Another rabbit hole to go down. Primer seating depth.

[DizzyJ]

Does Primer Seating Depth Matter?

For the longest time, seating depth on primers and especially primer pocket uniforming, has been discredit by almost all of the shooting community. Unfortunately, this tedious method has been pushed off by many individuals. Well, I decided to give it a shot despite what everyone has been saying...

www.reloadingallday.com

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[Catfishmoon]

If I am reading that correctly, he is trying to have the only variable in the ammo he is creating be the depth he seats the primer by .0005. Five ten-thousandths of an inch...
And then shoots a three shot group and measures deviation and shot accuracy, and he has found a "sweet spot" at least for himself...
I guess that I am skeptical that a person could eliminate all other variables; exact bullet shape and weight, neck tension, bullet seating depth, variables in the actual primers, etc, to the point where a primer seating depth variable of .0005 could be measured in a firearm's accuracy...

 

[DizzyJ]

If I am reading that correctly, he is trying to have the only variable in the ammo he is creating be the depth he seats the primer by .0005. Five ten-thousandths of an inch...
And then shoots a three shot group and measures deviation and shot accuracy, and he has found a "sweet spot" at least for himself...
I guess that I am skeptical that a person could eliminate all other variables; exact bullet shape and weight, neck tension, bullet seating depth, variables in the actual primers, etc, to the point where a primer seating depth variable of .0005 could be accurately measured in a firearm's accuracy...

After reading this article I started watching several videos and reading other articles online.
Seems there may be something to it. I never realized you can "overseat" a primer other than to crush it. Interesting for sure.

 

[DizzyJ]

 

[DizzyJ]

 

[Member 34319]

I never thought of these things until I talked to a benchrest rimfire guy. The benchrest rimfire guys go to great lengths to insure rims are of equal size and such. They also tune their firing pin/striker in effort to strike the rim exactly the same way each time and with the same force.

All of those things can be applied to center fire as well.

Myself, I don't see myself going down this rabbit hole any time soon. I'm not at the level of a benchrest shooter, nor is much of my gear. I see those shooting benchrest and what they do to put bullets into a single hole at 200 or further, and when compared to what I shoot and how I shoot I see a lot of it as unneeded.

Best of luck going down the rabbit hole!

 

[flashpan]

Sorry...I just assumed everyone used one of these.

K&M PRECISION PRIMER SEAT TOOL WITH GAUGE - Graf & Sons

Includes both large and small anvil assemblies. Requires Lee Auto-Prime series shell holders. If you want the ultimate in hand pocket priming tools – the K&M Primer/Gauge will fit the bill. Benchrest shooters seat the primer until they feel it touch the bottom of the primer pocket. Consistency...

www.grafs.com

 

[DizzyJ]

Sorry...I just assumed everyone used one of these.

K&M PRECISION PRIMER SEAT TOOL WITH GAUGE - Graf & Sons

Includes both large and small anvil assemblies. Requires Lee Auto-Prime series shell holders. If you want the ultimate in hand pocket priming tools – the K&M Primer/Gauge will fit the bill. Benchrest shooters seat the primer until they feel it touch the bottom of the primer pocket. Consistency...

www.grafs.com

View attachment 1195527

Was actually looking at one of those last night. WAY less expensive than some of the $650 bench mounted ones I looked at!

 

[RVTECH]

Sorry...I just assumed everyone used one of these.

Heck I didn't even know these existed! However I have to agree with Reno and this part of his post verbatim:
Myself, I don't see myself going down this rabbit hole any time soon. I'm not at the level of a benchrest shooter, nor is much of my gear. I see those shooting benchrest and what they do to put bullets into a single hole at 200 or further, and when compared to what I shoot and how I shoot I see a lot of it as unneeded.

 

[DizzyJ]

Heck I didn't even know these existed! However I have to agree with Reno and this part of his post verbatim:
Myself, I don't see myself going down this rabbit hole any time soon. I'm not at the level of a benchrest shooter, nor is much of my gear. I see those shooting benchrest and what they do to put bullets into a single hole at 200 or further, and when compared to what I shoot and how I shoot I see a lot of it as unneeded.

I just thought it was interesting that this is actually something that would make any difference at all. I figured fully seated and below flush was the end of it.

 

[RVTECH]

I figured fully seated and below flush was the end of it.

Oh, I have read about primer seating depth as an element of extremely precision loaded ammo but never gave it much thought as actually being something that would have much effect, as say some of the other aspects of loading which definitely do have an effect on accuracy.

I certainly do SOME things reloading-wise that have defiantly improved my accuracy over previous loads but they are still not anything near 'benchrest' techniques!

A good example is with my .30-30 loads. Hey I am NOT espousing a .30-30 as a 'precision' caliber but I now get ragged one hole 50-60 yard groups with it due to some basic loading improvements I have made.

 

[Bon Sauvage]

Oh good! Just the information I need to make my war torn M39 Mosin-Nagant a tack driver.

 

[DizzyJ]

Oh good! Just the information I need to make my war torn M39 Mosin-Nagant a tack driver.

Wouldn't THAT be something!

 

[flashpan]

Was actually looking at one of those last night. WAY less expensive than some of the $650 bench mounted ones I looked at!

I used one for a bit...then moved on to something else for 600yd Bench competition.
Let me know if I can give you any input on how the K&M worked for me.

 

[Caveman Jim]

Sorry...I just assumed everyone used one of these.

K&M PRECISION PRIMER SEAT TOOL WITH GAUGE - Graf & Sons

Includes both large and small anvil assemblies. Requires Lee Auto-Prime series shell holders. If you want the ultimate in hand pocket priming tools – the K&M Primer/Gauge will fit the bill. Benchrest shooters seat the primer until they feel it touch the bottom of the primer pocket. Consistency...

www.grafs.com

View attachment 1195527

Funny you should mention this, I took one of these in on a package deal and then I sold it because it was leading me down a different path that I wasn't ready for and probably never will. The guy that bought it online was from accurateshooters.com, so there's that.

 

[fstdraw]

Boxer primer seating depth is not nearly as important as Berdan primer seating depth. Both are rabbit holes, both are really personal preferance. I think for what we as recreational shooters do, pretty good is good enough. Prep the primer pocket well and there should never be an issue. For those that shoot 600 to 1,000 yards, I dunno, my eyes aren't that good.

Good information to have though.

 

[Certaindeaf]

Being able to correctly read the wind will yield 1000X smaller groups at 1000 yards than navel gazing primer depths ffs.

 

[flashpan]

Being able to correctly read the wind will yield 1000X smaller groups at 1000 yards than navel gazing primer depths ffs.

well said

 

[ma96782]

Aloha, Mark

 

[DizzyJ]

I used one for a bit...then moved on to something else for 600yd Bench competition.
Let me know if I can give you any input on how the K&M worked for me.

I'm all ears! I'm sure others could benefit from your feedback as well.