1. volunteer0925New Member

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Hello all.
I am new to the site and have found a lot of good info but nothing on this particular question.

I have been reading numerous books and manuals on the subject, one of them being "Reloading for Handgunners" by Patrick Sweeney.
In the section talking specifically about 40sw he describes a process of taking a dummy round of almost 10mm length and with the recoil spring removed from the pistol, cycling the round through and the resultant OAL of the ejected round is "the length for your gun" He also describes how to find the max OAL of your pistols chamber by first measuring the OAL of the separate bullet, dropping it into the the removed barrel, measure from the hood of the barrel to the base of the bullet. Add the length of that distance to the OAL of the bullet and that is the maximum "loaded" OAL of that particular pistol.
So I did all that. With a resized case of .843, and new bullet @.532 the measured depth was .721+bullet@.532= 1.253. I cycled a dummy round from the magazine, into the chamber and ejected it with a round of 1.207.

So I am not sure what this actually tells me?
Am I to assume that the longer OAL of the reloaded round will be more accurate given that if I were to back off the length a few thousands from the new length that the bullet has less distance to travel than a spec. OAL of 1.125 before it hits the rifling? The other effects being that there is more dead space in the shell, less brass to bullet contact, is he saying that I can load a heavier wt. bullet and keep the same grain weight of powder?
He ends the section saying that when crafting ammunition for your "competition" pistol the "correct" OAL of .40 ammo is what it is, there is no common or average length.Is this a common or even a safe process?
Thanks for any info or response's.

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4. Rick1967Well-Known Member

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While I have never heard of someone doing this with a handgun...people do it with rifles all the time. Often people will experiment by having the bullet as close to the lands as possible without touching. But people shoot rifles for precision. They often try to squeeze 3 bullets through one hole at 100 yards. You don't do that with factory ammo. That is when this type of thing comes into play.

You don't want it so long that it is going to force a bullet into the rifling. And I would not do this with hot loads. Sometimes when firing heavy loads, rounds in the mag can be affected. The last round in the mag could end up longer than the others. It is because as the gun is fired the rounds in the mag can "jump crimp". They will back out of the case ever so slightly under recoil. When you have a few thousandths to spare its not a big deal. When you are already 1 thousandth off the lands...now you many not go into battery. Or you may jam a bullet in the barrel.

5. msericNew Member

Here is how I find the Max OAL for all my handguns. Letting the action slam the round home may give false readings.

6. volunteer0925New Member

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Duddie Thanks,
I am slowly building up my library and reading different manuals for that exact reason. How does one go about getting the chamber cast and who would you suggest doing that?

7. volunteer0925New Member

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Thanks gr8oldguy (old guys rule)

As of now I will not be trying the process outlined, but I am always up for tying something new (and safe) that will improve my accuracy. It sounds interesting, but I don't feel confident in my reloading experience yet to "experiment" outside of the expected powder / bullet / primer combinations and load practice.

8. volunteer0925New Member

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Rick,
So the practice is in fact to improve accuracy then. I had read a similar article somewhere else but cant remember where, but the author suggested backing off the distance to the lands a few thousandths also. The problem I see with my experience is judging how much is a safe minimum brass-bullet contact surface and what kind of charge is safe since now I'm off the radar with data specs.
Like your Jeep. Ive got a 2001 Wrangler, love it!

9. volunteer0925New Member

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Mseric thanks for the diagram.
I went back and looked at what I have and compared it to your diagram and even at 1.207 OAL the brass is still maybe .010 shy of the butt of the barrel. But what I did find after paying closer attention to what I was doing, was even though I loaded it in the magazine first and racked the slide etc... when I attempted to push it fully into the mag again (as if I were loading more rounds) I realized it will not fit (too long). Hm, so how do other shooters get around that issue? I only imagine that not all pistols have as deep a chamber as the sig226 (seems deep) and going longer than the Spec. OAL to almost reach the rifling isn't extending the round much at all?

10. Rick1967Well-Known Member

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That mag is the deciding point on many guns. My 1911 mags are pretty shallow. And they are all the same for 1911 guns. They are all interchangeable. But I had a Ruger P90 that is a 45. It had much deeper mags. I know because I was loading much longer for that gun. But the rounds I made for that one would not fit in the mags when I bought my first 1911. That is when I stopped using my semi-wadcutters.

11. JonMModerator

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Using a round driven into the lands will ensure you kaboom your gun at some point. Sweeney is an idiot. I dont often recomend burning a book but that is a good candidate.

Three ways to get a real measurement of your max oal. One chamber gage, hornady locknload gage is good for that. Two chamber casting then measuring the cast. Three book values for coal (my preferred method as the other two also require a bullet comparator).

The issue with the first two is you need some way to measure bullet ogive since the tip of the bullet is as important as where the outside edge of the ogive is. Bullet makers provide that info in the form of max cartridge overall length.

If you look in a load manual you will often see different numbers for the same weight bullets of different types. This is because different ogive lengths need different seating depths and charge weights so you dont drift into over pressure.

Using a overlong case to smash into a chamber is stupid. The method sweeney describes is so stupid it illustrates a complete lack of understanding of handloading. The 40sw and 10mm both head space off the case mouth so rammining a 10mm case into a 40sw chamber will give false data and not even work as the 10mm is longer than a 40sw chamber by design. This is to prevent you from doing what sweeney says is smart.

Burn that book the man is an idiot

12. volunteer0925New Member

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Jon,
Although I cant pretend to understand your level of disdain for Mr. Sweeney, it is only because I do not know enough yet to gauge his ignorance on not, but believe me I have encountered many a person who puts themselves out there as an expert who in fact an idiot. Have you looked at his book, just curious.
Tell me if I am wrong. A chamber gauge is for testing external diameter only? I have looked to purchase one for 40 but everyone seems to be out of stock at the moment. I have seen bullet comparators, I thought they were for rifle rounds not pistol? how does a comparator differ than just using a set of calipers to measure OAL?
BTW, If I gave the impression that Sweeney was saying to put a 10mm round in a 40 that is not what I was trying to relay, it was to load a 40 round to an almost 10 length then chamber it, not that takes away from his ignorance or adds to his intelligence.
Don't mean to belabor the post but one last question. ( if you don't ask you wont learn, right) If the practice I tried to describe is used in rifle rounds why not pistol? I have taken that 40 is a bit of a caliber all unto its own from how it was derived, are you saying that this practice is foolish with any handgun caliber or just 40 s&w?
I like your quote, I might just steal it for use somewhere else, Ill give you credit though....

13. Axxe55The Apocalypse Is Coming.....

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most semi-auto pistols headspace of the case mouth, not the bullet. most revolvers headspace off the rim, with the cylinder being the factor for OAL.

and FYI, JonM is a pretty knowledgeable reloader and as a reloader myself, i have defered to his wisdom and knowledge several times when i was in doubt on something.

14. Rick1967Well-Known Member

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There is no way I would try to head space off a bullet in anything. That is just asking for an emergency room trip. That is why I mentioned about the possibility of jumping crimp in a mag and sticking a bullet in the rifling. Jon is right.

15. JonMModerator

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anyone that publishes an unsafe practice is not worth reading as how can you believe that he is correct in anything else??

when you force a bullet into the lands to measure chamber depth you are using more force than the metal can withstand so it gives a false reading. this is true with handguns rifles or cannons. so your reading that you get is going to be deeper than what is actually there in the firearm.

oal is not really that important to accuracy in a handgun. getting too close tot he lands is a bad thing in a handgun because the bullets have such a small bearing surface there isnt a lot for the case to grab to. so when you start seating long to get to the lands you start having issues with bullets pulling under recoil or on chambering leading to severe overpressure as the loose bullet is jammed into the rifling.

handguns just arent like rifles so the techniques that squeeze extreme accuracy from rifles dont really do anything with handguns. what you should focus on for accuracy with handguns is charge weights bullet construction especially with lead hardness as plain lead tends to be more accuracte in a pistol than jacketed and consistancy of the product. actual seat depth isnt important so long as it falls in the afe coal range.

Last edited: Dec 8, 2013
16. volunteer0925New Member

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Thank you Jon and everyone else.

When I played with a dummy round doing what has been talked about here it just didn't sit right in my thinking when I saw that the bullet was only seated less that 3/16" into the brass.

By no imagination am I questioning the legitimacy of any information I am gathering here, just asking questions to answer my own possible misinterpretations of what Ive read so far. Some things make sense and others raise questions in my mind, but then that is one reason why I am here.

Hope to be able to contribute eventually.

17. duddie10New Member

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Ive done it once came out alright. Heres the link to midwayusa.com ive used them a bunch of times. No worries about site security

http://www.midwayusa.com/product/462291/cerrosafe-chamber-casting-alloy-1-2-lb

18. Eagle1803New Member

Your right about that, I use a gage and gage every bullet, if it fits it will work. you will always have variances in OAL, I try to stay around 10,000 under Max oal.

19. volunteer0925New Member

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Standard for 40 S&W is 1.125, and then in some manuals it is stated as 1.135" which I had tried, I took it out to 1.165 OAL which is the max length my magazine will accept, although my chamber on my SigP226 goes out to 1.2xx"(can't remember exact length).
I wish I had the link at hand now, but it explained in very precise terms how the angle of rounds change as they stack up in a magazine. I could actually fit a round loaded at 1.185 in my mag as long as it was the first round loaded. I tried 1.175 and they fit until I got about 6 rounds in and then jammed up, 1.165 was the optimum length for my mag.

I started out shooting the 1.125 and at 10 yd. had a pattern aprox. 5" low and to the right. As I progressed through the different loads, all at 10 yd. I could see the pattern tightening / centering up, until I reached the round's loaded to 1.165 OAL which patterned out at 9 / 10 in the 1 1/2" DIA. bullseye. Ok, so to many of you this isn't necessarily great marksmanship, but for me not having much time target shooting with a handgun, I was pretty excited! I had loaded 15 rounds at 1.165 and since I had 5 left I ran the target out to 15 yds and hit the same bullseye 4/5 times, made my day!

I was shooting a Sig P226e 40 S&W. rounds loaded were with used WIN brass, Hornady XTP 155 HP ( 500 free for buying a Hornady LNL press) 6.3 grains of SR 7625, CCI 550 primer. I was using the 7625 powder because it was the only thing available at the time, and the same for the 550 primers instead of CCI 500 primers.

Now I wonder do I leave it alone or try hotter loads at this length?

20. volunteer0925New Member

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From the info I have gathered recently I understand that factory ammo of given caliber is loaded to SAMMI lengths to safely fit 99% of all handguns / rifles, what it doesn't mean is that it is necessarily the proper length for "your" particular firearm, but again it may be, investigation is required.

Loading the round with the bullet right up to the lands of your rifling is not a good thing, rifle or handgun.

The example given was a car trying to drive up a curb with the tire right on the curb. It takes a considerably longer and harder push to get it to go up as compared to back off and taking a running start at it, so goes with loading a round too close to the rifling too much pressure can be built up.
The general consensus also is that loading the bullet out further, which leaves more space inside the cartridge at a given powder weight does not create a situation of a hotter load because of having more time and space to ignite the powder,(which I have read a few times), and as I experienced less recoil and muzzle flip I tend to believe the former.