5.7x28 questions

[burrkiss]

Within a month or two, I will be reloading 5.7x28. I wanted verification on the size is the projectile? Is it the same as a 556? IE .224?

I have 6 months reloading exp, and have read that the 5.7 is a tricky round. I currently have reloaded

2k 9mm rounds w/ 124gr boolits
1.5k .45ACP rounds w/ 230gr boolits

I will be starting to reload
.327 magnum rounds (about 500)
7.62x39 (about 1500)

Is it recommended that I reload this round with my exp? What are the dangers that the 5.7 has that other rounds do not?

[alfloyd]

The 5.7 cases are polymer coated. DO NOT tumble clean them. You can get about 3 reloads out of the case before the coating wears off and causes problems. The slugs are the same size as the 223, (0.224 inch in diameter). Most loading data will stop at about 45 grain weight, but I have a friend that reloads them with the 55 grain slug I make from the 22 LR brass.

Just my $0.02 worth.

Lafaun

[Piedmont]

alfloyd, I am not questioning the truth of anything you said, but read something similar a couple years back and it left me scratching my head. I do not load the little 5.7.

Why did they poly coat them? If that wears off why wouldn't loading the round be just like loading every other case?

[burrkiss]

I use a little vibrating bucket thing (cant remember and its downstairs). Is that tumble cleaning?

If its the same projectile as a 556, why was it classified as a AP round in the beginning of its life?

[alfloyd]

"Why did they poly coat them?"

They poly coat them to help with the extraction. Most firearms that use this cal. is the blowback action. When the poly coat is gone the cases get stuck in the chamber and does not extract well.

After my friend loads them 3 times I get the brass to swage into 30 cal slugs.

Lafaun

[Hickok]

Being a very small case, pay particular attention to powder charges, as .1 or .2 of a grain of powder weight can cause major pressure changes, as well as any changes in bullet seating depth.

When approaching max loads, proceed carefully, for all the above reasons.

[Camba]

I reload the 5.7x28FN cartridge for my Thompson Center Contender RIFLE with 18" barrel. Note I said RIFLE and NOT pistol. It is one of my good cast boolit loads for small game and pure plinking. I believe the velocity I get with this combination is between 1800 to 2000 fps, using the RCBS 22-055-SP mold. My cast boolit gets sized to .225 and lubed and gas checked weights about 58gr. The coating on the case sometimes does affect pressure from chamber build up. You can get a decent load but it can go up in pressure if your chamber is dirty. It is best not to be at the max load so you can have some safety margin in case the chamber creates extra pressure. Since my shooting is for the contender rifle, I can reuse the cartridges up to 8 times before they split. I have loaded this round with many types of rifle and pistol powders and bullets from 33gr TNT to Speer 70gr SMPZ, as well as the RCBS cast. One that gives me more accuracy with a range of bullet weight is the AA1680.

Here are a couple of pictures of my 5.7x28FN load with RCBS cast boolit:
100220
100221
Camba

[JonB_in_Glencoe]

I don't reload the 5.7x28
but I've read that most reloaders that do load it, that they don't tumble the brass, they deprime and use a diluted cleaning solution..."simple green" sticks in my mind.