Question on first cartridge made

[Wing Rider]

Attached is a picture of the first cartridge (minus primer and powder) that I have made while setting up my dies. Here is what I observed: The new starline (357 mag) brass measured at 0.3755" diameter, after sizing it measured 0.3735" from the mouth down to about the last 1/4" which did not get sized. After seating the hornady FP/XTP 158gr bullet, the case diameter measured 0.3760". So overall, the bottom and top of the case is slightly larger than the center of the case. This may not be a problem, and I may be looking too close at this but being this is my first round I am just looking to see if this sounds normal or not. I compared it to a factory cartridge that I have and the bottom 1/4" of the case is larger than the rest of the case. I made 4 rounds like this and they all are consistent. Hope I am not asking too many silly questions but I would rather be safe.
Thanks for the info.

 

[reddog81]

Does the round chamber? If so you're good to go.

 

[Wing Rider]

Yes. It drops in easily. I guess I was not expecting the sizing die to make a new case smaller and then the bullet stretch it back out.

 

[Stew0576]

I don't load 357 but I load 9mm, 10mm and .270 and all my cases go almost all the way into the sizing die, you sure you have that set right?

 

[Charlie98]

That's normal. Question for you... does the bottom of the sizing die touch the top of the shell plate/holder? That size ring looks a little high.

All cartridges rely a bit on neck tension to secure the bullet, in some cases all of it (match rifle cartridges, for example.) The case needs to be sized smaller than the bullet diameter or there won't be any neck tension. It is more pronounced on thicker brass.

 

[FROGO207]

Some dies and some thick walled brass will show that "coke bottle" effect. It is normal as stated above. As long as you size the brass enough after it is fired (expanded more) and it fits back in the chamber after reloading your handgun brass will be good to go. The neck tension will be good. Also make sure all that brass is the same length so the roll crimp once set up will crimp all those brass equally and you will not collapse a round.

 

[Enfielder]

My advice for you, that was hard learned by me, for 357 is to crimp it. Don't forget to crimp it and put a crimp on each bullet. Make sure you crimp the case to the bullet and crimp the round by crimping it. Your powder won't leak from the other rounds in the cylinder then, but only if you crimp it properly.


Crimping is good, m'kay?

 

[Enfielder]

Crimp it

 

[Walkalong]

You test round looks great. If it shoots well that is enough crimp. If the ES & SD
numbers seem large, a bit more crimp may help. May be the powder though.

 

[ATLDave]

That coke-bottle effect is generally a good thing in handgun rounds. It means you probably have lots of neck tension, which is good in most cases.

 

[WestKentucky]

A very slight hour glass shape is normal on straight wall pistol cases, especially revolver cases. Keep up the good work.

 

[Walkalong]

. Make sure you crimp the case to the bullet and crimp the round by crimping it. Your powder won't leak from the other rounds in the cylinder then, but only if you crimp it properly.

I do not understand this, so I must be reading it wrong.

 

[ATLDave]

A charitable reading would be that a firm crimp, along with good neck tension, increases bullet pull force (resistance to the bullet's initial acceleration upon ignition), and that increased pull force helps build pressure in the cartridge sufficient to ensure complete ignition. Rather than "leaking" powder around the bullet (something that is certainly not happening if the bullet and case are of the same caliber!), unburnt flakes might be observed with some powders and loads without a firm crimp there to "get the party started" before the bullet moves and starts relieving pressure down the barrel.

 

[Charlie98]

I do not understand this, so I must be reading it wrong.

I think that was his attempt at humor... he was just emphasizing the need for a good crimp, somewhat obliquely.

 

[Enfielder]

I think that was his attempt at humor... he was just emphasizing the need for a good crimp, somewhat obliquely.

I do not understand this, so I must be reading it wrong.

Long ago, my first attempt at loading .357 was before I knew about crimping. I was going off of misplaced advice. As I shot the first cylinder, the bullets backed out of the case from the recoil. 2400 was leaking everywhere.
That's why I say that one should crimp and yes it was supposed to be humorous the way I delivered it in no uncertain terms. Crimp it.

 

[Walkalong]

As I shot the first cylinder, the bullets backed out of the case from the recoil. 2400 was leaking everywhere.

Ouch, poor neck tension as well is my guess.

 

[Wing Rider]

Thanks for the good words. Now for the primer and powder. Looking forward to shooting my first reloads.

 

[Shimitup]

As others have said I think your first reloads look great, a lovely hour glass profile. One thing I might add, do be careful not to over crimp, you will bulge the case and lose some of the very important neck tension.

 

[Charlie98]

As others have said I think your first reloads look great, a lovely hour glass profile. One thing I might add, do be careful not to over crimp, you will bulge the case and lose some of the very important neck tension.

Quite true. In my early days, opposite of Enfielder, I put the patented Charlie98 Death Grip Crimp on every round I made... and I paid the price. Crushed brass, brass rings swaged off the top of the case, deformed bullets... and once I started loading bottleneck cartridges, well, you all can guess. There is a happy medium. By and large, I use a taper crimp on everything except Magnum-level revolver cartridges... powders like W296 require a good roll crimp for proper ignition. Life is good, now.

 

[J-Bar]

Invest in a case gauge to check your finished round dimensions. I check every round before using them in competition, finding one SOB for about every 400 rounds I load. It’s worth my time for the peace of mind, and perhaps a bit safer than using a firearm’s chamber, particularly if is going into a rifle.

 

[Wing Rider]

I checked them in my gauge and they were fine. I just wasn't sure about the hour glass shape. Thanks for the comments.

 

[rfwobbly]

I guess I was not expecting the sizing die to make a new case smaller and then the bullet stretch it back out.

Only because you didn't think through the steps brass takes to get ready for the bullet.
• The object is to get the bullet OD to precisely fit the case ID.
• Because of the "spring back" quality of brass, you can't move brass by small increments.
• Therefore the Sizing die must make the case OD much smaller than needed.
• Then the Expander can enlarge the case ID to the proper size.

Cogitate on that for a while and see if things don't become clearer.

 

[Blue68f100]

Only because you didn't think through the steps brass takes to get ready for the bullet.
• The object is to get the bullet OD to precisely fit the case ID.
• Because of the "spring back" quality of brass, you can't move brass by small increments.
• Therefore the Sizing die must make the case OD much smaller than needed.
• Then the Expander can enlarge the case ID to the proper size.

Cogitate on that for a while and see if things don't become clearer.

This is not true with all sizing dies. Those of us using Bushing dies can select the bushing that gives us the fit we want. Nothing touches the inside of the necks. Then some actually have custom sizing dies made so they don't need bushing. Custom made to match a bushing.

 

[Bfh_auto]

As others have said I think your first reloads look great, a lovely hour glass profile. One thing I might add, do be careful not to over crimp, you will bulge the case and lose some of the very important neck tension.

Been there. It's not fun when you crimped too much.

 

[Wing Rider]

I understand the concept just was not expecting it because I dont recall seeing the hour glass shape on factory bullets that I have used. There are several comments about too much crimp. Just by looking at the picture I posted, do you think there is too much crimp?