Safe Bullet Profiles?

bullet 1

bullet 2

bullet 1 loads and chambers

but not bullet 2

bullet 2 has a different profile .. long and sleek .. it should chamber

what the hell is going on .. both weigh the same .. both are boat tails ..

damn Remington Brass .. needed to kick the shoulder back a bit more ..

1/4 turn on the die fixed that issue ..

..

The Ogive determines how far the Bullet can extend before touching the Barrel Rifling.
As far as weights being equal to charge: Bullets that are Coated such as Barns Bullets with their proprietary Blue coating use different charge weights and SPECIFICALLY tell you not to use those charges with other bullets.
Lots of times you can easily get by substitute one brand/design for another using the same charge weight of specified Powder, but you should reduce or stay with the start weight, try a few, and go from there.

Your max OAL changes with the bullet profile. The best explanation I've found on the subject is here. How to Determine Max OAL for a CZ/Dan Wesson Pistol

Link is about CZ's but applies to all chambers.

mgunner said:

1.Is it safe to substitute the same weight bullet with a different bullet profile assuming both bullets are made of the same material and have similar bearing surfaces?

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Yes, within reason. As was stated, the ogive is going to effect seating depth (and by extension case volume) and the bullet's side profile is going to effect the drag on the barrel. Always start at the starting charge and work your way up, looking for pressure signs as you go. That's the key to finding the difference between them, working up, and paying attention to the pressure signs.

mgunner said:

2. Is this stated in a reloading manual? I thought that I actually read that it was OK to do this in a reloading manual a one point but I can't find it in Modern Reloading by Richard Lee or the Lyman 51st edition.

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It's in the Lee manual. See page 158 of the second edition, at least for the copy I have.

"What I'm looking for, and surprised that it's not specifically stated if it's safe to substitute the same weight with similar, but not the same bullet profile."

It isn't in writing because it isn't true. Read the link in post #4 and you will understand why.

mgunner said:

Page 158 of my manual only gives specific examples of exceptions that you should not substitute. For example, it says do not use wad cutter data for round nose etc.

What I'm looking for, and surprised that it's not specifically stated if it's safe to substitute the same weight with similar, but not the same bullet profile.

I understand that reloaders do this anyway. What I want to know is if this has officially been stated as safe in a reloading manual. I find it surprising that with decades of testing by bullet and powder manufacturers, that no statement has ever been published in a reloading manual. And as I said, I thought I actually read that it was ok to do this in a reloading manual. But now that I actually want to check that fact, I can't find it.

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Pg 158 of Lee Modern Reloading:
"Jacketed: As the name implies, these are for jacketed bullets. In rifle loads, point styles may be used interchangeably. Handgun loads: be certain you do not use extreme hollow points with this data"

And no, cramming a bullet into the lands from the case mouth is never a good idea. That spikes the case pressure pretty damn quick. SAMMI Max cartridge length SHOULD be a safe distance from the lands. The article about CZ pistols covers the fact that CZ shortens the free bore in their barrels, and that needs to be accommodated when loading anything but round nose. The fact stands that an overly long bullet seat is going to be bad, but with SAMMI chambers, as long as you aren't over the max cartridge length, start low, and work up.

• At the opposite end of the spectrum are all CZ's models and Springfield's striker-fired models. These are all made in eastern Europe where they still respect quality pistols and fine craftsmanship. One of the ways CZ achieves such incredible accuracy is by shortening the "freebore"; .....

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You seem to be taking a cautious and thoughtful approach toward this endeavor, and that is a good thing.
Robin

Vantrepes said:

Pg 158 of Lee Modern Reloading:
"Jacketed: As the name implies, these are for jacketed bullets. In rifle loads, point styles may be used interchangeably. Handgun loads: be certain you do not use extreme hollow points with this data"

And no, cramming a bullet into the lands from the case mouth is never a good idea. That spikes the case pressure pretty damn quick. SAMMI Max cartridge length SHOULD be a safe distance from the lands. The article about CZ pistols covers the fact that CZ shortens the free bore in their barrels, and that needs to be accommodated when loading anything but round nose. The fact stands that an overly long bullet seat is going to be bad, but with SAMMI chambers, as long as you aren't over the max cartridge length, start low, and work up.

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Even round nose cannot be taken for granted. When you get into the higher weight bullets, 147 Gr. in 9 mm for example, the ogive can be fatter. In general you should determine the max COL for every brand and weight of bullet for your specific gun before even thinking of powder weight. While CZ's are more sensitive to this it applies to all gun manufacturers. Yes it takes more time and that's why I've found one or two bullet profiles I like and will only buy the same bullets from the same manufacturer.

The round nose comment comes directly from the article posted about the CZ. The charge weight range is useable from one bullet of the same weight to another, but there are other factors that have to be taken in account to safely reload, as always. No manual I have lists a MAX OAL other than the cartridge drawings. they all list a minimum OAL.

Max OAL for 9mm is 1.169. The OAL is usually limited by what will fit in a magazine. Minimum OAL is what will not reliability feed. I am only talking about physical cartridge dimensions without considering powder charges.

mgunner said:

Page 158 of my manual only gives specific examples of exceptions that you should not substitute. For example, it says do not use wad cutter data for round nose etc.

What I'm looking for, and surprised that it's not specifically stated if it's safe to substitute the same weight with similar, but not the same bullet profile.

I understand that reloaders do this anyway. What I want to know is if this has officially been stated as safe in a reloading manual. I find it surprising that with decades of testing by bullet and powder manufacturers, that no statement has ever been published in a reloading manual. And as I said, I thought I actually read that it was ok to do this in a reloading manual. But now that I actually want to check that fact, I can't find it.

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There are simply too many variables and combinations to try and list all the fringe cases. How to handle fringe scenarios comes with years of experience. For example if I had a powder that I knew was suitable for 9mm but had a bullet I have never used before and has no data in the mainstream, I would have to work from past experience and data that actually does exist. Compare bullet profiles, bullet lengths, seating depths etc. Most importantly when experimenting, start with low charge weights and work your way up. If you at least have a suitable powder and start low it would be pretty difficult to blow your gun up.

mgunner said:

Had a pretty basic reloading question about bullet profiles that I thought I knew the answer to. But I can't actually find reference to it in my reloading manual. Here's what I want to know:

1.Is it safe to substitute the same weight bullet with a different bullet profile assuming both bullets are made of the same material and have similar bearing surfaces?

2. Is this stated in a reloading manual? I thought that I actually read that it was OK to do this in a reloading manual a one point but I can't find it in Modern Reloading by Richard Lee or the Lyman 51st edition.

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1. generally yes it ia safe given same bore, frain, category. there will be exceptions with specialty bullets and loads, obviously.

2.Reloading manuals are useless and full of mistakes. Refer to the projectile manufacturing instructions but also powder and case makers by barnd. remember to compare the data from all sources to flush out inconsistencies.

If I changed anything in a load I designed, I back off 10% on the charge and work my way up. But that's me.