Sizing 375 bullet next to impossible...

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?

try wiping a little lube on them first.

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...

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

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.

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

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

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!

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?

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

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:bigsmyl2:

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.

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!

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

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??

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.

Quote:

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Originally Posted by 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??

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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.

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

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.