5.7x28 55gr Subsonic Ammo going about 1040 fps reliably.
These are some 55 gr subs I made for 5.7. They average about 1040 fps. The 1150 spike is when I put the suppressor on.
Use this info at your own risk!
I used the 55 gr Hornady Soft Points I got from their rebate system. I use Accurate #5 for my 40gr VMAX and 35gr Inceptor loads, but haven't found any forums mentioning Accurate #5 for subs. I did a bunch of testing from 3.5 to 5 grains of powder. All functioned and no signs of over pressure. 5 grains of powder was around 1370 and 4.6 was around 1300. These were indoors and the chronograph had a lot of trouble from the mag dumping glocks next lane over.
3.9 grains of powder averaged 1150 and 3.5 averaged 1040. The 3.5 grains of powder had zero issues cycling. No stuck cases, ripped necks, flat or messed up primers, no squibs, magazines locked back.
I tested for keyholing before using the suppressor, no keyhole at 3, 5, 15, or 20 yards in my experience.
Use this info at your own risk! Worked great for me but I'm not a master. I plan to test with other 55 gr bullets. I'd love to do a gel test. This thing is the most quiet gun I've heard. It sounds like every round is a squib. I was shooting a steel target so I know it exited the barrel, and I inspected every shot.
If anyone has questions I'd be happy to share. And yes, this is basically just .22 LR at this point lowkey lol.
These are some 55 gr subs I made for 5.7. They average about 1040 fps. The 1150 spike is when I put the suppressor on.
Use this info at your own risk!
I used the 55 gr Hornady Soft Points I got from their rebate system. I use Accurate #5 for my 40gr VMAX and 35gr Inceptor loads, but haven't found any forums mentioning Accurate #5 for subs. I did a bunch of testing from 3.5 to 5 grains of powder. All functioned and no signs of over pressure. 5 grains of powder was around 1370 and 4.6 was around 1300. These were indoors and the chronograph had a lot of trouble from the mag dumping glocks next lane over.
3.9 grains of powder averaged 1150 and 3.5 averaged 1040. The 3.5 grains of powder had zero issues cycling. No stuck cases, ripped necks, flat or messed up primers, no squibs, magazines locked back.
I tested for keyholing before using the suppressor, no keyhole at 3, 5, 15, or 20 yards in my experience.
Use this info at your own risk! Worked great for me but I'm not a master. I plan to test with other 55 gr bullets. I'd love to do a gel test. This thing is the most quiet gun I've heard. It sounds like every round is a squib. I was shooting a steel target so I know it exited the barrel, and I inspected every shot.
If anyone has questions I'd be happy to share. And yes, this is basically just .22 LR at this point lowkey lol.