!!Lead Cast bullet vs FMJ Seating depth pressure question and discussion!!

[AJG]

!!Lead Cast bullet vs FMJ Seating depth pressure question and discussion!!

Have some questions:

Data:
1. Lee 124 grain TC tumble lube 9mm Luger lead (wheel weight) cast bullets are Diameter: .355" lube grooves and .358" base.
2. Lee 124 grain TC tumble lube 9mm Luger lead (wheel weight) cast bullets are bullet Over all length (OAL): .578" Long.
3. 9mm Luger rounds loaded with Lee 124 grain TC tumble lube 9mm Luger lead (wheel weight) cast bullets are taper crimped to: .377" on case mouth (were the round head spaces in the chamber).

4. Winchester 115 grain FMJ round nose (reloading components) are Diameter: .354".
5. Winchester 115 grain FMJ round nose (reloading components) are bullet Over all length (OAL): .587" Long.

6. Original factory PMC 9mm Luger round is crimped to: .377" on case mouth (were the round head spaces in the chamber).
7. Original factory PMC 9mm Luger round is over all round length (OAL): 1.155" (OAL).

8. Reloaded 9mm Luger rounds loaded with Lee 124 grain TC tumble lube 9mm Luger lead (wheel weight) cast bullets are over all round length (OAL): 1.044" (OAL).

Is this normal? Specially the OAL of the rounds are considerably different. Original factory round has OAL of 1.155" and the reloads with cast bullets have OAL 1.044".
I had to seat the cast bullets deeper since they did not go all into battery since pieces of lead of the bullet was getting between the case mouth and chamber headspacing not letting headspace both. I seated the lead bullets deeper and then the headspacing Problem was gone similar to this YouTube Video: https://www.youtube.com/watch?v=POIBBivXPww.

Will there be an pressure issue? Case Volumen is reduced seating the cast bullets deeper but at the same time I load for cast bullets 3.3 grains of powder while for FMJ bullets I load 4.3 grains of powder. So empty airspace Volumen in the case should be equal again with the reduced powder Charge on this heavier cast bullet. I guess empty airspace Volumen is equal again and therefore should be the pressure (PSI or CUP) since P*V=n. P=pressure, V=Volumen of the case and n=powder Charge. Therefore: P=n/V while temperature is a constant as well crimping is considered constant and bullet weigth is variable but a constant since neutralised by reduced powder charge.
P (lead cast Lee 125 grain)=-n/V [more bullet weight but less powder. Case empty volumen equal].
P (FMJ 115 grain)=+n/V [less bullet weight but more powder. Case empty Volumen equal].

Is this my reasoning Logical? Will there be an higher pressure or not?

[RedHawk357Mag]

I find that this picture gives a pretty good visual about seating bullets deeper. It is something that was published by White Labatories.

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[RedHawk357Mag]

I will also add that today while working up some 40 S&W loads with CFE Pistol and a cast 170 grn bullet. Using Hodgen data for the Berry 165 grn I did work ups of 10 rnds starting at 6.8, 7.0, 7.2, 7.4. Everything was peachy over the chronograph and brass appeared normal. Until I recovered the last set of brass. The 7.4 brass brass had three flow back primers, seven other cases were normal. Data from chronograph was unremarkable. The Brass was separated by headstamp but I group Blazer, Speer, and any Federal head stamp with a year as alike brass and this is what I loaded today. So variance is possible with brass, as variance could also be from cast bullet weights. Powder charges were trickled to ensure powder measure would not influence data as these were first work ups for this bullet with this powder. Pressure can do funny things it seems. I was a tenth under book Max with a longer COL of 1.133" with their listed COL of 1.125". The old hats aren't kidding when they say work up you data for your guns and components.

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[AJG]

Yes that Picture is indeed very interesting and explanatory.

I wonder what would happen (how many PSI) if for 2.7 grains Bullseye the 148 bullet would have been seated right against the powder. All seems to depend of the empty airspace Volumen of the case. The Variation in my case is roughly 0.1" and the Variation in the Picture is roughly as well 0.1": and for an 0.1 Variation in the Picture the pressure is doubling for a heavier bullet as mine.
The heavier the bullet the more the pressure Variation I may assume. Otherwise the conical design basically ONLY ALLOWS FOR DEEP SEATING as such as only the cone is to be seen from the outside (as is in my case). In case of an wacutter only the dome should be stick outside the case as seen in the first Picture from the left.

[AJG]

I as well watched closely the primers for anormalities and primer pocket of spent brass as well as "ease of priming" or head case Separation. None of These signs of overpressure were observed. Es well the primers primed as normal (no one was abnormally easy).
I heavy lube the cast bullets (dip 'em completely in) with Lithium grease (Texaco Marfak) and do not Experiment leading. The lubing and lead bullet my contribute to a more Slick bullet but I believe I crimp 'em medium to heavy (by feel on the Hornady taper crimp die).

[reddog81]

Can you size the bullets? I'm guessing if you sized the bullets down to .356 or .357 you should be able to set the bullets out a little further before hitting the rifling. 1.04 is getting on the short side of things for 9mm.

[Forrest r]

It's always good to start low and work a load up.

[IMG][/IMG]

Ramshot used to put this in their reloading manuals.

[IMG][/IMG]

Chronographs are your friend.

[AJG]

Thank you all for those very informative technical drawings and info.

I guess I am still within specs. I can feel the recoil is on par with an normal factory 9mm Luger with this 125 grain lead cast bullet, seating depth and crimp but I use only 3.3 grain of Bullseye type powder (scavenged from 12 ga shotshells for reloading).
Fortunately it is a 9mm Luger and not 40 s&w.

To be on the safe side I will back off the Bullseye type powder from 3.3 grains to 3.1 grains in order to reduce pressure. I will see if the pistol cycles with 3.1 grains reliable.

[dverna]

AJG, I doubt that the 12 g shells are loaded with Bullseye. It is too fast for most 12 ga loads. It is probably, something like Red Dot or 700x. Hunting loads with more shot will have even slower powders.

[AJG]

I just finished reloading 3 9mm Luger 125 grain Lee TC tumble lube lead cast bullets but this time I used 3.1 grain of Bullseye/Universal type (scavenged shotshell powder).
They funktioned flawlessly.
The semi Auto pistol worked without any issue and loaded allways. They penetrated easily an 1" soft Wood woodsheet.

I will reduce the powder Charge in any further load to 3.0 grains for both types of powders (Argentinian Orbea shotshells and Spanish Saga shotshells) since they differ in about 0.3 grain in power. With that I believe I am in safe Limits for 9mm Luger and 9mm federal Rimmed with both seated at 1.044" and crimped to about .377".
So 3.0 grain for eighter of the two powders I should be fine I think.

[Shiloh]

I seat a LEE .358 RF in the 9mm. You MUST back of the charge. This boolit goes further into the case than a 9mm RN seated at the same OAL.

SHiloh

[AJG]

Explanation found for those wrinkled cast bullets:
<<Yes it should be zinc then. That explains particularly as well the difficulty I experiment with wrinkled bullets and not filling out well the cavities. As normal I get 3 good bullets (cavities filled out completely) and 3 did just fill half (out of a total of 6 cavities).
It may be very well there are lots of zinc wheel weights (maybe 1/3 of the total).
As I use a aluminum water kettle for casting I noticed the long pipe gets to cold in that manner the lead/zinc is getting hard while pouring/casting and it pluged once the whole pipe. That as well might explain the wrinkled bullets and partially filled out cavities.

I can live with wrinkled bullets since I shoot them as long they have sharp edges on the base and cone. >>

So those Lee 125 TC tumble lube cast bullets may have an fairly high content of Zinc in it.
I shot just 4 shots of the 125 grain TC tumble lube Lee 9mm Luger bullets/round charged with 3.0 grain of Universal/Bullseye type powder (scavenged shotshell powder) and they worked (cycled flawlessly) but I noticed the slide is on the slower side.
So I believe for the Saga (Universal type shotshell powder) powder I will use for 9mm Luger and 9mm federal Rimmed 3.1 grain of powder and for the Orbea (Bullseye type shotshell powder. It is 0.3 grain quicker/more power than Saga) powder I will use 3.0 grain powder with both the bullet are seated deep and OAL (over all length of the cartridge) is 1.044". With this 1.044" deep seating the 125 grain bullet it's lube grooves are completely entered in the case and only the cone is sticking out. I believe that is how the bullets design is supposed to be and there is no risk of overpressure with this reduced powder. I do not size the bullets.

[AJG]

PROOF NO LEADING IS PRESENT: I just ran a brass brush several times through both Barrels (pistol and Revolver) and NOTHING CAME OUT WHASOEVER on an White paper. The Barrels look cleaner know since the black powder residues are gone but nothing showed up on an White paper. So I may definitively affirm my unsized cast bullets DO NOT LEAD AT ALL.
Seems to be that FortuneCookie45 (on Youtube) has right: cast bullets cast with Lee molds do not Need to be sized. The best sizing does the rear back of the cylinder of an Revolver and the Barrel of an pistol. Obviously the cast bullets must be oversized to at least 0.001" (mine are between .357" and .361" and I shoot them as cast). I do not water quench in order they stay as soft as possible in order to be sized easily by the cylinder/Barrel and to better obturate. They are heavily lubricated with Texaco Marfak MP2 (NLGI 2) Lithium grease and I just scrape off the grease on the base of the lead cast bullet were it touches the powder. I may have heavy Content of Zinc in my bullets but they all weigh about 125 grain. Seating depth of These TC TL bullets is 1.044" below 3.0 grain or 3.1 grain scavenged shotshell powder.
I believe this is a recipe for success for at least my moderate Volumen of Shooting.