.375 Winchester resizing issues

[pinne65]

I'm having major issues resizing once fired .375 Win brass.

I did wet tumble, dried it and am now trying to resize. But I'm not able to push the case into the die. If I'd use more force I'd break my bench which is 1" thick plywood. I know wet tumbling can affect friction but I've tried both old style lube and Hornady spray on to no avail.

I was able to resize some of the brass but others are no-go. Some of the rounds had been fired with blackpowder others with smokeless.

I measured one the cases with issues and the diameter was just 3/1000" from the nominal .400 at the mouth. The case tapers from .403 at the mouth to .4195 1/4" inch from the bottom and then down to .4165 just above the rim.
The die measure .412 at the mouth.

I forced one case through and got it resized with risk of breaking my bench and the die created these weird little dimples on the case, right opposite from each other. Could the sizer die be too tight, or maybe it's too cold in the garage. I warmed one of the cases with my heat gun and it went through. Though it was still a struggle.
Could the chamber on the rifle be oversized and the cases get too expanded to fit the sizing die. The black powder rounds were at lower pressure so they didn't expands as much as the smokeless ones.

t's a head scratcher for sure. I'm reloading 45-70 and I was just about to say it's a walk in the park. But I just recalled I haven't gone through all my new brass yet. So I resized a few and it went fine. Though I had to use more force than straight pistol cases which I assume is expected.

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[JJ1911A1]

What brand of Dies are you using? I have Hornady and Lee dies for the 375 and dont ever have an issue resizing even after max loads out of a Marlin. I use case sizing wax with a very minimal amount applied by hand. The picture looks like to me there is excess case lube on the case when resizing. It could be an oversized chanber in the gun it was fired from. I would also take the die apart and checked it for any build up of lube or some other obstruction. Hope you can find the issue.

 

[gmerkt]

May we see pictures of .375 Win. cases before sizing is attempted?

This shouldn't be a tricky cartridge to load under ordinary circumstances.

 

[pinne65]

What brand of Dies are you using?.

It's RCBS. Compared to my 45-70s they look older. I took it apart cleaned it thoroughly. Ran a bore brush through several times after soaking with brake cleaner. I might re-visit that...

 

[pinne65]

May we see pictures of .375 Win. cases before sizing is attempted?

It's going to be a while :-/. The rifle and materials are with the owner. I just have two cases that both are resized. I did measure the last one before resizing and it seemd to be within limits...

 

[ageingstudent]

It's going to be a while :-/. The rifle and materials are with the owner. I just have two cases that both are resized. I did measure the last one before resizing and it seemd to be within limits...

Do you have a dry medium tumbler? Maybe try and Tumble the brass with a high quality polish first. I like Cabela's but nu finish car polish works quite well and it makes the brass slicker. That dimple looks like a Lube dent on the shoulder of a rifle case. If there's too much Lube in there it will cause a lot of resistance. If you want to polish the inside of your dies I would suggest flitz. It comes in a little blue tube it works wonders on the inside of a die after it's clean.

 

[pinne65]

Do you have a dry medium tumbler?

No I sold it and went all wet. I didn't care for the dust while dry tumbling. Maybe that was a mistake

 

[ageingstudent]

No I sold it and went all wet. I didn't care for the dust while dry tumbling. Maybe that was a mistake

Well I have to tell you, if you wet clean first and dry your brass in your chosen fashion and then run them in nice clean media with some brass polish it makes sizing a real pleasure and doesn't get your dies dirty. The media Almost Never gets dirty or Dusty it lasts forever. That 375 Winchester looks like a very tapered case so if there is too much Lube you might be getting some airlock inside the sizing dye that is making it harder to size. If you want to test out that theory without the dry media tumbler get some flitz and polish the brass by hand with a soft cloth like a diaper. Then just use a very little bit of lube if it is a steel die. If it is a carbide die you really don't need the lube if the brass is clean and Polished. For tapered or straight wall cases I like to use Redding sizing wax or Hornady unique. Slicker than caveman Jim's owl snot and neither one will air lock and leave Lube dents in my experience. Make sure your dies are super clean. You want that air to be able to escape out the top.

 

[Bon Sauvage]

Friend are you annealing any of your cases?

 

[bcp]

...if there is too much Lube you might be getting some airlock inside the sizing dye that is making it harder to size.

If the die has a vent, make sure is is not plugged. And try sizing with the stem removed, using just the die body.

Bruce

 

[ageingstudent]

If the die has a vent, make sure is is not plugged. And try sizing with the stem removed, using just the die body.

Bruce

Indeed. All dies are not created equal even though most of them have the same thread

 

[gmerkt]

Well, I'm going to follow along here. I used to have a Winchester Model 94 BB in .375, I loaded for that and it just whistled along with no problems. I am interested to see what comes of this when some smart person gets to the bottom of it.

Now .38-55 is another deal. I've dissected a number of really old pre-SAAMI factory cartridges and found some variations in materials and dimensions used.

 

[drstrangelove]

Find the die's vent hole and clean it. You could have an oversized chamber, but those calipers there should be able to determine that by measuring once fired unresized brass and comparing to resized brass. Should not be very far off. The dimple is from excess lube. Straight walled brass does not require annealing with any regularity.

 

[edzz]

What press are you using?
Not all presses are up to sizing rifle cases.

 

[po18guy]

No I sold it and went all wet. I didn't care for the dust while dry tumbling. Maybe that was a mistake

If you use Thumler's red (jeweler's rouge) walnut media, there is no dust. The same if you buy Harbor Freight crushed walnut shell and use liquid Flitz polish.

Are these cases headstamped .375?

 

[gmerkt]

If you use Thumler's red (jeweler's rouge) walnut media, there is no dust.

Yes, this reminds me. I noted OP's previous comment re. dust. Don't most vibratory tumblers have a dust cover on top? I use the cover on mine. When I pour it out, I make a point of doing it outside so the dust doesn't contaminate the working area. Or my lungs.

 

[DizzyJ]

Yes, this reminds me. I noted OP's previous comment re. dust. Don't most vibratory tumblers have a dust cover on top? I use the cover on mine. When I pour it out, I make a point of doing it outside so the dust doesn't contaminate the working area. Or my lungs.

A capful of mineral spirits eliminates the dust too.

 

[pinne65]

Thanks guys for all the replies and suggestions! I probably won't be able to try them out until this weekend at the earlieest.

It's not my rifle. I'm helping a buddy out. So that kinda rules out me rebuying dry-tumling equipment agai. Not that it's that expenisive but I'm out of room in the garage.

- I'll have him getting some Flitz. Though shouldn't the Hornady case lube be good enough?

- Think we did try to resize with the stem out last weekend.

- The die has no vent hole. That's new knowledge for me !

- Not annealing. I thought that was mostly for bottle neck cases?

- Cases are .375 Starline

- I'm using a RCBS Rock Chucker press

- Yea, remember creating dimples once on .308 Win now

- I spun a .45 bore brush in it with my cordless drill for a couple of minutes and cleaned again

Again thanks everyone! I'll get back once we've tried it all out.

 

[ageingstudent]

Thanks guys for all the replies and suggestions! I probably won't be able to try them out until this weekend at the earlieest.

It's not my rifle. I'm helping a buddy out. So that kinda rules out me rebuying dry-tumling equipment agai. Not that it's that expenisive but I'm out of room in the garage.

- I'll have him getting some Flitz. Though shouldn't the Hornady case lube be good enough?

- Think we did try to resize with the stem out last weekend.

- The die has no vent hole. That's new knowledge for me !

- Not annealing. I thought that was mostly for bottle neck cases?

- Cases are .375 Starline

- I'm using a RCBS Rock Chucker press

- Yea, remember creating dimples once on .308 Win now

- I spun a .45 bore brush in it with my cordless drill for a couple of minutes and cleaned again

Again thanks everyone! I'll get back once we've tried it all out.

After you clean that die out polish the inside of the die with some Flitz as well as the brass. It might help. I even use it on my carbide handgun dies. It seems to remove any microscopic brass galling inside the die and it really slicks up the surface of the brass. Since you are doing that by hand I would get a small tub of Redding sizing wax or Hornady unique Lube. They last forever. You won't get any Lube dents. If you are not used to loading a tapered case like that 375 it might just feel weird they do tend to give you a little more resistance. Wet cleaning works really nice but sometimes your brass can actually be a little too clean especially going into a steel die. A good metal polish fills the pores on the surface of the brass left by wet cleaning and things tend to size easier with less galling.

 

[pinne65]

Ok - problem solved. Flitzing the inside of the die was part of it. I wrapped some paper tissue around a 5.56 bore brush drenched it in Flitz and ran it w my cordless drill for 10 minutes. The inside is now like "Caveman Jim's owl snot".
Also, drenching the cartridges in Hornady spray lube and allowing it to dry sufficiently helps.
Then, some of the cases were indeed more expanded than others. Some, I believe the ones loaded with black powder, were less expanded by 2-3/1000", .4185 vs .4205 1.75" from the mouth. And were way easier to resize