What does C.O.L. effect?

[Stopsign32v]

You are quoting data for a 158 gr lead semi wadcutter which is as different from a plated 158 gr bullet as is a jacketed one. Do not think the data is the same. If the manufacturer will not furnish you with data including oal find a manufacturer who will or pay attention to the previous posters all of whom seem to know of what they speak.

I see what you are saying. So do you just go by the cannelure as to where to seat it? I guess the pressure difference isn't that big of a deal?

 

[BC38]

Stopsign32v, you need to take your own advice and READ READ READ.

As I advised you in another of your threads, you need to READ a couple of good books on reloading and at least get a good fundimental understanding of the basics before you reload another single cartridge.

If you don't know the difference between a LSWC and a plated RNFP, and what effects those differences have on the cartridges you produce, then you need to STOP reloading and learn that the heck you are doing first.

Your posts have made it very clear that you lack understanding of even the most basic principles, practices, and concepts involved in producing safe reloads. If you continue unchecked down this road you are going to get yourself or someone else hurt, or worse.

I implore you, stop trying to get your education on this topic by posting questions on the internet and read a damned book! THEN when you have some of the basics down, come back and ask questions. Seriously.

Understand that I am not trying to insult you. I am very concerned to read your posts and realize that you do not recognize the potential dangers in what you are doing. Reloading is in an activity that can be very dangerous, and you really need to learn enough about it to avoid the worst of those dangers BEFORE you jump in and start experimenting.

 

[Wise_A]

I'm using Xtreme plated bullets. Hodgdon says the XTP should be set at 1.455"

That one makes sense to me. But by them saying "158 GR. CAST LSWC"...Couldn't that be quite a few different bullets?

Here's the deal.

If the load data says something like "158-grain lead bullet", then the OAL they list is without context. It tells you what the OAL of the cartridge they loaded was, but we really have no idea what the bullet design was. In that situation, the OAL is utterly useless.

But suppose it says "158-grain LSWC"? Same issue. There are tons of different bullet designs for each weight and profile. You can have wildly different bullet lengths, with identical weights, simply because the two bullets have different ogives.

If I'm reading your posts correctly, you fall into this second category. You're using a 158-grain jacketed RNFP from Xtreme, but the listed data is for the Hornady XTP. Even though the bullets are of the same construction, weigh the same, and are of the same general design, they're unlikely to be identical dimensionally.

The only situation in which OAL data is truly useful is if they specific mold of the bullet, and you're also using that exact design. For instance, if you were looking through your Lyman manual and found data for a 158-grain LSWC #1234567, and you also happened to be using bullets poured from a #1234567 mold.

But...not always.

Sometimes, the manualmakers will pick an OAL almost arbitrarily, and intentionally seat the bullet deeper than normal. For instance, they might seat the bullet up to the shoulder. In which case, they list the "minimum OAL" as that--the shortest OAL they tested.

I see what you are saying. So do you just go by the cannelure as to where to seat it? I guess the pressure difference isn't that big of a deal?

The bulletmaker didn't simply place the cannelure at the top of the bearing surface, or pick it at random. The placed it such that if you seat to that depth and crimp there, the amount of case volume occupied by the bullet will be no more than what was tested in load data.

 

[Bosquebass]

I'm using Xtreme plated bullets. Hodgdon says the XTP should be set at 1.455"

That one makes sense to me. But by them saying "158 GR. CAST LSWC"...Couldn't that be quite a few different bullets?

You should understand that in this case XTP is the trade name Hornady uses for their full metal jacket hollow points.
"XTP" is not an abbreviation for "Xtreme Plated".

 

[Stopsign32v]

Stopsign32v, you need to take your own advice and READ READ READ.

As I advised you in another of your threads, you need to READ a couple of good books on reloading and at least get a good fundimental understanding of the basics before you reload another single cartridge.

If you don't know the difference between a LSWC and a plated RNFP, and what effects those differences have on the cartridges you produce, then you need to STOP reloading and learn that the heck you are doing first.

Your posts have made it very clear that you lack understanding of even the most basic principles, practices, and concepts involved in producing safe reloads. If you continue unchecked down this road you are going to get yourself or someone else hurt, or worse.

I implore you, stop trying to get your education on this topic by posting questions on the internet and read a damned book! THEN when you have some of the basics down, come back and ask questions. Seriously.

Understand that I am not trying to insult you. I am very concerned to read your posts and realize that you do not recognize the potential dangers in what you are doing. Reloading is in an activity that can be very dangerous, and you really need to learn enough about it to avoid the worst of those dangers BEFORE you jump in and start experimenting.

I really appreciate your reply. I've read the Lyman book so far and I also picked up "The complete book of Reloading" and I'm reading through it.

I understand a waddcutter, semi waddcutter, round nose, flat nose, etc. I do however, not understand how far a bullet should seat in the case. I understand I believe it was 1.55 to be the max overall size for the finished cartridge. However everything in the middle confuses me and each bullet has it's own seating depth. I'm going to give Xtreme a call tomorrow.

Again thanks for your reply and don't think I take constructive criticism hard, you make some great points.

These loads I checked on my weight scale about 15 times to make sure my powder measure was dropping the right amount. And every 20th or so I would check to make sure nothing has gotten out of whack. Hope I've done alright there.

 

[Stopsign32v]

You should understand that in this case XTP is the trade name Hornady uses for their full metal jacket hollow points.
"XTP" is not an abbreviation for "Xtreme Plated".

I know, I have a case of 125gr XTP right here. But I can see how someone would think that lol

 

[Stopsign32v]

Here's the deal.

If the load data says something like "158-grain lead bullet", then the OAL they list is without context. It tells you what the OAL of the cartridge they loaded was, but we really have no idea what the bullet design was. In that situation, the OAL is utterly useless.

But suppose it says "158-grain LSWC"? Same issue. There are tons of different bullet designs for each weight and profile. You can have wildly different bullet lengths, with identical weights, simply because the two bullets have different ogives.

If I'm reading your posts correctly, you fall into this second category. You're using a 158-grain jacketed RNFP from Xtreme, but the listed data is for the Hornady XTP. Even though the bullets are of the same construction, weigh the same, and are of the same general design, they're unlikely to be identical dimensionally.

The only situation in which OAL data is truly useful is if they specific mold of the bullet, and you're also using that exact design. For instance, if you were looking through your Lyman manual and found data for a 158-grain LSWC #1234567, and you also happened to be using bullets poured from a #1234567 mold.

But...not always.

Sometimes, the manualmakers will pick an OAL almost arbitrarily, and intentionally seat the bullet deeper than normal. For instance, they might seat the bullet up to the shoulder. In which case, they list the "minimum OAL" as that--the shortest OAL they tested.



The bulletmaker didn't simply place the cannelure at the top of the bearing surface, or pick it at random. The placed it such that if you seat to that depth and crimp there, the amount of case volume occupied by the bullet will be no more than what was tested in load data.

THANK YOU!

That is exactly what I needed to hear to stop 2nd guessing myself. That makes perfect sense.

 

[fredj338]

I'm using Xtreme plated bullets. Hodgdon says the XTP should be set at 1.455"

That one makes sense to me. But by them saying "158 GR. CAST LSWC"...Couldn't that be quite a few different bullets?

COL is the most misunderstood & seemingly difficult thing for most new & some exp Reloaders grasp. Its really this simple; COL is bullet & barrel specific. So any COL in data is only specific to the exact bullet or one very sim profile. A RNFP is mot. RN is not a SWC. What works in my gun might not in yours.
Yes seating a bullet deeper will increase pressures, but the amount depends on powder burn rate & case size. Also, rifles are diff than handguns. With rifles, seating deeper actually moves the pressure needle lower, as the bullet gets a greater run to the lands. Kind of like long throating in a Weatherby. The only concern with deeper seating in any revolver is full wadcutters & fast powders.

 

[rwsmith]

Revolver cartridges are forgiving......

Deeper and farther out in a .38 does raise and lower pressure, but because of the volume of the case, it is so insignificant that you can seat the bullet pretty much anywhere along the shank from the ogive to the base when you are below max pressure. The main problem in a revolver is that a too long cartridge stops the cylinder from turning.

A case with more limited capacity like the 9mm is very sensitive and pushing the bullet in deeper raises pressure pretty fast. Seatng the bullet out longer will decrease the pressure.

In a semi, the main problem is reliable feeding. I had some small ball bullets that had to be seated to 1.06" or they would get caught in the rifling. Because of that the powder charge in small ball is probably less than a more tapered round nose (of the same bullet weight) that can be seated out more. So, bullet profile also affects seating depth and therefore, pressure.

 

[rwsmith]

I'm only concerned....

I made several batches working up to the 3.8 but haven't shot any. My range time is very limited sadly.

I was told by some that the working up theory doesn't necessarily need to be applied to the 38 special due to its very low pressure to begin with.

.......when approaching max loads. I have a Sierra book that gives 7 grains max of Unique for a 125 gr JHP. Most books these days max out at 6 gr of Unique. Believe me, I worked up loads in my K frame and decided to quit at 6.4. I don't think it would be UNSAFE to go up, since the model 10 is a good strong revolver but the loads got a little raucous and I just thought that was enough for right then.

BTW Before the shortages when brand name bullets were in good supply and affordable, I could use the exact data from say, the Speer manual. After the shortages hit, I had to use whatever I could find and it was often different from what I had in the manuals. Also lead bullets have a LOT of different profiles. Anyway, what I'm saying is that I had to learn to adapt and compensate for different components, including AOL.

 

[Wise_A]

I was told by some that the working up theory doesn't necessarily need to be applied to the 38 special due to its very low pressure to begin with.

Really, it's more handgun cartridges in general. All of the visual pressure signs are only really reliable at rifle pressures (or the hottest of hot handguns). With a rifle, you can happily just load up in small increments until you flatten a primer or stick a case, and then back off.

With a handgun, though, you could be exceeding the SAAMI pressure spec, and those visual pressure signs simply never develop.

In other words, pressure signs are a definite indication of a problem, but that doesn't mean everything was hunky-dory until you saw them.

Note how rwsmith describes how he worked up his load with Unique. He doesn't say, "I kept going until I flattened a primer". He literally says that the cartridge simply felt and sounded a little too hot. That's a pretty decent way of doing business.

What are you trying to accomplish with your load, anyway? Not being sarcastic, but starting with a definite purpose usually makes things easier.

Doesn't have to be anything, well...I guess "snooty" like incredible accuracy, either. Matching the feel of factory ammo counts. Making a "fun" cartridge is worthwhile, too. For instance, I'm planning on experimenting with some warm-ish loads of Titegroup under a 185-grain LRN in my .44 Mag this week. Not because I think it'll be more accurate than my usual 240s. I'm just interested in seeing if they produce a more enjoyable combination of recoil and noise than what I currently load for plinking.

 

[Stopsign32v]

What are you trying to accomplish with your load, anyway? Not being sarcastic, but starting with a definite purpose usually makes things easier.

I want to match the recoil of factory ammo and I also want to make sure it was going to make it out of the barrel. I was loading some at 3.3gr of 231 and people posted up concerns of it not being enough. Most suggested 4.0 to 4.3, so that is where I put them.

What is the purpose of loading up starting at the bottom? Assuming the loader does his job correctly. I checked, double checked, and quadruple checked my loads to make sure it was correct. Feel free to be blunt, you won't hurt my feelings. I'm here to learn.

 

[BB57]

Lets not get stuck on what we can't determine and focus instead on the tools we do have that do work.

1. As others have noted, OAL isn't straightforward. It is at best an indirect measure of internal case volume under a bullet - for a specific bullet. If you're not talking about the exact same bullet, then a published OAL is largely meaningless.

2. Cannelures are there for a reason and all other things being equal for a handgun cartridge that's where the case mouth should be and/or be crimped into the bullet - although you may find some reasons to deviate from that, such as feeding considerations in a semi-auto.

3. A several thousandths or several hundredths of an inch just isn't going to make that much difference in most hand gun cartridges, particularly if you started with a mid range load and went up incrementally.

4. Set back in a semi-auto cartridge is often spoken of as a issue that can cause over pressure, but lets be real here. If the bullet is pushed back into the case by the feed ramp as it is chambered, it's still loose in the case and pressure spikes caused by this loose bullet sitting on top of the powder are just not that likely to happen. The bullet gets blown forward into the rifling anyway as soon as the primer detonates and that's when you start to see the pressure rise. Unless it's already a +P or +P+ load, it's going to be a whole lot of fuss over nothing.

Don't get me wrong - you want enough neck tension to avoid set back in a semi-auto, but that's more of a feeding consideration than it is a pressure concern in the real world (as opposed to theoretical internet discussions).

5. As noted above, there really aren't any reliable pressure signs for handgun rounds, at least until you've massively excessed the SAAMI pressure for most rounds.

In some rounds you may see some indications of pressure starting to increase, such as cases starting to stick in the chambers with .357 Magnum loads.

However, you'll find that:
a) the point at which a load starts to stick in one revolver isn't always the same as the point it starts to produce sticking cases in another revolver;
b) that point varies based on the age and other characteristics of the brass; and
c) sticking cases does not mean you've exceeded or even reached the SAAMI maximum.

You will see more subtle longer term effects, such as brass that work hardens and cracks sooner in higher pressure loads than in lower pressure loads, or in accelerated wear in a particular handgun.

6. You're best ball park method of determining pressure is to use a chronograph and determine whether the load is producing the velocity you'd expect from it.

Even that approach involves as much art as science. For example, differences in cylinder gaps in two otherwise identical revolvers can produce velocity differences of 100 fps with the same load in the same revolvers.

Barrel length differences obviously have an impact on velocity, but that difference per inch also varies based on the speed of the powder and weight of the projectile, so it takes a fair amount of experience choreographing loads with a variety of powders, bullets and barrel lengths with a particular handgun cartridge to be able to tell when something is odd with a load you're developing.

There are however some things that you can tell with any load, and there are trends you can see as you move up and down a ladder of charge weights. For example, a low standard deviation is a good sign that the load is burning efficiently in the cartridge/handgun combination.

More importunely however, an increase in SD can signal something going wrong. For example, if the SD starts to rise sharply as you approach the lowest published loads, that may signal the onset of pressure spikes due to excessively low load density (too much volume in the case). At the other extreme, an increase in SD as you approach the upper limit of the published data may suggest that you are no longer burning the powder efficiently (and in a rifle it may signal the onset of pressure spoke due to an excessively low load density (not all powders respond well to compressed charges).

7. In regards to the .38 Special, it's a really big case for the powder charges it holds, even if the .357 Mag is bigger. In fact, you can usually shoot .357 Magnum loads in .38 Special brass. After all .38-44 loads were basically short .357 Magnums and were what led to .357 Magnum development and .38 +P+ loads were basically an effort to get .357 Mag performance in a more politically correct .38 Special case.

So unless you're shooting it out of a pistol that is only rated for standard pressure .38 Special, I wouldn't get too concerned about the minor increase in pressure that will result from a slightly shorter OAL.

8. In regards to plated bullets, most plated bullet manufactures steer you toward cast bullet data, rather than jacketed bullet data, even though most of those same makers indicate 1200 fps velocities are fine.

This reflects the comparatively soft core of the bullet and the thinner plated jacket, which will generally start in the rifling easier than a jacketed lead bullet. Meaning you can potentially use a larger powder charge with a plated bullet than a jacketed bullet and/or that the same charge will drive a jacketed bullet a little faster than a plated bullet of the same weight.

9. There are other far more important variables than OAL. Different bullets of the same weight and general shape vary in:
a) jacket thickness;
b) jacket alloy hardness;
c) core alloy and hardness;
d) bearing surface; and
e) diameter.

All of the above factors affect what ballistics experts call the "stickiness" of the bullet in the bore and all of the above have effects on both pressure and velocity of the bullet with a given powder charge.

10. Hand loading manuals are not cook books. The 'exact' recipe only works when you are using the 'exact' same components specified in the book, and even then you have to consider that there is still some variation in the powder being used from lot to lot, even in canister grade powders.

If you are substituting components you need to be aware that the substitution will change the resulting pressure, and in turn the resulting velocity. That's an area where a chronograph can be very handy. Ever wonder how much difference in velocity is caused by substituting a primer? A chronograph will tell you, and it will also show changes in the SD in velocity.

The same thing applies with cast bullets, where the alloy used isn't always what is advertised and or may not match what was assumed in the load data.

 

[rwsmith]

If you have a moden strong gun....

I want to match the recoil of factory ammo and I also want to make sure it was going to make it out of the barrel. I was loading some at 3.3gr of 231 and people posted up concerns of it not being enough. Most suggested 4.0 to 4.3, so that is where I put them.

What is the purpose of loading up starting at the bottom? Assuming the loader does his job correctly. I checked, double checked, and quadruple checked my loads to make sure it was correct. Feel free to be blunt, you won't hurt my feelings. I'm here to learn.

If you have a good strong modern gun and components that are about equal to what the book calls for and back off about 20% or midrange, then work up. I make a few cartridges going up, take them to the range and shoot them successively until I get an idea how they perform.

Starting at the bottom is being ultra safe if anything is questionable.

There is no reason with a starting load why a bullet would stick in the barrel unless something else is wrong. Pay attention to each shot to make sure. If it feels or sounds funny or there isn't a hole in your target. Don't shoot again until you check it.

Get a chrony for about $100. Clock the ammo you want to emulate so you'll know what the real numbers are. Published velocities depend heavily on individual guns or test barrels. Choice of powder is important because all powders won't get the velocity without exceeding the pressure. Also, often books publish loads shot out of ten inch test barrels that don't have a cylinder gap, so don't be disappointed if you can't quite get there with a 2" snub revolver.

PS Why back off at all when you can put a factory bullet in your new gun and it will fire just fine. Reloading has more variables than factory ammo. One thing is that the bullets may be slightly oversized, which would raise pressures. We can't buy the same powder as the manufacturers, and they adjust the load after testing each lot of powder if there is variance. You may also have a tight barrel. The combination of oversized bullet and undersized barrel could jack up pressure pretty good. Your cylinder gap might be at min or max, which would change pressure. So the reason for working up is that you need to see how things perform in your SPECIFIC gun.

 

[Stopsign32v]

Get a chrony for about $100. Clock the ammo you want to emulate so you'll know what the real numbers are.

That is a dream, but I shoot at indoor ranges so I doubt they would allow that.

 

[rwsmith]

But possible....

That is a dream, but I shoot at indoor ranges so I doubt they would allow that.

I shoot at an indoor range too, but if I have testing to do, I drive about an hour to the national forest range where I can set up the chrony. Being able to see what you are actually getting in velocity can be real eye opener.

I'm retired on disability, therefore on a tight budget. A member here Karma'd me a chrony and knowing exactly what you are getting is big step up, especially approaching max loads. I was able to load and shoot safely, I just didn't know the end result of my labor. I made some general purpose .38 specials and shot one in my 'J' frame and got about 550 fps. I knew then that I was going to have to get strategic about loading to get up into the 900 fps range. I got some short barrel Speer bullets and right now I'm working with those to see what I can get in a defense type load.

PS Also remember that the .38 is a low pressure cartridge, but they are designed to withstand those .38 pressures so you still need to use caution approaching max loads.

 

[BC38]

That is a dream, but I shoot at indoor ranges so I doubt they would allow that.

No way to know unless you ask, right?

Around here a lot of them will allow you to set up your chrony if you are there during "off" times when things are slow - like in the middle of the morning during the week.

 

[Wise_A]

I want to match the recoil of factory ammo and I also want to make sure it was going to make it out of the barrel. I was loading some at 3.3gr of 231 and people posted up concerns of it not being enough. Most suggested 4.0 to 4.3, so that is where I put them.

I'd probably check out what the factory ammo's velocity was, look at powders that delivered that velocity at the middle of their range, and then (if I had a further choice) select a powder with a burn rate in the middle of that bunch.

WW-231 (also sold as HP-38) isn't the fastest-burning powder out there, but it does produce light recoil in my experience. That said, you'll likely be able to produce a load you're pleased with, as it's capable of delivering decent velocities.

What is the purpose of loading up starting at the bottom? Assuming the loader does his job correctly. I checked, double checked, and quadruple checked my loads to make sure it was correct. Feel free to be blunt, you won't hurt my feelings. I'm here to learn.

Usually, it's erring on the side of caution, and a desire to use as little powder, recoil, velocity, and gun wear as possible to achieve the desired results. Let's face it, if you were working up a light target load with a soft wadcutter, why bother going to the midrange?

Now, you don't always have to start at the bottom of a powder's range, once you get a little experience.

For instance, in my previous example of loading some funtimes .44 Mag with 185-grain LRNs and Titegroup, the Hodgdon data goes from 5.3 to 6.6 grains. The maximum pressure is 16,500 PSI, and the maximum velocity is 1,082 fps.

If my goal is a punchy, fun-to-shoot load, why bother with the 5.3?

Now, I'm familiar with the cartridge, powder, bullet and gun involved. Titegroup is stable all the way up to .44 Mag's maximum pressure. The max listed pressure of 16,500 PSI is around half of the cartridge's spec. And the velocity they stopped at with a cast bullet is 1,082 fps. They pushed it over 1,500 fps with jacketed data for the same powder.

Hence, I can reasonably conclude that they stopped at 6.6 grains and 1,082 FPS because they reached the limit of the bullet. The upper limit for lead is around 1,200 fps anyway, without a gas-check. That tells me that I've got a lot of headroom over the printed maximum.

So I'd probably start at around 6.6 grains. I might subtract a couple tenths of a grain to account for a little fluctuation in the powder measure's throws. Depending on the results, I might even go a little up from there--if the load didn't lead up the barrel, recoil too heavily, bang too loud, or perform inconsistently (recoil too heavily and bang too loud, but only sometimes, which would scare me more than if it just did it consistently ). After all, I know more or less what a cartridge in that range should feel and sound like.

I wouldn't recommend that as a starting practice, or even a general one. Start off slow, take it easy, and enjoy the process. It's more rewarding that way when you end up with something you really like. Most of my favorite loads took some figuring out, but that's probably why they're my favorites.

That said, as you gain experience in reloading, and spend time studying the performance of different cartridges and components, the amount of figuring-out you have to do decreases.

 

[rwsmith]

I find...

I find that a powder that gets high velocity in a .38 is Power Pistol.
I'd like to compare what PP gets vs. the 6+ grains of Unique I mentioned before, but I'm going to use my 686 to test it first as I don't want to stress my J frame experimenting with top max loads. And if the loads were 'raucous' in my 'k' frame, what would they feel like in a 'j' frame airweight? I gotta get me a 'K' frame.

 

[Stopsign32v]

Great information in here. Thanks guys, I foresee myself coming back to this thread periodically for a while.