Consistant seating depth...
- Thread starter 20PPC
- Start date
A mandrel is definitely gonna play a big factor in getting consistent neck tension. I also would use some imperial wax on the inside of your neck very very light amount. You also need to keep in mind your brass may spring back as well. Hopefully that’s helpful
Do you feel the thickness of the base of the case effects seating depth, or are you just throwing that out as general information?
I don't have this issue and never have while using a bushing and no mandrel, fwiw. I doubt that's the issue and is just another rabbit hole to crawl into chasing the problem. Possibly...if he's mistakenly running crazy neck tension but I know Dave well enough that he knows better unless something got by him in that regard. I don't even know how I could intentionally make my seating depths varry as much as his except the cracked stem that I've already mentioned, so I'm curious what he finds.
These simple things will improve seating consistency very much. Except, instead of imperial wax, I use graphite or Neolube. Your note about spring back is exactly why I mentioned in my comment that using the mandrel right before seating will help a lot.
I've noticed that even letting the brass sit for just a day or so after setting neck tension can affect seating consistency.
Everyone else has their 2 cents in. What’s two more.
My first impression is time to anneal but that is allot of variation in seating depth for just not annealing and the neck tension would be higher but consistent. It’s also allot for base to tip variation for Berger bullets.
One thing I didn’t read was how much neck tension you’re running. I did have your problem back before I switched to bushing die. The factory saami die was causing so much neck tension it would actually leave a small ring on bullet. I believe it was causing seating stem to spring enough to cause seating problems. It’s been awhile so my memory is a little foggy. I tried to find it in my notebooks but had no luck. I haven’t ran heavy neck tension in awhile.
Another time I accidentally moved the crimp down so it was just barely engaging. It was enough to completely mess up seating depth but so little you couldn’t see it. Took awhile to realize since I haven’t crimped a load since I was a kid reloading with my dad. I actually forgot they do that. Reading your post brings back that icky feeling. I don’t like to see .001” variations. I hope you figure it out.
jelenko
Gold $$ Contributor
Thanks for responding!
I must have misunderstood. [Not the first time.] With your obvious experience/expertise, I was concerned about my own understanding.
i have had problems when using an ill fitting stem (too near the tip) on light jacket varmint bullets, even with what i will term a 'reasonable' amount of 'neck tension'. one bullet i tried (i believe it was a nosler small caliber) had no lead under the contact area and the stem would collapse the jacket to varying degrees, causing some bullets to be seated long, even though the coal length looked about right.
i can imagine similar happening with lesser neck tension when running into the donut.
i put in my 0.00327 worth...
JMayo
Silver $$ Contributor
Yes, some the stamp is barely visible !
I’m a firm believer in the Accuracy One tool. I’ve only been shooting 600 yard matches for a year and a half but inconsistent results on paper and in seating consistency. First match last year I got small group, the next several matches groups anywhere from 1.5” to 3”. I anneal after each firing, very anal in the loading process but still not happy. Bought the before the last match and practice was great. Best group just over 1”. The next day at the match I shot a .941” group and won the match. I am very confident knowing ever round in each group of five was within .0005”. I’m hooked.
It was a similar deal for me. It made an immediate difference on target with no other changes to my routine.
Yes, I like my Accuracy One gauge and it is my primary tool to verify seating depth. However, every seating die made indexes off the case base while the A1 gauge indexes off the shoulder. If your sizing die produces a very consistent shoulder bump, then it doesn’t matter. But if you have significant variation in your shoulder bump, that will be directly related to variance in measurement from the Accuracy One gauge and bullet jump to lands.
What stamp, the head stamp?
Exactly what I do. The die rests on the shoulders instead of the base and you get amazing consistency of bullet ogive to shoulder.
Mulligan
Silver $$ Contributor
I checked the seater stem last night when I got home from work, inspecting it with a magnifying glass and good light.
There were clearly no cracks on the stem, I then turned it over and put a bullet in the stem pressing down on it and still no seperations.
Next thought is to try some other brands of bullets, I have some Bibs to try and some Barts.
There were clearly no cracks on the stem, I then turned it over and put a bullet in the stem pressing down on it and still no seperations.
Next thought is to try some other brands of bullets, I have some Bibs to try and some Barts.
Is the stem making good contact all the way around and not bottoming out
@Bc'z yes after having it drilled out and polished it is making perfect contact.
I'm about ready to screw my 30 BR barrel back on the action and just shoot score.
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