Sizing 375 bullet next to impossible...

[RICKLANDES]

I am using a RCBS 375-250 mold casting bullets that drop at .376 to .3765 from an alloy of WW and a bit of tin to make a bullet showing a hardness of BH 12. I am sizing to .375 with a Lyman H&I .375 sizing die in a RCBS Lub-2 press. I am using a homemade lube of beeswax, tallow, and olive oil.

I find that the bullets are next to impossible to get in and worse out of the sizer die. When I can these measure a frog hair (.0002) over .375. I have had to drive some out with an oak block and a hammer...
Any idea what is up here?

I have used the same alloy for 45 cal bullets and it sizes like a dream.
Anythings to check?

[runfiverun]

try wiping a little lube on them first.

[RICKLANDES]

Thanks. I tried lubing before, plain bullet w/o gas check, different lubes...no avail.
I even went back and re-read the set-up directions just to see if something was not as it should be...

[oteroman]

I spray my bullets with Horndy case lube. After bending my handle on my Star sizer i discovered this tip. Night and day difference.

[RICKLANDES]

got some on the loading bench and will give it a try. Many thanks.

I had tried (just because it was near me on the bench) a fingertips lubing with synthetic 5-20 motor oil. It did not do anything.

[Wayne Smith]

Air cooled or water dropped, and if the latter, how long did you wait until sizing?

[JonB_in_Glencoe]

Brand new die??? I suspect???

I've had a brand new die act like that. I removed it from the press, cleaned it well, looked inside ....it wasn't polished, it was ribbed with machining lines. Once I polished it, it worked fine.
Good Luck.
Jon

[RICKLANDES]

air cooled

Yes it is a new die and bullet mold. Working cast bullets for 375 H&H and 38/55.
The few bullets I have sized appear smooth as glass. I will do a visual check.
I may also run an ID gauge down through it to just to see if there is a "mid-die" variation.
If I see lines, etc I will polish out.

I really appreciate the input and help!

[OS OK]

On the lift stroke...is the interior of the die coming to near top of the die or is it not adjusted to rise high enough?

[Kraschenbirn]

Would definitely take a long look at the inside of your sizer die. I've got a Lyman 375248 (essentially the same boolit design as your RCBS) that, after some judicious lapping, drops a bit over .380. I shoot these 'as cast' in my Highwall but have sized some that were cast fairly hard...like Lyman #2 'hard'...for a buddy's .375 Win to .377 without a bit of difficulty.

Bill

[SSGOldfart]

My sizer die did the same thing after removing and cleaning/boiling out the lube,the next time I tried it it worked great,must of had a burr in there somewhere?? It works great with my Ranch Dog mol now,I'm sizing to .377

[Wayne Smith]

Reason I asked about time from casting is that if there is arsenic in your mix they will continue to harden, even air cooled boolits, just slower than the water dropped ones.

[RICKLANDES]

This one got the gold star. I disassembled the die and the internal plunger showed a very fine wire on the outside edge of the top. I polished this off. Next, I took an under sized drill bit from the index, wrapped it with a fine sandpaper and chucked the bit into a press. I slide the die body onto the covered bit and crosshatched the inside for a bit. Put everything back together and it works great.

What I found interesting was the plunger moved without resistance through the die body BEFORE I had done anything. It was only under pressure of resizing that the difficulty showed up.

I will be checking all of my sizing dies and giving them a once over polish. I think a light touch will do them all well. I will probably just use a Flex-Cut rouge to polish them. I do not want to change I.D. on die body.

Many thanks to everyone's input. The later entries seemed to have many zeroing in on the problem, too!

[runfiverun]

process of elimination usually works things down to the root issue.

[Montana Silver]

I have a buddy who wants me to load a 375 Winchester for him, now after reading this I don't know. The only sizer I have found is for a
lube type sizer and all of mine are push thru Lees. The Lee mold is a 379?? What to do??

[DonHowe]

Why size to .375"? If your barrel is of modern dimensions, .375" groove diameter, it seems to me your mold/alloy combo is right on the money as cast. Were it my setup I would pan-lube or get a .377" sizer die to lube with.

[JonB_in_Glencoe]

I have a buddy who wants me to load a 375 Winchester for him, now after reading this I don't know. The only sizer I have found is for a
lube type sizer and all of mine are push thru Lees. The Lee mold is a 379?? What to do??

you need to slug the Rifle, size will vary from manufacturer.
My Interarms 375 H&H was right at .375 so I sized boolits to .376
There are custom sizer die makers that can make a .376 push thru die...Lee will make customs also.

[rockrat]

Heck, I shoot .379's in my H&H and it works just fine

[wmitty]

I agree with rockrat; if the throat will accept a larger than groove diameter boolit, use as cast diameter and be glad you didn’t have to size.