Which Primer Do We All Like?

[PA_Allen]

I use Rem 7 1/2 exclusively. Always had good luck and no worries of pierced primers.
- PA

[sneaky one]

PA , that's cool. Do they seat deeply like the Winchester WSR units?

[Savage Shooter]

Sav Shooter- google primer thicknesses- there are lots of sites to analyze all the primer specs.

Thanks, Sneaky. Over the years I have read many different sites regarding primer specs, including of course cup thickness. Is the primary concern with the Grendel slamfires, and thus cup thickness is the driving force behind primer selection instead of accuracy? I have fired about 3000 rounds through my two AR15s in .223 and never had a problem using 205s and 71/2s, but admittedly I have only fired about 400 rounds through my AA Grendel (using 205Ms in my handloads). And maybe 1/3 of those rounds were Hornady factory loads and another 1/3 were single loaded during OCW load development. So, should I be much more concerned about using Fed 205s and Remington 71/2s? Are slamfires (if that is the primary reason that 450's and 41s are preferred) more common to particular bolt groups and/or buffer spring set-ups than others? Should I ask Bill about my AA Overwatch and their experience ?

[Savage Shooter]

PA , that's cool. Do they seat deeply like the Winchester WSR units?

I hand seat ALL my primers in ALL my reloaded rounds (pistol calibers included) using Lee's ERGOPrime primer unit. As part of my priming process, I "feel" each one for seating depth to be sure that they are seated slightly below flush. If not, I put it back in the ErgoPrime and give it an extra "squeeze". I have never had a failure of a primer, regardless of gun, to at least go "bang" so "deep seating" has never been a problem for me in any of my guns. (Although I admit that my wife (yep, she helps me with reloading) and/or I have occasionally left powder out of the case). As long as my primers are slightly below flush am I "safe" for not getting slamfires? Or is there something peculiar about Grendels that should make me more cautious?

[mwilkins]

Wolf SRM, 8208, 123 Scenar

[PA_Allen]

PA , that's cool. Do they seat deeply like the Winchester WSR units?

Sneaky,
I haven't noticed any difference in seating depth. The Rem 7 1/2 cups are thick like the CCI 41 and 450 to prevent primer piercing. A few years ago I had some pierced primers with my 5.56 service rifle using CCI 400s and Varget that made me wary of thin primer cups in the AR platform.

Here's a link to an old but still useful chart

http://www.jamescalhoon.com/primers_and_pressure.php

- PA

[lwminton]

I hand seat ALL my primers in ALL my reloaded rounds (pistol calibers included) using Lee's ERGOPrime primer unit. As part of my priming process, I "feel" each one for seating depth to be sure that they are seated slightly below flush. If not, I put it back in the ErgoPrime and give it an extra "squeeze". I have never had a failure of a primer, regardless of gun, to at least go "bang" so "deep seating" has never been a problem for me in any of my guns. (Although I admit that my wife (yep, she helps me with reloading) and/or I have occasionally left powder out of the case). As long as my primers are slightly below flush am I "safe" for not getting slamfires? Or is there something peculiar about Grendels that should make me more cautious?

I hand seat all my primers and do the finger feel thing on each one and have never had a slam fire. If you chamber a round and then pull it back out (without firing!!) you can see a slight dent in the primer.

I am OK with all of that but am surprised that beside cup thickness there doesn't seem to be a difference in flame or speed or whatever.

[bwaites]

The powder charge in the Grendel is so small that any of the SR magnum primers will easily ignite it, thus there probably isn't going to be as much difference as you might see between LRM primers with 60-100 grain charges, and I suspect that is why so many different primers have been found to allow good groups. The reason the magnum primers was recommended was due to cup thickness. Shooters at Camp Perry firing AR's found that slam fires did occur, often enough that it wasn't worth risking use of thinner primers.

[Klem]

I use CCI450 for the thicker cups and availability where I am.

450 is Popular here because the F Class/Target Rifle crowd use it to push their 80gn 223's projies out to 1,000yds. To do this they push pressures higher than SAAMI in long 30" barrels. Part of the system is to have a thicker primer to minimise the chance of pierced primers.

Point being, they get competition results from them and that works for me.

[6.5 Jerry]

I use CCI 450s with all loads, H335, 8208 and CFE223.

[lwminton]

From what I read, nobody has a clue why they use this or that primer, but we are all experts on powder charges and bullets!
More research is needed, if you ask me.

I will use up my BR 4s for now until 65grendel organizes a survey.

[Klem]

From what I read, nobody has a clue why they use this or that primer, but we are all experts on powder charges and bullets!
More research is needed, if you ask me.

I will use up my BR 4s for now until 65grendel organizes a survey.

Good for you!

If you are less than satisfied with our assistance and unconcerned about slam fire issues then you might want to read this;

http://precisionrifleblog.com/2012/07/02/most-accurate-rifle-primers-for-precision-reloading/

This is also reasonable review although done in 2008 and do not include 450's. The comparison chart at the bottom might help you;

http://riflemansjournal.blogspot.com.au/2009/06/primers-small-rifle-primer-study.html

Then you can organize the '65forum' primer survey given you are part of us. Or you can hold your breath and wait for others to take the initiative. I look forward to reading your findings.

[jawbone]

I'm happy enough, for the time being, with my CCI 450's, but both links were still good reads, Klem. many thanks.

[Klem]

Me too, and it's a hard cup for floating firing pins.

[LR1955]

From what I read, nobody has a clue why they use this or that primer, but we are all experts on powder charges and bullets!
More research is needed, if you ask me.

I will use up my BR 4s for now until 65grendel organizes a survey.

LWM:

Everyone who likes one primer over another knows exactly why.

First, when the Grendel appeared on the scene, the only load data was from Alexander. He ran pressure tests on the loads he published. He used CCI-450's almost exclusively. When the only source for loads advises one primer, people tend to heed the advice and use that primer.

Second, CCI-450s withstand the inertial firing pin strikes so rarely if at all slam fire. That is a huge thing with AR's. I have had slam fires with AR-15's and they were because I used a primer with a thinner cup. I think they were Winchester small rifle -- but can not recall as it was close to 20 years ago.

Third, go to a High Power event and see what small rifle primers the top end shooters are using. CCI-450, Wolf Small Rifle Magnum, Rem 7 1/2 will probably be the primary choices. For guys shooting small necked cases with decent powder charges, a magnum primer is normally used. Of these, it appears the CCI-450 is the one of choice. Whether a myth or not, people who shoot ball powders tend to think they are harder to ignite uniformly so use magnum primers. Personally I think there may be some credibility for this belief.

We had a guy on the last forum who swore by BR-4's so you aren't alone. I think most guys avoid them primarily due to cost.

So, those are the primary reasons why guys use what they use. Some is due to safety issues, some due to proven value, and some to outright prejudice. However, they know exactly why they use what they use.

LR55