OAL question. Just to make sure


September 30, 2011, 08:13 AM
I am loading my first 40 S&W rounds. Working up some 155 GR plated RN. Using Bulleseye.

Here is my question. I have read from other threads that the proper OAL is determined from dropping the round in the barrel of the gun, reducing the OAL untill it spins freely. The MAX OAL listed for this bullet spins freely. My common sense tells me not to go longer than the max oal listed, (not to say my common sense hase not been wrong before.)

If I use the max OAL based on the drop test, does that make the load need more powder?

Handgun is my recently aquired Glock 22
Bullet is ranier leadsafe 40 S&W 155GRflatnose
Lyman lists max OAL for 40 S&W 1.135
150 gr #2 Alloy lists OAL 1.09

Plan on loading increments 4.8-5.4 of bullseye.

Have loaded about 2500 rounds thus far. And am now seeing the benefit of having a cronograph. Plan on buying one on my next order. Will be interesting to see what my various rounds I have come up with actually are doing.

Any thought tips or corrections are appreciated. I am still very new and learning.

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September 30, 2011, 10:18 AM
Glock barrels have longer leade (space the bullet jumps from the case neck/chamber to the start of rifling) than other factory/match barrels and will feed much longer OAL than published. So, instead of the Max OAL, I would use the Ideal OAL that will reliably feed/chamber from the magazine when the slide is manually released without riding the slide with your hand.

For most FP bullets, 1.125" OAL will feed/chamber well from the magazine, but conduct your own test to be sure.

1. MAX OAL determines the longest OAL that will drop freely in your chamber without hitting the rifling. Using your barrel out of the pistol, drop a sized case into the chamber to ensure you are full-length sizing your case (it should fall in freely). Next, make a dummy round (no powder/primer) starting at SAAMI max length and taper crimp .020" wider than the diameter of the bullet (.420" for .400" bullet). Drop the dummy round in the chamber and incrementally decrease the OAL until the round fall in freely and spin without hitting the rifling.

2. IDEAL OAL determines the longest OAL that will feed and chamber reliably in your pistol/barrel/magazine. Starting at the MAX OAL, manually feed your dummy round by releasing the slide (do not ride the slide with your hand). Incrementally decrease the OAL until the dummy round feed/chamber reliably.

3. POWDER WORK UP. Once you determined the MAX and IDEAL OAL, then conduct your powder work up from published start charge to identify the charge that will reliable cycle the slide and produce consistent accurate shot groups.

September 30, 2011, 12:46 PM
Any thought tips or corrections are appreciated
Are you saying you have loaded 2,500 rounds so far, and are now wondering what the correct OAL should be??
And you haven't tried shooting any of them yet?

Have I got a Tip for you!

Load a very few test loads and go try them before you load 2,500 rounds of untested loads!!


September 30, 2011, 12:57 PM
For the most part, with Glock's longer leade and more generous chamber mouth of G22 barrel, OAL below SAAMI max should work in Glock barrels for most bullet profiles.

Although I have test loaded 40S&W using faster powders, I would recommend slower powders than W231/HP-38. It provides softer recoil than even snappier Bullseye powder (and 40S&W is already a snappy recoiling round). And even with W231/HP-38, I use mid-to-high range load data to give me some headroom buffer chamber pressure wise.

September 30, 2011, 08:16 PM
Thanks for the comments they were very helpfull.

Rcmodel.....I dont see how you deduced that from my post. I just got the glock and just started loading for it. So no I did not load 2500 hundred rounds before shooting any.

I do have Hp 38 as well and will try both to see the difference. Thnaks for pointing that out

September 30, 2011, 09:18 PM
I dont see how you deduced that from my post.
Well you said you Have loaded about 2500 rounds thus far.
So I thought you said you had loaded ------ ahhhhh Nevermind!


September 30, 2011, 11:42 PM
Just my 2 cents here from some recent experience that I had loading for my FNX .40S&W. The key to to OAL is what will fit in your magazine, a lot of people load longer and it will chamber check fine, but then won't fit in the mag or hard to load the mag.

The OAL length's that are listed are usually for the minimum. As for working up your load, OAL is a function because of case volume, and that will change based upon bullet length and or type. The problem that I had is using a charge for a OAL of 1.125 and loaded the rounds to 1.156, needless to say they didn't work to well in my gun.

As for powder that was suggested earlier, I started using titegroup and didn't like it, fast burning powder and little case volume. So after some research went with a slower burning powder HS-6 and worked up to 6.7grs. and really like that load, so now my load is

180gr RNFP Berry's Plated
HS-6 @6.7grs
OAL 1.125 +/-.002
Crimp Dia. .422

October 1, 2011, 07:29 AM

Never thought about that bit about the magazine. Yet something else to check.

You were talking about volume in the big case. When I load 38 special I am really amazed to see how little powder (bulleye) is in there. I have to pull the case off the shellholder to see it.

October 1, 2011, 08:10 AM
Lots of good info above.

Summing up we can say...
• The dimension given in the diagram in your RL manual is the SAAMI maximum for roundish nose. Rounds longer than that will definitely NOT fit into the magazine.

• A good many hollow points and flat points will need to be an additional .010 or .020" shorter than the SAAMI max so that their sharp corners don't catch on anything, thus allowing them to slide freely inside the magazine.

• The chamber drop testing is always nice to know, but in my experience discovers more trouble in the 9mm than in the 40. 40's have fairly generous freebores.

• Let's say you find that a certain bullet shape feeds best at 1.240", then you can use any published load with an OAL shorter than that, and work up the load up from the "starting load".

• Working up from the "starting load" in small increments will safely cover up a host of variables having to do with the bullet, the gun, the chamber fit, etc. and result in maximum safety. Once you discover what one 150gr lead round likes in your gun, then the second brand of the same weight can begin much closer to that, so your work is reduced. That's why keeping a log book is important.

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