Advice on sizing a TC style conical bullet

[LaneP]

I have a Pedersoli Lyman Great Plains Hunter .50 cal 1:24" twist and I'm narrowing down the diameter for a TC style conical mold. Pedersoli specs state the rifle has a .500" bore with .512 groove diameter. Arsenal Molds offers a stock .504" mold but diameter can be customized.

So I took a Hornady Great Plains conical bullet, threaded a drywall screw in the nose, tapped it partway in the barrel and after removing it, the base measures exactly .500", spot on to Pedersoli's specs. However that bullet is a VERY tight fit and I'm looking at compromising with a diameter that is better suited to the field than the range, with a size that is close enough to afford a good gas seal without me having to hammer the bullet down the bore on a second shot, while providing acceptable accuracy. I just have this sense a .504" bullet would be way too tight for field loading.

I'm leaning toward getting a .502" diameter, and have the option of getting a Lee .501" sizer die to decrease size slightly if needed. I would expect sizing to bore diameter (.500") would permit easy loading but not provide a good gas seal.

Wondering if anyone here has gone through this conundrum or has recommendations from prior experience. Thanks all.

 

[Grenadier1758]

The flat based conical bullets with several driving bands are designed with the base band diameter to be bore sized to establish alignment of the bullet to the bore. The middle band is slightly greater that the land to land diameter to slightly engrave the rifling ib the bullet and do the secondary alignment of the bullet. The top band is designed to equal the groove diameter of the barrel. The barrel becomes the custom sizing die for the conical as the bullet fully engages the rifling and is perfectly aligned in the barrel. The grooves in the bullet are filled with grease to lubricate the bullet to ease loading and to soften fouling on firing. The T/C conical bullets need to be soft lead. A hard lead T/C style or Lee REAL bullet will be very hard to load.

 

[Old Hawkeye]

What Grenadier1758 said. Those bullets are tapered & the diameter given is usually for the top band. I've never heard of anyone sizing that type of bullet. The lower band will start down the barrel without effort. They also are designed for pure lead & obturate to fill the rifling when fired, which creates a gas seal. You are overthinking it. They have to be "tight" somewhere or they will fall out of the barrel or at least away from your powder charge. A .504" top band will load easily in a .500" land to land barrel. Remember your groove to groove diameter is .512". Before you buy a mold, why not try the TC style Maxis sold by TOTW. Measure them & see how they compare to your "custom" mold. Then decide what you need. The Hornady GP bullets are a whole different animal & comparison not applicable.

 

[stikshooter]

Do not size and None for My Lyman Plains or the Lee REAL ,same principle and along with soft lead do not forget a oversized under the base (next cal up felt wad) if you want accuracy ! Ed

 

[nkbj]

I have a Pedersoli Lyman Great Plains Hunter .50 cal 1:24" twist and I'm narrowing down the diameter for a TC style conical mold. Pedersoli specs state the rifle has a .500" bore with .512 groove diameter. Arsenal Molds offers a stock .504" mold but diameter can be customized.

So I took a Hornady Great Plains conical bullet, threaded a drywall screw in the nose, tapped it partway in the barrel and after removing it, the base measures exactly .500", spot on to Pedersoli's specs. However that bullet is a VERY tight fit and I'm looking at compromising with a diameter that is better suited to the field than the range, with a size that is close enough to afford a good gas seal without me having to hammer the bullet down the bore on a second shot, while providing acceptable accuracy. I just have this sense a .504" bullet would be way too tight for field loading.

I'm leaning toward getting a .502" diameter, and have the option of getting a Lee .501" sizer die to decrease size slightly if needed. I would expect sizing to bore diameter (.500") would permit easy loading but not provide a good gas seal.

Wondering if anyone here has gone through this conundrum or has recommendations from prior experience. Thanks all.

Well, it's a toughie to give advice on.
What works for you and how that bullet is intended to work are two different subjects.
If use in the field is intended then do you want to reload without cleaning the bore? If that is the case then let that be your guide. The bullet's diameters, your rifling, your type of powder and how much, your lube, card wad, lubed felt wad... everything comes into play.

Now to stick my toe in the water. That bullet is lighter than what your gun is made for.

 

[Rifleman1776]

Lane, I am in the anti-bullet crowd for use in most modern ml rifles. Couple reasons. In the popular calibers (.45 and up) they are not needed for killing deer. Their trajectory is very rainbow and a predictable point of impact is difficult to learn for most shooters. e.g. that bullet is dropping maybe more than going straight to the target. And, I don't like them for another reason. The ml deer seasons are usually fairly early in the year. Meaning mornings are cold but temps can rise as the day progresses. I have found the steel barrel, as it warms relaxes it grip on a bullet in the bore. I have had those bullets slide half way up/down the bore. Dangerous happenings. A patched ball stays put. Thems my druthers.

 

[bubba.50]

With proper bullets cast from the proper soft lead there's absolutely no need to size them. This holds true whether they be maxi-balls, Lee r.e.a.l. bullets, Hornady/Lyman Plains bullets or whatever.

 

[Idaho Ron]

You could go with a paper patched Lee 500S&W bullet. Two wraps of 9 pound onion skin size to .501
Now with an adjustable peep sight your ready for any game animal in North America out to 200 yards.

 

[deerstalkert]

if you are set on getting a mold, get the smaller dia. then if it doesn't work you can have it opened up.

 

[LaneP]

Lane, I am in the anti-bullet crowd for use in most modern ml rifles. Couple reasons. In the popular calibers (.45 and up) they are not needed for killing deer. Their trajectory is very rainbow and a predictable point of impact is difficult to learn for most shooters. e.g. that bullet is dropping maybe more than going straight to the target. And, I don't like them for another reason. The ml deer seasons are usually fairly early in the year. Meaning mornings are cold but temps can rise as the day progresses. I have found the steel barrel, as it warms relaxes it grip on a bullet in the bore. I have had those bullets slide half way up/down the bore. Dangerous happenings. A patched ball stays put. Thems my druthers.

Good point and something to be cautious of for certain.

With proper bullets cast from the proper soft lead there's absolutely no need to size them. This holds true whether they be maxi-balls, Lee r.e.a.l. bullets, Hornady/Lyman Plains bullets or whatever.

I've been researching on and off all day and it looks like commonly found bullets like the Lee REAL and TC style do indeed have multiple driving band diameters, which would make sizing them not really beneficial (per their original design.

You could go with a paper patched Lee 500S&W bullet. Two wraps of 9 pound onion skin size to .501
Now with an adjustable peep sight your ready for any game animal in North America out to 200 yards.

I have read this suggestion several other places as well, and I like the idea. It's something I would certainly consider. Molds are so scarce right now, if I found one I'd snag it in a minute. Do you happen to have the Lee stock number handy? I appreciate it.

if you are set on getting a mold, get the smaller dia. then if it doesn't work you can have it opened up.

Good suggestion!

 

[dave951]

With proper bullets cast from the proper soft lead there's absolutely no need to size them. This holds true whether they be maxi-balls, Lee r.e.a.l. bullets, Hornady/Lyman Plains bullets or whatever.

Not so much for minies. For best accuracy, they respond very well to sizing.

 

[bubba.50]

Not so much for minies. For best accuracy, they respond very well to sizing.

A minie is not a “TC style conical”.

 

[Idaho Ron]

This is the link to the Lee bullet

https://leeprecision.com/mold-dc-c501-440-rf.html

https://leeprecision.com/new-lube-size-kit-.501.html

 

[Gordoncourtney]

The flat based conical bullets with several driving bands are designed with the base band diameter to be bore sized to establish alignment of the bullet to the bore. The middle band is slightly greater that the land to land diameter to slightly engrave the rifling ib the bullet and do the secondary alignment of the bullet. The top band is designed to equal the groove diameter of the barrel. The barrel becomes the custom sizing die for the conical as the bullet fully engages the rifling and is perfectly aligned in the barrel. The grooves in the bullet are filled with grease to lubricate the bullet to ease loading and to soften fouling on firing. The T/C conical bullets need to be soft lead. A hard lead T/C style or Lee REAL bullet will be very hard to load.

Just to add this is what Henry Krank offers in uk. All Lee moulds