Neck sizing for semi auto?

[AngloSaxon]

I can't seem to find any info on this topic.

I use Lake city brass which I used full length sizer on, now this same brass that I shot in my colt ar (.223) I used neck sizer die, I guess the idea of it is that the brass is formed to your rifles chamber and only neck needs the resizing (which is great for bolt action). I've loaded 100 rounds of the brass that was shot out of my ar and used only neck sizer. When I manually cycle the rifle, the rounds seem to be a bit harder to extract, I have not been able to take it to the range and test it yet. Will that make it unreliable to use? Does anyone else use neck sizer for their semi?

I am a cheap college student and just trying to get the most use out of my brass.

Thanks

[Alleykat]

You should always full-length size brass that's to be used in an AR, whether you're a cheap college student or not.

[mniesen89]

+1 for alleykat

[NuJudge]

Stiff feeding, and perhaps problems with extraction are not a major concern. Cartridge ignition before the bolt fully closes will ruin your rifle, and your day.

CDD

[AK Shooter]

I am very curious of this as well. I have a friend who claims he only neck sizes in his DPMS and has had absolutely no issues with it. Loads and ejects without a hitch along with achieving very accurate results.

Before everyone jumps on me to let me know what an idiot my friend is for doing this, he is the most knowledgeable person I know when it comes to firearms and reloading. I would have no reason to doubt the method to his madness.

Does anyone else do this??

[hodaka]

When attempting to squeeze the most accuracy out of one of my heavy barrel AR's I have tried treating like a bolt gun. Neck sizing only does work, most of the time. I don't recall having an issue when single loading but I have had the bolt fail to go into battery a couple of times when loading from the mag. In the end, I decided the accuracy improvement was so slight that it was not worth the potential of increase in unreliability. I now full length size for all my semi's. BTW- I don't think an AR can fire out of battery due to the bolt/cam design and how the firing pin works.

[AngloSaxon]

Going to the range on monday or wednesday and will try to go through 3 mags and see what happens.

[gandog56]

All I can say is your knowledgeable buddy is going completely against everything I have heard.

But so did Copernicus and Columbus.

[30Cal]

There are two or three guys out there that neck-size. I can't see what the benefit would be. If you FL resize and shoot them 5x, your cost for brass is what? Something under 1¢ a shot. There's not a lot to be saved, frankly.

If you want to save $$, buy in bulk (>5k primers, >8lbs powder, >500 bullets) and split your hazmat fees with others in your area. Powder an bullets will be, by far, the largest expense.

[Lavid2002]

Primers are expencive too! Mine run me 13 cents a pop. WOW Bucled case walls are AGGRIVATING! :P

[Sevens]

Dude, 13 cents a pop would be $13 per 100. You can't be paying $13 per 100 primers. Highest price I've seen primers is $35 for 1,000. Or $3.50 per 100.

Either your math is suspect or you are really bad at shopping.

[Alleykat]

On the other hand, his "knowledgeable buddy" might just be reflective of the knowledge of his buddies!

[steve4102]

Neck sizing is not a good idea for semi-autos, and here's why.
When a round is fired in a bolt action the brass expands to the exact dimensions of the chamber then springs back just a little to allow for easy extraction. Things are a little different in a semi-auto. When a round is fired in a semi-auto it expands to the chamber dimensions similar to that of a bolt action. The problem is that the brass is still under a little bit of pressure when the round is extracted. This tiny bit of pressure can and does cause the brass to expand longer and fatter than the chamber it was fired in. Brass fire formed in a semi-auto is NOT a true replica of the chamber as in a bolt action. Go shoot 20 or so rounds with powder X and bullet Y then measure the "Head to Shoulder" with a gauge like the Stoney Point gauge. Odds are that these 20 rounds will not measure the same. Then load up 20 rounds of powder Z and bullet Y and let em fly. Odds are these 20 rounds will measure completely different that the first 20, especially if the change in powder is from fast to slow.

This is not only dangerous it is not good for accuracy. One of the keys to accuracy is consistency. If your brass is not consistant accuracy suffers.

[NuJudge]

http://www.fulton-armory.com/ReloadingThoughts.htm

The AR does not have any primary extraction: no gradual extraction initially as the bolt is withdrawn. The bolt simply turns and the bolt is yanked to the rear. Bolt closure is the inverse, with no gradual closing the last little bit of closure. Very abrupt, combined with a floating firing pin, combined with dirt and debris accumulating shot to shot.

In addition to concerns over explosions, I would worry about occasional stuck cases. I've shot a lot of cartridges with neck sized cases. The fit became tighter with every reloading. Operating the bolt, even with powerful primary extraction, became gradually more difficult. How long is it going to be before you rip that bit of rim off and have a stuck case.

[hodaka]

Well, I guess after reading Mr. Suckow's rant we need to take up different hobbies. I guess needlepoint is pretty safe. I like reloading, I like experimenting, and I like semi's. I like my eyes as well, but there is risk in everything we do. Anglo, let us know how the neck sizing goes.

[crowbeaner]

I full length size my brass for every semiauto every time. Once fired LC 223 brass is what, a nickel or so apiece? I just bought 1000 for $68 shipped. Why take the chance of a jam or KB when the cases are that inexpensive? Different guns have different chambers, and no two are exactly alike even if they have consecutive serial #s. What one guy is able to do with his rifle IS NOT what the next guy is able to do with his.

[AngloSaxon]

My personal experience with neck sizing .223.

Today (07/08/08) I went to my local rifle range and tested 120 rounds that were previously fired in my rifle before and were only neck sized. The bullet was Hornady 55gr FMJ. Using 4 different PMags, and shooting my Colt match Hbar, I did not experiency jams, hang ups, or any other malfunctions that would cause the rifle not to fire, all 120 rounds shot just fine, in both slow and rapid fires. (I did not have a rest and cannot commit on the accuracy.)

In conclusion, only you can decide what kind of ammo to feed in to your rifle, but I can tell from personal experience that at least in my rifle I was able to shoot neck sized rounds with no problems, again that is not to say that something can't happen. Just to be on safe side I think I'll stick to full length dies.

Thanks

[30Cal]

In conclusion, only you can decide what kind of ammo to feed in to your rifle, but I can tell from personal experience that at least in my rifle I was able to shoot neck sized rounds with no problems, again that is not to say that something can't happen.

It also doesn't mean they won't cause problems if you kept neck sizing them.