandrel on each and every case while opening them back up. In 6mm I went from a .268 bushing down to a .266 bushing (followed by a .241 mandrel), and while only a couple thou, it made a big difference, and my cases have ended up more consistent since. (YMMV, it's definitely worth a try...)

 

[Dolomite]

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[Dolomite]

I didn’t see a topic specific to the Cortina Precision mandrel dies, and now that I’ve gotten to use it a bit (350 rounds-ish), I thought I’d share a couple observations and open the discussion for anyone that may be considering these dies.

My primary interest was in the mandrels/armoloy coating, however one of the selling points of this die is that it also acts as a base sizer die. In the product video, it is described as “the same as your sizing die” and “not a small base die.” Supposedly it will help with “clickers,” which has been an issue with some chamberings. I’ve never had a clicker that wasn’t a snipershide level pissing hot handload (with no pressure signs, of course), but I figured there may be some merit to holding the base of the case during the mandrel operation so I ordered a 308 win family die as well.
View attachment 8244517

Fit/finish on the dies and mandrels are very nice. The inside is smooth, and sizes smoothly. I like the wrench flats and wrench holes on the lockring. The lockring has two sides, one rounded, and one squared that is allegedly machined true to the threads and perfectly square. I have no way to test it, but it sounds good. There are two set screws on the lockring. Mine came so loaded with yellow threadlocker that I couldn’t screw them in far enough to engage the die and stop it from spinning using a standard allen key. I cleaned most of the threadlocker off so that I could use the set screws.

I’m using this die to resize Lapua 6mm Creedmoor brass. It has been fired 10x in a standard PVA chamber and has never been annealed. There is a Mighty Armory FL sizer in station 1 (mandrel/decapper removed), and the Cortina die in station 3 of a 550. I measured several pieces of brass from fired, resized, and after the mandrel operation using Mitutoyo calipers.

Body diameter at the .200 line (ish)
Fired - .471
Resized MA - .470
Resized + Cortina - .469
For comparison, CIP/SAAMI maximum cartridge drawings put the base diameter at .4708” and .4703”.

With it squeezing an extra thousandth after I set the shoulder back, I did see headspace grow .0005” after the mandrel die. I did not think to measure overall lengths while I was reloading. I may next time just for giggles. Visually, there is a good amount of additional body sizing going on compared to the Mighty Armory die. The sizing appears very consistent within my small sample size.

Here’s an example of the base sizing, although it is a 6.5CM not from my rifle and received a little less of a squeeze, it conveys the idea/results...

View attachment 8244514

Overall – It does what it says on the tin. I like the armoloy mandrels. I’m interested in hearing other’s experiences and if the extra base sizing is helping anyone outside of the PRC calibers.
Link to the Product video.

Sorry not quite on topic. What’s interesting is the sizing of the base. I have a ring die and its ID is .4675 which will size the base from .470 down to .4685 - .469 (Lapua Brass) so it depends on your brass spring back. I confirmed with RCBS, Redding and Forster on their small base die and the ID is roughly (give or take .001 or more) .466 and it will size the base down to roughly .468.

It really depends on the spring back of brass you are using. Others might get different results.

Some food for thought.

 

[CK1.0]

The design is reminiscent of a 9mm Lee Factory Crimp Die which similarly has a sizing ring at its base. They’re often used by high-volume USPSA guys who go through loads of rounds in order to make sure every last round will chamber.

The thing is, with those, there are basically two different schools of thought: some guys use them in the last station of their progressive press to ensure every last round passes the gauge and will chamber at the expense of some accuracy potential, whereas others (like me) only use the Lee FCD on the handful of rounds per thousand that don’t pass the gauge and then those rounds go in the practice-only pile.

I’m weary of the effect an extra sizing pass would have on a precision rifle round when I know it has a negative impact on 9mm rounds…

 

[AllenOne1]

The armoloy coating is interesting... I haven't seen that before in the gun market (though I'm skeptical as to what it has over something like TiNi)...

IDK if he's reinventing the wheel here, I actually tend to view the extra sizing pass on the base of the cases as undesirable and am skeptical of whether holding the case at the bottom matters, as a mandrel already self-centers cases without any help.

That said, another mandrel die in the marketplace isn't a bad thing for those who want to go there.

@AllenOne1, I've experienced what you're describing with the mandrel where it seems to barely kiss some cases and then there's obvious engagement with other cases... for me, it led to some experimentation with tighter bushings, and I've ended up purposely squashing my necks a little more than previously in order to get a more even engagement with the mandrel on each and every case while opening them back up. In 6mm I went from a .268 bushing down to a .266 bushing (followed by a .241 mandrel), and while only a couple thou, it made a big difference, and my cases have ended up more consistent since. (YMMV, it's definitely worth a try...)

Interesting that you bring up the concept of sizing more not less. I have also played with that and have come to the conclusion that if you are not moving the metal enough you are just playing with the spring back. You have to move the metal a certain amount for it to stay in place and overcome the normal spring back of the metal. I think messing with that may have brought me to the alignment questions I have floating around in my head. I intend to do more testing around the neck sizing and mandrel process going forward.

The one concern I have about the additional sizing is if it's enough to effect head space and will I need to readjust my sizing die to account for it. I'll see as that is one area I will be watching closely. Maybe that's how he gets you to buy his sizing die. lol

 

[CK1.0]

Interesting that you bring up the concept of sizing more not less. I have also played with that and have come to the conclusion that if you are not moving the metal enough you are just playing with the spring back. You have to move the metal a certain amount for it to stay in place and overcome the normal spring back of the metal. I think messing with that may have brought me to the alignment questions I have floating around in my head. I intend to do more testing around the neck sizing and mandrel process going forward.

The one concern I have about the additional sizing is if it's enough to effect head space and will I need to readjust my sizing die to account for it. I'll see as that is one area I will be watching closely. Maybe that's how he gets you to buy his sizing die. lol

The cool thing is there’s never really been a die like this one before… so I’m curious to see the results you guys get…

 

[TheOfficeT-Rex]

What’s interesting is the sizing of the base. I have a ring die and its ID is .4675 which will size the base from .470 down to .4685 - .469 (Lapua Brass) so it depends on your brass spring back. I confirmed with RCBS, Redding and Forster on their small base die and the ID is roughly (give or take .001 or more) .466 and it will size the base down to roughly .468.

Rough measurement of the Cortina ID is about .468" where the MA resizer is .469" (nice). Those are grain of salt measurements, eyeballed to where the sizing starts -some of my measuring tools were victims of a move so calipers again. Seems to match what I'm seeing on the brass. I don't own a small base die, or know enough about them, to make a comparison.

I’m weary of the effect an extra sizing pass would have on a precision rifle round when I know it has a negative impact on 9mm rounds…

I don't spend enough time on brianenos, what negative impact is seen on 9mm?

The one concern I have about the additional sizing is if it's enough to effect head space and will I need to readjust my sizing die to account for it. I'll see as that is one area I will be watching closely. Maybe that's how he gets you to buy his sizing die. lol

Depends on the resizing die you have, you may/may not see the level of sizing I do. I would assume his two dies match. I was surprised by how much scuffing I could see the first time I used the die - but it's also nowhere near new brass. I wish I hadn't tossed this last rounds in the tumbler before i took a pic. I thought I did, but I am a dumb.

 

[AllenOne1]

Rough measurement of the Cortina ID is about .468" where the MA resizer is .469" (nice). Those are grain of salt measurements, eyeballed to where the sizing starts -some of my measuring tools were victims of a move so calipers again. Seems to match what I'm seeing on the brass. I don't own a small base die, or know enough about them, to make a comparison.



I don't spend enough time on brianenos, what negative impact is seen on 9mm?



Depends on the resizing die you have, you may/may not see the level of sizing I do. I would assume his two dies match. I was surprised by how much scuffing I could see the first time I used the die - but it's also nowhere near new brass. I wish I hadn't tossed this last rounds in the tumbler before i took a pic. I thought I did, but I am a dumb.

My cases are currently sizing down to .4695 measuring with a caliper so give or take a little. Based on your measurements I might see an additional .001 of sizing.

 

[CK1.0]

I don't spend enough time on brianenos, what negative impact is seen on 9mm?

Take this with a grain of salt because we’re talking 9mm out to ~25 yards, but in general, rounds that have seen a Lee FCD don’t group as well as ones that were loaded “traditionally” (FL sized, then finished with a normal crimp die)…

…and you’re right about my source, there are pages and pages of back and forth concerning the Lee FCD on benos. Some guys swear by them and some guys act like using one is the worst thing one could possibly do…

ETA: when I was trying to decide whether to use one in the last station of my XL750 or not I loaded a bunch of rounds both ways and the “traditional/no-FCD” rounds won every time for me… thus I still keep one around to throw in my single-stage to fix up rounds that won’t pass the Hundo (but I don’t use those rounds in matches).

 

[abn31c]

Mine should be here tomorrow, I was just wanting another mandrel body and this looked interesting. One more point of control can't be a bad thing in my mind, but I've been wrong before...

 

[Haney]

Holy crap now we have to read about neck sizing because he is trying to reinvent the world . I guess those childish t-shirts do sell .

 

[CK1.0]

I honestly have no f’ing idea if the Cortina die will induce any issues like the Lee FCDs seem to in 9mm… I was just pointing out that they’re sort of similar.

It might work awesome, IDK? Let us know…

 

[Kadams1563]

I am needing a mandrel doe for .223 and was looking at his but he only does .308 and up sizes. They look interesting.

 

[abn31c]

Holy crap now we have to read about neck sizing because he is trying to reinvent the world . I guess those childish t-shirts do sell .

I get what yer sayin, but his bushings have the shoulder bump covered. It is atleast an interesting concept.

If it came with a dorky t-shirt I'd be all in....

 

[AllenOne1]

I am needing a mandrel doe for .223 and was looking at his but he only does .308 and up sizes. They look interesting.

I just sent them a message asking them about a mandrel die for the .223 size class, we'll see what we get in response.

 

[Yondering]

I honestly have no f’ing idea if the Cortina die will induce any issues like the Lee FCDs seem to in 9mm… I was just pointing out that they’re sort of similar.

It might work awesome, IDK? Let us know…

Speaking as one of those guys who loads thousands and thousands of 9mm - the Lee FCD affect on accuracy depends A LOT on the specific load and bullet being used. I was originally in the camp of avoiding them, but after trying mine with a lot of different loads, I realized I could use a load not negatively impacted by the die, and save a lot of time after loading by not needing to check every round.

But the entire reason the Lee FCD (pistol version) can theoretically have an effect on accuracy is because it can size the bullet down*. The Cortina die can’t do that, and is a different thing entirely. Not really Eve worth comparing with a FCD in that context.

*The pistol FCD sizes bullets down when brass in the neck area is thicker than usual. CBC 9mm brass is an example; that stuff is trash anyway and does affect accuracy of a group if some of that is mixed in, FCD or not. With cast bullet, CBC brass through a FCD usually means a loose bullet - that’s a wasted round but is at least an easy way to sort out and trash that brass. (My high volume ammo always gets tumbled after loading; loose primers or bullets fall out, and those rounds can be identified easily when loading into boxes.)

 

[straightshooter1]

I didn’t see a topic specific to the Cortina Precision mandrel dies, and now that I’ve gotten to use it a bit (350 rounds-ish), I thought I’d share a couple observations and open the discussion for anyone that may be considering these dies.

My primary interest was in the mandrels/armoloy coating, however one of the selling points of this die is that it also acts as a base sizer die. In the product video, it is described as “the same as your sizing die” and “not a small base die.” Supposedly it will help with “clickers,” which has been an issue with some chamberings. I’ve never had a clicker that wasn’t a snipershide level pissing hot handload (with no pressure signs, of course), but I figured there may be some merit to holding the base of the case during the mandrel operation so I ordered a 308 win family die as well.
View attachment 8244517

Fit/finish on the dies and mandrels are very nice. The inside is smooth, and sizes smoothly. I like the wrench flats and wrench holes on the lockring. The lockring has two sides, one rounded, and one squared that is allegedly machined true to the threads and perfectly square. I have no way to test it, but it sounds good. There are two set screws on the lockring. Mine came so loaded with yellow threadlocker that I couldn’t screw them in far enough to engage the die and stop it from spinning using a standard allen key. I cleaned most of the threadlocker off so that I could use the set screws.

I’m using this die to resize Lapua 6mm Creedmoor brass. It has been fired 10x in a standard PVA chamber and has never been annealed. There is a Mighty Armory FL sizer in station 1 (mandrel/decapper removed), and the Cortina die in station 3 of a 550. I measured several pieces of brass from fired, resized, and after the mandrel operation using Mitutoyo calipers.

Body diameter at the .200 line (ish)
Fired - .471
Resized MA - .470
Resized + Cortina - .469
For comparison, CIP/SAAMI maximum cartridge drawings put the base diameter at .4708” and .4703”.

With it squeezing an extra thousandth after I set the shoulder back, I did see headspace grow .0005” after the mandrel die. I did not think to measure overall lengths while I was reloading. I may next time just for giggles. Visually, there is a good amount of additional body sizing going on compared to the Mighty Armory die. The sizing appears very consistent within my small sample size.

Here’s an example of the base sizing, although it is a 6.5CM not from my rifle and received a little less of a squeeze, it conveys the idea/results...

View attachment 8244514

Overall – It does what it says on the tin. I like the armoloy mandrels. I’m interested in hearing other’s experiences and if the extra base sizing is helping anyone outside of the PRC calibers.
Link to the Product video.

I've had this mandrel die for a little while now for my 6.5 PRC brass, which I've always FL sized without an expander ball and then run an expander mandrel through them. I use a Forster FL sizing die in a Forster Co-Ax press which brings my .200 line measurement to .532. After running Cortina's mandrel die afterwards while my cases still have lube on them, my measurement was still .532. So, no additional sizing for me, though it did feel a little like it was doing a little sizing there, and no additional headspace growth or case length growth. The one thing that did change for me was the neck's runout (the necks have been turned), where I am now consistently getting better than before with less than .001 runout (most often at ~.0005) and I had the same results with both my 10X fired Lapua brass and my 4X fired Peterson brass in pic below.

 

[Rio Precision Gunworks]

Nice review. Thanks for sharing.

 

[Kadams1563]

I just sent them a message asking them about a mandrel die for the .223 size class, we'll see what we get in response.

I got a reply of “We do have a few .223 Expanding Mandrel dies but I am unsure of the release date”

The only reason I am looking to get one of these is my CDG .223AI expands the brass at the base just enough where it won’t chamber in an a “regular” .223 AI barrel after fired.

Haven’t checked to see if my does are going to size it enough that far down though yet lol.

 

[Kadams1563]

So I received my Cortina .223 mandrel and it is VERY nice and very well machined. It is well designed and I enjoy using it more then my other mandrel does. It seems much “smoother” with the same process as my other ones as well.

I’ll be ordering one for my GT eventually but they are kinda if expensive. $110 or $115 shipped.

My other mandrel dies are Sinclair Gen II’s.

Praise to Cortina shipping as my die was ordered, shipped, and received in two days.