Major Factor in Primer Seating Depth Variability

[M-61]

I clean the primer pocket.
I seat the primer until it is bottomed.
Never had a problem since I started long ago.

 

[Bill Norris]

So what you are saying that the $675 Primal Rights got spanked by a $190 Lee?

Orkan will not be pleased.

No doubt, Orkan will be screaming "It Ain't So" really load in a few mins. LOL. Popcorn anyone?

 

[quest450]

and he has every right to do so, I've been using CPS for years and I was puzzled with the OP results as far as the CPS goes but I think there might be an agenda in the original post but I could be wrong

 

[danny]

Why not get a little deeper into this rabbit hole and uniform primer pockets since you're going thru all the trouble measuring and eliminating cases that are out of spec, it might make your primer seating depth more consistent, It's a simple task and you do it only once, 21st Century adjustable tool makes it easy and you can clean primer pockets using the same tool if you'd like.

I uniform my primer pockets every reload.

Danny

 

[Bottom Fodder]

After reading this and some other threads I now know why I can’t hit the broadside of a barn

 

[Bryan Z.]

So what you are saying that the $675 Primal Rights got spanked by a $190 Lee?

Orkan will not be pleased.

That’s a $100 Lee

 

[Bryan Z.]

Not even close to being worse than rim variances. I use the Lee Acp and my results are very similar to the OP's. My primers are always within .0005 variance.

I have a forster bench primer that uses a shell holder and it can vary by as much as .003, even with a hard stop.

Yep, I’ve now primed several hundreds of primers in four different calibers and brass brands and all but a few have been within .0005”. Seems like this Lee is designed to eliminate the flaws inherent in shell holders and other variables that would create error in seating depth. I have been contacted by a few shooters about the Sinclair hand primer which seems to be designed to do the same. I haven’t actually seen one but I’ve been told it locks the brass into place so that the case head locks to the case head-shell junction on the shell holder which eliminates the rim thickness dependence. I would love to get one to examine and test it.

 

[Bryan Z.]

I'm waiting for @orkan to reply........got my popcorn ready

View attachment 1490521

Not sure who this orkan person is but I’ll have my popcorn out too

 

[BoydAllen]

The case is lifted when seating within the primer shell holder. Rim thickness affects clearance for lift.
That could wiggle results around.

Speaking of hand priming tools, the Sinclair is different, with it the head is loose when the case is inserted, and then it is tightened so that the head is held firmly against the body of the tool. Differences in rim thickness do not matter. The seating punch height is adjustable, but to be fair that is not all that easy, but it can be. Here is a video, and while it emphasizes the feature as a way to make sure the primers are all inserted squarely, at the same time it does what I said. Added a little later: I have mine set to seat by feel.

 

[Bronsin]

Just tested my own Sinclair tool, and even with .003 difference in rim thickness, all primers were at the same depth.

 

[Bryan Z.]

@Bryan Z.
Thanks for posting your test results. More guys should test for themselves and be comfortable with their own results .

Sure. If nothing else, my tests can show you how to test to get reliable and valid results from your own shooting results. The key is to conduct valid and logical test methods and analyze the data with statistical equations. Without both, the results are not likely valid. People can be comfortable with their own invalid results so I would be careful asserting that more people should test for themselves because a lot of people don’t know how to devise a test and analyze the results to produce a logical conclusion. It’s not a common thing that a lot of people do which is why I provide not only data but the template on how to do so.

 

[Bryan Z.]

Just tested my own Sinclair tool, and even with .003 difference in rim thickness, all primers were at the same depth.

I haven’t seen or used the tool but from what Boyd and others have told me, it should eliminate the rim thickness variation. I looked to get one recently but it looks to be out of stock. Anybody want to sell one? I know somebody who might trade you a primal rights for a Sinclair.

 

[Bryan Z.]

Bryan.
The only thing that matters to me is consistent results on long range targets. I really don’t give a hoot about Computor spread sheets. Good tools and a little bit of common sense goes a long ways when testing.

Jim

Let’s see these consistent targets and test results.

 

[BoydAllen]

There is no use in seating to same 'depth', as that does not represent same preload(crush).
You need the indicated K&M to do this right. It accounts for each pocket depth, each primer height, each rim thickness, all at once.

If you believe that shooters who own world records and seat by feel need to do their primer seating differently, good luck with that. On the other hand if you are doing something that you have proven to yourself gives superior results, good for you. Seriously. One of the neat things about hobbies is that we get to make these kind of choices, based on our own judgement.

 

[Bronsin]

I haven’t seen or used the tool but from what Boyd and others have told me, it should eliminate the rim thickness variation. I looked to get one recently but it looks to be out of stock. Anybody want to sell one? I know somebody who might trade you a primal rights for a Sinclair.

I think I'm gonna keep mine

 

[stavey]

If you listen really closely. You can actually hear the Primal Rights CPS owners crying. LOL

Seriously though, consistency can only contribute to better accuracy.

 

[Bryan Z.]

Really ? I’m not disputing your testing or results, I thank you for posting and suggest more fellas should test. I don’t use spread sheets, I just test for myself and be comfortable with the results at 500 yards, there’s nothing fancy here.

Didn’t mean to be disrespectful.

Yes, but your post actually demonstrates exactly what I am saying. A good test of group averages requires several 5-shot groups for each variable that changes so that there is adequate statistical power to see if the changes are actually meaningful. This is where spreadsheets that you appear to not give a sh-t about are actually meaningful.

 

[Bryan Z.]

If you listen really closely. You can actually hear the Primal Rights CPS owners crying. LOL

Seriously though, consistency can only contribute to better accuracy.

Well, that is what I have found…consistency improves precision. Many months before I even went down this path of extending my testing on primer seating, I contacted Primal Rights and this is what one of their employees sent me (see attached). Doesn’t seem like they even care about testing anything.

 

[DLT]

Well, that is what I have found…consistency improves precision. Many months before I even went down this path of extending my testing on primer seating, I contacted Primal Rights and this is what one of their employees sent me (see attached). Doesn’t seem like they even care about testing anything.

Yep. That’s old news

 

[quest450]

I'm not a pencil pusher so I don't geek out looking at spreadsheets, some nerds get a tingle up their leg analyzing all that nonsense, paper target never lies and most of the time tells me all I want to know, I'm a meat and potatoes kinda guy and have zero interest in all this overload of statistical crap it is just a waste of time IMO of course.