Help with oal .45 ACP (plunk test)

I have been attempting to figure out the “best” oal for my new pistol. I read all I could, and most say that you should remove the barrel and make many different sized rounds until they hit the lands, or protrude beyond the barrel hood. I made a few rounds, in both 185 JHP (zero) and 200 SWC of varying lengths. The rounds are far beyond Saami spec for oal, and still pass the plunk test. Do I just set them to max Saami and be done? This should not be this hard...

Thanks for any insight.

Wish I could help you Joe, but I never considered any Jump, Jam or Touch for pistol projectiles, though it is something we benchrest shooters play with as a regular load development process.

Look forward to seeing the responses from those in the know.

Bob

Not sure where you found that "most say" to headspace on the bullet ogive.  You might just start with recommended OAL's for your specific bullet.  1.200-1.210" comes to mind for the Nosler 185 HP (similar to Zero) but look that up and don't take my word for it.  "Best" implies significant experimentation and testing in your specific system.  You might start with a value that many have used and found to be accurate, including commercial manufacturers like Asym and Atlanta Arms.  

Best of luck to you.

As said 1.210 for jhp
And .920 base to shoulder on lead.
Spend more time dry firing and less on re-engineering a perfectly good wheel

Thank you the advice. I will set to 1.210 and .920

Appreciate the help and understanding 

Joe

With lead SWC bullets, I seat so the case head is flush with barrel hood and then I work up the load. COL depends on your gun. SAAMI is for ALL guns, so it is for the lowest common denominator. 
Create two inert dummy cartridges at a long COL and reduce COL until they feed and chamber easily. This is your COL.

For 185 gr. Noslers follow the COAL from sharkdoctor. For SWC bullets, just seat the bullet so that the shoulder of the bullet is just above the mouth of the case. Some say a fingernail thickness. You just need enough sticking up to aid in feeding. I think you are using rifle loading information to load pistol ammo. Don't do that. This is somewhat what you are looking for, but this isn't one of my match loads, just plinking (note the plinking coated bullet) and some knowledgable bullseye competitors would say that this round is seated out too far. 

For my 45 ACP handloads, with all bullet types, I start with book OAL and check with the plunk test. For my 3, 45 ACP guns this has worked quite well. I have only needed to adjust OAL for one gun and that was for a "fat" 230 gr. RN in my HP carbine...

My apology for my brief answer above re:OAL.  It might be interpreted as just another opinion of some anonymous interweb denizen and worth what you paid for it.

So, briefly, I will add that the OAL I provided was part of a load developed by Dave Salyer and Al Dorman, adopted by the marines and used by many top shooters in subsequent years.  One can read the development of the load at ssusa.org/articles/2016/4/07/usmc-match-45-load.  That likely isn't a complete reference but should get you there.  I mention that because it provides a great starting (and end!) point for a majority of shooters.  If one wants to modify it to improve it, have at it, but understand it takes a lot of careful work to demonstrate improvements, and most of us can better spend our time training.

Hope that helps, and keep 'em centered!

Thank you for the information. I have no desire to re-engineer what has already been tried and proven. I am sure that any of these rounds will be more accurate than I am!

Working with .38 special wadcutters, was much easier- 148 Gr. HBWC, 3.1 Gr. of W231, seat flush, small crimp- done. Take that to the range and shoot. It was a nice easy starting point.

I would love to read the article that has been linked, but I am unable to find it. I assume it is 2016, but I tried looking through July and April....

Thanks again!

https://www.ssusa.org/articles/2016/4/07/usmc-match-45-load/

Thanks Brian!

Perfect, excellent article

Thanks!

Regarding LSWC bullets; Most 45acp match chambers headspace at 0.900-0.905". A lot of Kart barrels will come out around 0.910 because they don't really short chamber them and the slide tolerances dictate the final headspace. Most older factory Colt barrels used in Clark's (etc) run about 0.920".
In my experience if you seat your bullets out (long) to try and headspace the case bottom flush with the hood, you'll end up with a lead ring that will eventually start to cause malfunctions; cartridge cannot seat fully into the chamber because the lead ring shortens the headspace.
I recommend seating LSWC bullets from case bottom to bullet shoulder at 0.920-0.925". I have rarely seen a lead ring form when seated at this measurement. Another thing to remember is that the extractor can control/limit how deep your loaded cartridge goes into the chamber (old Clark's at 0.920" headspace).
I truthfully don't why the shorter seated bullets are less likely to form a lead ring. I've typically seen lead form at the bottom of the chamber and the lead angle and think this is because the cartridge is resting on the bottom of the chamber from gravity. Most commonly seen with swaged bullets.
My 2 cents....
Jon

Thank you for the explanation. I will seat to .920 and make up a few different loads. 

I appreciate everyone’s detailed responses

Never had a lead ring, so don't know what or how it forms.
All I know is after over 40 years of seating LSWs to the barrel hood, every thing has been great.
For those who want more information on the Plunk test:
Take the barrel out of the gun (or, open the cylinder of the revolver). Drop rounds in until you find one that won't chamber. Take that round and "paint" the bullet and case black with Magic Marker or other marker. Drop round in chamber (or gage or cylinder chamber) and rotate it back-and-forth a few times.
Remove and inspect the round:
1) Scratches in the ink on bullet--COL is too long (not a revolver issue)
2) Scratches in the ink on edge of the case mouth--insufficient crimp
3) Scratches in the ink just below the case mouth--too much crimp, you're crushing the case
4) Scratches in the ink on case at base of bullet--bullet seated crooked due to insufficient case expansion (not case mouth flare) or improper seating stem fit
5) Scratches in the ink on case just above extractor groove--case bulge not removed during sizing. May need a bulge buster.

K.I.S.S. Start with manual or bullet manufacturer's recommended OAL. Check with a plunk test. Adjust OAL if necessary after the OAL is determined to be too long. This has worked for me since I got my first 45 ACP in '90 (and in 5 other semi-auto pistols). I have never found "chasing the lands" to be of any value in a handgun.

There are other reasons why a cartridge may fail the plunk test, such as case bulge from too much crimp, failure to remove flare and bent/dinged rims. Any time there is a fit problem, measure...

mikld, 

Of course the safe way and a fundamental rule is to follow manufacturer's recommendations for loads and not deviate.

However, precision pistol shooting is a specialized sport with ammo and other requirements not found in the general shooting populace.  Manuals may provide a range for amounts and types of powder and bullets, but those might not meet a precision pistol shooter's needs.  A few examples: experienced shooters and gunsmiths in this thread and others note to set 45ACP SWC length to shoulder of 0.920-5".  I have never seen that in any manufacturer's manual.  I don't recall seeing Zero jacketed bullet load data listed by powder manufacturers; VV used to list Nosler 185's but others don't, and so on.  So manual recommendations may be a (mostly) safe bet but trusted and verified advice can help us find excellent loads for our sport without having to go through the rigors of testing myriad variations ourselves.

I hope that helps.

Sorry for the attitude, but we are adults, right:
I get so tired of arguing with someone's theoretical ideas vs my experience over many decades.
  Just remember, SAAMI specs are NOT for reloaders, and particularly NOT for handloaders, but for the industry ONLY so ammo is safe in all guns so chambered.
A handloader can load to minimize head space gap in their gun, knowing that there could be problems using such ammo in someone else's gun. A handloader's basic restraints are basic safety, feeding, chambering, and keeping pressures safe.
   If you want to be a reloader, buy manuals from specific bullet manufacturers and NEVER deviate from anything they print. Of course, your loads will be hotter than you need for competition and your COL (you know, Cartridge Overall Length and NOT OAL [everything has an Overall Length, so you really should say cartridge OAL to be clear] or AOL [whatever that is]) will almost certainly not be optimum for accuracy in your gun(s).
   Of course, staying with SAAMI, if your cases are trimmed to 0.888", your chamber's head space will be somewhere between 0.898-0.920", so your head space gap, at best, is 0.010 and could be as high as 0.032". Now, go ask any body who has been loading for accuracy what sort of head space gap they find acceptable.
   Thank God, it is hard to load BAD .45 Auto ammo. The cartridge and guns really WANT to be accurate.

I set my bullets out so the base does not line up with the barrel hood. I want the base slightly less than the barrel hood. And this is because, I found throats vary. Ammunition that fed and chambered well in the  Colt that I set the rounds to the barrel hood, jammed in my Kimber.  The slide would not close and it was hard getting the slide open!  The length of the round, based on the throat position of a Colt barrel was too long for a Kimber. The solution was to seat the bullet a little deeper. And set it deep enough that my rounds feed and extract from all my 1911's.

If there is any difference in accuracy, I am not going to see it shooting offhand. My error offhand is in terms of feet!