Making Progress with my Dillon SDB. Need more knowledge, though.

[IDescribe]

Also, everything Wobbly said. 

[HossMan]

Ran out of Small Pistol Primers. Used 70 Federal GM205M rifle primers (found in the basement) in a reduced load. All of them shot fine without any need for double strikes.

The LGS only had CCI Small Rifle Primers, so I bought a box of them. I guess this means "Back to the drawing board"

Is there anything I should watch out for when loading Small Rifle Primers? Should I do a different ladder load? What I did at first was a 3.8, 3.9, 4.0, 4.1 ladder load with small pistol primers and Hodgdon Universal. None of the loads showed any signs of over pressure on the brass or primers. I settled on 3.9

What kind of ladder load should I do with small rifle primers and Hodgdon Universal? I'm still using the Acme 124 RN seated at 1.075"

Thanks for helping this Greenhorn, guys.

[Wobbly]

Small rifle primers will physically load just like the small pistol primers. No probs there.

If you have velocity data on previous loads, then drop back to your lowest recorded load and use the rifle primers. If there is no more than ~10 fps difference, then you can assume there is little or no difference in primers. Whatever happens, try to equate the load with pistol primers to a load with rifle primers so you can develop a rule of thumb for your type shooting.

 

[HossMan]

Hello, friends and Merry Christmas!! Before heading over to my family's house I decided to make the most of my free time by reloading. This batch was 175 rounds with the same old 124gr RN from Acme and 4.0gr of Hodgdon Universal Clays. I had about 7 rounds out of that batch fail the plunk test in my SP-01. My COAL is averaging at 1.078" with the Xtreme brass cartridges reading around 1.070", curiously enough. Anyways, 6 out of 7 of these cartridges that failed the plunk test were Winchester brass with, IIRC, Glock primer strikes on them. There were a few cartridges out of my batch that barely caught the rifling with a modicum of resistance, so I felt that was "good enough" and gave them a pass. Is that an ignorant thing to do? Anyways, I'm not sure if I'm still loading too long or if there other factors that playing into my failure rate. Thanks so much for all your wisdom and enjoy all the time with your family!

PS I found my first completed cracked case, which happened to be Blazer Brass.

[painter]

If you have 'some' loads engaging the rifling at your chosen OAL, then yes, you need to load shorter.

It also sounds like you have an excessive spread in your OAL's. You speak of an average, and mention .008 less. What's the deviation over 1.078?

Not trying to be preachy, but you need to tighten things up.

[HossMan]

There were a few cartridges out of my batch that barely caught the rifling with a modicum of resistance, so I felt that was "good enough" and gave them a pass. Is that an ignorant thing to do?

With respect to this comment, every round I plunk test gets fully rotated while in the chamber and I periodically make sure the chamber is free of any debris. When I encounter some rounds that barely contact the rifling at a certain point in rotation, I deem it harmless. This is why I am asking you knowledgeable fellas if that is a bad policy.

[HossMan]

If you have 'some' loads engaging the rifling at your chosen OAL, then yes, you need to load shorter.

It also sounds like you have an excessive spread in your OAL's. You speak of an average, and mention .008 less. What's the deviation over 1.078?

Not trying to be preachy, but you need to tighten things up.

I give my Dillon press the benefit of the doubt. On the other hand, I'm not always confident in the quality of the Acme coating. On some of them, there are high spots I can visually see and feel with my fingers. I'm not sure why cartridges with Xtreme brass are a tinge shorter...

I haven't measured all of them to determine a standard deviation.

Edit: if I had to guess, my deviation is about 0.002"

[painter]

If you have 'some' loads engaging the rifling at your chosen OAL, then yes, you need to load shorter.

It also sounds like you have an excessive spread in your OAL's. You speak of an average, and mention .008 less. What's the deviation over 1.078?

Not trying to be preachy, but you need to tighten things up.

I give my Dillon press the benefit of the doubt. On the other hand, I'm not always confident in the quality of the Acme coating. On some of them, there are high spots I can visually see and feel with my fingers. I'm not sure why cartridges with Xtreme brass are a tinge shorter...

I haven't measured all of them to determine a standard deviation.

Edit: if I had to guess, my deviation is about 0.002"

I give my Rockchucker a squirt of oil once in a while, but it otherwise gets no benefits.  [weak attempt at humor]

So if you can be .002 long, and .008 short then your deviation is .010. If your bullets, or the coating, is touching the rifling at only .002 long then you didn't reduce enough from your pushtest result to allow for deviation.

Did you do a push test with that bullet, and what were the results?

I went back to the beginning of this thread, and you were having the same issue at 1.095 OAL. I'm guessing your target is 1.075 now, and you're still having a similar issue.

Something isn't right.

[HossMan]

Something isn't right.

Well, there doesn't seem to be a consistent correlation between length and passing/failing the plunk test. For example, a few of my failures are 1.072" and you can't turn them while they're in the chamber and they don't freely fall out. However, the vast majority of my rounds are 1.078" and they pass the plunk test with flying colors.

[nicky]

So you have done the push test correctly and deducted .010-.015 from what you got and find that you are getting some failures.

 I would suggest that you take one of those failures and color the whole thing with a magic marker from the nose of the bullet to the base of the case. Then take that, put in your barrel and spin it around. When you take it out you will see that the marker got rubbed off where it was hitting in the chamber.

Where did it get rubbed off?

Picture would be helpful.

[painter]

Something isn't right.

Well, there doesn't seem to be a consistent correlation between length and passing/failing the plunk test. For example, a few of my failures are 1.072" and you can't turn them while they're in the chamber and they don't freely fall out. However, the vast majority of my rounds are 1.078" and they pass the plunk test with flying colors.

Like I said...

Try nicky's suggestion.

[Wobbly]

I would suggest that you take one of those failures and color the whole thing with a magic marker from the nose of the bullet to the base of the case. Then take that, put in your barrel and spin it around. When you take it out you will see that the marker got rubbed off where it was hitting in the chamber.

Where did it get rubbed off?

Picture would be helpful.

^^ This is the answer. ^^

? Lead is ALWAYS more trouble. Go back to plated or jacketed and work out your process issues.

? The SDB needs lubrication on all the linkage pivot positions in and around the bottom of the press. The one SBD I purchased and re-furbished had galled aluminum to steel in that area. A couple of drops of synthetic motor oil each month, or a shot of CLP will do the trick. I got so tired of lubing my 550 that I converted it to grease.

 

[HossMan]

I will report back later with my findings. Thanks for the help, guys.

[HossMan]

I re-seated some of them 0.008" shorter and that seemed to fix the problem for a lot of them. I also ran out of Universal Clay powder, so I just went out and bought some TiteGroup. I have heard all about the sharp pressure curves and what not, but I'm assuming I'll be fine as long as I exercise caution. I plan on doing a ladder load of 3.5, 3.6, 3.7, 3.8, 3.9, and 4.0. With the same bullet this time seated to 1.070". Any advice? Thanks, guys.

[Wobbly]

It's not the press and it's not the gun....

? ACME makes five different 9mm bullets from 122gr up to 125gr. Are yours the ones they call "124gr RN-NLG" or what ?? We need exact information on the bullet.



? Secondly, take your caliper and measure the diameter of the bullet with the thick portion of the blade running along the length of the bullet. That way you'll avoid any low spots and get a realistic picture of their average diameter.

I think you simply got some bullets running .357/.358" and the full diameter is wedging into the freebore. That will not hurt you; that's not an issue. As long as the ogive is out of the lands of the rifling, then you'll be OK. I also think that larger diameter explains why some of these fail the spin test.


That's a very shallow ogive. You should be able to load those at 1.130" or so.