Does primer seating depth matter

[TTE]

comments on this video -

 

[Rsadams]

Honestly I just install them till they stop going in....

 

[Ron Blain]

I just seat them till I feel them bottom out in the primer pocket.

Below, up close and personal, a CCI 200 Large Rifle primer. We see the same in other primers. The anvil extends just a few thousandths above the cup.

I always hand seat my primers and after awhile you get a "feel" as to when the primer is bottomed out. This generally leaves them a few thousandths below the case head. A white card leveled over the case heads makes the gap apparent between primer and case head.

Works For Me.

Ron

 

[Bill Norris]

I seat it bottomed out without crush. Never had an issue with it.

 

[Webster]

comments on this video -

I think he may be correct but their is to much opinion on internet. He said he shoots competition. If I shoot groups like his for a varmint hunting rifle I would junk the rifle. The easy way is to just do it like the guys that set National Records and forget the details.

 

[6bra1k]

testing by the mil, says to the bottom and then a small crush in place..i use about .002 others use more. failure to uniform pockets means ununiform ignition. failure to seat to the bottom means the firing pin is doing the final seating and thus ununiform ignition.
just 2 cents worth, long range mainly, score groups and trophies support my opinion. do what you please.

 

[MUP]

I've always taken the term at face value, "seat" the primer. As in press it in till it seats.

 

[old_heli_logger]

I use a uniformer then hand seat them, they all seem to seat the same...nothing to prove that it helps, but it makes me feel like I've done what I could to keep everything close to the same. Plus, brass grows, "that direction" too.

 

[markm87]

Some brass, like Hornady 6.5 CM, I'm lucky if I can muscle the primer to flush.

 

[BoydAllen]

Most of us have carefully removed a live primer from a case. Taking this a bit farther, if one wanted he could measure the thickness of a primer, seat it, carefully remove it and then remeasure its thickness in order to better understand what had been done. I actually called CCI and asked a technician about what they recommended. He told me that the primer should be compressed until the bottom of the anvil is flush with the cup. You might want to give that a try and then examine the primer held, top and bottom, between the jaws of a caliper, using a 20X loupe. You may be surprised.

 

[David Milisock]

comments on this video -

I've seated flush to the head for over 50 years. The only problem I've ever seen was on an M1 Carbine with the primers not seated deep enough and the bolts at maximum specification.
The bolts in a Carbine just sit in the receive, nothing maintains pressure on it, a sloppy bolt and a primer not seated makes the hammer having to move the mass of the bolt, cartridge and primer causing a failure to fire.

 

[ronemus]

The anvil is worked brass, and I doubt that it's (fully) annealed, so it will spring back when a primer is removed. Primers are made by hand, and if you look closely they are anything but uniform - the anvils are at various heights above the cup, and there are wildly varying distributions of the goop that cements the anvil to the primer (and that's just what you can see). I believe that primers must be seated by feel to get a uniform result, and it's been demonstrated that "crush" is necessary to uniformly activate primers, It's nice when you can measure things for uniformity, but it just doesn't work for primers = there's just too much variability built in to primers, and a lot of it is internal where you can't see or measure it.

 

[K22]

I use a Sinclair hand priming tool which gives me an excellent feel in seating primers. I seat slightly below flush and or to the bottom of the primer pocket, but I've never had to apply excessive pressure to achieve this level of seating.

Is this making too much of something that isn't that complicated?

 

[mikecr]

With hunting capacity/LR cartridges, primers simply going bang is not the end of the story.

 

[Bottom Fodder]

I normally let the firing pin do the final seating and let the powder start The unseating

 

[Uncle Ed]

 

[Doom]

There have been anecdotal test published on numerous forums but I have not seen any tests that would clearly indicate that seating beyond what Uncle Ed has posted above will/does/ might have an effect on SD or velocity.

 

[Webster]

Nice images. Looks like your limited to the cup edge touches the case. You cannot push it any deeper because you cannot crush/compress the cup itself. I am getting tired of all the primer talk. Do we need 100's of post every year explaining the same thing.

 

[BoydAllen]

If you do what I suggested in my earlier post, you will probably discover that try as you might, with a hand tool, you may not be seating them quite to where CCI recommended. I am not saying that I know of any problems from not hitting that mark, just that based on my experience I do not believe that anyone using a hand tool is harming the primer or its performance no matter how hard they squeeze, but of course most would rather discuss without doing any real measuring.

 

[Larry Koch]

I have a 100 dollar primer seater that I'll sell ya for 800