5.7x28 Random Reloading Discussions

[panzermk2]

Pretty normal. Shoulder movement will be greater even more when fired from P90/PS90

[Rapier1772]

Those are fine. If the shoulder is about 1/2 way up the neck (more or less), that's when you should be concerned. But like Jay said, depends on the gun used (PS90/AR57/FsN/TC)

[CoryS78]

Yeah, this was with my PS90 so I guess I'm doing pretty well then. Time to ramp up the press! I have about 200 cleaned and trimmed cases waiting to go

Thinking I'll run 250 SS190s next, since I still have about 900 from my 1000 order. So many projectiles, so little time...

EDIT: is there a way to reduce the shoulder setback without affecting feed reliability, perhaps with a slightly stiffer recoil spring? I imagine if one was to be made it would be on EA's site, maybe I missed it... I think I saw there is a heavier weight for the bolt as well...

[panzermk2]

We have both a heavier rate reducer and heavier springs. In this case I would leave the recoil springs alone! and go with the heavy duty rate reducer.

[catalina2014]

Grantness, do you or any of your numerous followers have any data for Unique??

[Rapier1772]

Grant hasn't dropped in for over a year unfortunately but from this thread: 5.7x28mm Reloading

The IMR powders are more than likely too slow... Unique is too fast.... Best powders I know of are HS7, True Blue, Blue Dot, Acc#7, VVN105, VV3N38, Longshot, and Alliant ProReach looks good so far, but Im still testing...
Browse the reloading subforum for more info. Try the search. Check out the forum wiki.

[lawraven22]

Recently worked up a decent subsonic 5.7x28 load for my AR-57 SBR (9" barrel) for use with my Gemtech SAR57 suppressor. Two powders worked pretty well, but case prep is a bear. Not an easy or quick round to reload. Used a single stage Hornady press I found on sale on Amazon. I do case cleaning one day (simple green/water soak and agitate for 10-15 min then water wash and dry), sizing and deprime second day, hand prime on third day and powder measure (with powder trickle by hand to get charges EXACT) and bullet seating on fourth day. Use Lee die set. I didn't crimp but Lee makes a crimper if you so need.

First:
Powder: True Blue 3.0 gr
Bullet: Hornady 55gr FMJ-BT
Case: once fired American Eagle
Primer: Winchester small pistol
COAL: 1.575

Second:
Powder: Power Pistol 2.8 gr
Bullet: Hornady 55gr FMJ-BT
Case: once fired American Eagle
Primer: Winchester small pistol
COAL: 1.575

The true blue is very fine grained compared to the round flakes of the power pistol. Both burn pretty clean and leave little residue with the TB being a little cleaner. These loads are just enough to cycle the heavy, heavy AR57 bolt (it's a simple blow back design) but remain subsonic through the 9" barrel. Be careful not to remove the case lacquer by tumbling them in case tumbler. However, I also apply a little dry lube spray to the rounds just before loading into the FN 50rd mags to help feeding. Seems to help a little.

As always: Use these loads @ your own risk.