How much do you expand a .45-70 case mouth for cast bullets?

[JimGnitecki]

I am new to cast bullets! When loading .45-70 cases with cast lead bullets, some of the bullets coated and others instead conventionally lubed, how much should I be expanding the case mouth to avoid shaving the lead bullet?

My measured average bullet diameter on the first type of bullet being loaded, the Missouri 405g cast bullet with "Hi-Tek" coating = .4588"

My SIZED case OD on brand new cases = .468"

My Winchester case wall thickness = .0110

So, 2 x wall thickness = .0220"

Doing the math, for a "slip" fit with ZERO clearance and NO tension, the case OD would be
= .4588 + .0220 = .4808"

So, what case OD should I be targeting to have the "right" amount of belling for inserting the bullet and seating without shaving the lead?

I will be using a Lee Factory Crimp die.

The ammunition will be used ONLY in a single shot Pedersoli Sharps.

Jim G

 

[Remington1911]

I don't measure this aspect, don't know why as I am known to weigh every bit of brass, and sort bullets, I just don't measure this and never really give it a second thought till you brought it up.

How much to expand it, just enough to stop it from shaving lead, plus a hair to deal with different bullets in the batch, no two are going to be just alike. Have not had any issues yet and have gotten some good results.

This is not bad for me and an old trap door.

 

[lightman]

I've never measured any of mine but I expand the least amount that allows a bullet to seat without catching on the case mouth. I do the same with pistol cases.

 

[JimGnitecki]

The shaving, if it occurs, will start and be obvious before you go far enough to destroy the bullet and necessitate disassembly of the primed and powdered cartridge? Or do you discover it once the bullet comes out of the seating die along wth some slivers of lead?

Also, can you get a situation where the bullet seats but the COATING on it gets scraped?

Jim G

 

[dartor]

I don't measure mine, but I expand with a RCBS expander so that about 1/16" of the bullets base fits into the case. I haven't had any problem shaving lead yet.

 

[Obturation]

Don't over think this , just big enough is perfect. If you're shaving a little ring then put the expanded down some. You don't need to be ultra precise . I stopped using the lee expander , I find the rcbs. (M die??) Expander does a more even /less cone shaped expansion. Cast lead likes that .

 

[JimGnitecki]

Don't over think this , just big enough is perfect. If you're shaving a little ring then put the expanded down some. You don't need to be ultra precise . I stopped using the lee expander , I find the rcbs. (M die??) Expander does a more even /less cone shaped expansion. Cast lead likes that .

I forgot to mention I am using the Hornady 3-die Custom set for 45-70. It has some really nice features including a sliding tube in the seating die that encloses the case and bullet and slides up as the die slides over it. Plus, I ordered the Hornady "Microjust" which enables micrometer adjustment of the seating height. That is important to me because I will be using multiple different bullets requiring different VERY different COALs.

Jim G

 

[mdi]

Flare/expand as much as needed to be able to start the bullets easily, straight. If concerned about too much neck tension, seat a few bullets, then pull using an impact puller and measure the bullet diameter for swaging.

 

[JimGnitecki]

Flare/expand as much as needed to be able to start the bullets easily, straight. If concerned about too much neck tension, seat a few bullets, then pull using an impact puller and measure the bullet diameter for swaging.

Actually, I am going to use the Lee Factory Crimp die for getting consistent tension on each cartridge. So, to prevent any bullet shaving or scraping of the Hi-Tek coating, I should, if anything, go for sure with a large enough expansion to ensure no shaving or scraping?

Jim G

 

[AJC1]

These are what I use... the bottom .460 would probably be ideal.

 

[JimGnitecki]

Should I also be chamfering the inside of of the case mouth when using brand new cases, and also later when the cases have been through a trimming?

Or, is that unnecessary when loading for a single shot rifle, expanding just enough, and using a Lee Factory Crimp die?

Jim G

 

[Shooterbob]

I always chamfer cases . I believe it will aid in not shaving lead bullets.

 

[mdi]

If you're asking about chamfer to aid/add to a flare, no. I use a countersink to remove sharp edges and burrs. I flare every case I reload; handgun and rifle, some a lot, some just barely. I don't believe an FCD (other than a collet style) is of any merit and can be detrimental. Post sizing crimping has never been a part of my reloading. When I tried one it swaged down my perfectly sized cast bullets. None of my handloads have needed fixing any chambering issues, my loads are plunk tested and dummies checked for feeding/chambering before they get into "production"...

 

[ArchAngelCD]

I have never thought to measure like you do. I just expand the neck enough to seat the bullet straight and without shaving, no more, no less.

Just keep it simple and you will enjoy loading more IMO instead of stressing. Save your time for checking powder weights, using the correct powder and all the other small things we need to do to be safe.

I'm sure you will do fine, good luck...

 

[gwpercle]

Lubed cast bullets and especially Coated cast bullets diameters will vary , some being larger than others . Coatings can vary dramatically .
The correct answer isn't a number but to advise you to expand the case untill the bullet no longer shaves lead / coating from the bullet .
When you can , use of a gas checked bullet makes seating a bit easier ... the gas check protects the base , prevents shaving and sizing down of the base when seating .
Some hate gas checks but I use them with soft alloy bullets ...they help with shooting , leading barrel and seating bullets ... Do Not Fear the Gas Check ... they can solve a lot of problems.
Gary

 

[MEHavey]

go for sure with a large enough expansion to . . .

. . . allow the bullet base to seat easily into the case about a dime/nickel's width.
(rocket science units of measure)


.

 

[JimGnitecki]

Ok, the specific type of bullet I am expanding for today has a chamfer on its base. That is obviously a smaller diameter than the shank of the bullet. I assume you guys mean that I have to be able to get the SHANK above the chamfer started into the case "about a dime/nickel's width" (MEHavey probably meant "thickness of a dime or nickel, not width!)

Jim G

 

[MEHavey]

Yes.
Post-It Note: Coins have diameter. . . and width.


.

 

[EricBu]

I am new to cast bullets! When loading .45-70 cases with cast lead bullets, some of the bullets coated and others instead conventionally lubed, how much should I be expanding the case mouth to avoid shaving the lead bullet?

My measured average bullet diameter on the first type of bullet being loaded, the Missouri 405g cast bullet with "Hi-Tek" coating = .4588"

My SIZED case OD on brand new cases = .468"

My Winchester case wall thickness = .0110

So, 2 x wall thickness = .0220"

Doing the math, for a "slip" fit with ZERO clearance and NO tension, the case OD would be
= .4588 + .0220 = .4808"

So, what case OD should I be targeting to have the "right" amount of belling for inserting the bullet and seating without shaving the lead?

I will be using a Lee Factory Crimp die.

The ammunition will be used ONLY in a single shot Pedersoli Sharps.

Jim G

You want to expand it juuuuusssst enough that the bullet drops in. One thing with cast bullets, either coated or lubed...you'll save yourself a huge amount of pain if you seat and crimp in different steps. It's very hard, especially with mixed brass, to have it seat and crimp in one step consistently without getting a touch of "bullet shave" or crimp bulge. Also, I'd set up your flare adjustment so the coated bullets drop in easily, just because the coated tend to be a hair thicker, if the coated drop in, the lubed will as well. Cliff notes: Flare just enough that when you set your bullet in the case mouth, it drops in enough to stand up on it's own and drops in level. No more, the less flare the better. If you flare to much, you might see that the crimp causes the case to kind of bulge a bit when you apply the crimp. Also, I will say that I've been doing this a LONG time, and I load around 15k to 25K rounds of 45-70 every year....trying to "math it out" and come up with a measurement to set it by is just over thinking it and will cause you undo stress and pain. Just flare a little at a time until your bullet drops in clean far enough to stand up straight on its own and you don't get shave when seating it, and you can't hear that awful sound of the brass scraping inside your seating die as you seat the bullet...that scraping/dragging sound/feel is a sure sign you've over flared.

 

[EricBu]

Actually, I am going to use the Lee Factory Crimp die for getting consistent tension on each cartridge. So, to prevent any bullet shaving or scraping of the Hi-Tek coating, I should, if anything, go for sure with a large enough expansion to ensure no shaving or scraping?

Jim G

I do NOT ever recommend the Lee FCD with cast bullets. It has it's place for sure, but cast bullets isn't it. Yeah, I know, plenty of people swear by it....but those people either got a Thursday FCD, or they've never pulled a bullet and measured it after it's been through the FCD. If your 45-70 isn't chambering (and you have a case gauge right??? Right????) without the FCD, then figure out why, because the FCD is just hiding something wrong at the expense of your bullets.

 

[AJC1]

I do NOT ever recommend the Lee FCD with cast bullets. It has it's place for sure, but cast bullets isn't it. Yeah, I know, plenty of people swear by it....but those people either got a Thursday FCD, or they've never pulled a bullet and measured it after it's been through the FCD. If your 45-70 isn't chambering (and you have a case gauge right??? Right????) without the FCD, then figure out why, because the FCD is just hiding something wrong at the expense of your bullets.

I am no Lee fan boy for sure, but knowing case thickness can really help or hurt the love hate relationship with the fcd. Thick cases and big bullets don't play well together.... a better solution would be to be able to change or order a sizing ring to meet your needs. My sizing ring almost never does anything. I figure worst case senerio is mixed cases and big bullets....

 

[JCSC]

I love the Lee FCD for jacketed loads, however It swaged my cast 9mm loads and when I pulled and measured they were garbagio.

I’ll keep using it for the store bought bullets.

 

[Shooterbob]

Rifle and pistol factory crimp dies are not the same.Rifle fcd do not size down cast bullets they do not have the carbide sizing ring. You will like your factory crimp die I believe.

 

[dartor]

Should I also be chamfering the inside of of the case mouth when using brand new cases, and also later when the cases have been through a trimming?

Or, is that unnecessary when loading for a single shot rifle, expanding just enough, and using a Lee Factory Crimp die?

Jim G

If you're using new cases I recommend sizing, trimming, inside and outside chamfering, then expanding. You'll be surprised how much brass shavings you'll have. You need your brass to be consistent in length. I'm using Starline and It wasn't consistent in length.

 

[JimGnitecki]

Ok, here is what did today:

I chamfered the case ID, not the D, and I did it very lightly - just making sure there are no burrs basically.

I set the expander die up and starting slowly, incrementally increasing the expansion of the case mouth. The 405g bullets I am loading have a chamfered base - maybe .06" high. I went deeper with the expander by maybe less than .06" more, so that I was catching the unchamfered shank of the bullet, and the bullet would stand up reliably in the case without falling off. I noticed that once I hit a certain point in expander depth - far below the .10" to 12." TOTAL expander depth - the expander no longer increased the diameter of the case iD.but rather simply went deeper into the case at the same ID, which was a thou or 2 less than the .4587" average bullet shank diameter. So, evidently, Hornady ENSURE that you do not over-expand on diameter.

Also, the expander left a clearly visible "band" on the case ID, from mouth of the case to the maximum expander depth, so I could easily visibly confirm after expanding each case that no individual case was noticeably different length than any others.

I made one complete case & bullet assembly (no primer and no powder), set up the Hornady seating die, and incrementally seated the bullet deeper and deeper, until I got to 2.550" COAL. But, at that COAL, the mouth of the case was a little lower than at the crimping groove on the bullet. I found that if i seated it just a few thousandths deeper (about .008"), the case mouth aligned with the crimping groove. Given I will be running CAS level loads (1200 to 1400 fps range) at 14,500 to 16,000 pressure levels), not high power loads, I figure the .008" thousandths shorter COAL is not a pressure raising problem.

I made sure I had the seating die set to near the bottom of its micrometer range for the 405g bullet, because the other weight of bullets I want to try is 500g, and those bullets will be MUCH longer (one of the 500g samples my buddy gave me has a "pointed" tip and is about .40" longer than the 405g bullet!

Then, I disassembled the dummy cartridge using an inertia hammer, and checked the condition of the bullet shank. Found NO shaving or scratching of the Hi-Tek coating. Also found that the shank diameter was unchanged: the bullet started at the batch average shank diameter somewhere between .4585" and .4590", and stayed there through the seating process and the inertia hammer removal process.

So, I THINK my setup is good to go. Just need to settle on a powder range for both Accurate 5744 and IMR 4198 for the ladder testing, and also set up the Lee Factory crimp die for a modest crimp.

Did I miss anything or do anything wrong?

Jim G