Sizing

[Danth]

been using a 25cal mold which casts a bullet .261". I made a .255" sizing die to reduce the bullets down to a size required for my 25 Hornet. Sizing reduces the lube grooves significantly, and completely eliminates the grooves along one side on some bullets. Are these bullets useable?

[Dusty Bannister]

That is a lot of sizing down in one pass. Do you have the correct fitting top punch to center the bullet in the lube/size die. If the alloy is still a bit soft, you could be bending the casting due to unusually high pressure as you try to press the bullet deep into the die.

I had a similar problem with a larger caliber bullet and found that if I sized the bullet nose first into the Lyman/RCBS presses, then reversed to base first, and lube, things went a lot better.

I doubt your deformed bullets will shoot to your expectations, but you will not know if you do not give it a try.

[super6]

Yea, You might try a different mold or do a two step sizing, Being that one side loses the grooves I am in agreement as to alignment. The grooves must be shallow to begin with. As to being usable..? Wish you luck!

[Larry Gibson]

Also, lube the bullets (fill the lube grooves) before sizing. The lube is not really very compressible and will help keep the lube grooves in the bullet. I've sized .314 TL 30 cal bullets down to .311 in one sizing w/o wiping away the grooves if the bullets are lubed first.

[Shuz]

My suggestions are twofold;
First try sizing down to .258 and apply lube as Larry suggested. Next size in your .255 die.
Secondly Get a Lee type sizer that pushes the boolit up thru the die.Either .258 or .257, and then put into your .255 die.

[earlmck]

Do you really have to go down to .255? That is unusually skinny for 25 caliber. All you need to do is reduce the diameter enough for the cartridge to chamber freely and you are good to go: my preference is for the least sizing that will let the ammo chamber OK.

[Bent Ramrod]

I’ve found, with boolits of .30 caliber anyway, that 0.003” is about the maximum I can size in one step without deforming the boolit to uselessness. And that is predicated on initially lubing the grooves (presumably with a light coat of lube on the driving bands) in a die that barely touches the outside surface.

So I run a 0.313+” diameter boolit into a 0.314” sizing die, fill the grooves with lube, and then run the boolit into a 0.311” die (without using the lube function) and then the boolit goes into a 0.308” die, again with no lube. The boolit looks like it did originally, with no side scuffing, nose distortion or crushed lube grooves.

I only do this for my very persnickety rebarreled .30-40 Krag, which consistently shows better accuracy with boolits put through this treatment. Any time I can get away, accuracy-wise, with using a minimally-sized and lubed boolit that still fits in the case and chambers, I generally do that.

[gwpercle]

I try to size down boolits as little as possible ... 0.002" is the most I like / will go .
The wear and tear on sizer / lubricator is too much and the boolits get deformed ... just don't go there .

Never pass up a great reason to buy a new mould ... This is a great reason , .261" down to .255" is a reduction of .006" .... that's way too much to size down !
Get a new mould and get that new mould sized for .256" ... Life will be a whole lot easier on you .
Gary

[Winger Ed.]

If the grooves are gone on one side, the weight will probably be different on that side too.
Just a guess, but I think they might not stabilize, and fly like a cork screw.

[stubshaft]

If the grooves are gone on one side, the weight will probably be different on that side too.
Just a guess, but I think they might not stabilize, and fly like a cork screw.

+1 - Probably won't group well.

[Danth]

Want to thank everyone that responded to this thread. I've been shooting 1 1/2" groups at 25 yds. This is with a Steven's Tip-up pocket rifle. This gun was wildcat'd from a 25 Stevens rim fire. The case is similar to a 25 Hornet but with rim dimensions of the 25 Stevens. I've tried all the suggestions above: here's what I found. I've increased the bullet hardness and opened up the sizing die to .257". I had "assumed" the bore was .251" as it was believed to be proper for the 25 Stevens. I have since found most 25 Stevens are .257", as is the case with mine. I increased the lead in the sizing die. I tried lubing the bullet prior to sizing. None of the above improved the sizing problem. I tried reversing the bullet in the sizing die prior to lubing and things improved. I am now making usable bullets, but far from perfect. The next step is to open the sizing die up to .259"-.260". I'm afraid the main problem is the mold itself. Although I can see no light between the faces, I still get minor fins near the base. I think these fins cock the bullet while sizing. So I guess the search is on for a lighter bullet mold in good shape.