This article written by CBA member Pat Ifland was published in the Sept/Oct 2007 #189 issue of the Fouling Shot.
In my opinion the best and least appreciated tool for sizing bullets is the Lee Push Through Sizer. I’ve included a picture of two bullets, one sized with a Lee die and one sized with a Lyman Lubrisizer. I also have an RCBS lubrisizer and ran the same test with similar results so this is no indictment against Lyman‘s machine.
Both lubrisizers were totally cleaned before testing because of some lube trials I have coming up so the H&I die was free to center itself. The top punch was left loose so that it would have as little chance as possible of pushing the bullet into the die at an angle, and I did the best I could to get everything straight. As you can see in the picture the bullet on the left was sized off center using the Lyman lubrisizer while the bullet on the right is symmetrical using the Lee die.
In my opinion the best and least appreciated tool for sizing bullets is the Lee Push Through Sizer. I’ve included a picture of two bullets, one sized with a Lee die and one sized with a Lyman Lubrisizer. I also have an RCBS lubrisizer and ran the same test with similar results so this is no indictment against Lyman‘s machine.
Both lubrisizers were totally cleaned before testing because of some lube trials I have coming up so the H&I die was free to center itself. The top punch was left loose so that it would have as little chance as possible of pushing the bullet into the die at an angle, and I did the best I could to get everything straight. As you can see in the picture the bullet on the left was sized off center using the Lyman lubrisizer while the bullet on the right is symmetrical using the Lee die.
Bullet on left was sized in the Lyman 450, that on the right in the Lee Push Through Sizer
Lyman (left) & Lee (right)
You’ll have to beg borrow or steal an LBT style straight diameter bullet to run the test but if you’re not getting the accuracy you think you should be it might be worth checking. In my past testing of the effect of using a lubrisizer with an assortment of bullets in various calibers the amount of off center sizing this bullet displayed is on the low end. Where I feel the Lee doesn’t shine is in seating the gas checks, and of course there’s no lube option. The other picture shows that the check is seated more firmly against the base of the bullet using the Lyman lubrisizer if the quality of the picture allows you to compare lube width, I used a caliper. To over-come this I size the bullet minus the gas check in the Lee die and then seat the check and lube using a .001” oversize H&I die in the lubrisizer. Once lubed and the gas check seated you can run the bullets back through the Lee die if a .001” over gas check diameter bothers you.
To illustrate what you can get away with, my current barrel requires a .3095” oven HTWW bullet to fit a .310” ball seat throat. As soon as the bullets are cool enough to handle after casting I run them through the Lee die without the check. Following this they go into a toaster oven set at 440 degrees for an hour. After quenching in cool water they’re set aside for another hour to gain a lit-tle strength. They’re then lubed and the gas check installed in the lubrisizer. You might not have to send them for another trip through the Lee die so the check and bullet are the same diameter but I do it as a feel good measure. You have to be fairly gentle during the initial sizing with the butter soft bullets so the check shank doesn’t get bumped up but after miking a couple of shanks or slipping a gas check on to see that it fits you get the feel for it and it’s clear sailing.
As far as the die itself you might find the soft bullet gets sized down a little more than you’d like. I started with a .309” die and the just cast WW bullets were coming out .3088” or .3089”. To cure this and get up to the .3095” I needed I coated 20 bullets with 320 grit aluminum oxide compound and ran them through the die until a sized bullet measured .3095”. Go slow because these things cut faster than you might think and it took two tries to get it right, the first die coming out too big. Start by running five compound coated bullets through the die, measure a bullet, and go from there checking often. I think it took 10 coated bullets to open the die up .0005”. I make new push through pins because the ones Lee supplies are a little rough on the contact surface but I’m sure a little careful polishing would be just as good. It’s often stated that sizing more than a couple of thousandths destroys a bullet’s accuracy potential. I think a better way to put it would be the tool used to size a bullet might destroy its accuracy potential. The bullets pictured cast at .313 and I’ve had other oversized moulds which performed very well sizing them down what would be considered an accuracy destroying amount using the Lee die.
Since I mentioned Heat Treating I’ll give my opinion about that too based on my testing. It’s thought that siz-ing diminishes the HT. To find out what was really happening I chucked some heat treated bullet up that were allowed to harden for an hour after quench and filed .100 or so off the nose so I’d have a place for the tester’s needle to rest and to find out if the HT was only skin deep. For equipment I used both the Saeco and LBT hardness tester. One hour after quench the filed surface the bullets had a reading of 10 on the Saeco and low twenties on the LBT. According to the SAECO’s BNH conversion graph 10 is the equivalent of Linotype or around 21 BNH. After letting my other samples sit overnight the Saeco scale read 12 and the LBT low to mid 30s. Again SAECO’s graph called it close. What this proves to me is that HT is more than skin deep and if filing .100 of the bullet doesn’t affect the HT sizing down a couple of thousandths shouldn’t be much to worry about.
The disclaimer of “Your Results May Differ” applies as usual.
To illustrate what you can get away with, my current barrel requires a .3095” oven HTWW bullet to fit a .310” ball seat throat. As soon as the bullets are cool enough to handle after casting I run them through the Lee die without the check. Following this they go into a toaster oven set at 440 degrees for an hour. After quenching in cool water they’re set aside for another hour to gain a lit-tle strength. They’re then lubed and the gas check installed in the lubrisizer. You might not have to send them for another trip through the Lee die so the check and bullet are the same diameter but I do it as a feel good measure. You have to be fairly gentle during the initial sizing with the butter soft bullets so the check shank doesn’t get bumped up but after miking a couple of shanks or slipping a gas check on to see that it fits you get the feel for it and it’s clear sailing.
As far as the die itself you might find the soft bullet gets sized down a little more than you’d like. I started with a .309” die and the just cast WW bullets were coming out .3088” or .3089”. To cure this and get up to the .3095” I needed I coated 20 bullets with 320 grit aluminum oxide compound and ran them through the die until a sized bullet measured .3095”. Go slow because these things cut faster than you might think and it took two tries to get it right, the first die coming out too big. Start by running five compound coated bullets through the die, measure a bullet, and go from there checking often. I think it took 10 coated bullets to open the die up .0005”. I make new push through pins because the ones Lee supplies are a little rough on the contact surface but I’m sure a little careful polishing would be just as good. It’s often stated that sizing more than a couple of thousandths destroys a bullet’s accuracy potential. I think a better way to put it would be the tool used to size a bullet might destroy its accuracy potential. The bullets pictured cast at .313 and I’ve had other oversized moulds which performed very well sizing them down what would be considered an accuracy destroying amount using the Lee die.
Since I mentioned Heat Treating I’ll give my opinion about that too based on my testing. It’s thought that siz-ing diminishes the HT. To find out what was really happening I chucked some heat treated bullet up that were allowed to harden for an hour after quench and filed .100 or so off the nose so I’d have a place for the tester’s needle to rest and to find out if the HT was only skin deep. For equipment I used both the Saeco and LBT hardness tester. One hour after quench the filed surface the bullets had a reading of 10 on the Saeco and low twenties on the LBT. According to the SAECO’s BNH conversion graph 10 is the equivalent of Linotype or around 21 BNH. After letting my other samples sit overnight the Saeco scale read 12 and the LBT low to mid 30s. Again SAECO’s graph called it close. What this proves to me is that HT is more than skin deep and if filing .100 of the bullet doesn’t affect the HT sizing down a couple of thousandths shouldn’t be much to worry about.
The disclaimer of “Your Results May Differ” applies as usual.