How precise really?

[wnchstrtnfldvlle]

Ok. Have been trying to set up my lee classic turret press for some training 9mm rounds.
The data I am using is

Berry's 124gr plated rn bullets
Titegroup 4.1 grains and 4.2 grains
Range brass
CCI small pistol primers.

The overall length I am trying to use is 1.130, now I'm not sure if its just the cheap digital caliper set, but the col will vary from 1.129-1.131, without changing the dies at all. I will get it set right at 1.130, and the next bullet will be off. Then I rezero and recheck, and it will change again.

So how precise? Is a 2/1000 difference a deal breaker?

 

[b.a.customkydex]

When you are seating a billet are you doing it with a full turret or just one round at a time ? Do it with a full turret as there could be some flex ......

But for the most part you'll get sight variation due to bullet length and different brass headstamps

 

[ne ga pappy]

probably is the cheap caliper set. Measure the same round 9 or 10 times and see if the calipers vary. If they don't, then there is something flexing or moving on the press. Check it out closely.

 

[woodstock]

Ok. Have been trying to set up my lee classic turret press for some training 9mm rounds.
The data I am using is

Berry's 124gr plated rn bullets
Titegroup 4.1 grains and 4.2 grains
Range brass
CCI small pistol primers.

The overall length I am trying to use is 1.130, now I'm not sure if its just the cheap digital caliper set, but the col will vary from 1.129-1.131, without changing the dies at all. I will get it set right at 1.130, and the next bullet will be off. Then I rezero and recheck, and it will change again.

So how precise? Is a 2/1000 difference a deal breaker?

you are well under max overall length, and the 1.13 should feed in most pistols. Is your die locknut tight ?

 

[steve s&w]

I have never had an issue with 1 or 2 thousandsths, not uncommon for my cowboy loads to very as much as 5 some times. I would recommend investing in a real caliper set if you are going to reload on a regular basis. You will find that certain guns and certain loads will be pickier. I am always much more precise when it comes to magnum loads or when reaching near the upper limits.

 

[jba6511]

Sort the brass by manufacturer and take a look at the length. Could be your issue. I use to have the same problem until I started grouping by head stamp.

 

[$nipertime]

also look at your up-down slop in your turret. This caused mine to vary. I load at 2.808 but + or - .001 is where I like to keep it. To do that I have to use a single stage Lyman

 

[wnchstrtnfldvlle]

The locknut is hand tight per directions. I have noticed the turret will slide up slightly. But I figured it would still be a consistent amount.
I am leaning towards it being the calipers. Since it changes without actually altering the cartridge.

 

[noylj]

That is about as good as anyone can hold COL.
Measure some of your bullets. Many times they vary. Many times, the meplat or ogive varies, so they hit the seater stem a little different.
First you're loading plated bullets, so accuracy is not a main concern. Secondly, you are almost certainly shooting a gun that will group about 2.5-3" at 25 yes on the best of days. That is something like a 10-12MOA rifle. As such, ANY variation in COL will have no affect on group size, pressure, or any thing else.
I try to control COL as much as I can and I generally can't get the COL that repeatable.
Shoot and stop worrying.

Some one some day has to explain how case length can affect COL since we are talking about the case head and the bullet as the determinators of COL.

 

[Chuckdog]

I'll echo what others have posted.

There are many variables including the bullet's shape and dimensions.

My average handgun shooting distance is around 50'. I doubt you'll need to worry about accuracy being adversely affected at average handgun distances.

Being over anal when it comes to c.o.l. varying a couple of thousandths on most handgun ammo will likely only lead to useless frustration.