224 valkyrie subsonics

[Jfoley]

Hi there,
new to posting on forums, but have spent many nights reading them, and found many solutions to past problems, so I'm hopeful that you guys can help me with another.

Recently I picked up a 224 valkyrie, and for all intensive purposes is just an expensive 223. Same bullets are used between both guns at real similar speeds , up until you throw 77grns or heavier in it.

Anyway I'm making a subsonic load for it using 85grn Nosler RDF's and Trailboss. At 5.8 grns of trailboss I get speeds just above 1000fps, which is where I want to be, considering I'd like to eventually produce these in a auto progressive press. However here is my issue...

This is an ar platform, and although I've made subsonics for a 6.5 creed bolt gun with good results and the same powder, I have issues with these cases getting stuck in the chamber. Yesterday after my first shot I had to pull fairly hard on the charging handle to get the case out , and by the fourth had to move to tapping on a cleaning rod and the charging handle lightly to get the case out...

Now expectation wise, I do not expect to be able to cycle the action with these rounds , although it would be nice. I just don't want to have such an issue removing the case..

One thing I did notice is that as the shots progressed, the cases were each slightly dirtier on the outside... Like the case isn't properly sealing and some particles are getting back in the chamber.. any thoughts at how this would be fixed..?

I don't want to give up on subsonics completely, but am open to suggestions .
Thanks.

 

[PatMiles]

One thing I did notice is that as the shots progressed, the cases were each slightly dirtier on the outside... Like the case isn't properly sealing and some particles are getting back in the chamber.. any thoughts at how this would be fixed..?

You probably answered your own question with this statement.
I'm no expert on subsonics but it sounds as if you are not letting the gun build enough pressure to expand the case and seal the chamber thus the chamber getting progressively dirtier with each shot. The fix is to dial up the powder and build more pressure. Maybe a different powder? Again, I'm not an authority on subsonics.
Just out of curiosity, what's up with this statement...Same bullets are used between both guns at real similar speeds , up until you throw 77grns or heavier in it.

 

[Richard Coody]

why would anyone buy a 224 valkyrie and load subsonics for it. not at all what it was created for. just do the blackout thing if you want subsonic.

 

[Beau]

why would anyone buy a 224 valkyrie and load subsonics for it. not at all what it was created for. just do the blackout thing if you want subsonic.

Or a 9mm.

 

[dcali]

Shooting a subsonic valkyrie is like driving a drag racer around town. It's not meant to do that. If you must persist, get a copy of quickload and see what powders might work out, and be careful. Weird stuff has been known to happen with mostly empty cases and low pressures, as you're finding out.

Honestly, though, just buy a blackout upper.

 

[rebel]

Hi there,
new to posting on forums, but have spent many nights reading them, and found many solutions to past problems, so I'm hopeful that you guys can help me with another.

Recently I picked up a 224 valkyrie, and for all intensive purposes is just an expensive 223. Same bullets are used between both guns at real similar speeds , up until you throw 77grns or heavier in it.

Anyway I'm making a subsonic load for it using 85grn Nosler RDF's and Trailboss. At 5.8 grns of trailboss I get speeds just above 1000fps, which is where I want to be, considering I'd like to eventually produce these in a auto progressive press. However here is my issue...

This is an ar platform, and although I've made subsonics for a 6.5 creed bolt gun with good results and the same powder, I have issues with these cases getting stuck in the chamber. Yesterday after my first shot I had to pull fairly hard on the charging handle to get the case out , and by the fourth had to move to tapping on a cleaning rod and the charging handle lightly to get the case out...

Now expectation wise, I do not expect to be able to cycle the action with these rounds , although it would be nice. I just don't want to have such an issue removing the case..

One thing I did notice is that as the shots progressed, the cases were each slightly dirtier on the outside... Like the case isn't properly sealing and some particles are getting back in the chamber.. any thoughts at how this would be fixed..?

I don't want to give up on subsonics completely, but am open to suggestions .
Thanks.

Hey, I say go for it. This is the deal, suppressed subsonics are just plain nasty for a variety of reasons. I'm not familiar with the case capacity you are dealing with but 5.8 gr is a lot for TB compared to 300 blk(what i'm used to). You might try N120 or N110. It won't cycle rifle gas but you can get to work with carbine gas if your port is huge like most 300 barrels. I imagine yours isn't. But since you don't have those expectations anyway, give that a go. Those powders are the cleanest sub powders I have used to date.

 

[Jfoley]

You probably answered your own question with this statement.
I'm no expert on subsonics but it sounds as if you are not letting the gun build enough pressure to expand the case and seal the chamber thus the chamber getting progressively dirtier with each shot. The fix is to dial up the powder and build more pressure. Maybe a different powder? Again, I'm not an authority on subsonics.
Just out of curiosity, what's up with this statement...Same bullets are used between both guns at real similar speeds , up until you throw 77grns or heavier in it.

I just meant between a 223, and a 224 the only real trajectory difference is when you get beyond the 70 grain bullets and step back to longer differences

 

[Jfoley]

Distances...

 

[Jfoley]

why would anyone buy a 224 valkyrie and load subsonics for it. not at all what it was created for. just do the blackout thing if you want subsonic.

I'm making the subsonics as a temporary/ plain fun solution for a good varmint control round that will not inform my neighbors of what I'm doing. Live in the country but have a couple houses about 80yds away.. I will eventually pick up a 300 blackout

 

[Jfoley]

Hey, I say go for it. This is the deal, suppressed subsonics are just plain nasty for a variety of reasons. I'm not familiar with the case capacity you are dealing with but 5.8 gr is a lot for TB compared to 300 blk(what i'm used to). You might try N120 or N110. It won't cycle rifle gas but you can get to work with carbine gas if your port is huge like most 300 barrels. I imagine yours isn't. But since you don't have those expectations anyway, give that a go. Those powders are the cleanest sub powders I have used to date.

Thanks , I'll look into those. I have the savage msr15 lrp, which has a midlength and an adjustable gas block.. so I'll open it up and see what I get. TB powder is super dirty, which I'm sure is what is causing it to lock up so fast maybe I'll have better luck with the others.

 

[#40Fan]

I had a similar issue as the OP with my 300 BLK. I was getting jams because the powder wasn't being fully burnt and plugging everything up. But, my jams were coming from the attempt to chamber the next round, not from ejecting. They were getting stuck bad enough that it took a screw driver to pry the bolt back to free them up.

Switched to a faster burning powder and have been jam free since.

 

[Knotwild]

I shoot a lot of .223/5.56 supersonic suppressed with Benchmark and 55gr Varmeggedon's in a mid length gas system with an adjustable gas block tuned to just hold open on the last round.

The brass comes out filthy and the chamber stays dirty enough that it will discolor the next un-fired round if I leave it in the chamber for a day or two.

 

[brutalwarpig]

I realize this is an old thread but I've had this same issue. The solution is to fireform and neck size your cases, get an adjustable gas block and possibly a lighter buffer and/or buffer spring. Fireforming the cases then neck sizing will probably take care of the problem since the cases will already be expanded to your chambers dimensions.