[Taterhead]

Here is what I measure - hope I'm not doing something wrong?

View attachment 807192 View attachment 807194

Tough to get a good ID measurement that way. For the neck ID, it would be easier to measure the OD. Then subtract twice the average thickness of the brass.

Alternatively, measure the neck OD prior to seating, then measure it after seating. The difference is the amount of neck tension, assuming the bullet doesn't swage.

Another useful measurement is the diameter of the shank of the expander. Allowing for maybe a thousandth of springback, that should be the neck ID.

Lastly, be sure that the heel of the bullet is not wider than the shank of the bullet. Otherwise it acts like a neck expander as it passes through the neck.

 

[Taterhead]

Deleted

 

[Taterhead]

I have ~1500 357 sig brass cases.

I measured OD and then wall thickness and my ID measurement jives with it - I just rotated and manipulated the case around in a circle along the caliper and took the fattest measurement (though I probably should have taken an average of multiple points but oh well).

The case illustrated above I just loaded and I cannot make the thing set back no matter how hard I push the projectile on to the desk from the base of the case. I'm a 200lb+ guy so that shouldn't be the problem (I hope) - though if that's the issue then I've got a lot bigger problems. This is with 7 grains of titegroup also so I'm not running into powder.

I can't even get the formed nickel .40 to shave a thousandth off of the COAL. This is the case with the rest of my nickel plated stuff.

I can usually get my 357 sig brass (or formed brass .40) to give up a thousandth or completely set-back.

So either I'm a 200lb weakling, this nickel plated brass I got is freakishly strong or the properties of nickel make it better suited for this type of application where maximum neck tension is required.

My brass .40 and 357 sig consistently measure at ~.350 ID or thereabouts.

If I had more steel I'd measure that but I don't.

I can't say that nickel plating is the panacea. In this example, mere thumb pressure pushed the bullets into the case, as discovered when loading into mags. Everything else being equal to the brass cases. The brass cases held firm.

 

[Taterhead]

I can't say that nickel plating is the panacea. In this example, mere thumb pressure pushed the bullets into the case, as discovered when loading into mags. Everything else being equal to the brass cases. The brass cases held firm.

I believe all R-P 10mm headstamps. They have otherwise been decent brass with some with 20+ reloads. This was a case of tolerance stacking. Thin cases and undersized Nosler 150 JHPs.

I am pretty sure that I did shoot a few, with no noticeable affect. Pretty much all the nickel cases had zero neck tension, I later learned. That's when I discovered the myth that a "firm taper crimp" could "increase the hold on the bullet". I went back through the loaded rounds to try to fix the setback issue with the crimp die. Nope.

 

[Taterhead]

Fast powders in magnums or high vel rounds, might as well step down to a smaller case size. If I wanted 1200fps with a 124gr bullet, I would shoot a 9mm. I have the same philosophy with downloading rifles & magnum hamdguns. I see little point in loading a 300winmag to 308 levels just buy a 308. I bought a 10mm to shoot full power 10. If I want 40 level vel, then I would just shoot a 40. Kind of right tool for every job. Though I get it one only has a 10mm, then downloading would make some sense, but then I would probably just shoot 40 out of it.

I generally agree except that sometimes it is about the gun. Example: I like the way my G20 handles, and tend to grab it first for just about anything. So if running a Steel Challenge course, sure I'll download it big time. Glock doesn't make a similar frame/slide in 40. That is one reason I think the Glock 20 is one of the greatest handguns on the planet. Bone stock it cycles ammo from pf 135 to 255+ or ME from 134 to 850 (or 900 with a 9x25 conversion). Just about any ammo you want. Same gun.

Also reduced loads can get a newer shooter acclimated to recoil gradually for a given platform. That's how I got my wife to transition from 22s to bolt rifles. My kids are next.

 

[Taterhead]

There are times to reduce from full power loafs but most pf us have more than one gun. Even if I only had a g20, then I would have 357sig & 40 bbls.
Btw, I dont shoot 38sp or 44sp in my magnum revos but do come off the top end for much of my shooting. I actually wore out a RBH back in the day shooting full house 44mag in met sil. I dont feed my classic N-frame full power loads but I dont shoot sp either.

The G20 isn't my only gun. Just my favorite. I don't see any need for a 40 barrel, although I do have a 9x25 and the Sig has some intrique. I just long load 40 cases in the regular barrel.

 

[Taterhead]

What barrel do you have for the 9X25? Lonewolf nor KKM make one.

I got on a list at KKM in early 2019. Apparently they do infrequent runs when demand is sufficiently high. Out of the blue, someone from KKM called me early this year. I specified a 6.2" non-threaded barrel. It arrived a few days later.

https://www.glocktalk.com/threads/kkm-9x25-dillon-barrel.1754838/

 

[Taterhead]

I haven't tried that. Interesring that just that little amount of abraded surface would make a difference.

With pistol volume I probably wouldn't incorporate a step like that in my routine.

Have you tried taking off a touch of diameter from your expander shank?

 

[Taterhead]

Yes i have. I barely have any expansion. Just enough to get the projectile in.

This step is just insurance on yellow brass as i dont have nearly the issues on nickel or steel.

I'm newer to reloading but I think you two are talking different things.

Taterhead is asking if you modified your resizing die.

You are talking about flaring the case to seat a bullet.

I could be wrong based on how you worded your response.

I'm asking about the expander shank, nit the sizer. You are correct that I wasn't asking about case mouth flair.

No Tater is talking about reducing the expander a small amount. I found just 0.0005" made a diff in setback. Also using 0.356" bullets is helpful.

Fred is correct. I am not asking about the case mouth flair. I'm referring to the shank of the expander that plunges down into the neck. Sometimes taking just a smidge of diameter from the expander will improve neck tension.

Neck tension can be increased by increasing bullet diameter or by reducing the neck interior diameter.

What is the diameter of the expander shank?

The sizer makes neck exteriors universal diameters that are round on the exterior of the neck. With mixed brass that is not perfectly uniform with respect to brass thickness, that means the neck interior diameters are of varying diameters and they are not uniformly round. The interior diameter is a bit too small (on purpose) when it comes out of the sizer.

The expander plunges down into the neck and 1) makes the neck interior uniformly round and 2) of uniform diameter. Removing a touch of diameter from the expander shank will reduce the neck interior diameter and increase the interference fit with the bullet (neck tension).

I have taped expander shanks and buttons and chucked them into a drill. Using some 1000 grit sandpaper and a bit of oil, a tiny but can be removed. Makes a big difference to beck tension. Too much can cause other issues though.

The case mouth flair is another thing and a separate function of the expander.