need more gas pressure

[Sincerd]

what are the ways to increase gas pressure at the gas block? I'm running a piston system and this load i have is Soooooo close to being perfect. Except, only locks back maybe 60% of the time. Cycles perfectly other than that. Very quiet and accurate. Anyway what should I do? Seat deeper, crimp? Seat longer?

I know seating deeper will increase chamber pressure but I dont think that's exactly the same thing as pressure at the gas block? Or maybe I'm wrong. Anyone?

[dellet]

what are the ways to increase gas pressure at the gas block?yes
I'm running a piston system and this load i have is Soooooo close to being perfect. Except, only locks back maybe 60% of the time. Cycles perfectly other than that. Very quiet and accurate. Anyway what should I do? seek help
Seat deeper,yes/no
crimp?maybe
Seat longer?no/yes

I know seating deeper will increase chamber pressure but I dont think that's exactly the same thing as pressure at the gas block? dependsOr maybe I'm wrong.it's happened before Anyone?someone, has an answer

Best I can do with the information provided.

Bullet , powder & charge, current COL, Max/min COL you can load to, current velocity.

[Sincerd]

what are the ways to increase gas pressure at the gas block?yes
I'm running a piston system and this load i have is Soooooo close to being perfect. Except, only locks back maybe 60% of the time. Cycles perfectly other than that. Very quiet and accurate. Anyway what should I do? seek help
Seat deeper,yes/no
crimp?maybe
Seat longer?no/yes

I know seating deeper will increase chamber pressure but I dont think that's exactly the same thing as pressure at the gas block? dependsOr maybe I'm wrong.it's happened before Anyone?someone, has an answer

Best I can do with the information provided.

Bullet190 grain nosler CC

, powder & charge, 8.6vv n110 (quickload has this velocity way high. Estimated velocity is 1200 actual velocity per labradar is 1035 avg

current COL, 2.240

Max/min COL you can load to, lancer mags. 2.260 but never care to go that high. Always stay below 2.250 or above 1.900


current velocity.
1035

Also as far as quickload. I've trued the h20 case capacity but the case fill is always off. Sometimes as much as 1 full grain or more. Is there a way to change the amount of room a grain of powder takes up in quickload if anyone knows?

[gds]

What is the set up of the firearm?
I will assume an AR15 type.

You stated a piston system. Not my first choice for subsonic, but to each his own.

Length of barrel?
Position of gas port?
Diameter of gas port?

Did you per chance do any research before buying/building a 300blk piston system?

[dellet]

what are the ways to increase gas pressure at the gas block?yes
I'm running a piston system and this load i have is Soooooo close to being perfect. Except, only locks back maybe 60% of the time. Cycles perfectly other than that. Very quiet and accurate. Anyway what should I do? seek help
Seat deeper,yes/no
crimp?maybe
Seat longer?no/yes

I know seating deeper will increase chamber pressure but I dont think that's exactly the same thing as pressure at the gas block? dependsOr maybe I'm wrong.it's happened before Anyone?someone, has an answer

Best I can do with the information provided.

Bullet190 grain nosler CC

, powder & charge, 8.6vv n110 (quickload has this velocity way high. Estimated velocity is 1200 actual velocity per labradar is 1035 avg

current COL, 2.240

Max/min COL you can load to, lancer mags. 2.260 but never care to go that high. Always stay below 2.250 or above 1.900


current velocity.
1035

Also as far as quickload. I've trued the h20 case capacity but the case fill is always off. Sometimes as much as 1 full grain or more. Is there a way to change the amount of room a grain of powder takes up in quickload if anyone knows?

I don't remember if the 190 can be loaded to 2.260", if it can't and you're in the lands that would explain a lot. That's what I meant by Max length, I really don't care about magazine length, that's a false maximum.

Quickload is pretty spot on for case capacity. The way to check calibration is with a flat base bullet seated in the neck. You will never force a large grain powder like N110 up between the case and bearing surface of the bullet. So even compressing the powder will not be 100% fill. If you are not using a drop tube or some method of settling the powder it will also be off. It takes a 10X6x6 pile of would to make a cord.

When loading for subs, you can't get what you want, you get what you need. Pre-conceived powders, lengths, charge weights and velocities give way to function. You may never get that powder working with that configuration,which is why gds asked the additional questions.

I would back off the crimp if you use one first thing after confirming max length.

Easiest thing to do is add .10 grain powder.

The hard way I would drop .50 grains and see what happens

[Sincerd]

What is the set up of the firearm?
I will assume an AR15 type.

You stated a piston system. Not my first choice for subsonic, but to each his own.

Length of barrel?
Position of gas port?
Diameter of gas port?

Did you per chance do any research before buying/building a 300blk piston system?

Mcx virtus and yes it's exactly what I want. If I can't get it to cycle this particular load I have other stuff it will.

[Sincerd]

The answer was to increase COAL.

I ran a test

Loaded up 20 round of each seating depth at the same charge. Hand loaded each round with an empty mag to check for lock back.

2.020
2.050
2.080
2.100

2.020 - only had 3 of 20 lock back.

2.050 - this was the original seating depth I had. This was locking the bolt back roughly 60% of the time the last time I was out. This time it was 9 of 20.

2.080 - 20 for 20 all lock back

2.100 - 20 for 20 all lock back

[dellet]

The answer was to increase COAL.

I ran a test

Loaded up 20 round of each seating depth at the same charge. Hand loaded each round with an empty mag to check for lock back.

2.020
2.050
2.080
2.100

2.020 - only had 3 of 20 lock back.

2.050 - this was the original seating depth I had. This was locking the bolt back roughly 60% of the time the last time I was out. This time it was 9 of 20.

2.080 - 20 for 20 all lock back

2.100 - 20 for 20 all lock back

If you start working on accuracy keep the ratio of charge to seating depth as close as possible. This will keep the burn rate and pressures close.

You can probably reduce/increase COL by .010” and charge by .1 grain and keep function and velocity very close to why you have now.

That was the reason for suggesting a drop in charge weight at 2.020”. Slows the burn rate, increases muzzle pressure. You accomplished the same by moving the bullet out. Manipulating that pressure curve can be tedious.

The crimp will effect starting pressure, which also comes into play.

Good to hear you got it going