Jarhead66
Member
The max oal for 9mm is 1.169 I believe. What is the lowest minimum you should not go under.
minimum OAL
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Blue68f100
Member
You have to set the length for it to function in your gun. Make sure you you eject a live round too. Once that is determined, workup your load. You must not seat the bullet too deep in which your getting into the ogive. Stay on the straight base area of the bullet.
Like Blue68f100 said but I'll add as long as it'll feed & plunk without issue. This is going to leave less room for powder. Meaning pressure increases faster & has more energy then it would with more space.
As for max OAL it has to plunk & not fall out the end of the case.
With that said if your asking this question then you may not be ready to start messing with shortening lengths of 9mm just yet. The space is so tiny to start with that the pressure curve is going to climb really fast.
As for max OAL it has to plunk & not fall out the end of the case.
With that said if your asking this question then you may not be ready to start messing with shortening lengths of 9mm just yet. The space is so tiny to start with that the pressure curve is going to climb really fast.
papaairbear
Member
If you're new to reloading, the advice to stay within the OAL range published in the load manuals is sound and safe advice. You'll learn a lot and have a lot of fun while learning. There is a thread on this forum, started and managed by our own bds, that will answer many of your questions and provide a base of experience you can draw from. There's a ton of information there and you'll be better able to assess your own current capabilities while gaining a knowledge of what's possible. 9mm isn't difficult to reload, but it does require us to use more diligence. Go slow, research the information available, always check your processes, and verify your work. And ask questions. https://www.thehighroad.org/index.p...ed-reloading-concepts-and-discussions.778197/
LiveLife
Member
That's determined by the bullet length/seating depth and powder charge you are using. Pour the powder charge into a resized case and measure distance from case base to top of powder charge (transfer top of powder charge mark to outside of case using end of calipers). To this length, add bullet length to determine minimum OAL/COL which won't compress powder charge. But this length won't ensure the round will fully chamber in the barrel or reliably feed/chamber from the magazine.
But as many posted, it is generally better to go longer with small case volume 9mm to give you some buffer with chamber pressure, especially if you experience bullet setback with your rounds when fed from the magazine. Determining max/working OAL is outlined in Walkalong's thread - https://www.thehighroad.org/index.p...l-with-your-bullet.506678/page-2#post-8864541
While I usually suggest using working OAL for load development, there are times when you want/need to use shorter OAL:
- If you are loading lower powder charge target loads that barely reliably cycle the slide and extract/eject spent cases but accuracy is not great and you do not want to increase powder charge, you can try incrementally decreasing the OAL (say by .005" down to minimum OAL outlined above) to improve accuracy. So if 1.125"-1.130" shoots more accurate than 1.150"-1.160" and feed/chamber reliably from the magazine, use shorter OAL that produces smallest groups.
- If your barrel's groove-to-groove diameter is oversized (.356"+) and/or have long leade/freebore that allow longer than SAAMI max of 1.169" and your bullet diameter is .355" which will leak a lot of gas, range test incrementally shorter OAL down to minimum OAL outlined above to see if accuracy trend improves with shorter OAL. FYI, if your barrel is oversized, chances are using larger sized bullet (.356"-.357") will improve accuracy more significantly than using shorter OAL.
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SAAMI drawing with dimensions are easy to find on the Internet
https://www.google.com/search?hl=en-US&ie=UTF-8&source=android-browser&q=9mm+saami+drwing&gws_rd=ssl#gws_rd=ssl&imgrc=uGtFlZ_JHwJ8NM:
https://www.google.com/search?hl=en-US&ie=UTF-8&source=android-browser&q=9mm+saami+drwing&gws_rd=ssl#gws_rd=ssl&imgrc=uGtFlZ_JHwJ8NM:
LiveLife
Member
Since published load data often uses single shot "universal" test barrel fixtures that doesn't feed from a magazine, using published OAL will not ensure reliable feeding/chambering in pistols that use magazines and reloaders must determine what OAL will fully chamber in barrels and reliably feed from the magazine.
While Hodgdon lists 1.169" for 124 gr Lead RN bullets with WSF, there are many non-stepped RN bullets with shorter/rounder nose that must be loaded around 1.100" or the ogive will hit the start of rifling in many barrels. I for one load MBC 124 gr RN at 1.080"-1.100" to feed/chamber in various barrels I have.
OP did not ask what the SAAMI minimum was rather "What is the lowest minimum you should not go under."
I offered the OP a practical process for determining the minimum OAL for particular bullet and powder charge so as to not compress the charge.
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follow load data for the bullet and powder you are using, DO NOT go below a min oal listed as pressure will rise and could result in an accident or worse an injury, you can go longer but NOT below the listed min oal for the listed load data, why take chances ?
get a good reloading manual and read it front to back most modern manuals have really good info for learning to reload well worth the money
get a good reloading manual and read it front to back most modern manuals have really good info for learning to reload well worth the money
I don't see where you're providing information that can't be found easier in at least one reloading manual. You say that you've found that some 124gr bullets require a COL (cartridge overall length) of 1.008" - 1.100", Hornady's 9th edition reloading manual specifically states that their 124gr FMJ-FP should use a COL of 1.050" so if a reloader followed that manual's recommendation for that specific bullet then he'd use a COL that's within the dimensions that you mentioned without having to go through any special load development process. It seems to me that it's common sense that if I were wildcatting some lead bullet without any information from the manufacturer then I'd have no choice but to use your process or something like it to find a useful COL but as long as the manufacturer recommends a COL then I'd start with that specification.
And as for your comment about the SAAMI minimum (1.000") not being what the OP asked for; my opinion is that regardless of what you might come up with experimentally, a reloader should never use a COL that's less than the SAAMI minimum for that cartridge. The SAAMI dimensions are used as a reference by all gun manufacturers so no cartridge should ever need to be shorter than the SAAMI minimum to function properly. Your experimentation proves that because your minimums are still longer than the SAAMI minimum.
If you need to load shorter than the data you are using shows you must reduce the max charge. In that tiny case pressures go up fast when reducing OAL while using the same powder charge.
That's in manuals too, but worth repeating.
That's in manuals too, but worth repeating.
rfwobbly
Member
There is no published minimum OAL, because SAAMI is primarily concerned with maximum cartridge dimensions. It's obvious that the minimum distance is based on the ability to feed correctly, which will change with different bullet ogive shapes. However, most reloaders use 1.000" as the "rule of thumb" for the 9x19 Luger minimum OAL.
Hope this helps.
You're wrong. Simply go to SAAMI's web site and look up the cartridge and chamber information for the 9 mm, the dimensional drawing shows that 1.000" is the specified minimum.
SAAMI specs are now part of the American National Standards program which means that any of the dimensional information contained in their cartridge drawings is a standard, not a simple "rule of thumb", further, that standard states "The material presented provides the commercial manufacturer of factory-loaded ammunition with pressure and velocity performance and dimensional characteristics."
The 1.000 number is irrelevant IMHO. The max (1.169) is relevant because longer may not fit some mags or be a jam fit into the lands on some guns. Find an OAL that feeds well in your gun(s), lots of folks prefer longer vs shorter, then adjust the max powder charge used relevant to the OAL used with the data you are using.
It is relevant because it relates to safe pressures. Through experimentation and testing a consensus of manufacturers have agreed that the minimum spec is the shortest safe dimension that they can recommend. I'm sure that there are probably situations where shorter will work with some calibers but when you are promulgating information to the general public you aren't going to tell them that they can just guess as to what works, you have to provide a standard that will always be safe and that's what ANSI/ SAAMI safety standards are.
These standards are actually provided for the manufacturers rather than the reloading public. With an agreed upon set of standards the manufacturers can design ammunition and firearms based on universally agreed upon pressures and dimensions that will allow the public to buy products that work safely without having to guess at what fits what and whose ammo is safe. Imagine what it would be like if we had unique ammo for every model of every gun ever built. I've seen guys buy .45 ACP ammo for their brand new lever action .45- 70 because they thought a .45 was a .45, imagine if they had to choose from 10 or 15 loadings for each rifle, carbine, or handgun that they owned - the gun industry would be so dangerous for the shooters that the market would collapse and we wouldn't see such a great spectrum of weapons and ammo for our choosing.
These standards are actually provided for the manufacturers rather than the reloading public. With an agreed upon set of standards the manufacturers can design ammunition and firearms based on universally agreed upon pressures and dimensions that will allow the public to buy products that work safely without having to guess at what fits what and whose ammo is safe. Imagine what it would be like if we had unique ammo for every model of every gun ever built. I've seen guys buy .45 ACP ammo for their brand new lever action .45- 70 because they thought a .45 was a .45, imagine if they had to choose from 10 or 15 loadings for each rifle, carbine, or handgun that they owned - the gun industry would be so dangerous for the shooters that the market would collapse and we wouldn't see such a great spectrum of weapons and ammo for our choosing.
I have to say some of you "by the book" guys miss a great deal of knowledge that is offered by others. It isn't always unsafe to go outside of published data. It isn't always safe to go by published data.
I'll say it again. Published reloading data isn't a law. It's a story about what they had & what they did with it. It might even go as far as to tell you what happened. However this is a different day & we wish you good results in what you do. Nothing wrong in suggesting the new guy mimic until they understand more but it isn't the end all word. If you want to use that data as your standard & base a religion on it then I'm fine with that also but I'm one that isn't drinking the kool-aid.
I'll say it again. Published reloading data isn't a law. It's a story about what they had & what they did with it. It might even go as far as to tell you what happened. However this is a different day & we wish you good results in what you do. Nothing wrong in suggesting the new guy mimic until they understand more but it isn't the end all word. If you want to use that data as your standard & base a religion on it then I'm fine with that also but I'm one that isn't drinking the kool-aid.
I covered that.
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