Seating length in 9 mm 1911?

All guns are different so there is no telling what one will like until you try.
My 9mm 1911 seems to prefer deeper seated bullets. Of course seating deeper raises pressure so you need to be careful.
Most of what I load is nowhere near book MAX so I can seat deeper and still be safe..


Unless you want different ammo for each gun determine what is the longest OAL that will work in all the guns with that bullet.
Just as an example say that is 1.12 (you didn't say what the bullet weight was but lets just use 124/125gr for fun)

W231=HP38 so some numbers from Hodgdon
125 GR. SIE FMJ Winchester 231 .355" 1.090" 4.4 1009 24,600 CUP 4.8 1088 28,800 CUP
125 GR. LCN Winchester 231 .356" 1.125" 3.9 1009 25,700 CUP 4.4 1086 31,200 CUP
124 GR BERB HBRN Plated Winchester 231 .356" 1.150" 3.9 920 27,400 PSI 4.4 1037 31,900 PSI
125 GR HAP Winchester 231 .356" 1.069" 2.8 753 25,300 PSI 3.3 876 33,600 PSI
(note the HAP OAL is much shorter and has a lot lower charge, also note the difference between the FMJ load and the lead load)

If it was me I would take the Bayou bullet (assuming its a 124/125gr bullet) back the charge off to about 4.0gr
then load some at 1.12, some at 1.10 and maybe some at 1.08 and see if it makes a difference in accuracy for you.
If there seems to be one that your gun likes then you can work the charge back up and see what it likes charge wise.

Then sort of repeat the process for any other bullets you have.

My PM9 has a very generous leade and will take a really long COL. I had a very limited COL precision test and didn’t see a huge difference in group sizes. At one time I was wondering if pistol loads were influenced by bullet jump but decided, again based on very limited testing, there were other factors more pronounced.
You may find that the COL will affect feeding in a 1911 platform more than precision. I was loading the Bayou 124 FP at 1.150” and had it sized to .357 for my barrels. That COL also worked for the RMR FP. With so many other variables in play I haven’t stepped into the SWC for 9mm pile yet.

► 100% agree with Mr Dudedog.

Plus... Auto pistol cartridges do not use a crimp cannelure to position the bullet, as revolver cartridges do. Therefore, cartridge OAL for the auto pistol is actually not a single, fixed dimension, but rather an acceptable range within which you’ll be safe. This “range” is defined by 2 sets of measurement “limits”. Some of these limits are set by the realities of reloading, other limits are imposed by SAAMI physical limits. Both these "limits" represent hard boundaries which the reloader MUST obey, and thus work within.

• The outer limits are set by SAAMI. The 9x19 Luger cartridge cannot be longer than 1.169” or it may not physically fit into the magazine. SAAMI also advises that the cartridge should not be shorter than 1.000” due to feeding considerations. You can look this up on the SAAMI web site.
  
  
• The inner limits are defined by the bullet-to-barrel fit for the longer dimension. The shorter dimension should be the shortest published OAL you can find in your load manuals. (Of course with calculation, you can always compensate and go shorter. But if you don’t have the means or the experience, then stay with the book OAL.)

Taken together these 2 sets of limits result in a graphic that looks like this…



Hard facts forming hard rules, which result in "bad things", if you ignore them. That's the "Science of Reloading".

Within the range of safe limits, the final chosen OAL to build your cartridge will be determined by experimentation and experience. That's the "Art of Reloading".


Also realize:

► The OAL shown in your load manual is not a suggestion. It is part of the Load Data used in the manual, and the lab crew is merely reporting the OAL they used during testing.

► Given: 1. All chambers are cut differently. 2. All bullet makers produce a bullet of slightly different dimensions. The inner limit Max OAL is a result of how the unique bullet fits into your unique barrel. Only the person with both the bullet AND the barrel can determine this dimension with any precision. IOW, no person here can answer your question; each individual reloader must make these measurements for themselves.

► In some special cases, a bullet-to-barrel fit may allow a Max OAL of (say for instance) 1.220”, which of course exceeds the SAAMI Max of 1.169”. In this case, the useful OAL range is then defined by the SAAMI Max as the longer limit, and then the load manual OAL as the Min OAL limit.


Hope this helps.
.

I have shot hundreds of thousands more 147 RN than anything else as that’s my minor 9mm load. 1.160” is where I try and put them. Long enough to run well in my 1911/2011 pistols without any rear spacers and short enough to work in everything else too.

Dudedog said:

If it was me I would take the Bayou bullet (assuming its a 124/125gr bullet) back the charge off to about 4.0gr
then load some at 1.12, some at 1.10 and maybe some at 1.08 and see if it makes a difference in accuracy for you.
If there seems to be one that your gun likes then you can work the charge back up and see what it likes charge wise.

Then sort of repeat the process for any other bullets you have.

Click to expand...

I am about to do my 1st batch of 9mm.

You are saying to choose a starting load with whatever powder (in my case Titegroup). Load several at that powder weight with different lengths. Find the one that functions and shoots the best, then adjust the powder load to see if I can find increased accuracy?

My tightest barrel is slightly longer than 1.160" with the bullet I am going to use. What I have read here and elsewhere says to back it off 0.015". So start with 1.145" and make some smaller- say 1.125" and 1.105".

Or am I overthinking this (as usual)?

eddiememphis said:

Load several at that powder weight with different lengths. Find the one that functions and shoots the best, then adjust the powder load to see if I can find increased accuracy?

Click to expand...

No.

You should first determine the longest max/working OAL that will work reliably with your barrel/magazine BEFORE conducting powder work up - https://www.thehighroad.org/index.p...-and-discussions.778197/page-10#post-11419509

1. Determine Max OAL using the "plunk" test - https://www.shootingtimes.com/editorial/reloading-tips-the-plunk-test/99389
2. Determine the Working OAL by feeding dummy rounds (No powder, no primer) from the magazine and releasing the slide without riding it (Max OAL can work as Working OAL but if not, incrementally decrease OAL by .005" until dummy rounds reliably feed from magazine)
3. Conduct powder work up using Working OAL (If Working OAL is shorter than published OAL, consider reducing start/max charges by .2 - .3 gr of most conservative load data as you can always go higher)
4. Initially identify the powder charge that will reliably cycle the slide and start to produce accuracy (If start charge produces reliable slide cycling and accuracy, consider "working down" by .1-.2 gr to see if reliable slide cycling and accuracy are maintained - These could be lighter target/bullseye loads)
5. When most accurate powder charge is identified and you are not at max charge, consider incrementally decreasing the OAL by .005". If accuracy improves, use shorter OAL. If not, use longer OAL.

I read both articles you linked earlier this week. That is why I was confused.

eddiememphis said:

I read both articles you linked earlier this week. That is why I was confused.

Click to expand...

Determine Max/Working OAL first then conduct powder work up.

And if powder charge that produces smallest groups is not at max, you can squeeze a bit more accuracy by testing shorter OAL.

So while most 115/124 gr FMJ/RN bullets can work at longer 1.145"-1.160" OAL in most pistols, shorter 1.130"-1.135" will produce smaller groups. (With 115 gr FMJ/RN that has shortest bullet base length, I even load them shorter at 1.110" to increase neck tension)

Buck13 said:

Dan Wesson PM9 ... 9mm carbine ... CZ P-01 ... truncated cone bullets ... Hornady HAP ... Bayou coated lead ... SWC

... any predictions about spacing for them?

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As I mentioned in post #7, Max OAL should be determined using the barrel "plunk test" and then Working OAL determined by feeding dummy rounds (No powder, no primer) from the magazine and releasing the slide without riding it - https://www.shootingtimes.com/editorial/reloading-tips-the-plunk-test/99389

For SWC (which is usually made from RN profile with non-feed ramp bump contact areas removed), most load with thumbnail thickness of shoulder above the case mouth to determine the OAL. For MBC 124 gr SWC, that's 1.045"



These are various Working OAL for HAP 115/125 gr and MBC CN depending on the leade length of barrels used so Working OAL for your barrel/pistol/carbine/magazines may differ -
https://www.thehighroad.org/index.p...col-for-reference.848462/page-2#post-12249361

• Glock 22, KKM 40-9 conversion barrel - Hornady 115 gr HAP: 1.145
• Glock 22, KKM 40-9 conversion barrel - Hornady 125 gr HAP: 1.125"
• Glock 22, KKM 40-9 conversion barrel - MBC 124 gr CN Hi-Tek (Cone 9): 1.169"

• M&P Shield - Hornady 115 gr HAP: 1.130"
• M&P Shield - Hornady 125 gr HAP: 1.120"
• M&P Shield - MBC 124 gr CN Hi-Tek (Cone 9): 1.165"

• Glock 22, Tactical Kinetics 40-9 conversion barrel - Hornady 115 gr HAP: 1.085"
  
• Glock 22, Tactical Kinetics 40-9 conversion barrel - Hornady 125 gr HAP: 1.070"
• Glock 22, Tactical Kinetics 40-9 conversion barrel - MBC 124 gr CN Hi-Tek (Cone 9): 1.115"
  
  
• Glock 23, Lone Wolf 40-9 conversion barrel - Hornady 115 gr HAP: 1.070"
  
• Glock 23, Lone Wolf 40-9 conversion barrel - Hornady 125 gr HAP: 1.045"
• Glock 23, Lone Wolf 40-9 conversion barrel - MBC 124 gr CN Hi-Tek (Cone 9): 1.105"

Buck13 said:

I'll play with the SWCs some in the DW but forget about them in the other guns. Not worth the aggravation! Again, any predictions about spacing for them?

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► Generally speaking, most auto pistols of any caliber will feed the SWC bullet better if you'll pay attention to how much of the shoulder is exposed, rather than the cartridge OAL. Thus....



Start with about 0.035 to 0.040" of shoulder exposed, and then seat the bullet deeper in 0.005" steps until it starts to feed reliably. All this because the position of that shoulder is what chambers this type bullet. This is unique to the SWC.

► This means to get highly repeatable feeding, the seating stem or anvil you use should really push on the SWC at the shoulder, and not on the meplat (as most dies will do).

Hope this helps.

Faster powders can be used with 147s but in general faster powders do tend to be less "forgiving"
If it was me I would
#1 find the MAX OAL that will work- plunk test so you know they need to be shorter than X
#2 start a thread asking to see if anyone has loaded 9mm for the 150s you have
#3 if I couldn't find any info I would take a 147 lead bullet start charge and back of 5-8% to start, then work up.

I agree with rfwobbly with about a thumbnail above the case mouth for the shoulder on SWCs.

Ima plunk it first and document kind of guy for my pistols.

I have some guns that will chamber a 125 gr HAP seated way out at 1.160”, and others that are nowhere near chambering with that load. Just depends how that company’s chamber reamer is cut.

Buck13 said:

Data for a 147 that's loaded considerably shorter might be not too reckless? Hodgdon data for the Blue bullet 160 maybe, using starting loads for Longshot and #7 would be safest.

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You’re wise to be wary about loading shorter especially in 9mm with fast powders, but keep in mind it’s the seating depth that is important, and, the competition crowd loves the really heavy bullets with really fast powder in 9mm. There’s even a 165gr offering a lot use, usually with an Uber fast powder like TG. 231 isn’t as fast as TG and, well behaved. The Hodgdon online data for the 160 blue is for a round nose but it’s out to 1.150”. I’d start with the thumbnail of shoulder exposed and see how that COL compares to the Hodgdon data.