Need Input for Building a .338 WINMAG Round

[cephas]

Just a note from my experience with brass of unknown history.
Had a case head separation with "once fired" brass I got somewhere. My fault as I didn't check the cases as well as I should have.
Many use the paper clip method to check.
"Another useful method for checking incipient separation is to use a sharpened paper clip. To do this, use a small file to sharpen one end of a straightened paper clip. Bend the end to 90 degrees approximately 1/8-inch from the sharpened end. The paper clip is then used as a “feeler gauge” to check the interior case walls. Insert the bent end of the paper clip into the case mouth, and drag the sharpened point along the interior case walls. Any thinning or cracking can be readily felt as the point dips across the damaged area."
https://www.sierrabullets.com/reload...ading-process/
Also while trimming notice how the trimmer is working and it can give an indication of how work hardened the brass is.
If it comes off in chunks it's hard, I'll anneal. If it comes off looking like a coil spring I consider it good.
When using the chamfering tool make the last spin opposite of the way you went for a smoother surface.

[Walleye Hunter]

Just a note from my experience with brass of unknown history.
Had a case head separation with "once fired" brass I got somewhere. My fault as I didn't check the cases as well as I should have.
Many use the paper clip method to check.
"Another useful method for checking incipient separation is to use a sharpened paper clip. To do this, use a small file to sharpen one end of a straightened paper clip. Bend the end to 90 degrees approximately 1/8-inch from the sharpened end. The paper clip is then used as a *feeler gauge* to check the interior case walls. Insert the bent end of the paper clip into the case mouth, and drag the sharpened point along the interior case walls. Any thinning or cracking can be readily felt as the point dips across the damaged area."
https://www.sierrabullets.com/reload...ading-process/
Also while trimming notice how the trimmer is working and it can give an indication of how work hardened the brass is.
If it comes off in chunks it's hard, I'll anneal. If it comes off looking like a coil spring I consider it good.
When using the chamfering tool make the last spin opposite of the way you went for a smoother surface.

Thanks. I do have a paperclip and did perform that test along with visual inspection of them. I agree, never expect any brass from anyone/anywhere else to be up-to-snuff until properly inspected.

[Walleye Hunter]

After sanding down the stock on the .338, I took it for a walk today. The vertical string is gone but the barrel is still tight on the stock after a few shots so some more sanding is in order. I wasn't particularly happy with the rounds I loaded so I didn't photograph the target, tough it's still within 1 MOA. It feels like .5 MOA is attainable. And the fucking Labradar eats batteries like a kid eats Cheerios so I didn't get any data on those rounds. I have a rechargeable battery pack on the way to end that problem.

[Walleye Hunter]

I have another question...I have a set of micro measuring tools to measure headspace and bullet length at ogive. I got some processed brass at a show and the headspace is shorter than it's supposed to be by like a few thousandths. How big of an issue is this?

[85MikeTPI]

I have another question...I have a set of micro measuring tools to measure headspace and bullet length at ogive. I got some processed brass at a show and the headspace is shorter than it's supposed to be by like a few thousandths. How big of an issue is this?

It may cause accuracy inconsistency issues initially, but should fire form to your chamber
Quickly and should soon match the other brass you have fired.

[Delkal]

I have another question...I have a set of micro measuring tools to measure headspace and bullet length at ogive. I got some processed brass at a show and the headspace is shorter than it's supposed to be by like a few thousandths. How big of an issue is this?

For a production rifle using commercial cases brass has to be a few thousands under the chamber spec or it won't fit. And unless you are a trained machinist it is difficult to accurately measure a case with any precision. For production rifles the no-go gauge is set for 0.003 inches over the go gauge minimum. Anything over 0.010 is excessive and that is the reject distance shown on the military field gauges.

But you do know that a .338 mag head spaces on the belt and not on the shoulder of the case.

[Walleye Hunter]

It may cause accuracy inconsistency issues initially, but should fire form to your chamber
Quickly and should soon match the other brass you have fired.

Good, that's what I was hoping to hear.

For a production rifle using commercial cases brass has to be a few thousands under the chamber spec or it won't fit. And unless you are a trained machinist it is difficult to accurately measure a case with any precision. For production rifles the no-go gauge is set for 0.003 inches over the go gauge minimum. Anything over 0.010 is excessive and that is the reject distance shown on the military field gauges.

But you do know that a .338 mag head spaces on the belt and not on the shoulder of the case.

<shrug> beats me, I just put it in the jig, screw it together and read the notches. If I read the 'structions right, 0 is the minimum measurement and plus .010 or thereabouts is the maximum for standards with each chamber ultimately being different on the top end.

[Walleye Hunter]

For a production rifle using commercial cases brass has to be a few thousands under the chamber spec or it won't fit. And unless you are a trained machinist it is difficult to accurately measure a case with any precision. For production rifles the no-go gauge is set for 0.003 inches over the go gauge minimum. Anything over 0.010 is excessive and that is the reject distance shown on the military field gauges.

But you do know that a .338 mag head spaces on the belt and not on the shoulder of the case.

I was thinking about this one some more and I do recall reading that about the headspacing. The kit that I have is an RCBS micro measuring kit and the case is fully enclosed in a two piece device with measuring slots on the side, where the two pieces come together. I think it has to be measuring from the base of the shell. Imma have to look into that.

[Walleye Hunter]

I am still moving along on this. I had to get different bullets than the Horady's I have because I can't find any. I am also unable to find any IMR 4831 powder. However, there does seem to be a decent supply of H 4831 SC around, which claims to be exactly the same composition as IMR 4831. I would expect it to act at least a little bit different but how much different and is it a good option? Is there a better option out there?

[85MikeTPI]

I am still moving along on this. I had to get different bullets than the Horady's I have because I can't find any. I am also unable to find any IMR 4831 powder. However, there does seem to be a decent supply of H 4831 SC around, which claims to be exactly the same composition as IMR 4831. I would expect it to act at least a little bit different but how much different and is it a good option? Is there a better option out there?

The SC (short cut) versions run pretty much the same, but you should drop down a bit to verify the loads if your non-SC are near the top of the pressure charts..

The 4350 series (IMR, Hodgdon, Accurate, etc..) are all pretty generic in large magnum calibers, but then you're back to load development.

I run Reloader33 and Accurate Magnum in my 338Lapua, but it's a different animal all together ..