SAINT .300 BLK Pistol: will it function unsuppressed with subsonic ammo?

[Neubs]

HI. FNG / New Forum Member today, registering just after my first range session with my new SA SAINT .300 Blackout pistol.

First, I do not care for the description in the Operation & Safety Manual about the Adjustable Gas Block (AGB). It does not specify anything empirically about bullet weights, velocity and AGB settings. I'm left to assume that a Shooter needs to readjust the AGB for different bullet weights and especially moving from supersonic to subsonic ammo.

Today - first range session - it took me about 20 rounds - one round at a time in the mag (for safety) - to get through the AGB adjustment process. I was using Hornady 135 gr supersonic rounds. After those first 20 rounds and the AGB set correctly, full magazine, rapid fire was flawless (and fun).

I did not record how many turns with the supplied hex wrench from fully-seated were needed to back-off the set screw in the AGB.

Switching to subsonic 200 gr ammo (no suppressor installed), I could not get a satisfactory setting of the AGB to eject a spent round and lock the bolt reward. I tried twice from AGB set screw fully-seated to set screw on it's last thread. Shoots fine, ejects fine, does not lock open.

Am wasting my time with subsonic ammo with this weapon until I can attach a suppressor?

Bottom Line: It's fun to shoot. I zero'd my Trijicon MRO also and am now able to drive tacks, once I get the AGB reset for the supersonic rounds.

Thanks for any / all replies.

Cheers, Neubs

 

[Keystone19250]

I owned a SA 300BO Pistol and I won’t say your wasting your time but I sold mine for that and other reasons. It was frustrating having so many issues with subsonic rounds and I had no interest or desire to get a suppresser.
Shoot supersonic until you get the suppresser.

 

[10mmLife]

I'd recommend holding onto the subsonic .300blk ammo until you get an approved tax stamp for a suppressor.

From experience the .300blk subsonic is an amazingly fun round to shoot suppressed and it's the only way to shoot it reliably, but it's well worth it!

If you don't have any experience with a suppressor I recommend you do your homework on the different models as cost doesn't always mean best sound suppression or quality.

Check out Rugged brand suppressors as they make an awesome product with probably the best warranty in the business having an unconditional lifetime warranty that covers everything from baffle strikes to user error.

 

[Classified]

There's no purpose in running subs uncanned. The backpressure will not be enough to run reliably (if at all), and the accuracy will will also suffer. The can boosts the pressure and affects trajectory. If you are set on wasting them though, you can get a hatebrake or a similar compensator that boosts the pressure.

 

[TEXASforLIFE]

There's no purpose in running subs uncanned. The backpressure will not be enough to run reliably (if at all), and the accuracy will will also suffer. The can boosts the pressure and affects trajectory. If you are set on wasting them though, you can get a hatebrake or a similar compensator that boosts the pressure.

I agree! Why shoot subs and not have a can? What would be the purpose? Who am I to judge though! One day I might get a shusher/husher? Filling out a living will and adding family for users and/or ownerships.

 

[Bear007]

I have the SA Victor .308 rifle with the adjustable gas block. I also do not like the lack of adjusting information. I sent an email request to SA with a single question that was never responded to. So, being new to AGBs, here are my few thoughts and what I think I've figured out on their AGB.

Mode 1 set screw (all set screws get fully seated) regulates the maximum amount of gas possible to the BCG.

Mode 3 adjustable screw will only regulate a portion of the maximum gas possible in Mode 1. It can not regulate more than Mode 1. So if you have a round that has too little pressure (not able to lock the BCG back on the last round) Mode 3 adjustable screw will not help you. It is solely for over pressure loads, I'm guessing suppressors here.

I've done nothing with Mode 2 but the 3 color coded and vented set screws apparently again, only allow a portion of the maximum gas in Mode 1. It lowers the pressure and overall amount of gas by venting the unwanted gases away from the BCG and from the barrel in highly over gassed systems. Not sure what these are for but specifically says "not for surpressor use" in the manual.

Like I said, this is what I believe I've figured out and if any of it is incorrect I'm sure someone here will let me know!

Pages 35 & 36 in your manual. Hope something here helps.

 

[Neubs]

Thanks for your replies.

I first used the term 'wasting my time' - but, I guess none of this is a waste. It's getting farther into a hobby/passion/subject that we all love. I'm new to the AR platform. New also to sub- vs supersonic ammo choices. My Retailer just sent me a note that my suppressor application has been approved by ATF.

For Bear007: I have nearly memorized those two pages in the manual - Thanks.

- Would I ever want to use the Mode 1 set screw? I did speak with a Rep @ SA. She indicated that the Mode 3 screw was what I (always) needed to use.

- So, the Mode 1 set screw, fully inserted, allows the maximum amount to gas to be used in cycling the weapon?

- And the Mode 1 set screw should only be used fully inserted, correct?

- And the Mode 3 screw allows a varied amount to gas to be used in cycling, and the correct amount of gas (and the setting of the AGB) is dependent on correct cycling, using the procedure outlined on page 35?

 

[TEXASforLIFE]

I don't have a single SA rifle of any kind, so all I do is read other peoples post about any SA rifle (M1A and other AR types). An M1A would be cool too have, but going custom on my first buy. Somewhere in south Texas I think makes or sells M1A actions, barrels and other parts.

 

[Bear007]

Thanks for your replies.

I first used the term 'wasting my time' - but, I guess none of this is a waste. It's getting farther into a hobby/passion/subject that we all love. I'm new to the AR platform. New also to sub- vs supersonic ammo choices. My Retailer just sent me a note that my suppressor application has been approved by ATF.

For Bear007: I have nearly memorized those two pages in the manual - Thanks.

- Would I ever want to use the Mode 1 set screw? I did speak with a Rep @ SA. She indicated that the Mode 3 screw was what I (always) needed to use.

Curious why she said always use Mode 3. This screw is adjustable but also requires you to remove it, counting your turns, apply blue locktite, reinsert it the number of turns you counted ... for each new setting. Otherwise it will move/change and may eventually even fall out.

- So, the Mode 1 set screw, fully inserted, allows the maximum amount to gas to be used in cycling the weapon?

- And the Mode 1 set screw should only be used fully inserted, correct?

Yes, always fully inserted. MODE 1 is actually the only MODE I've used since the MODE 3 adjustable screw could not regulate more gas than the maximum and my ammo works well using max pressure.

- And the Mode 3 screw allows a varied amount to gas to be used in cycling, and the correct amount of gas (and the setting of the AGB) is dependent on correct cycling, using the procedure outlined on page 35?

Yes, varied amounts up to Mode 1 max pressure but not more than max pressure. So it will not work for your subsonic loads without the suppressor. There simply isn't enough gas pressure to cycle the BCG without the suppressor attached.

I did increase my buffer on the Victor .308 from 3.6 oz to 4.5 oz and it helped my low pressure ammo to cycle much better and made the rifle cycle smoother. Don't know if this will work on the 300 blk or not. Plus I believe you said yours was a pistol.

 

[JDSchwalb]

HI. FNG / New Forum Member today, registering just after my first range session with my new SA SAINT .300 Blackout pistol.

First, I do not care for the description in the Operation & Safety Manual about the Adjustable Gas Block (AGB). It does not specify anything empirically about bullet weights, velocity and AGB settings. I'm left to assume that a Shooter needs to readjust the AGB for different bullet weights and especially moving from supersonic to subsonic ammo.

Today - first range session - it took me about 20 rounds - one round at a time in the mag (for safety) - to get through the AGB adjustment process. I was using Hornady 135 gr supersonic rounds. After those first 20 rounds and the AGB set correctly, full magazine, rapid fire was flawless (and fun).

I did not record how many turns with the supplied hex wrench from fully-seated were needed to back-off the set screw in the AGB.

Switching to subsonic 200 gr ammo (no suppressor installed), I could not get a satisfactory setting of the AGB to eject a spent round and lock the bolt reward. I tried twice from AGB set screw fully-seated to set screw on it's last thread. Shoots fine, ejects fine, does not lock open.

Am wasting my time with subsonic ammo with this weapon until I can attach a suppressor?

Bottom Line: It's fun to shoot. I zero'd my Trijicon MRO also and am now able to drive tacks, once I get the AGB reset for the supersonic rounds.

Thanks for any / all replies.

Cheers, Neubs

I have the same pistol. Love the gun now, hated it at first. Here is what I found works. The stock buffer and buffer spring work great with supersonic ammo or subsonic if suppressed. I quit pissing with the adjustable gas port along time ago. I changed out the buffer and buffer spring and now it runs fine all kinds of ammo, suppressed or not. If you are going to be running suppressed or supersonic it will probably put a bit more stress on the bolt carrier group but unless you are going to be shooting 10k rounds you probably will never have to replace it.

 

[Neubs]

Thanks JDSchwalb.

Yesterday - with suppressor in-hand - I went to the range and dialed-in the adjustable gas block. Shooting 200 gr subsonic rounds with the suppressor, it took three full turns counter-clockwise to function correctly. Ran several magazines and a total of 80 rounds. Flawless performance.

Have not yet 'loctite'd the AGB set screw - I want to get more rounds downrange first. Also, I'll experiment with supersonic ammo without the suppressor. Last, I need to get onto a longer-range facility, I'm driving tacks @ 25 yds.

Cheers.