Do Primer Seating Methods Affect Performance?

[J. W.]

As in, can you tell on target, the difference between using different methods/tools to seat your primers?

If so, what’s been the most consistent method for you?

Reason I ask is I have been using a RCBS hand-priming tool for years. Every time I prime cases I think about how even a careful hand has to be delivering inconsistent force when seating the primer, and I wonder if it’s enough to matter on target. My guess is “probably not,” but I can’t say that definitively.

 

[memilanuk]

I think it probably depends on the level of precision you're looking for.

Unless you're shooting Benchrest or maybe F-class at a very high level and looking for that extra edge... probably not.

Will it hurt anything if you do go the extra mile anyway for any given precision rifle? Also probably not.

For a good sampling of the level of improvement - and the level of precision you need to be shooting at to begin with - @Bryan Zolnikov has a number of videos on his YT channel.

 

[MarkyMark007]

f-class boys are now priming on a dillon, so probably they are not worried about those things...

 

[Stavey]

Yes. It has been proven to affect group size. If you are trying to put every bullet through the same hole . You need to be consistent . Bryan Z. has YouTube videos and threads here and on accurateshooter where he covers this.
If you are after Benchrest accuracy . Priming on a Dillon isn’t worth messing with.

 

[memilanuk]

f-class boys are now priming on a dillon, so probably they are not worried about those things...

To be fair, *some* of us load on a Dillon. They are surprisingly consistent at priming depth - my 550 is, and from what I've heard from a couple of the more prominent YT/F-classers, theirs are as well.

The question becomes whether that consistent spot is the best one for your load, or if it's close enough to not care.

 

[Sniper King 2020]

I think it probably depends on the level of precision you're looking for.

Unless you're shooting Benchrest or maybe F-class at a very high level and looking for that extra edge... probably not.

Will it hurt anything if you do go the extra mile anyway for any given precision rifle? Also probably not.

For a good sampling of the level of improvement - and the level of precision you need to be shooting at to begin with - @Bryan Zolnikov has a number of videos on his YT channel.

Thanks for referring people to the channel. And I do agree with you about the level of precision you want. If you’re a plinker, then my videos may be informational to you but nothing you would waste time doing on your loading bench. I was just chatting with one of my Patrons about this at the range the other day. All he does is hunt but subscribes to my YouTube and is a paid Patron on my page because he has an engineering background and just like to see the methods used in testing and the results.

One thing I have found is that even though I test with a lot of small cartridges at relatively short distance, a lot of the results from that testing generalize to long range. I do what is called mixed method testing where I test in highly controlled conditions and then go to matches to see if the results generalize to the real world. I shot a record at the last long range match I shot so I think I met the criteria for the results having “real world” applicability.

 

[Seymour Fish]

Yes. It has been proven to affect group size. If you are trying to put every bullet through the same hole . You need to be consistent . Bryan Z. has YouTube videos and threads here and on accurateshooter where he covers this.
If you are after Benchrest accuracy . Priming on a Dillon isn’t worth messing with.

I beg to differ. Priming on a Dillon works just fine if you develop a feel for it.

 

[Stavey]

I beg to differ. Priming on a Dillon works just fine if you develop a feel for it.

In terms of Benchrest accuracy. Priming on a Dillon isn’t even an option. However if you are happy with the accuracy you are achieving, that’s all that matters.

 

[Seymour Fish]

In terms of Benchrest accuracy. Priming on a Dillon isn’t even an option. However if you are happy with the accuracy you are achieving, that’s all that matters.

Lmfao !

 

[DownhillFromHere]

I primed my Peterson 6.5CM, Alpha 6BR brass, and Starline .223 brass three different ways: On my Dillon RL550, using a buddy's super-duper hand primer (I forget which one but he was an F-class shooter who was anal enough to cut H4350 kernels to get 0.01-grain accuracy via his Sartorius scale), and using a Franklin Arsenal hand tool.

My ES/SD values didn't change across the three. Nor did a brief trial of CCI BR2 match primers versus CCI 450s. Powder loaded to +/- .02gr on an A&D FX-120i scale. Rifles are Defiance Deviant or Terminus Apollo with Bartlein barrels.

Did primer seating method make a perceptible accuracy difference? No. Am I a good enough shot to uncover possible differences? [shrug]

 

[Stavey]

I primed my Peterson 6.5CM, Alpha 6BR brass, and Starline .223 brass three different ways: On my Dillon RL550, using a buddy's super-duper hand primer (I forget which one but he was an F-class shooter who was anal enough to cut H4350 kernels to get 0.01-grain accuracy via his Sartorius scale), and using a Franklin Arsenal hand tool.

My ES/SD values didn't change across the three. Nor did a brief trial of CCI BR2 match primers versus CCI 450s. Powder loaded to +/- .02gr on an A&D FX-120i scale. Rifles are Defiance Deviant or Terminus Apollo with Bartlein barrels.

Did primer seating method make a perceptible accuracy difference? No. Am I a good enough shot to uncover possible differences? [sh

Not sure what “super-duper hand primer” you used . As far as es/sd , it’s irrelevant. At least for short range Benchrest . The target (group size) is the litmus test. If you did all those things including changing primers and saw no difference on target. I would have to ask what your accuracy standards are. Because something is not right . I’m trying to shoot zeros. If my rifle is shooting in the 3s. There’s a problem. Again it’s all in what you’re trying to do. If your goal is Benchrest accuracy snd you’re trying to shoot zeros or if shooting a 3/4” group at 100 yards is your goal. Every variable makes a difference when trying to shoot dots. It’s a rabbit hole . Sorting bullets, testing what jam the bullets like, bumping the shoulders properly , testing to find what neck tension your bullets like. If you aren’t doing all these things and more. Then simply playing with primer seating depth might be a waste of your time.
Again it comes down to what your trying to achieve.

 

[Sniper King 2020]

Not sure what “super-duper hand primer” you used . As far as es/sd , it’s irrelevant. At least for short range Benchrest . The target (group size) is the litmus test. If you did all those things including changing primers and saw no difference on target. I would have to ask what your accuracy standards are. Because something is not right . I’m trying to shoot zeros. If my rifle is shooting in the 3s. There’s a problem. Again it’s all in what you’re trying to do. If your goal is Benchrest accuracy snd you’re trying to shoot zeros or if shooting a 3/4” group at 100 yards is your goal. Every variable makes a difference when trying to shoot dots. It’s a rabbit hole . Sorting bullets, testing what jam the bullets like, bumping the shoulders properly , testing to find what neck tension your bullets like. If you aren’t doing all these things and more. Then simply playing with primer seating depth might be a waste of your time.
Again it comes down to what your trying to achieve.

Agree. This is why I ask people for their data and what testing method was used when they claim that they tested something and it didn’t make a difference. If their standard is .4-.6MOA then not much will “make a difference” and, like you wrote, trying these things is likely a waste of time. Now, if the goal is teen or low .2MOA groups consistently, then primer seating depth is a big deal. I liken it to Bryan Litz’s tuner testing he published in his books…he was shooting rifles with a baseline .4-.6MOA capability given the rifles, shooting styles, etc. He showed that a tuner couldn’t take a bad load and make it better. When I did my series of tuner tests, I was shooting teen and low .2 aggs and showed that when the tune falls (I.e., mid .2 aggs and groups shaped like the tune is falling), you can turn the tuner to regain tune. It’s all a matter of the level of precision you are trying to achieve.

 

[memilanuk]

Oh shit. This just turned into another tuner thread... hang onto your britches!

 

[J_D]

Not sure what “super-duper hand primer” you used . As far as es/sd , it’s irrelevant. At least for short range Benchrest . The target (group size) is the litmus test. If you did all those things including changing primers and saw no difference on target. I would have to ask what your accuracy standards are. Because something is not right . I’m trying to shoot zeros. If my rifle is shooting in the 3s. There’s a problem. Again it’s all in what you’re trying to do. If your goal is Benchrest accuracy snd you’re trying to shoot zeros or if shooting a 3/4” group at 100 yards is your goal. Every variable makes a difference when trying to shoot dots. It’s a rabbit hole . Sorting bullets, testing what jam the bullets like, bumping the shoulders properly , testing to find what neck tension your bullets like. If you aren’t doing all these things and more. Then simply playing with primer seating depth might be a waste of your time.
Again it comes down to what your trying to achieve.

I'm guessing it's the Primal Rights primer.

 

[MarkyMark007]

Bryan, I follow your testings on YT, and I'm wondering how your technic for reloading and brass prepp is changing now after all those testings ?
and how much your group shink after all that work?

 

[Sniper King 2020]

Bryan, I follow your testings on YT, and I'm wondering how your technic for reloading and brass prepp is changing now after all those testings ?
and how much your group shink after all that work?

I am data-driven so I do what the data says. If the data says drilling flash holes does nothing, then I don’t do it. If it says that seating a primer within a certain degree of anvil compression gets better precision, then I do that. I followed the data all of this last shooting season and won shooter of the year for the NW region in the USA. Also set a record in a 600 yard match. I do what’s called translational testing which means that I do experimental tests and “real world” tests in matches. Id say that the data I’ve collected thus far in experiments has definitely led to greater precision in real world application. I had the smallest aggregate groups last season than any other season so, yes, definitely has shrunken the groups.

 

[MarkyMark007]

thank you.