Possible problem with Mighty Armory .223 sizing die

[HemiPowrd]

I recently received a Mighty Armory .223 Gold Match sizing die. I currently use a Redding Type S bushing die and then mandrel size the cartridge neck. I'm hoping to use the MA die to reduce the two steps into one step. Based on all the reviews here I thought it would work well, but testing it out yesterday says otherwise. I'm using Lapua brass so that might be a factor since it is thicker than many other types of brass.

When sizing a piece of brass it easily sizes the neck and body on the press upstroke, but on the downstroke it requires quite a bit of effort to get the case back out of the die. Investigating this, I removed the mandrel and sized a piece of brass. The neck ID measures .214". The finish size with the mandrel installed is .221 which is exactly where I want it. Given this the mandrel has to size the neck ID from .214 to .221! That seems like too much sizing going on in the neck to me. Also seems like it is way overworking the brass. It also explains the amount of effort required on the downstroke with the mandrel installed. I've spoken to Wayne about it and apparently everything is dimensionally correct with the die. Has anyone else experienced this?

I'm thinking I need to machine the MA die neck bore to a larger size? With my Redding die I use a .245 bushing which results in a .219 neck ID. The final sizing operation with a separate mandrel die requires little effort and consistently results in a .221 neck ID.

 

[TheOfficeT-Rex]

Are you using any lube inside of the necks? Most FL dies are going to undersize the brass to some degree. I'm not sure I'd machine the die, but it could fix your issue at the expense of not sizing brass enough in the future if you move to different brass.

I have several calibres of MA die, and using alc/lanolin lube. I always try to spray a little in the necks, and I've not experienced an increase in force on the downstroke.

 

[CK1.0]

Sounds like you're correct in the necks getting overworked... if it were a bushing die I'd go to a larger bushing for sure.

Also, it sounds wonky to me that you're having to use so much effort on the second part of your stroke... IMHO half the point of using a mandrel is to NOT have any sizing happening while pulling out of the case (and thus, pulling on the shoulder), the mandrel is supposed to do its work on the "push" while going into the case.

I totally think someone could make a die to do both steps at once, but I don't think there's anything out there yet that has been specifically designed to do it correctly (at least with the MA die or anything else out there that I'm aware of yet)....

 

[HemiPowrd]

Are you using any lube inside of the necks? Most FL dies are going to undersize the brass to some degree. I'm not sure I'd machine the die, but it could fix your issue at the expense of not sizing brass enough in the future if you move to different brass.

I have several calibres of MA die, and using alc/lanolin lube. I always try to spray a little in the necks, and I've not experienced an increase in force on the downstroke.

I'm using Imperial dry neck lube on the inside of the necks and Hornady Unique lube on the outside. I guess I could try the Hornady lube on the inside of the neck which might fix the high effort issue, but that won't fix overworking the brass.

 

[CK1.0]

Another thing is: I've looked into the Mighty Armory dies myself, and I don't think what they call a "mandrel expander shaft" is really the same thing as what we are referring to when we refer to a "mandrel" in the precision rifle world... I can't find any OD dimensions listed anywhere for the "mandrel expander shafts" and knowing that number to set neck tension is a pretty big deal to most of us.

Probably unrelated but, MA's "claim to fame" came from making great dies for automated pistol presses, think the rifle dies are a relatively new thing. IIRC there weren't any rifle dies available a year ago from them (other than decapping)...

 

[TheOfficeT-Rex]

I totally think someone could make a die to do both steps at once, but I don't think there's anything out there yet that has been specifically designed to do it correctly (at least with the MA die or anything else out there that I'm aware of yet)....

If you figure it out, I'll take one immediately. I really prefer all sizing on the down stroke, but the MA is the best of the 'one die' solutions I've tried.

I'm using Imperial dry neck lube on the inside of the necks and Hornady Unique lube on the outside. I guess I could try the Hornady lube on the inside of the neck which might fix the high effort issue, but that won't fix overworking the brass.

I'd try different lube, but if the over working bothers you, that's right- you'll need a different die or to re-machine the inside.

Another thing is: I've looked into the Mighty Armory dies myself, and I don't think what they call a "mandrel expander shaft" is really the same thing as what we are referring to when we refer to a "mandrel" in the precision rifle world... I can't find any dimensions listed anywhere for the "mandrel expander shafts" and knowing that number to set neck tension is a pretty big deal to most of us.

Probably unrelated but, MA's "claim to fame" came from making great dies for automated pistol presses, the rifle dies are a relatively new thing. IIRC there weren't any rifle dies available a year ago from them...

They're all sized for 2k under bullet diameter. As an aside - I've been using the 6,5CM die since Feb 18, so they've been in the wild a while now. I always thought their claim to fame were the decapping dies...

 

[whatsupdoc]

Yes the lube matters, try a different lube.
I no longer use expander buttons or mandrels to set the neck ID, I hone the die neck to the
diameter I want and the bullet is the mandrel. Seems to work just fine.

 

[918v]

I recently received a Mighty Armory .223 Gold Match sizing die. I currently use a Redding Type S bushing die and then mandrel size the cartridge neck. I'm hoping to use the MA die to reduce the two steps into one step. Based on all the reviews here I thought it would work well, but testing it out yesterday says otherwise. I'm using Lapua brass so that might be a factor since it is thicker than many other types of brass.

When sizing a piece of brass it easily sizes the neck and body on the press upstroke, but on the downstroke it requires quite a bit of effort to get the case back out of the die. Investigating this, I removed the mandrel and sized a piece of brass. The neck ID measures .214". The finish size with the mandrel installed is .221 which is exactly where I want it. Given this the mandrel has to size the neck ID from .214 to .221! That seems like too much sizing going on in the neck to me. Also seems like it is way overworking the brass. It also explains the amount of effort required on the downstroke with the mandrel installed. I've spoken to Wayne about it and apparently everything is dimensionally correct with the die. Has anyone else experienced this?

I'm thinking I need to machine the MA die neck bore to a larger size? With my Redding die I use a .245 bushing which results in a .219 neck ID. The final sizing operation with a separate mandrel die requires little effort and consistently results in a .221 neck ID.

How are you measuring the neck ID?

 

[918v]

My MA 223 FL die takes the neck OD down to .241” which is .004” more than my Lee collet neck die does. That’s not out of line for a sb fl die designed to to resize machine gun fired brass back to spec.

If you want a die that sizes the neck less then you have to use alternatives.

 

[mightyarmory]

I recently received a Mighty Armory .223 Gold Match sizing die. I currently use a Redding Type S bushing die and then mandrel size the cartridge neck. I'm hoping to use the MA die to reduce the two steps into one step. Based on all the reviews here I thought it would work well, but testing it out yesterday says otherwise. I'm using Lapua brass so that might be a factor since it is thicker than many other types of brass.

When sizing a piece of brass it easily sizes the neck and body on the press upstroke, but on the downstroke it requires quite a bit of effort to get the case back out of the die. Investigating this, I removed the mandrel and sized a piece of brass. The neck ID measures .214". The finish size with the mandrel installed is .221 which is exactly where I want it. Given this the mandrel has to size the neck ID from .214 to .221! That seems like too much sizing going on in the neck to me. Also seems like it is way overworking the brass. It also explains the amount of effort required on the downstroke with the mandrel installed. I've spoken to Wayne about it and apparently everything is dimensionally correct with the die. Has anyone else experienced this?

I'm thinking I need to machine the MA die neck bore to a larger size? With my Redding die I use a .245 bushing which results in a .219 neck ID. The final sizing operation with a separate mandrel die requires little effort and consistently results in a .221 neck ID.

We offer a honing service for those wanting a 242-244 OD neck diameter if you want it. On the other hand, .0035 expansion on both sides of the neck is not overworking brass. It basically amounts to 2 human hairs per side. Our sizing allows for a tighter neck radius which means more of the neck ID is in contact with the bullet. You're welcome to call and speak with me anytime if you have questions. I'm always available.

Wayne

 

[HemiPowrd]

We offer a honing service for those wanting a 242-244 OD neck diameter if you want it. On the other hand, .0035 expansion on both sides of the neck is not overworking brass. It basically amounts to 2 human hairs per side. Our sizing allows for a tighter neck radius which means more of the neck ID is in contact with the bullet. You're welcome to call and speak with me anytime if you have questions. I'm always available.

Wayne

.244 would be perfect! I'll call you Friday morning to set it up.

 

[mightyarmory]

Sounds good, we just finish one yesterday for another customer. Perfect!