Wild variances on OAL

#1 · February 14, 2010, 10:38 pm

I am fairly new to reloading.

I bought a SDB for my brother many years ago and about 4 months ago, it ended up back with me. I have had so much fun that I have just recently ordered a second one.

I have been mostly loading 124 gr. FMJ Montana Gold bullets.

Yesterday, I decided to start loading 147 gr. FMJ Montana Gold bullets, Winchester cases, Federal small pistol primers with an OAL of 1.158.

I mixed loads last night with Titegroup powder. I made small batches with 3.0, 3.1, 3.2 and 3.3 grains of powder.

I shot them today and liked the 3.3 the best. When I got home, I checked all the settings on the SDB and set to reloading some more.

I loaded 25 rounds and began running them through my caliper to double check. I was shocked! The lengths ran from 1.155 to 1.171!

I figured that I must have royally screwed something up - BTW there is no TV, radio, windows or people in my room with me. So, I checked and re-checked everything, and did adjust the seating stem.

I ran another batch of 25, being extra diligent about all my actions. I checked this batch through calipers also. Again, I had the same wild spread.

I checked all of the adjustments and then I then loaded a handful one at a time. The came out perfect (+/-0.02).

I then ran two batches of 4 through. All but one were larger than 1.162.

I gave up before my frustration got the better of me.

Any help is greatly appreciated.

Thanks in advance.

Don

#2 · February 15, 2010, 4:03 pm

It helps if you put a fired case in station one when adjusting the bullet seating die. This keeps consistant upward pressure on the toolhead. If you do this, the variation you get should be in the variations from one bullet to the next. BTW, up to .025" variation between bullets is not unheard of.

#3 · February 16, 2010, 12:22 am

Thanks!

It appears that your answer worked. Keeping all of the stations full resulted in a tolerance range of +/- 0.02 or less.

New problem...

I was having an issue with the shell plate carrier not rotating fully, and then jumping into position causing powder to fly from the cartridge at station 3.

I did a search, and discovered that it may be fixed by adjusting part number 13789 (set screw). The only problem is that my SDB does not seem to have the set screw or a hole for one (I looked, thinking maybe the screw fell out).

Any ideas or suggestions? I looked at the schematics of the machine and think I'm looking in the right place but who the heck knows!

Thanks in advance,

Don

#4 · February 19, 2010, 10:06 pm

Dillon,

Any answers to the second question?

#5 · February 23, 2010, 4:12 pm

The SDB has only had this set screw for about 10 years. Older machines do not have this. It sounds like the index lever is worn and in need of replacement. Please phone or e-mail us and we'll send a warranty replacement to you.