Pistol World Forums banner
1 - 5 of 5 Posts

·
Registered
Joined
·
9 Posts
Discussion Starter · #1 ·
I'm loading a 230 gr TMJ RN bullet for .45 ACP, and am finding
wide varriance in the load data. Speer's 14th edition indicates
5.2-5.7 grs of Bullseye. Lyman's 49th edition shows 3.8-5.3 grs
of Bulleye. I was thinking of using 5.5 grs, but that exceeds the maximum on the Lyman book. Are there other sources I should be checking?
 

·
Registered
Joined
·
640 Posts
There will be little, if any consensus on load data. Load books are a general guideline as different guns can and will show pressure signs at different points. Some gun and load combinations will "max out" at less than the published while other combos can go to greater amounts without signs of pressure (though I don't recommend that). Every source will be different as each test barrel will produce different measurements, even with the very same loads. The bullet used will also be an important factor as they are not all alike. The different manufacturers use different alloys for thier jackets so some are "slicker" than others which will lead to lower pressures and allow for greater powder charges. Even in the same bullet weights, the bullet shape will be different causing more/less of the bullet to be in contact with the bore which again affects pressures, velocity, and therefore powder charge.
This is why the manuals always suggest using ONLY the EXACT data published and to start at the minimum and work up looking for signs of pressure which is why they are included in reloading manuals. It is also why more advanced literature recommends starting back at the minimums and working up whenever any substitution of components is made. It is also not uncommon to see the suggestion that one get a chronograph and measure velocities as they are also a product of pressure so when one hits the maximum listed velocity, they should stop as that quite possibly is nearing the pressure limit.
What I would do is find if there is any literature for the specific brand and style of bullet being used and follow that. If there is no specific info, then I would begin at the lowest suggested start load and advance up to the lowest "maximum" load checking for pressure signs. I would also compare point of impact in regards to the sights to the loading I was trying to simulate and stop when they seemed to match and the gun functioned correctly regardless of powder weight.
Though loading data is often referred to as "recipes," they are not as precise as baking a cake. Load data is a more of a general boundary description with some cloudiness on where they really end. It is better to stop a little short than go beyond for the most part.
 

·
Registered
Joined
·
606 Posts

·
Registered
Joined
·
9 Posts
Discussion Starter · #4 ·
Thank you very much. I checked the Alliant site, and they
indicate 5.7 grs. (no range--just exact), with no indication
of the barrel length used in testing. Remington makes the
230 gr FMJ RN, and I could not find ballistics for this bullet.

Think what I will do is to prepare 5 rounds of 3.8, another
5 rounds at 4.2/4.6/5.0 and 5.5. If I get an acceptable grouping with my 1911 S&W at one of these loads, I will
stop there and make that my reload.

Given Uglydog's information, I should do the same for the
230 gr. FMJ FN bullet made by Hornady. Previous to UD's
information, I would have assumed the same load for 230
gr FMJ bullets, whether they be flat nose or round nose.
Thanks for all your help
 

·
Registered
Joined
·
606 Posts
The shape of the bullet nose, although it has a great deal to do with ballistic coefficient, does not directly affect loads & pressures. What matters is the length of that portion of the bullet that bears against the bore and must conform to the rifling.

For bullets of equal weight, different shapes will have different bearing lengths. Hardness of the jacket material also plays a part.
 
1 - 5 of 5 Posts
Top