AR15 and Primers

[JonB]

Hi all -

After reading this thread I thought I would ask in this forum about what kind of primers are 'best' for AR 15 reloading.

I used CCI small rifle when reloading a bunch of .223 that I haven't had the chance to shoot yet.

Anyone have experience good/bad with different brands and reloading for an AR?

 

[strat81]

Most folks recommend the CCI #41 SR military primers as they are less sensitive than regular primers. I use the #41s most often, but I have used standard CCI SR primers and had no problems with slamfires.

If you are a match shooter with special needs, you might use something different.

Regardless of what you use, be sure to seat the primers correctly. Any primer sticking out of the pocket is prone to a slam fire.

 

[rcmodel]

And any primer crushed and flattened during seating is also subject to slamfires.

In fact, that is the leading cause of slam-fires, not high seated primers, IMO.

Back years ago, I had problems with AR slamfires and finally cured them when I started swaging my GI brass correctly, and using an RCBS hand priming tool instead of mashing them in with the Rock-Chucker priming arm. Never had another one in 30 years.
All I will use is standard Winchester or CCI Sm. Rifle Primers.

rcmodel

 

[Steve in PA]

I've reloaded over 5k rounds of .223 just this year for my AR rifle using CCI SR primers. Not one problem or issue.

I also use the CCI LR primers for reloading in my M1 Garand.

 

[Slamfire]

In fact, that is the leading cause of slam-fires, not high seated primers, IMO.

I believe the leading cause of slamfires is overly sensitive primers. If crushing and whatnot makes the primer more sensitive, then I am in agreement.

I shot tens of thousands of the old nickel plated WSR primers in my AR's for years. Then they changed the primer, about 1999, made them thinner with a brass finish. Thinner cups made the primers more prone to piercing. I got tired of replacing firing pins, so I have walked away from Winchester.

I picked up CCI #41's and found them to be an excellent primer.

I have shot CCI standard and they give excellent accuracy.

I know folks who use Remington.

I will not use Federal, large or small, in a semi automatic mechanism. Too darn sensitive.

If you can't get tiny groups with any of the primers on the market with an AR, it ain't the fault of the primer.

 

[brighamr]

I use Federal Match Premium primers. Not for any specific reason, but they were on sale and I picked up a large quantity.

Thus far, they've functioned perfectly when primed correctly. If they are smashed or crushed (even a tiny bit), they will slam fire (which could be because they are ultra sensitive). BUT when loaded correctly, I haven't had an issue with the 800 or so rounds loaded and shot thus far.

 

[JonB]

Back years ago, I had problems with AR slamfires and finally cured them when I started swaging my GI brass correctly

rcmodel - can you explain 'swaging correctly' ?

I had a bit of GI brass - maybe 35 or so - and basically used the chamfer tool I had. It was a bit tedious, but allowed me to seat the primers using a Lee Auto Prime hand tool. Since I am fairly new to this, I am wondering if there is a better way.

 

[rcmodel]

I used to ream them with a pocket knife, then a primer pocket reamer, but sometimes that didn't get it all. Then when I would seat a primer in my bench press, it would hang up and get squashed when it finally went in.
Too much leverage to feel what was going on.

I then bought a set of RCBS primer pocket swaging tools and they do a much better job of getting 100% of the crimp out of the way. The RCBS or Lee hand priming tool allows you to "feel" if it is taking too much pressure to seat a primer.

Now, the Dillon swager is the best way to go if you can afford it, and have high volume production to do.

rcmodel

 

[JonB]

Thanks - guess I am ok with my method. I do like using the hand priming tools as you are correct about the 'feel' for the pressure to seat the primer.

 

[NuJudge]

I've loaded quite a few thousand CCI Small Rifle primers in .223 with no problems. I've also loaded a lot of Winchester Small Rifle with no difficulty.

CDD

 

[ocabj]

Remington 7-1/2

 

[shc1]

Shot my AR today, only fifty rounds.
21 to 22 Grains of IMR 3031 Powder
LC Brass from Georgia Arms
Bulk 55 Grain Bullets from Midway
and
CCI Small Rifle Primers .

The only problem was the only 50 rounds
But I did clean two pistols and the AR---

 

[Rokman]

I use CCI small rifle with good results and am going to try some Remington 7-1/2 with my next loads.

 

[Hiaboo]

Winchester primers - GOOD. Magtech primers - GOOD, Wolf primers - GOOD...

That's all I have to tell you right now, I haven't use any others just yet.. Probably ran through about 2,000 of each.

 

[nitesite]

I use #41s for a lot of my AR loads. They are nearly identical to CCI 450s, with just a little bit different anvil design.

I load with Varget and H335 and BL-(C)2 and the CCI primers have been quite satisfactory, even exceptional.

If i didn't have any CCI primers I would choose Remington 7½.

 

[amlevin]

can you explain 'swaging correctly' ?

Criming a primer often deforms the primer pocket, sometimes giving it a slight "hour-glass" shape. Merely reaming the lip using various tools (drill bit, pocket knife, chamfer tool, etc.) does not re-form the pocket. On cases where this is extreme a primer can be somewhat inverted due to the extra effort needed to insert and the drag on the primer pocket walls.

A swaging tool like the Dillon (as well as RCBS and others) not only swages the mouth of the primer pocket leaving a slight radius but it also makes sure that the primer pocket is opened up leaving more perfect cylinder shape (not hour-glassed).

Swaging means just that. Using a swaging tool, not just a "quicky" like pocket knife, or chamfer tool.