Hornady XTP Bullets vs. Cast Boolit Load Data

[daddyseal]

You would load a cast boolit with a bit higher load of powder than an Hornady XTP jacketed bullet, Right?
Is there a rough percentage of how much higher?

[HATCH]

The opposite.
Jackets bullets normally are higher

sent from my mobile.

[daddyseal]

Oops...My mistake...Sorry
So, is there a rough percentage less?

[mpmarty]

There is no correlation between the XTP and cast AFIK.

[shooter69]

You realy, realy, realy, need to get atleast a few reloading manuals and read them before you get hurt! Just my 2cents.

[daddyseal]

You realy, realy, realy, need to get atleast a few reloading manuals and read them before you get hurt! Just my 2cents.
I have 6, and use them...I'm just looking at the Hodgden online load data, trying to correlate all there copper lated loads to cast...that's all, friend.

[MT Gianni]

It depends on what I want the load to do.

[Larry Gibson]

No offense meant here but don't "correlate" unless you really know what you're doing. The fact you ask the question should provide that answer. As mentioned there is no specific % or even a good guess because, in reality, it dos not "correlate". Work up your loads using proper loading technique following load data specifically for the specific bullet used and watch for the psi signs indicated most all major reloading manuals.

Larry Gibson

[daddyseal]

daddyseal,

In general, a jacketed handgun bullet and a cast handgun boolit of equal weight, seated to equal depth (not L.O.A.), over identical powder charges in the same lot of brass using the same lot of primers will result in the cast boolit having a higher velocity at a lower pressure.

How much difference depends on the components and the firearm. With the usual precautions taken while developing a load, I have never encountered any safety issues substituting a cast boolit in jacketed bullet handgun data.

There is no formula for calculating charge weights, just good judgment.

PB

Thank you for that, friend~

[Moonie]

When changing components from those listed (brass, bullet brand/shape/composition, primer or even powder lot#) please reduce 10% and work up your load again. Keep in mind, you are not shooting yours in the same gun/pressure barrel as the people that wrote the book you are consulting. You do not want them calling you Leftie Mongo.

[daddyseal]

When changing components from those listed (brass, bullet brand/shape/composition, primer or even powder lot#) please reduce 10% and work up your load again. Keep in mind, you are not shooting yours in the same gun/pressure barrel as the people that wrote the book you are consulting. You do not want them calling you Leftie Mongo.

Right...I do that, friend~
Mongo need shooting arm...

[runfiverun]

"generally" the xtp's have longer bearing surfaces and are deeper seated than other jaxketed bullets.
so even making a direct comparison between those and regular jaxketed is futile.

[fredj338]

As noted, you load a lead bullet with less powder for sim vel/pressures. So using starting jacketed data is a good place to go. I don't by into the lower pressure thing, it makes no sense. Lead has a higher coef of friction, but is more malleable. There is no free lunch for vel vs pressures. Some think the lead bullet has less friction, if so, then vel would also be less. Hmm? So IMO, you are getting slightly higher pressures, maybe diff peak, but slightly higher. Since none of us has pressure equip, it's theory, I just know less friction means less vel all things being equal.

[olaf455]

I just know less friction means less vel all things being equal.

Per my understanding, a Jacketed bullet having a harder substance that needs to be engraved by the lands inside the bore, will resist moving until a larger amount of pressure has developed as compared to a similar weight cast bullet.

+1 on reducing your load by 10 percent and working back up until velocity goes away or you see signs of pressure.

Sent from a cold damp basement near you.

[runfiverun]

thats the rub, things aren't equal.
even if the engraving pressure is equal, the length of the bearing surface,the hardness of the jaxket and it's thickness will change the numbers again and again.
lead engraves easier so should have lower pressure at that point, it also seals the bbl better [gain,loss]

all you can do is make an educated guess and work UP untill you are happy or encounter a problem [accuracy/leading] you need to overcome.

[MT Chambers]

There are many ways of looking at it, similar loads in both jacketed and cast will have less pressure with cast, so you could load a cast bullet heavier than a jacketed bullet for higher velocity, of course your cast bullet must be up to the task ie: right dia., hard enough, and gas checked. I was just looking over some .454 Casull data where a similar load(300gr. bullets), showed 12,000psi more pressure with jacketed bullets.

[10 Spot Terminator]

+1 MT Chambers

In a basic readers digest edited form you put it into words where daddyseal ( OP ) can get an idea of what the variables are that werent stated earlier that give rise as to why you cant just equate a redux or increase from a listed jacketed load and apply it to a cast load. It starts with the cast bullet composition and correct fit and goes on from there to dictate its own load data parameters.

[fredj338]

thats the rub, things aren't equal.
even if the engraving pressure is equal, the length of the bearing surface,the hardness of the jaxket and it's thickness will change the numbers again and again.
lead engraves easier so should have lower pressure at that point, it also seals the bbl better [gain,loss]

all you can do is make an educated guess and work UP untill you are happy or encounter a problem [accuracy/leading] you need to overcome.

Kind of my point. The lead is more maleable, easier to engrave, but lead has a higher COF than gilding metal. Lead bullets are larger in dia & seal the bore better, increasing the vel w/ probably equal pressures. Without pressure testing & near identical bullets shapes, hard to to tell, but for sure it's not because a lead bullet is slicker. That would be less pressure & less vel, much like moly coating a jacketed bullet. My theory, until someone can prove pressures are lower using pressure equip.;-)

[Larry Gibson]

"Since none of us has pressure equip, it's theory, "

Some of us do have pressure measuring equipment so it is not "theory".

There is no % correlation beteen jacketed and cast bullets using the same load.

Larry Gibson

[daddyseal]

"Since none of us has pressure equip, it's theory, "

Some of us do have pressure measuring equipment so it is not "theory".

There is no % correlation beteen jacketed and cast bullets using the same load.

Larry Gibson

Thank you All for your great answers~

[trixter]

When I switched from jacketed bullets to cast boolits I got a manual for cast boolits. I believe it is Lyman's Cast Bullet Handbook, 4th edition. I used Speer manual for jacketed stuff. Also look online in the powder company's data for the projectile that you want to use. It isn't too confusing, I just look for a boolit that is same in weight and configuration and start at the lowest and work up till you like it.

[daddyseal]

When I switched from jacketed bullets to cast boolits I got a manual for cast boolits. I believe it is Lyman's Cast Bullet Handbook, 4th edition. I used Speer manual for jacketed stuff. Also look online in the powder company's data for the projectile that you want to use. It isn't too confusing, I just look for a boolit that is same in weight and configuration and start at the lowest and work up till you like it.
I have 6 manuals...Including Lymans Cast Bullet Handbooks 2nd, 3rd and 4th Editions, friend.
And I Use Them...But I was still curious about the answer to my question...Which was thoroughly answered by knowledgeable members here.

Again...Thank You ALL~