Hey, just wondering how many of you guys use the plunk test. I'm starting to load 45acp. I've read COL should be 1.20 to 1.25. I have some factory Remington 230gr FMJ RN rounds for some reference. That plunks, spins freely and comes out freely when I invert the barrel. Bullet I'm loading is Campro FCP RN, Campro says COL should be 1.25. Hodgdon site says 1.20. When I use 1.25 my round will plunk but not spin freely or drop out freely when I invert the barrel. If I drop the COL to 1.22 then it'll pass the plunk test. My barrel is from a Norc 1911 5" if it's relevant info. Anyone using the same bullet as me care to chime in? I plan on using Titegroup 4.4gr and S&B LPP.
Plunk Test
- Thread starter rayzorloo
- Start date
Now you know the reason for doing the test. Specs say 1.25, gun says 1.22, believe the gun. Titegroup burns with a high pressure spike and wouldn't be my first choice for this application. I use Autocomp myself for .45ACP but also load to max with a 200 grain bullet.
Unless Campro borrowed your pistol for the load development, their OAL means nothing.
Seat deep and then longer and longer until the bullet hits the rifling (fails the plunk test). Then seat a half rev deeper and note that distance.
That number is only valid for that bullet. A different maker or different weight will need its own development in your pistol.
My experience with Norinco is that they have short throats. CZ, too. Need bullets seated a bit deeper than other pistols.
Seat deep and then longer and longer until the bullet hits the rifling (fails the plunk test). Then seat a half rev deeper and note that distance.
That number is only valid for that bullet. A different maker or different weight will need its own development in your pistol.
My experience with Norinco is that they have short throats. CZ, too. Need bullets seated a bit deeper than other pistols.
HS6 is an excellent powder for making full power loads.
TiteGroup is best for making mid-power accurate loads.
The danger of TG is that the small powder charge can be double charged and over looked. A double charge with HS6 is more obvious.
I use TG in 45 for target loads. Your proposed 4.6 gr load should be nice and mild to shoot.
TiteGroup is best for making mid-power accurate loads.
The danger of TG is that the small powder charge can be double charged and over looked. A double charge with HS6 is more obvious.
I use TG in 45 for target loads. Your proposed 4.6 gr load should be nice and mild to shoot.
- Location
- Nova Scotia
Are you using a factory crimp die? I find that solves a lot of my issues with slightly not aligned and small bulges.
Experiment with the different COAL's to see which is most accurate, always checking for pressure signs. I've read that just touching the lands slightly isn't necessarily a bad thing for accuracy but you need to be vigilant about making sure of those pressure signs. Just a for instance, I recently had a small batch that came out about 10 thousands shorter than my usual COAL. I put them aside for practice. Lo and behold, they ended up shooting like lasers. That's now my standard COAL. It pays to experiment.
Last edited:
Make sure you are crimping the rounds properly too.
I was not able to get my 9mm Campros to pass the spin/plunk tests. Didn't matter how short I seated them; ended up being too light of a crimp and the case neck was still belled out just a tad too much.
I was not able to get my 9mm Campros to pass the spin/plunk tests. Didn't matter how short I seated them; ended up being too light of a crimp and the case neck was still belled out just a tad too much.
I've never used that powder for anything so I can't say. Titegroup and HP3 both work great for 9mm and .40S&W, it just seems 'snappier" than Autocomp in the .45 to me. But one of the cool things about reloading is the ability to customize your stuff exactly the way you like it. Enjoy the ride, it's a hoot
It was a total fluke. That's why it pays to experiment. Touching the lands or not I'll leave to the experts to debate, just something I read, it's above my expertise.
Then why did you post the information and illustrations by Wobbly from the link below.
Plunk test, they say your own barrel is the best gauge. And the same applies to the cartridge OAL, pistol or rifle.
How to determine Max OAL for a CZ Pistol
http://www.czfirearms.us/index.php?topic=34225.0
Long range load development at 100 yards. (rifle load development below starts at .020 off the lands, but some shooters use jam)
http://forum.accurateshooter.com/threads/long-range-load-development-at-100-yards.3814361/
1. Find Jam by seating a bullet long on a dummy piece of brass (no primer nor powder) and apply die wax to the bullet ogive and record it's base to ogive length.
2. Chamber the round and close the bolt.
3. Snap the bolt open and measure the base to ogive measurement. If it is shorter than previous measurement, this is your jam. Do it a few times with different cases to make sure.
4. Load a known powder/primer/bullet combination. I load 4 of each powder charge in 0.5 gr. increments and seat bullets at jam - .020". I use one shot of each to get barrel fouled up and also keep an eye for max pressure at the same time. You can also use these rounds to break in a barrel if you are inclined to. If I encounter pressure on the hotter rounds, I will not shoot groups with the other loaded rounds and will pull bullets when I get back home. Do not shoot in round robin style because position and natural point of aim will be compromised.
5. Shoot 3 shot groups starting from lowest to highest. All groups are shot over a chronograph.
6. Examine target and find the place where consecutive groups line up vertically and ES is the lowest and speed increases the least from one group to the next.
7. Load to the middle of the powder node and do a seating depth test.
8. Load 3 shot groups starting from Jam - 0.005" all the way out to Jam - .040" in .003" increments.
9. When you find the seating depth test that shoots the best, load towards the longest side of the node to allow more room for throat erosion.
10. Final step is to load the new seating depth and load 5 shot groups in 0.1 gr. increments 0.5 gr. on each side of node (if pressure limits are not reached). This will cover an entire grain of powder and you will be able to pinpoint where the powder node starts and ends. In the summer, load towards the low end of the node, and do the opposite in the winter.
Works for me. I don't care why it tightened my groups, just that it tightened my groups.
A quick google comes up with numerous hits. It seems to be touted primarily for SWC's and lead bullets. Also no shortage of people who agree with you as well. It's all hearsay to me so as I said, I'll leave it to the experts to debate. I guess the only solution, for each individual pistol and load, to see what works best for you, is to experiment.
Always always always being careful about pressure, needless to say.
