Variations in seating depth

[rsbhunter]

vancewalker007 gives ALOT of very good advice...didn't think about ram speed or force at end of stroke, but it is very important....I've noticed .001-.003 difference in seating depth by varying it. I now try to do everything as close to the same every time....

 

[Varmint Hunter]

The most significant factor that actually causes inconsistent CBTO measurement (IMO) is COMPRESSED loads. Compressing powder to any degree will frequently result in OALs that vary.

Just thought I'd mention it in case you had a case full of powder. :>)

 

[338 dude]

vancewalker007 gives ALOT of very good advice...didn't think about ram speed or force at end of stroke, but it is very important....I've noticed .001-.003 difference in seating depth by varying it. I now try to do everything as close to the same every time....

Also dwell time when you press the handle down pause for just a second or two before you release it you may see an improvement

 

[vancewalker007]

The other process that helped a lot with consistency as to shoulder bump and seating depth was when I started annealing...my annealing machine isn't a $1000 machine, maybe $60-90 total , but is an awesome help in keeping consistency....here's a pic of the one I built....there are definitely better, but my budget didn't go that high...

Annealing is so critical to neck tension consistency.

 

[rsbhunter]

Dwell time, true.....I notice it a lot on doing shoulder bump, gives the same measurement every time....the info given on this forum is AWESOME ! Stuff some of us take as normal procedure, comes to light here.....I learn something every time I read the forum....

 

[Vettepilot]

Dwell time, true.....I notice it a lot on doing shoulder bump, gives the same measurement every time....the info given on this forum is AWESOME ! Stuff some of us take as normal procedure, comes to light here.....I learn something every time I read the forum....

I like your annealer. I'm a "maker" too. Where did you source the motors and speed adjusters with read outs??
Thanks,
Vettepilot

 

[rsbhunter]

There are videos on YouTube, a lot of the parts are ebay, the hubs for the drums (this is the secret) are propeller hubs for gas model airplanes...you can find them at RC model sites on the web. If I built it again, I would use just a flat sheet of sheet metal with an angled base, the box I used works, but is more than needed....pretty easy to do...and impressive , repeatable results....keep your flame time around 5 sec. + or- and the flame distance the same, and it will be great.

 

[Vettepilot]

I'm heavily into R/C too. I've seen the Y tube vids. Still need a source for the motor drives with digital readout.

Thanks,
Vettepilot

 

[Vettepilot]

OP--> the tips of the bullets almost always vary a bit, even with quality bullets. The important measurement is "Cartridge Base to Ogive", (CBTO), which is from the base of the cartridge to the point on the curve of the bullet that has just achieved bore size. There's tools made to measure this. As mentioned, the COAL, or Cartridge Overall Length is important for magazine fitment, but other than that is not critical as long as it is in the "ball park". Others have also provided very valid points here.

Vettepilot

 

[Vettepilot]

Lee's Dead Length Seating Die. It contacts the shell holder when seating. This may remove any slop in the press linkage.

As said, measure off the buillets ogive. Remove the seating plug from the die and use it to compare/measure case head to ogive between rounds.

Well slap me up aside the head!!! I have a comparator, etc.; lots of tools... I even drew up plans to make myself a comparator that would use a dial indicator. Yet I never thought of using the bullet seating plug to assist in measuring CBTO! Great idea for those that don't have comparators!! Well done!

Vettepilot

 

[rsbhunter]

The motors and digital readout displays ( basically speed controllers) are seperate items...if that helps....

 

[Vettepilot]

Yeah, I have and/or can make the speed controllers. It's the DRO's I am interested in. (Didn't know if they had been included as part of the speed controllers when you sourced them.)

Vettepilot

 

[rsbhunter]

If I'm understanding your question right, the digital read outs, and speed controller with knob are a single unit . But maybe I'm confused about your question ? Will see if I can find a link...

 

[Vettepilot]

Found it. Thanks.