Sig .40 S&W OAL reloading question

[Labiofus]

Let me start by clarifying that I am NOT attempting to do any MAX reloads. Quite the opposite actually, rather I’m attempting to reload a medium to light load that will be accurate and consistent more than anything. By ‘accurate’ I don’t mean trying to thread a needle at 50 yards! The loads I want to load will be used for IDPA, and general target shooting to hone and practice my fundamentals, so while they need to be accurate, I'm not worried about match-grade precision.

The Firearm: stock Sig Sauer P229 chambered for .40S&W (ran about 500 rounds of Remington UMC 165gr FMJ through it flawlessly so far)

The Press: Hornady Lock-n-Load AP with all carbide dies including a powder cop die.

The Supplies: Bullseye powder, Winchester Primers, once shot and range brass, 155gr lead truncated cone and 180gr round-nosed/flat-top bullets. (Awaiting FMJ Ranier 180gr bullets) I do visually inspect each case then de-prime and clean/polish the cases. After the cleaning/polishing I visually inspect each case to ensure none of the cleaning medium is lodged in the primer hole, there are no cracks or damaged casing, etc. I don’t do every case, but I do spot check many cases to ensure they were all with tolerances mainly focusing on the length of the case and the thickness of the case walls .

Goal: Reduce recoil for increased speed, accurate, consistent, flawless feed and cycle just like factory ammo

I am new to reloading but have done extensive research to minimize any chance of making a drastic error in the process, so I’m fairly well informed and understanding of the whole process although I know I have much more to learn.

My first question is regarding OAL. From the books, forum posters, and other reloaders I’ve heard the ‘optimum’ OAL is 1.125” for the .40 S&W. SAMMI specs is min OAL 1.085” and maximum is 1.135”.

While setting up my press, I loaded some ‘test’ rounds (no primer or powder) just to set/check the seating depth and OAL. I also wanted to load them in the magazine and cycle them through the pistol a few times to look for things like setback, etc. I dialed the die in to 1.125” (+/- .015 roughly) and to my surprise I could only load 1 round into the magazine. The 2nd round pushed the 1st round down and it lodged in the magazine. I removed it and decided to measure the factory ammo I had bought which had functioned and shot flawlessly. The OAL was 1.085 (-.002 to +.005) over 20 rounds or so.
That being said, my question is it’s obvious that I will need to seat the bullets to an OAL of near the minimum OAL of 1.085”. (I plan on checking/testing to see what the max OAL will work in the magazine but I know the length of the factory loads cycles flawlessly so I'm thinking I'd like to try to stay around the factory length)

Apparently, Sig’s magazines have less room than other models of firearms so seating the bullets to OAL near 1.125” is not going to work. Seeing as I plan on decreasing the powder charge by 10-20% of the maximum, does anyone foresee any drastic issues with seating the rounds to the minimum SAAMI OAL? I understand the whole issue surrounding the decrease in case volume versus the increase in pressure and fortunately my lack of experience makes me hesitant to just start loading rounds and pumping them through my pistol to see if anything ‘bad’ happens. However, seeing as the factory loads are at the minimum OAL I would assume it would be safe to load to the minimum OAL especially considering I’m not using a max powder charge. Am I thinking about this correctly? Any advice on this from other Sig owners who have experienced the same issue?

My second question is regarding expanding and crimping the case. I followed the set-up instructions for the press and dies to a ‘T’ and the bullets seat fairly effortlessly in the case with no visible signs of shearing lead off the sides which would indicate that the case was not expanded properly nor is it so open that the bullet seats too easily.(At least from what I can tell.) Why I question this is because on the factory loads you can see the seat depth ‘ridge line’ on the case. The loads I made you cannot see that slight ‘ridge line’. Is that due to the fact I’m using lead bullets and not FMJ bullets? How do I tell if I have the expansion and crimping correct? (I.e. not too tight/not too loose)

As you all know the casing disappears inside the die so it’s impossible to tell how deep the expansion flare is or if the crimp is adjusted right. At least from my beginner stand point it’s nearly impossible to tell. For a task that requires precision it seems as though there is a fair amount of ‘questimation’ when it comes to these two parts of the process. Are there any tricks or methods I can use to tell if I have these two important steps correct?

My only ‘test’ was to use my bullet puller hammer and it took 6-8 solid whacks to remove the bullet from a factory load and only 2 to remove the lead bullet from the one I loaded. Obviously, this is about as accurate a measurement test as trying to use ‘Kentucky windage’ during hurricane winds, but at least it made me question the seating and crimp part of the process before putting any rounds through my firearm.

Thanks in advance to any replies. I appreciate the help from all you with so much experience to lend!

[OKFC05]

1. Beginners obsess about OAL, but the fact is that in moderate loads in straight-walled pistol cartridges, it is all about function, not some "optimum" length for accuracy. The critical thing is that your load must work in your magazines and feed flawlessly in your chamber.
The nose shape of a bullet has a lot to do with how deeply you must seat it so it does not jam in the rifling or stick in the magazine.
2. Lead bullets always pull easier than jacketed. Push the loaded cartridge firmly against the bench, and if the bullet does not move, you're golden.
3. Measure the crimp and adjust so it is a few thousandths smaller than the case body; you want to remove the flare.

[Labiofus]

I appreciate your response. I wasn't so obsessed with the OAL in regards to accuracy as much as some of the posts I've read about the spikes in pressure being so bad in the .40 cal shells. I don't know how that can be any worse than any other pistol shell like .380, 9mm or .45 but I'm certainly no expert. Personally, I would think that for liability reasons, ammo and gun manufactures put A LOT of 'give' in their products and information they provide. If the gun could handle a load of 6+gr they publish that 5.6 is the MAX so they have a safety factor built in as well. That way they know if someone blew up a gun, that it would have had to be a double charge or far exceeding the MAX to accomplish that. Maybe I'm wrong but I don't know of one manufacture of a product with so much liability attached to it that wouldn't do that out of sheer protection for themselves in court.

Thank you for confirming what I thought was the reason for the lead bullets pulling so much easier than the factory loads FMJ.

I'll check the crimp measurment to verify, thanks again for the advice!

[jepp2]

Push the loaded cartridge firmly against the bench, and if the bullet does not move, you're golden.

I know a lot of people use this technique, so I am not faulting it. But my preferred method is to measure the OAL of your loaded round and make it the first one in the magazine. Load one more, and chamber and fire it. Now remove the one from the chamber and measure it. This is the one you originally measured. This will tell you if your are getting any setback on your loads. The dynamic forces of chambering the round after actually firing a round can be quite different than the static load of pressing against the bench.

Factory rounds will have some movement when checked this way. LEO's have had failures due to setback since they may remove the same round and rechamber it daily (unloading their service pistol when going home and reloading the next shift).

The 40 S&W has a fairly short range of OAL's (normally 1.125" to 1.135") as compared with the 9mm (1.050" shortest to 1.169" SAAMI max length). But do check to determine the max length for your combination.

For jacketed rounds I only flare .002", and for lead I flare about .003". My taper crimp only closes the flare. Neck tension is the key to the strength in holding the bullet in place. If you flare too much, crimping will NEVER gain back what you lost in flare. So don't flare too much. My flare works for me, but find out what is your minimum amount of flare for you loading process.

[noylj]

COL is determined by the bullet ogive (and where it becomes bore diameter). Thus, COL is different for each bullet. Next, it is determined by your magazine and the magzine's lips (how soon the round is striped from the magazine, the feed ramp angle, and the barrel's chamber. Noting those variable, where does the idea of a universal COL come from? It comes from the fact that most guns are not that fussy and there is a range of COL that will work.
Run a bullet into your chamber and measure the distance from bullet nose to muzzle. Then, measure the distance from breech to muzzle. The difference is your gun and that bullet Max COL.
I start my inert dummy rounds a little short of this COL and work down until the rounds chamber easily, fit the magazine, and feed 100% by hand. Then I take a few round to the range to "prove" that the COL is good--may even take a few sets of rounds at various COL.
I learned reloading back in the '70s. At that time, manuals very seldom referenced COL as the handloader was unlikely to use the same bullet and there is just too much variation for the manual's COL to be of any real significance--other than not loading to a smaller COL without care.
If you see Max COL in a manual, it generally refers to the SAAMI max COL for the manufacturers to perform testing--where the handloader is expected to load to a longer COL.
COL is not at hard to understand or work out, as long as you remember that it is bullet and chamber specific and not a universal number. Take a couple of different bullets and see haw much the max COL for each bullet varies from one to the next.
Also, I personally like to keep the barrel or cylinder at the bench to use as a case gage. The round must drop in and fall out freely. For autoloaders that head space on the case mouth, the SAAMI case drawing shows the case mouth diameter to aim for--that or no more than 0.002" smaller.
Finally, use your bullet puller to remove and check a bullet or two from your loading to be sure you are not damaging or swaging the bullet.
To me, the most critical step, and the one that too many handloaders ignore is case expansion. Other than jacketed bullets of the cartridge's nominal diameter (0.355" for 9mm, say), custom expanders are very important. The goal should be that the case ID, over the length the bullet is seated, should be 0.001" less than bullet diameter. Any closer, and you lose bullet "grip." Any more, and the seating operation will either swage the bullet down anyway to achieve the 0.001" difference or the case will be bulged due to the bullet not seating straight and bulging the case where the case walls are thinnest. You can read lots on the forums about crimp and COL, but almost nothing about case expansion or how many less than ideal rounds are loaded by those who ignore this step and think all they need is to flare/bell the case mouth.