What does C.O.L. effect?

[Stopsign32v]

I know it is a big deal in semi autos but with revolvers it isn't an issues. However does it effect pressure? Reason I ask is all of my cartridges seem to be shorter than the books say it should be. Here is an example of what I'm talking about.

These are loaded with 3.8gr of TiteGroup.

 

[Leonard]

Yes it does effect pressure the deeper a bullet is seated leaves less space for powder, probably not a significant factor unless your really pushing a maximum charge.
If you seat a bullet all the way out to where it is almost flush with the cylinder face you are reducing bullet jump which at least in theory helps accuracy.
In revolvers you should always roll crimp the bullet so your COL is controlled by the case length and bullets crimp groove.
Your example is probably a case that is shorter than specs, I would not worry about it.

 

[Stopsign32v]

In revolvers you should always roll crimp the bullet so your COL is controlled by the case length and bullets crimp groove.

That is what I did

Your example is probably a case that is shorter than specs, I would not worry about it.

They all came out this way, 200 or so

 

[Leonard]

They are consistent I was paying attention to your question of length.
Have you worked up to this load?
You should always work up to the maximum load not use it as a starting point as maximum varies from gun to gun as well as loading components used.

 

[Wise_A]

Your overall length looks okay. I can just about make out the crimping cannelure. You'll note that the book load is a 158-grain lead semi-wadcutter, and you've got some sort of RNFP, plated I'm guessing.

Take a look at this little lineup of bullet designs:

You'll see that if you loaded them all to the same OAL, then they would have vastly different case volumes. Hence, with revolver cartridges, I generally ignore the printed OAL data and use the crimping groove. The bullet and die makers know what they're doing.

I'd also suggest that your load is probably a little hotter than necessary. You could likely back off a fair bit and get the same or better results. Typically, if I'm looking for a low-recoil target load, I first try the starting load and then adjust up or down from there. If I want something with more heat, I start in the middle of the range and work up.

If nothing else, you'll be saving some wear and tear on your gun.

 

[Stopsign32v]

They are consistent I was paying attention to your question of length.
Have you worked up to this load?
You should always work up to the maximum load not use it as a starting point as maximum varies from gun to gun as well as loading components used.

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.

 

[H Richard]

What makes a difference is the amount of bullet inside the case. The amount of space for the powder to burn can increase or decrease pressure. The OAL is dependent on the structure of the bullet. Take two 158 gr. 38 caliber bullets, but one is a Round Nose and the other is a JHP. The JHP will be considerably shorter than the OAL of the RN because of the structure of the bullet. If you seat both to the same OAL the RN will be seated deeper into the case than the JHP.

 

[Kp-100]

Definitely great advice from Leonard. I just wanted to add to keep an eye on how many times you are reloading your batch of cases. Running
hot loads minimizes the times you can reload them. Inspect them for case
defects. I've found out that some ammo companies will make cases to minimum specs, so don't be surprise they are short when you check them,

 

[Stopsign32v]

Definitely great advice from Leonard. I just wanted to add to keep an eye on how many times you are reloading your batch of cases. Running
hot loads minimizes the times you can reload them. Inspect them for case
defects. I've found out that some ammo companies will make cases to minimum specs, so don't be surprise they are short when you check them,

Yea there is some gold as far as information in here. I will search but what are some of the things to keep an eye out for? This is all "once fired brass" I'm using. I already found a cracked case, was nickel too.

 

[Wise_A]

You're really not going to see any reliable pressure signs in any handgun cartridge. Certainly nothing you can "load up" to. If a gun suddenly starts flattening primers, or doubling or dragging the firing pin mark, or if cases are suddenly very difficult to eject, or you get black soot rings around fired primers, that's a sign you should head back to the bench and examine the cartridge. Standard pistol and revolver cartridges are around 20k psi or under, with most magnums in the 40k psi range, but the "reliable" pressure signs you hear about from rifle reloaders don't start appearing until the 60k psi range.

Really, it's a matter of having a calibrated hand and ear when you start pushing maximums.

For you brass, don't worry. Revolver chambers, by nature, do a great job supporting the casing. The cracks you find will tend to start at the case mouth, and they develop almost exclusively from the brass being brittle though the process of work-hardening. Every time you resize, expand, seat, and crimp, you stretch the brass a little bit, and every time that happens, it grows a little more brittle. Discard cracked cases, but beyond that, don't worry.

If you become very interested in accuracy, the "age" of brass matters. The more the brass work-hardens, the less consistent it becomes. Ideally, you want to match headstamps (not just manufacturer), and have each piece once-fired or twice-fired. Optionally, you can sort by length in addition. But frankly, that degree of sorting isn't worth the effort for what most shooters expect.

 

[sbrmike]

Aside from all the other advice you are comparing apples and oranges. The data is for a 158 grain LSWC you are showing a jacketed bullet in the case. Data is specific for a reason.

 

[len917]

Your overall length looks okay. I can just about make out the crimping cannelure. You'll note that the book load is a 158-grain lead semi-wadcutter, and you've got some sort of RNFP, plated I'm guessing.

Take a look at this little lineup of bullet designs:

You'll see that if you loaded them all to the same OAL, then they would have vastly different case volumes. Hence, with revolver cartridges, I generally ignore the printed OAL data and use the crimping groove. The bullet and die makers know what they're doing.

I'd also suggest that your load is probably a little hotter than necessary. You could likely back off a fair bit and get the same or better results. Typically, if I'm looking for a low-recoil target load, I first try the starting load and then adjust up or down from there. If I want something with more heat, I start in the middle of the range and work up.

If nothing else, you'll be saving some wear and tear on your gun.

+1 I use the cannelure also. It's a great guide and keeps the cartridge from bulging when crimping

 

[Stopsign32v]

you are showing a jacketed bullet in the case.

Ummm, no I'm not.

 

[Alk8944]

Ummm, no I'm not.

Ummmmmm, yes you are! Don't you know the difference between a cast lead bullet and a jacketed one? If you meant it is plated as opposed to being jacketed that isn't obvious in a photo. The bullet shown will also fill more case volume than a cast SWC as specified does, thus raising pressures. Bullet shape does make a difference, not simply weight. The admonition of plated bullet makers to "Use Lead data" makes an assumption, that the reloader understands the plated bullet style and specified data are for the same style of bullet.

As everyone has pointed out, if the bullet has a crimping cannellure simply seat and crimp to the cannellure. Don't even worry about measuring the OAL.

You say you "worked up" to 3.8 grains Tite Group, but you haven't shot any of them yet. Obviously you do not understand the concept of "Working Up". That doesn't change the fact that you can use book maximum charges without concern, but your combination of components has to exactly match what is shown in the manual to be sure the load is safe!

To answer the original question. Yes COL affects cartridge performance. There two effects it may have. (They are two different words and do not mean the same thing!) If too long the cartridge may not function properly, or at all, in the gun. This includes revolvers! If too short it may increase pressure to possibly unsafe levels.

A classic example of function is Lyman bullet 358429, 358431, or 358439** when loaded in .357 Magnum for an N-Frame revolver. If seated to the cannellure the cartridge will be too long for the cylinder. The bullet was designed to leave maximum case capacity in S&W .38 Specials to allow heavier loads and higher velocities. The .38 & .357 cylinders at the time were the same length. The longer .357 case makes the cartridge too long with these bullets, the bullet extends from the face of the cylinder and the cylinder won't turn. Gun won't close either.

(** Same basic bullet, Solid, Hollow-point, Hollow Base variants.)

 

[Rule3]

The load data you show from Hodgdon is for that SPECIFIC brand and style of gullet that THEY used.

Your Picture is some other bullet (correct??)

But you did not tell us what it is.

So you can not compare the two, they are different.

 

[Stopsign32v]

Ummmmmm, yes you are!

Ummmmmmmmmmmmmmmmmmmmmm, NO I'm not!

38- 158 RNFP

Those are not jacketed bullets.

 

[Stopsign32v]

The load data you show from Hodgdon is for that SPECIFIC brand and style of gullet that THEY used.

Your Picture is some other bullet (correct??)

But you did not tell us what it is.

So you can not compare the two, they are different.

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?

 

[Alk8944]

Ummmmmmmmmmmmmmmmmmmmmm, NO I'm not!

38- 158 RNFP

Those are not jacketed bullets.

Look at your first post! The load data in the first picture is for a LSWC, the bullet shown in the second photo is a plated or jacketed RNFP as you say.

I repeat, don't you know the difference? Everyone else who has posted seems to understand.

 

[Stopsign32v]

Look at your first post! The load data in the first picture is for a LSWC, the bullet shown in the second photo is a plated or jacketed RNFP as you say.

I repeat, don't you know the difference? Everyone else who has posted seems to understand.

READ, what I said was I didn't have a jacketed bullet. I was replying to this

you are showing a jacketed bullet in the case.

Again READ READ READ

Again I DO NOT HAVE A JACKETED BULLET. I don't want to keep arguing with you over what I originally said. It is right there. Now lets move on

 

[mtgianni]

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.