Squib load tonight

[LiveLife]

It will be the best $1 you spend for reloading equipment.

The modification will meter W231/HP-38 down to 2.0 gr and Bullseye down to 1.5 gr, great for people loading for 380Auto and smaller calibers.

I just wanted to echo ... not trying to shade the Minor Power Factor. I was chasing that for a while as well

+1. Instead of targeting a particular velocity, you should conduct a full powder work up with your working OAL to identify accuracy nodes.

Since powders are often temperature sensitive, most will load to 130 PF on warmer summer days to meet PF on cold winter days unless you are using reverse temperature sensitive powders. W231/HP-38 is quite temperature sensitive and on warmer days, your muzzle velocity will go up. So if you are meeting power factor on colder winter day, you will be fine in the summer.

Here's a short list of popular match powders' temperature sensitivity - https://www.thehighroad.org/index.p...s-and-discussions.778197/page-7#post-10117881

 

[DLrocket89]

Started chrono-ing things today, had another squib. Same symptoms, some unburned powder, big smoke cloud, some fizzle.

At this point, I'm gonna call the adjustable transfer bar complete crap and go back to the discs, With the mod bds suggested at some point.

Thanks for the help everyone!

 

[thomas15]

I shoot a lot of 9mm (about 10,000 per year) in a revolver (S&W 929). The revolver has a tendency to push the bullets forward in the case, my homemade snap caps will grow noticeably longer after about 2 weeks of dry fire practice.

Last summer, I had several times over the course of about 2 weeks had bullets push forward and even spilled powder into the cylinder, the bullet out of the case but by simple luck I had not shot those particular rounds, just had the bullet drop to the ground when I opened the cylinder and unburnt powder all over my hands. This would be the 7th or 8th bullet in an 8 rounds revolver. I'm shooting steel so shoot 5 shots unless I have a miss.

Not saying this is the cause of the issue and not saying this will fix the problem but I agree with those that say you don't have enough case mouth tension. In my situation I started using the EGW undersize die which undersizes by .001 and went from .357 to .358 coated bullets. I haven't had a problem since.

I offer this simply as something to consider. The Lee U-die I think undersizes by .003 Both dies I mention are actually made by Lee. The fact that you have a hissing sound suggests to me you have powder ignition with little or no pressure. I think with even say 2 grains of powder the bullet would make it out of the barrel if everything else was correct, the slide of course just would not move. It's all dependent I suppose on how tight the bullet fits in the bore.

 

[DLrocket89]

Sorry, should've clarified - the squib load was the first round of a magazine. No opportunity for forward motion....

Thanks for the thoughts though!

 

[DLrocket89]

Wait - rethinking about that, you're saying there just isn't enough tension in general, regardless of bullet motion? There's enough neck tension that the bullets aren't moving under recoil. I loaded a magazine with a dozen, shot 10, and the one left behind in the magazine was still original COAL.

The other issue I see with neck tension is that I've had about 1000 rounds of this exact bullet/brass/primer/powder/powder weight/COAL/neck tension combo run great. SD of 20, ES of 40ish when I chrono'ed it last. Not what I'd expect out of my f-class bolt action, but certainly OK for pistol (I think). Solid, reliable ignition. The only thing that changed is that I put that variable transfer bar in.


Ultimately, this one is on me for not doing enough verification work on the charges that the variable charge bar was following. I looked in the cases and made sure there was some powder, but I didn't weigh anything (was working with Lee's volume measurement instead of weight). Due diligence would have found this problem before I had to pound out two squibs in 3 days.

I have about half an inch to go pounding out the %@^@ing squib. After this, more diligence will be had.

 

[DLrocket89]

Got the squib out. One unrelated side note is that I'm remarkably impressed by the HITEK coating on the ACME bullet I just pounded out. Check this out:

 

[thomas15]

Wait - rethinking about that, you're saying there just isn't enough tension in general, regardless of bullet motion? There's enough neck tension that the bullets aren't moving under recoil. I loaded a magazine with a dozen, shot 10, and the one left behind in the magazine was still original COAL......

Yes that is what I'm saying. It is the case mouth tension that holds the bullet into the case not the crimp. On 9mm the cartridge headspaces on the case mouth as another poster on this thread mentioned, when the slide strips the cartridge off the magazine it pushes the round into the chamber until it is stopped when the case mouth gets to the end of the chamber. The forward momentum of the bullet will continue if there is not enough case mouth tension to hold it in the case. I'm not saying that this is what happened but it is possible.

I handload a lot of 9mm using range brass and once in a while I come across a case that even after resizing doesn't retain the tension required to hold the bullet in place. Not often this happens but I have concluded that it is possible that some brass can for reasons unknown loses its ability to resize. I cannot prove this btw.

 

[Blue68f100]

Are you using mixed head stamps? If so there are a few mfg know to be thinner and softer than others.

 

[LiveLife]

Neck tension - As already discussed ad nauseam, for straight walled semi-auto calibers, it is resized brass friction/tension with bullet base that produce neck tension and not taper crimp. If a round has poor neck tension, when the bullet bumps the feed ramp, it is likely to be pushed deeper resulting in shorter "chambered" OAL which would further increase pressure build. I don't think chambered round headspacing on case mouth will move the bullet forward. (I could do a myth busting thread on this if you like)

Chamber pressure build - If a round has poor neck tension, this will affect initial pressure build. As primer flash burns powder charge, which is usually powder forward for semi-autos (as each round slams the powder charge towards the bullet base when chambered), you may get inefficient powder ignition as primer flash jumps across airspace to powder granules (more likely with lighter loads with dense powders like W231/HP-38). If bullet base moves forward due to poor neck tension from initial expansion of gas, chamber pressure build will be less than optimal and inconsistent.

Adjustable Charge Bar - Light powder drops from adjustable charge bar is a known issue as small opening must be precisely over the drop tube to fully drop all the powder granules and there are many mods to address this issue when using smaller powder charges. I prefer the "DIY micro adjust Pro Auto Disk" mod instead as each disk hole slides over the drop tube consistently and brass screw allows for infinitely adjustable powder drops.


My guess for OP is that .31 cc volume amount of powder charge is quite small and not enough powder granules got dropped into the case which caused the squib rounds. With DIY PAD mod, OP will be able to meter W231/HP-38 consistently to .31 cc volume with .1 gr variance.

And AFAIK, I am not seeing bullets' OAL change in the magazine from recoil.

 

[DLrocket89]

Back after driving back and forth across Wisconsin today. Good times.

First off - as I was sitting there last night attempting to fall asleep, I got to thinking...I turned off the powder flow on the Pro 1000 to install the powder measure/drop thing, maybe I didn't turn it back on again and I didn't check for powder for 50 rounds? Got home tonight, checked it, and *drumroll please* the powder flow was on, so that's not it.

Blue68 - No, everything is Starline, one shot on it, previously loaded by me. About as "the brass is all the same" as things can get.

bds - you are correct, it was powder levels:
I pulled several bullets with an inertial/hammer type puller. #1 - it took about 10 really hard whacks to get the bullet to come out. I doubt it was neck tension. #2 - powder load varied from 0.2 grains to 2.5 grains. I had several of these actually go off correctly in addition to the squibs. And they seemed "weak", but they cycled the action. That jives with what I saw in the rounds I pulled, a mix of almost no powder and a bit lower than normal.



Having thought about it, I think I have root cause:

Going back through what I did, like I said, I didn't weigh the loads, I was going off of volume. And honestly, I'm not sure that it matters that much. I've chrono'ed 0.34, 0.32, and 0.30 discs and I know I'm not running dangerous high pressures, so why not just use volume instead of weight?

So, what I did when I set up the Lee adjustable powder drop thing, I held a primed piece of brass under the powder drop die and then cycled the powder drop by hand, not using the press lever. I looked in the brass, it looked just like a 0.30 disc sample that I had sitting there, so I carried on. Switched to 0.31, did the same thing. By hand, not using the press lever. Continue on.

What it comes down to is that when I operate the press with the lever, the powder drop doesn't quite move through its full range of motion, so the charge amount varies a lot, between basically zero and mostly full. I've NEVER had that problem with the normal disc thing, so I'll be doing the mod suggested by bds above and I believe I'm good to go.

......what a lesson to learn, holy crap.



Thank you so much everyone! I learned a ton not even related to what's going on here, I greatly appreciate it. You all are what make The High Road fantastic!

Dustin

 

[Blue68f100]

Glad you found the root of the problem. Sticking or short stroking a powder dispenser is just trouble.

 

[Zendude]

I’ve experienced bridging on the autodisk, where the powder jams itself at the mouth of the hopper. Some powders are more prone to this than others. Tapping the hopper or making sure the hopper shakes a bit when you cycle the press will help prevent bridging. Also, set a good lamp by the press and glance into the case before putting the bullet on to see if the powder level looks right.

 

[Dudedog]

You can get an estimate of what a disk will throw if you figure out the VMD of the powder.
VMD*gr=cc
Disk size cc/gr of powder =VMD
Some listed VMDs are close some are not.
Here is a spreadsheet I set up when I was using my LPD to do calcs, no macros in the sheet.

 

[Chuck59]

I quit using the adjustable powder measure because of inconstancy with some powders and small charges.

 

[LiveLife]

I quit using the adjustable powder measure because of inconstancy with some powders and small charges.

I have two adjustable charge bars that work with larger drops of powders but yes, they are inconsistent with smaller drops with some powders.

That's why I use the DIY micro adjust mod for Pro Auto Disk mentioned on post #22 - https://www.thehighroad.org/index.php?threads/squib-load-tonight.835194/#post-10806885

The DIY mod consistently drops in-between disk holes and smaller than .30 cc drops with .1 gr variance.

 

[DLrocket89]

Quick (and hopefully final) update. I pulled the adjustable bar out and made a few observations. 1) there was quite a bit of powder on top of it, so it wasn't sealing properly against the silicone "mouth" on the bottom of the powder hopper. 2) it was lined with powder stuck to it...mold release maybe? I gave it a wipedown before I installed it, so not sure what happened there. Regardless, the volume of the pocket left over should've been enough to give non-squibs.

I loaded and burned another 250 rounds in the last 48 hours. Loaded them with the stock "disc", and everything was fine. So, yeah...adjustable measuring bar it was.

Haven't yet modified the disc per the thread from bds. I'm moving in a month and a half, so the current plan is to load up about 1500 rounds to get me through the next 2.5 months. Going to load that to my "standard" ~3.3 grains coming out of the .32 disc, live with that for now, and do the mods later once life slows down some.

Thanks again everyone!

 

[LiveLife]

Great.

I love happy endings.

Keep us posted.