Issues resizing Lapua Brass

[slowworm]

So I decided to try some Lapua brass, and I'm having a few unexpected issues.

When sizing the brass, the expander in the die is sticking and it is taking way more effort to size than I think it should. I know it's the expander because with it removed the operation is as smooth as silk.

This is happening with both 308 Win and 260 Rem brass with Hornady and Redding dies. At first I thought this might be a faulty expander, but no, it happens on the 308 die that has never given me an issue with Winchester & Remington brass. When I put the expander into a Lapua case I sized with the expander removed I can see that it actually has to do a lot of work to expand the neck on the way out of the die.

I think this is happening because Lapua brass is pretty thick, and that few extra thou in the neck means that the inside diameter of the neck is smaller than with say Winchester brass. So the neck is getting worked way more with Lapua brass than Winchester.

Sizing lube inside the neck helps a lot, but it's got me wondering if I should look at using bushing dies to control the size of the neck better. Any advice would be welcome.

 

[spife7980]

You seem to be pretty on point with your diagnosis, you walked through the steps I would, but I’d also take some actual measurements of each step along the way if you haven’t.

the top row of numbers is the neck diameter at fired, sized, expanded and seated.

 

[KZP]

I had the same results as you when using a standard die. Eventually picked up a .305 bushing for .308 resizing. Still needs some lube in the neck, but it isn't a struggle to run back over the expander.

 

[ken4570tc in WY]

I had a similar problem once and figured out I didn't have the expander adjusted low enough. It cleared up when I turned the expander/decaper down about one additional turn. Another solution would be to ditch the expander and use a mandrel.

 

[slowworm]

So I did a few measurements on the neck:

Sized - 0.282
Expanded - 0.290
Loaded - 0.293
Fired- 0.297

By my reckoning that's an 8 thou expansion of the neck, and that's rather a lot. The expander is .261, so if I assume no spring-back that makes the neck wall about .015 thick, which is about right.

I like the neck tension I have when loading so I think I want a .290 and a .289 bushing for a bushing die.

 

[Another Casual]

Tumbling and cleaning the necks with a brush before sizing may offer some more immediate relief than tracking down a bushing die.

 

[Dthomas3523]

One of the several advantages of running bushing dies and mandrels.

 

[slowworm]

Yeah, I'm beginning to discover that.

I'm also finding that every planned upgrade incurs other unplanned costs. Want better brass - buy an unplanned new bushing die. I'll always be a poor at this rate

 

[Dthomas3523]

Yeah, I'm beginning to discover that.

I'm also finding that every planned upgrade incurs other unplanned costs. Want better brass - buy an unplanned new bushing die. I'll always be a poor at this rate

It gets bad. I started out with a tikka and sig tango 4 with intentions of shooting factory ammo.

I now have a stack of rifles, zero press, amp press, idod, and all kinds of either shit I really don’t need.

Strap in and work overtime.

 

[bunny too]

It gets bad. I started out with a tikka and sig tango 4 with intentions of shooting factory ammo.

I now have a stack of rifles, zero press, amp press, idod, and all kinds of either shit I really don’t need.

Strap in and work overtime.

How do you like your idod? That is next on my list (probably the AUTODOD). How much does it weight? Will I need another bench?

 

[Jrb572]

I run a widden non bushing die and an expander die on both my 308 and 260 Lapua brass. It runs super smooth.

 

[Dthomas3523]

How do you like your idod? That is next on my list (probably the AUTODOD). How much does it weight? Will I need another bench?

I like it a lot. Its not heavy at all. You can run it on the kitchen table if you want. I'm not sure the weight, but you can easily pick it up with one hand. The Auto DOD has some extra parts which make the foot print larger with the controls. But still isn't going to be very big. I've been debating upgrading mind to an auto. But I kinda enjoy manually operating it.

Few things to keep in mind. You aren't going to skim turn with an idod. The 21st century lathe for example has a floating head and the brass rides an arbor/mandrel. So you can skim off something like .0005 if you want since it self centers. The idod grabs the case like a lathe. So, you are limited by the case runout. I.E. if there's .002 runout, you will have to cut at least .002 off to completely clean the inside and outside.

Thats only an issue for brass life with split necks, if even then. Some people get nervous if they have something like .010 neck clearance (I prefer .006 when I have the choice). But I haven't been able and don't know anyone who's able to show having more than .006 actually affects anything on paper. Bryan Blake has tested out to .011 clearance without any negative observations.

I've known guys who bought idod thinking they could skim turn, so just keep that in mind.

 

[Dthomas3523]

For example's sake, my current batch of Hornady 6gt has a .0125-.0135 neck. Hovers around .013, but definitely has variance.

To completely clean the inside and outside, I end up at .0105 neck. So about .0025 has to be cut out for a complete clean up. So I'm running about .009 clearance on a standard 6gt reamer. I haven't had any negative experience with the .009 clearance yet.

 

[bunny too]

For example's sake, my current batch of Hornady 6gt has a .0125-.0135 neck. Hovers around .013, but definitely has variance.

To completely clean the inside and outside, I end up at .0105 neck. So about .0025 has to be cut out for a complete clean up. So I'm running about .009 clearance on a standard 6gt reamer. I haven't had any negative experience with the .009 clearance yet.

Thank you, an excellent write up, I may go with the idod (I like working with my hands and tools.) Right now I have the 21st century, even so I do not skim, however I would like something that cleans the inside as well. Thank you for the information.
Regards,
David