Noobie Question: How Exact Do You Need to Match Load Data?

[FoundFather]

OK, I know the right answer is: completely exact. But with shortages of many components, some producers discontinuing production, and high haz mat and shipping charges making small purchases uneconomic, it's tough. So I am hoping you guys can help out the new guy here!

I am just starting out in reloading. I bought a press, dies and some supplies a couple years ago and would like to try to use what I've got. My current goal is to load some .40 S&W, mild not wild, for practice reloading. Later I would like to load 10mm where cost savings are greater and facotry loads often unsatisfactory.

The powders I have on hand I origianlly bought with a different goal in mind, to relaod for .32 S&W ("short") which is super hard to find factory loaded. I was persuaded that wasn't a good calber for a beginner, so I am putting that off for a while. Powders I have are Unique, Red Dot and Bullseye. All fast burners, maybe not ideal for .40 and certainly not for 10mm. I have the most Bullseye so would like to get some use out of it loading for .40.

Alliant publishes limited data for Bullseye in .40. One recipe I am eying is for Speer 180 gr CPFN, Federal cases, CCI 500 SPP primers, and 5.7 grains of Bullseye. Alliant recommends -10% for starting load.

I assume other brands of cases are subsitutable. I have been saving .40 brass but it is mixed headstamps. Fortunately, I have CCI 500 SPP.

Problem is the bullets. I have large quantities of two bullets. Both are by Montana Gold, which is no longer operating but had a reputation for good quality. They are both jacketed. I have the most of 180 grain FMJ FN: http://montanagoldbullet.com/10mm-40-180gr-fmj-1-000ct/

These are pretty close, but not identical, to the Speer 180 gr CPFN in the published recipe. The Speer bullets are plated, not jacketed. I understand my jacketed bullets may casue higher pressures. Are they safe to use with this recipe?

I also have some 165 grain bullets from Montana Gold that are similar to the 180's, but CMJ "Complete Metal Jacket" with copper jacket on the base as well, sort of like a gas seal. (They no longer show these on the web site.) The data Alliant publishes for 165 grain bullets are for 165 gr Speer GDHP. Can I use my bullets with a receipe that calls for hollow points? I would like to use the 165's for this and save the 180's for 10mm.

Any guidance most appreciated.

[Ricklin]

Load plated bullets the same as plain unjacketed lead.
Do you have a chronograph? Really useful tool esp if you are reloading.
I picked up a plastic version of my old shooting chrony very recently from a china website. most anyone can afford 32 bucks. Temu. com Not only that it works far better than my old Chrony. Instead of the Rube Goldberg "sky screens" it has a strip of IR LED's at each end. So far so good. Heck I pd. 100 bucks for my old Chrony 20 years ago.
Gonna miss some of this cheap chinese stuff.

[ligonierbill]

My latest Speer manual lists Speer's 180 FMJ bullet with a starting load of 4.9 gr Bullseye, 5.5 max. Should be OK with your FMJs. This is, of course, a <1,000 fps target load. Personally, I use Power Pistol in 40 S&W.

BTW, you are wise in not starting with 32 S&W. With smokeless powder, charge weight is ridiculously low. And with the top break revolvers typically chambered for it, a slightly hot load will break the latch. Yes, I've done it. Before I sold my old H&R (with a new latch), I was loading 5 gr of a BP substitute.

A chronograph is not required for load development. Many do fine without one. But not me. I always use a chronograph.

[44 AMP]

Bullseye is a fast powder, Unique is considered a medium burn rate pistol powder and Red Dot is a bit faster than Unique.

Are they safe to use with this recipe?

In your gun? probably, but no one can answer that with 100% certainty until the load is tested in your gun. Very high likelihood it will be safe, but whether or not it will be suitable is a different matter.

Reloading data are guidelines, not holy writ. Very precise and accurate information for what they tested and the results they got.

You and I don't have what they tested. We have similar but different components and guns, and while most things fall within the middle of the bell curve (and so their data is useful guidelines) there are combinations that are at each end of the spectrum, and no one knows what any specific combination will be in your gun, until its tested in your gun.

I got a chronograph back in the last century, when the price had come down to $100. Used it off and on, for a few years, then put it away, have no idea where it is, haven't seen it in decades. Don't need it.

What it did teach me is that the velocities listed in the loading data is within the range of data you get firing the same ammo from different guns.

And that extreme uniformity of velocity is not always needed for good accuracy, what matters is how your gun shoots them. Some guns will group well even with ammo that has relatively "large" variations in round to round velocity, and while this might not be a good thing for shooting one hole groups at hundreds of yards, shooting a pistol at 25yards, can be a lot more forgiving.

[Ricklin]

I think our old Chronographs may be related, my folding steel box shooting Chrony was about a hunert bucks back in the day.
I use the chronograph very little for pistol, less yet for shotgun, but really like having a Chronograph for rifle rounds.
Really like the cheap charlie China unit, it works indoors or out not at all fussy about lighting. The "window" is smaller, but quite useable. Since getting in to the PCP guns the chronograph gets used more.

[FoundFather]

Thanks, all. 44 AMP this is the guidance I guess I was looking for:
[QUOTE]Reloading data are guidelines, not holy writ. Very precise and accurate information for what they tested and the results they got.
You and I don't have what they tested. We have similar but different components and guns, and while most things fall within the middle of the bell curve (and so their data is useful guidelines) there are combinations that are at each end of the spectrum, and no one knows what any specific combination will be in your gun, until its tested in your gun./QUOTE]

As I mentioned, I really would like to use the 165 grain bullets I have. Alliant publishes a load for 165 grain Spper GDHP with 5.8 grains of Bulleseye max and 5.2 grains starting. Although my 165 grain bullets aare Montana Gold FMJ, if I start at the 5.2 grains it seems I should be OK. I will try them out in a few different guns and see how they work. I am more interested in getting hands on practice reloading without losing a finger or an eye than I am interested in producing the perfect load at this point. Plinking ammo is fine.

[44 AMP]

The standard advice, for generations, has been that, when you change any component, you take the listed starting load, drop 10% in powder charge, load a few and fire them, to ensure you don't have something freakishly out of the usual, and if not, then go to the starting load, and load a few of them, and test fire. IF that load level gets you what you want, you're good to begin loading in volume. IF not, then you start CAUTIOUSLY experimenting, one small step at a time.

(note, there are a couple of powders where the maker specifically warns not to go below the starting load. Bullseye Red Dot and Unique are not those powders. I mention this only to show that there are exceptions to the general rule, and that the makers inform the loader when those are the case.)

You may find that a below listed starting load, may not cycle your pistol. Sometimes the listed starting load may not cycle your pistol reliably. That's why they are called starting loads. A safe place to start, and work up from, as needed.

I am just starting out in reloading.

Congratulations! And Welcome!
You mention a press, dies, and some supplies, but you do need a few more things than just those. You don't need every tool in the shed when you're first starting out, but you do need a few more than you named.

A BOOK is first on the list. Not a website or a U tube video, an actual physical book from Lyman or any of the bullet makers have sections on the mechanics of loading ammo, as well as data tables of loads. Get one, or more, and read them. The other basic tools are a way to measure powder. Scoops may do what you need but a scale is my recommendation.

For mixed brass, you need to sort them, twice. And you'll need a caliper for measuring. Sort first by headstamp. You may find you have enough of one headstamp to make up a full box. But if not, its not critical, the small variations between different makers cases won't be an issue at starting load levels.

And then sort each batch by case length. What you are looking for are cases longer than the listed max length in the loading manuals. If any are too long, set them aside for later on down the road.

There are a lot of things you can do, and should do but don't need to get into right away. Get an understanding of the very basics first, then work on more advanced things.

A loading block is very useful and while not an absolute necessity, you will want one (or more).

When you have questions (and, you will) or something you don't quite understand the how, or the why, TFL is a very, very good resource, and we're here to help.

[FoundFather]

Thanks again, 44 AMP. I had not heard the 10% below starting load before. I had thought that 10% below max WAS the starting load. I will try a few of those first. Failure to cycle is a problem, but it is not in the same league as blowing up your gun and your hand!

I do have a basic pile of other equipment, including powder metering device, dipper and powder scale. I have tried to avoid mention of specific equipment because I wanted to stay focused on the load. I am on number of gun forums and I know how easy it is to get sidetracked into a "Ford vs. Chevy" "Remington 870 vs. Mossberg 500" kind of discussion.

[Unclenick]

I don't think I've ever seen an example where an additional 5% off didn't cover pretty well for all potential sins among canister grade powders, except outright powder deterioration. Western used to recommend -15% for handgun starting load, and -10% for rifle. You will note some published starting loads are only 5% or 6% below maximum, and this can be because you don't want to let the powder fill get to be less than 60% of the space below the bullet (and many recommend 70% just for a margin). Going below 60% can cause some powders to ignite erratically and bounce both high and low.

The other consideration is climate. I don't live in a dry climate, and I don't test on very hot days. If you do live in a bone-dry climate and your powder sits a spell, even in an original container with a closed lid, it will eventually equilibrate with outside RH, and that increases powder burn rate, raising pressure. So, if you live in Arizona and are shooting on a very hot day and the powder has been in your dry air long enough to lose moisture, you can see where an extra 10% off might come from. Just don't go that low if it makes too much empty space in the case.

[BJung]

From my records:

40-170TC Lee Cast. Winchester case, Rem Primers. Group was only 3" with 9/10 shots at 25 yards.
4.6 BE with an OAL 1.250"

I get better groups with AA5 so Unique.

[FoundFather]

I got my first cartridges loaded! The closest published data I could find to match the components I have on hand was from Alliant's website. It was for 180 grain Lee Copper Plated Flat Nose bullets, 5.7 grains max of Bullseye powder and CCI 500 SPP. I had the Bullseye and CCI primers. My bullets were close but not exact. The Montana Gold 180 grain bullets I have are jacketed, while the Lee bullets are plated. The Lee bullets are supossed to measue 0.585" long, while my bulelts were 0.595" long. I debated whether to seat them less deep for a COL 0.01" longer in order to keep the empty case volume the same as the recipe, but decided against it.

I loaded 15 cartridges using a batch method, performing one step at a time. I weighed each charge, checked and measured eerything three times. Probably the slowest 15 cartridges ever loaded. But I learned a lot about my equipement and the process along the way. Recipe called for COL of 1.12", and mine were all between 1.115 and 1.125. Recipe max was 5.7 grains of powder, I loaded these to 4.9 grains, approximately 85% of max.

Went to an indoor range today. All 15 functioned great. Shot them throguh three different guns and they cycled fine. Sample size with three guns was a little small to judge accuracy, but my impression was that I was accurate with the two guns I normally shoot well, and not accurate with the one that I don't. Funny how that works

I don't feel much need to increase powder load, since these function fine for plinking, and I want practice reloading.

I recovered 11 of the 15 cases (popular indoor range with random brass everywhere). I suspect the firing pin strikes might be a little deep, deeper than they were with the factory ammor that I also shot. I need to research that a bit. I may put up photos of the primer strikes, but I need to clean the case heads first, I marked them with a Sharpie so I oculd identify them.

In the meantime, I have a problem with my press, but I am going to start a new thread for that, it is a different subject.

Thanks to everyone on here for the inputs and encoragement!