Loading 45 ACP - trying to understand the variables

[hotrail]

OK another newb question here...go easy.

Trying to understand reloading data. I am loading some 45ACP with 230 gr. Berry's plated RN and "CFE Pistol" powder. I looked at the data on the Hodgdon web site for this powder. They have data for a "230 gr HDY FMJ FP" with a starting load of 6.0 and a max of 6.8. Then they have "230 gr. LRN." with a starting load of 5.4 and a max of 6.2. The stated C.O.L. is the same for each.

So I understand the general rule is the plated bullets load to the same spec as the cast bullet, not the FMJ. So I started my loads in a safe range for the LRN bullet.

What is interesting is that the tested velocities (as shown on Hodgdon website) for the two loads are almost identical, both starting and max, despite the projectile being the same weight and the FMJ bullet having about 10% more powder. I am curious to understand why no difference in velocity for the difference in powder charge?

Second, chamber pressure is about 10% higher for the FMJ starting load, but at the max loads chamber pressure is listed as about 1.5% higher for the LRN load (which was 10% less powder). This seems totally counter-intuitive.

I would have expected a more linear relationship between the powder charge and the velocity, for an equal weight projectile. Are the differences a functon of the relative shape and length of the projectiles, giving a different volume inside the case? Or is it something else?

Also how much difference should I expect if I don't seat the bullets down all the way to the quoted 1.200? I assume that gives a bigger case volume and will result in lower chamber pressure (and presumably lower velocity)?

[Win231]

A jacketed bullet has more resistance in the barrel than a lead bullet, so it needs a bigger powder charge to generate the same velocity. The plating on a plated bullet is soft, unlike a copper jacket & should only be loaded to mid-range velocities. At high velocities, the plating can come off & become stuck in the barrel.

And, when loading jacketed bullets for a pistol-caliber rifle, target velocities made for lead bullets should never be used. The bullet needs to clear a much-longer barrel.

[robert101]

I know you didn't ask, but in general I don't shoot lead or plated bullets over 1,200 fps. Check your target to make certain no fragmenting or plating has pealed off at what ever velocity you shoot. I have some Rainier plated bullets in 10MM that I regularly push to 1,200 fps without a problem. It depends on the bullet and plating really.

[acourvil]

You will not get a 230gn bullet to 1200fps in 45acp with any reasonable load. Most factory loaded 230gn rounds are 800-850fps.

The fps/powder charge curve is not linear because the pressure curve is not linear, and the exact curve will vary depending on the powder and projectile used.

My experience is that for 45ACP the seating depth doesn't have a great effect on the observed pressure/fps (at least for the powders I've used). Depending on the gun, it can have significant effect on how smoothly the gun cycles (and whether you get feed problems). 1.200 is on the short side for a 230gn round; if you have feed problems, try moving it out to 1.250 or so.

[kcheung2]

The weight is not the only consideration, the construction and shape are also factors. That's why loading tables have different data for the same weight but round nose vs flat vs hollow point.

Take a fmj projectile and try to scratch it with your fingernail. You won't make a mark. But try the same thing with a plated or full lead projectile, and you'll leave a mark. The harder projectile means it take a bit more force to push it down a barrel, which is why fmj charges are higher. That extra resistance also explains why the velocity is approximately the same despite higher chamber pressures.

Charges are not perfectly linear. They may be approximately linear in a small range but it's not a reliable indicator.

[bazineta]

I haven't a clue why there are manuals listing 230gr bullets at a COL of 1.200; that combination just isn't found in common usage -- if you measure any factory 230 ball round, you'll find it to be around 1.260.

[noylj]

The jacketed bullet has more resistance? Yet, the lead bullet produces the same velocities and near the same pressure with LESS powder.
First of all, accept the fact that lead bullets and jacketed bullets are different.
Next, be aware that you START all loading at the START load and not somewhere in the "safe" zone.
If you look at three manuals, you'll quickly see that there is no safe zone--pressure depends on the gun, the lot of powder, the exact bullets used (including, often, the lot number—as manufacturer's replace molds as they wear out or decide to make improvements and don't tell anyone), the cases used, the primers used, and the COL. So, NO manual can tell you what you'll get with your mix of components and no manual is more "accurate" than another manual. Learn to check a couple of sources and don't assume anything.
For SAAMI ammunition testing, it is common to use a short COL (as a worst case situation for pressure testing). Some manuals follow this test procedure and some use a more normal COL.
STOP looking at the test COL and start working up the COL for YOUR gun, YOUR magazine, and YOUR bullet.

[rm1911]

You will not get a 230gn bullet to 1200fps in 45acp with any reasonable load.

Someone needs to expand their horizons a bit

In actuality, 45 is probably one of the easiest rounds to load for. There's a large list of powders that will work, and most give pretty good results. Because it's got a generous case, runs at lower pressures, pretty much any faster burning powder will run well. For some real fun with a 45, go to a rifle range at night and sling some jacketed slugs downrange. You can literally see the round in flight.

And since it's a lower pressure round with no threat to push velocities above 1000fps data for jacketed and lead kinda interchange. Any jacketed load will work for lead. And since most lead data is lighter, it will usually work fine with jacketed. And plated bullets honestly any published data will work fine.

[hambam105]

Plated bullets in any caliber bite. Cast or a real FMJ is fine.

[Socratic]

Hi hot rail,

You've got the right cartridge to reload. The .45 ACP is vey easy to reload. Lots of powder will give good results. I've tried a lot. Don't overlook Unique.

If you can get your hands on a copy of Ken Waters', Pet Loads, I'd suggest that you grab it. Ken has a lot go excellent info on hand loading the .45 ACP, and just about every other cartridge. It's my primary source of load data:

https://www.amazon.com/Pet-Loads-Complete-Ken-Waters/dp/1879356643/ref=sr_1_1?ie=UTF8&qid=1492875006&sr=8-1&keywords=ken+waters+pet+loads

[stilly]

That book needs to be redone. They whored the hell out of it as cheap as possible...

Data quality = 8+
Artwork/ photos quality = 2

It would be NICE to know what a particular round looks like when it is loaded if it is not a normal one and photocopied photos from magazines aint cool. Not even half toned half of them....

[noylj]

Per Ramshot:
"SPECIAL NOTE ON CARTRIDGE OVERALL LENGTH “COL”
It is important to note that the SAAMI “COL” values are for the firearms and ammunition manufacturers industry and must be seen as a guideline only.
The individual reloader is free to adjust this dimension to suit their particular firearm-component-weapon combination.
This parameter is determined by various dimensions such as
1) magazine length (space),
2) freebore-lead dimensions of the barrel,
3) ogive or profile of the projectile and
4) position of cannelure or crimp groove.
• Always begin loading at the minimum ‘Start Load.’"

Your COL (Cartridge Overall Length) is determined by your barrel (chamber and throat dimensions) and your gun (feed ramp) and your magazine (COL that fits magazine and when the magazine lips release the round for feeding) and the PARTICULAR bullet you are using. What worked in a pressure barrel or the lab's gun or in my gun has very little to do with what will work best in your gun.
Take the barrel out of the gun. Create two inert dummy rounds (no powder or primer) at max COL and remove enough case mouth flare for rounds to chamber (you can achieve this by using a sized case—expand-and-flare it, and remove the flare just until the case "plunks" in the barrel).
Drop the inert rounds in and decrease the COL until they chamber completely. This will be your "max" effective COL. I prefer to have the case head flush with the barrel hood (or a few mils higher than where the head of an empty case aligns with the barrel, as all cases are too short and I prefer to minimize head space). After this, place the inert rounds in the magazine and be sure they fit the magazine and feed and chamber.
You can also do this for any chambering problems you have. Remove the barrel and drop rounds in until you find one that won't chamber. Take that round and "paint" the bullet and case black with Magic Marker or other marker. Drop this round in the barrel and rotate it back-and-forth.
Remove and inspect the round:
1) Scratches on bullet--COL is too long
2) Scratches on edge of the case mouth--insufficient crimp
3) Scratches just below the case mouth--too much crimp, you're crushing the case
4) Scratches on case at base of bullet--bullet seated crooked due to insufficient case expansion (not case mouth flare) or improper seating stem fit
5) Scratches on case just above extractor groove--case bulge not removed during sizing. May need a bulge buster.

[BajaJames83]

I normally seat between 1.23 and 1.25 1.20 seems a little short

[Ktm45]

Just to jump in here the OPer said he is/will be using coated (poly ) rounds. How are those working out for you guys? Any feed issues? I have CZs and I've been told they can be finicky.....but my CZ will eat anything....brass cased.

[JagerDog]

OK another newb question here...go easy.

Trying to understand reloading data. I am loading some 45ACP with 230 gr. Berry's plated RN and "CFE Pistol" powder. I looked at the data on the Hodgdon web site for this powder. They have data for a "230 gr HDY FMJ FP" with a starting load of 6.0 and a max of 6.8. Then they have "230 gr. LRN." with a starting load of 5.4 and a max of 6.2. The stated C.O.L. is the same for each.

So I understand the general rule is the plated bullets load to the same spec as the cast bullet, not the FMJ. So I started my loads in a safe range for the LRN bullet.

What is interesting is that the tested velocities (as shown on Hodgdon website) for the two loads are almost identical, both starting and max, despite the projectile being the same weight and the FMJ bullet having about 10% more powder. I am curious to understand why no difference in velocity for the difference in powder charge?

Second, chamber pressure is about 10% higher for the FMJ starting load, but at the max loads chamber pressure is listed as about 1.5% higher for the LRN load (which was 10% less powder). This seems totally counter-intuitive.

I would have expected a more linear relationship between the powder charge and the velocity, for an equal weight projectile. Are the differences a functon of the relative shape and length of the projectiles, giving a different volume inside the case? Or is it something else?

Also how much difference should I expect if I don't seat the bullets down all the way to the quoted 1.200? I assume that gives a bigger case volume and will result in lower chamber pressure (and presumably lower velocity)?

1.5% is well within the variability of the testing itself.

Those loading lead tend to seek modest (target) velocity, so more data is generated for the intended use. Jacketed can be from "plinking" to SD.

As stated above, jackets create more resistance (engraving by the rifling), so pressure tends up and more powder is required for same velocity.

I think you'll find most factory 230 gr FMJ to measure 1.230" - 1.250" COAL.