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!

[44 AMP]

A slightly deeper firing pin strike on your reload's primers than seen on factory ammo could simply be the difference in cup metal hardness between the primer they used and the one you used. Or it could be the difference between different guns.

As long as the primers are not pierced and otherwise look normal, I would not consider it a real concern.

[FoundFather]

I think the firing pin strikes were not acutally deeper on my reloads than the factory ammo. I had marked the reloads with a black Sharpie so I could identify them. I think the black ink made the firing pin strikes look deeper. Once I cleaned it off, I couldn't tell any difference from firing pin strikes on facotry ammo.

I think my first relaoding experience was a complete success! My plan now is to increase the powder charge .1 grain at a time until I get to 5.2 grains. That is the listed starting load. I will probably be happy with that for plinking.

I want to load one or two thousand .40's for practice, before moving to 10mm and gradually working up a full power load on that platform. I will buy some slower buring powder before I do that

[FoundFather]

I loaded up and shot another batch of .40’s. The 180 grain FMJ’s shot great, with my starting load of 4.9 grains of Bullseye, 5.0 and 5.1. These are all below the “official starting load of 5.2 grains. Data I have says 5.7 max load but I see no need to go much higher for plonking. These rounds are cycling fine out of three pistols. But I really want to hoard the 180 grain bullets for later use in 10mm, and use some 165 grain FMJ’s I have.

I bought the Lyman manual and it has a load for 165 grains of Bullseye for Speer jacketed hollow point. The starting load was 4.8 grains. I loaded some up like that and gave them a try. Out of 30 rounds, I had one stove pipe and one failure to eject that didn’t even get to a stove pipe. Guess I need to increase the powder charge.

I am surprised a .1 reduction in powder will cause such failures when bullet is 15 grains lighter. Especially since with the 165’s I started with the “official” starting load, and with the 180’s I started 5% below the starting load. Does this make sense to you guys?

[Jim Watson]

That's where the business of "working up" comes in. Put in more powder for the 165s.

I must say, reducing a -10% "starting load" by another 10% or even 5% is news to me, but I have only been doing this stuff since about 1970 with Lyman and Speer books at hand. (Some calibers in Lyman have very light starting loads apparently chosen for 7000 psi, not any particular reduction in powder charge.)

You may be satisified with reliable function, I started out that way. Then I got a chronograph and now I adjust my loads for velocity. I have loaded
Factory equivalent.
USPSA Major power factor*.
USPSA Minor power factor*.
Least that will function the gun without getting too erratic.

*Power factor = bullet weight in grains X muzzle velocity in fps. Truncate to three most significant digits. 124999 -> 124 not rounded up to 125.
Minor is at least 125, Major is at least 165.

[Aguila Blanca]

Originally Posted by FoundFather

I am surprised a .1 reduction in powder will cause such failures when bullet is 15 grains lighter. Especially since with the 165’s I started with the “official” starting load, and with the 180’s I started 5% below the starting load. Does this make sense to you guys?

It makes perfect sense. Stop and think about it.

When a cartridge fires, the expanding gasses push the bullet down the barrel. Those same gasses also push the slide back, opening the breech and ejecting the empty case. Basic Newtonian Physics: action <==> reaction.

Once the bullet exits the muzzle, the gas pressure in the system drops nearly instantly to zero. Lighter bullets accelerate faster, so for the same powder charge (energy) they spend less time in the barrel.

Example: I opened up the Hodgdon web site and looked at some .40 S&W data for Winchester 231, the powder I use.

For 165 grain bullets, they list two: a Berry's plated flat-point, and a JHP. For the Berry's plated bullet, starting load is 4.7 grains / 25,200 psi. Max load is 5.4 grains / 33,400 psi.

The 165-gr JHP starting load is 4.8 grains / 28,100 psi. Max load is 5.3 grains / 32,500 psi.

They also list two 180-grain bullets, a Berry's plated flat-point and an XTP JHP. For the Berry's plated bullet, starting load is 4.4 grains / 26,400 psi. Max load is 5.1 grains / 33,500 psi.

The 180-gr JHP starting load is 4.1 grains / 23,800 psi. Max load is 5.0 grains / 32,900 psi.

See what's happening? For the heavier projectiles, both the starting and maximum loads are lighter than for the 165-grain projectile, but the pressures (which is what we're concerned with) are in the same ballpark. This is basically because a heavier projectile accelerates slower, resulting in more dwell time in the barrel.

You can run this comparison for any cartridge and any powder. The lighter bullets will call for a higher powder charge, not lower.

[FoundFather]

Originally Posted by Jim Watson

That's where the business of "working up" comes in. Put in more powder for the 165s.

I must say, reducing a -10% "starting load" by another 10% or even 5% is news to me, but I have only been doing this stuff since about 1970 with Lyman and Speer books at hand. (Some calibers in Lyman have very light starting loads apparently chosen for 7000 psi, not any particular reduction in powder charge.)

You may be satisified with reliable function, I started out that way.

LOL, I started at 15% below max rather than 10% based on some inputs upthread. As thread title makes clear, I'm a noobie, I know less about this than almost everyone on this board. My problem is, most of you have been doing this since Moses sold you his equipment, and for every 6 of you's, there are at least 12 opinions. What's a noobie to do?

And yes, for time being, I am satisfied with reliable function and safe operation. I plan to be at this for a while, so plenty of time to get "fancy" down the road.

Aguila Blanca, thanks. That is starting to make sense for me.

[Aguila Blanca]

To expand on those numbers I cited and the notion of the projectile's dwell time in the barrel, remember that smokeless powder is not an "explosive," it's a "propellant." When it goes off, it's not an instantaneous jump right to the maximum pressure -- the powder burns, and the pressure increases as the powder burns. For handguns, in general the powder is never completely burned up before the bullet leaves the barrel, so the dwell time is what allows the pressure to build up.

This may help you to visualize what I'm attempting to put into words. I fired up Gordon's Reloading Tool and dropped in a hypothetical .40 S&W load using Bullseye. NOTE: I had GRT on another computer. I didn't have it on this one, so I just downloaded it and installed it. Can't remember how to change units to Imperial, and I see a note that one of my inputs is incorrect. DO NOT use this as valid load data -- it's just to illustrate the idea of the pressure curve and the impact of barrel dwell time. The shape of the preesure curve will change if you use a faster or slower-burning powder.

[Nathan]

Looks like you are finding your way.If you are going below minimum loads, I would call the powder manufacturer. Below min loads can have wonky results. There are reasons for most min loads in books like position sensitivity, etc. those things won’t show up in GRT and quickload. Might be worth a call.