New TS Customs 300BLK



  • Been working on this fun little toy for a few days now. Subsonic 300BLK is pretty challenging to wring accuracy out of! Boy it's been a fun time trying though. ;)

    I'll be getting load data published in the next few days.

    https://www.gunhive.com/firearms/5727a0348ead0e51328b4567/

    IMG_8627.jpg

    IMG_8637.jpg

    IMG_8635.jpg

    Load Development

    I have gone through about a 8-10 different types of powder, trying to find a solid accuracy load for this rifle. Turns out there is a LOT of 300BLK data out there which is complete garbage. Apparently most people shooting 300BLK are using it for more of a toy than a precision rifle round. Finding a subsonic and accurate load was pretty difficult. It's been a very fun experiment though. Here's some preliminary data.

    I started with 220smk, but the throat on this chamber places that bullet WAY down into the case. Well past the neck/shoulder junction. I measured the lands at 1.700 lands putting the BtO at 1.690 when seated. I have 2500 or so of these, and they are like a freight train, but couldn't get them to perform well with any of the early powders I tested. Trailboss was very quiet, as was N320, but the accuracy just wasn't there. I didn't even record a lot of the data because the velocity, case fill, or accuracy was so poor that it wasn't worth sharing.


    With a 175smk I measured the lands at 1.655, which put the 175SMK bearing surface well up into the neck. Here's some rough notes in no particular order.


    Trailboss - Very quiet, but not accurate enough. Also doesn't run out of the Prometheus due to it being a big flake powder.


    175SMK 1.640 to ogive - N320
    7gr - 1125fps
    6.5gr - 1035fps
    6.4gr - 1000fps

    **Velocities: **
    962
    1012
    1013
    1003
    1010

    954 half mil low
    1018

    964 half mil low
    1018

    949 half mil low
    1012

    974 .3 mils low
    999

    Noticing a trend there? First shot from each string was about 50fps slower than the rest of the shots in the string. Very odd behavior, but with this powder, it happened like clockwork. My guess is that this powder leaves a residue that drastically changes the bore condition shortly after the barrel cools a bit. It isn't as if the 300BLK gets very hot anyway. I didn't wait as long between strings on that last one, which is why you see a smaller fps swing. In any event, 1.5-2" groups was all it could manage.


    175SMK 1.640 to ogive - N110
    10gr - 1250fps
    8gr - 980fps

    I didn't spend much time with this powder. It didn't like running out of the Prometheus very well. Seemed to shoot ok, with about 1.5" being average. I still wasn't blown away by it.


    After changing powders, it takes 10-15rnds for the barrel to stabilize. Interesting behavior that I've only ever seen before to this degree on a rimfire. No doubt subsonic rounds are a bit more finicky!


    175SMK 1.640 to ogive - N350
    7.1gr
    1080
    1070
    1066
    1080
    1069

    Very stable, but pretty dirty. The accuracy was not very good however. 1.5" - 2" groups with lots of unexplained flyers.


    175SMK 1.640 to ogive - IMR 4227

    10.5gr
    1043
    1036
    1043
    1054
    1046

    11gr
    1108
    1105
    1126
    1083
    1121

    11.2gr
    1115
    1126
    1110
    1126
    1121

    I started at 11.2gr, just shooting from the hip on powder volume. I got close, but it was a little fast. I worked my way down to 10.5gr and realized I had finally found something. Velocities were real good, and the accuracy was stellar. This will probably be where I stay. It will take a few hundred rounds to really get a lock on how it behaves over time and temperature swings, but I'm pretty excited. This load is accurate enough to show all of my errors. That was the main reason I put this Blackout together in the first place. There's enough recoil here to test your position extremely well, and due to the very slow velocity, you must drive the rifle flawlessly in order to have those bullets land where they are suppose to.

    This load is not the quietest, but silence doesn't help me if I can't hit what I'm intending to. Also I learned that Thunderbeast Ultra cans have some NASTY first round pop when working with subs. Subsequent rounds are nice and quiet, but that first one is holy-shit loud.

    100yd 5-shot group: (of course there had to be one that slipped away from me)
    d9i3Yjql.jpg

    300yd 5-shot group: Shots on bottom of plate. Bottom shot was first round, so I made an adjustment and fired 5 more. That's just on the plus side of 3" at 300yds. I'm pretty pleased with that considering it's subsonic 300BLK.
    ykitbWSl.jpg



  • I'm a big fan of .300blk. The ability to convert fired 223 range brass is awesome IMO.

    And complete powder burn in about 9 inches. Big plus too.

    Just running it subsonic? I'd be interested as to how it performs in supersonic as well.



  • Another beauty...lookin' mighty fine:heart_eyes:



  • Wow. That is a high end blackout. I love the build components.

    Have you considered sbr'ing the rifle and recessing the suppressor in the stock? I have considered sbr'ing my break action blackout, but just don't want to spend the $200 tax stamp.



  • Remington action?



  • @norcal_in_az said:

    Remington action?

    Surgeon action!!! From what I can tell every part on that rifle is top of the line.



  • @dddoo7

    That makes sense. The bolt handle is for sure not a Remington.



  • Those magazines look different.

    I got to ask, how are you liking the KMW sentinel stock so far?



  • @rhyno said:

    Those magazines look different.

    I got to ask, how are you liking the KMW sentinel stock so far?

    Mags look like poly AI 223 mags



  • @dddoo7

    I think they're the actual .223 AI polymer mags, and unfortunately I think they've been discontinued. I can't find them anywhere anyhow.....

    I know MDT makes them too, but from what I've seen online the AI ones look better thought out



  • @dddoo7 ah, hadn't thought of that, I have only recently seen AI mags.



  • The Sentinel is pretty awesome. Definitely the best "thumbhole" stock I've used. Very well done. If you are going to grab one... look up OTM Tactical. Great outfit. Very friendly and knowledgeable people. Reminded me of talking to myself. ;) Joe didn't pull any punches and knew just what he was talking about. I grabbed the sentinel and the surgeon action from him.

    Yes, those are poly AI 223 mags. Tough to find these days. They work with the 300BLK quite well.

    ddd, Yes, our first plan was to recess the can back into the stock, however given the rifle was intended to be a switch-barrel, I figured I'd leave it alone. The KMW has the room in the stock to do it I think.

    I tell you one thing... I'm getting pretty disappointed in Surgeon. This is the second 591 I've had built recently that had horrible bolt lift. Then to top it off, this action would only set off about 2 out of 3 rounds fired. Light primer strikes. We spent the better part of a day digging through it. Replacing the cocking piece is the only thing that seemed to fix it. Upon inspection, the surgeon cocking piece provided had sharp edges everywhere, and was dragging on the action and bolt shroud. Put a stock rem700 cocking piece in and problems solved. Pretty goddamn disappointing, considering what these actions cost. I'm sure this one will smooth out after a few thousand cycles... but it is just sad that companies making good products aren't willing to adhere to QC which will keep them good. My 591 on my 22-250 had even worse bolt lift... but at least it didn't light-strike everything. Travis swung through there and got things smoothed up as best he could... so I'm pretty happy with it now. No mistake there... this thing is so damn fun to shoot!

    I shot a cottontail right through the chest broad-side with it at 40yds. Ridiculous is the only thing to describe that. NOTHING stops those 220SMK's. It zipped a pencil sized hole through the bunny, and the bunny ran a couple feet and just stood there. It was as if I shot a deer with an undersized cartridge. He eventually bled out and tipped over. It was quite a sight.

    I spent some time launching them down to the 300yd line. Suppressed subs at that distance is a pretty unique experience. I smile every time. ;)



  • @orkan said:

    The Sentinel is pretty awesome. Definitely the best "thumbhole" stock I've used. Very well done. If you are going to grab one... look up OTM Tactical. Great outfit. Very friendly and knowledgeable people. Reminded me of talking to myself. ;) Joe didn't pull any punches and knew just what he was talking about. I grabbed the sentinel and the surgeon action from him.

    Yes, those are poly AI 223 mags. Tough to find these days. They work with the 300BLK quite well.

    ddd, Yes, our first plan was to recess the can back into the stock, however given the rifle was intended to be a switch-barrel, I figured I'd leave it alone. The KMW has the room in the stock to do it I think.

    I tell you one thing... I'm getting pretty disappointed in Surgeon. This is the second 591 I've had built recently that had horrible bolt lift. Then to top it off, this action would only set off about 2 out of 3 rounds fired. Light primer strikes. We spent the better part of a day digging through it. Replacing the cocking piece is the only thing that seemed to fix it. Upon inspection, the surgeon cocking piece provided had sharp edges everywhere, and was dragging on the action and bolt shroud. Put a stock rem700 cocking piece in and problems solved. Pretty goddamn disappointing, considering what these actions cost. I'm sure this one will smooth out after a few thousand cycles... but it is just sad that companies making good products aren't willing to adhere to QC which will keep them good. My 591 on my 22-250 had even worse bolt lift... but at least it didn't light-strike everything. Travis swung through there and got things smoothed up as best he could... so I'm pretty happy with it now. No mistake there... this thing is so damn fun to shoot!

    I shot a cottontail right through the chest broad-side with it at 40yds. Ridiculous is the only thing to describe that. NOTHING stops those 220SMK's. It zipped a pencil sized hole through the bunny, and the bunny ran a couple feet and just stood there. It was as if I shot a deer with an undersized cartridge. He eventually bled out and tipped over. It was quite a sight.

    I spent some time launching them down to the 300yd line. Suppressed subs at that distance is a pretty unique experience. I smile every time. ;)

    What is your drop at 300? I haven't shot mine much past 150. I know the bullet will maintain speed, but if you are off on range by 10 yards at 300 you would miss a deer. It is a rainbow.



  • @dddoo7 said:

    What is your drop at 300?

    12.6 mils. :stuck_out_tongue_winking_eye:

    I laid down, dialed in the firing solution... and went 5 for 5 with the first shots at 300. I only shot 40yds and 100yds prior to that. I was pretty pleased. Even had a witness. ;)



  • @orkan said:

    I tell you one thing... I'm getting pretty disappointed in Surgeon. This is the second 591 I've had built recently that had horrible bolt lift. Then to top it off, this action would only set off about 2 out of 3 rounds fired. Light primer strikes. We spent the better part of a day digging through it. Replacing the cocking piece is the only thing that seemed to fix it. Upon inspection, the surgeon cocking piece provided had sharp edges everywhere, and was dragging on the action and bolt shroud. Put a stock rem700 cocking piece in and problems solved. Pretty goddamn disappointing, considering what these actions cost. I'm sure this one will smooth out after a few thousand cycles... but it is just sad that companies making good products aren't willing to adhere to QC which will keep them good. My 591 on my 22-250 had even worse bolt lift... but at least it didn't light-strike everything.

    Well that sucks. I just bought my first 591 from Joe too....
    Fucking CA and its ten day waiting period. Now I want to want to go through mine.



  • Right... makes me feel shitty for recommending them when this type of thing happens. ... but the truth must be told. I truly hope yours is good to go.

    In hind sight, I misspoke, I didn't get this action from OTM. I got my 6BR action from him very recently... and that one runs awesome. Good bolt lift and I haven't had one single problem with it. So hopefully you'll be just fine too. If you get a good one, you'll love it.

    This action on this 300BLK I bought from brownells I think... and it's been laying around for about a year before being built. The 591 on my 22-250 had horrific bolt lift on it. That one was bought at the same time as this 300BLK and from the same place. So it could be just a bad period of time for them there about a year or so ago. Things tend to go in cycles.

    Very soon, I won't be recommending 591's anymore anyway. ;) There are new actions from companies that are still truly passionate about what they do... and at that point, surgeon will feel the weight of making these mistakes.



  • @orkan
    Here's hoping.



  • I don't know if a guy could stay mad while shooting this (as long as the load isn't bad :smiley: )

    Orkan handed me 5 rounds and said "shoot". When finished he asked how they shot and I was like a kid in a candy store. I was so thrilled I didn't even pay attention to how they grouped...or where on the steel plate.

    He then beat up the 300 yard plate (5 for 5) and let me have a go to which I had 3 hits out of 5 (so excited holding for wind exited my mind for a bit). Being able to watch the bullet travel to the target always gets me going. I wonder how many rounds it would take for me to settle down with a setup like this. I know something like this or very similar is getting added to my future build list.



  • Updated the original post with some load development logs. I have already launched 454rnds through this rifle. Thing is friggin fun!



  • Another thing... this website came in handy for targeting my velocity. In case you didn't know, the speed of sound is determined by air density, which is different than air pressure, and the only mechanism we have for determining air density is temperature.

    http://www.srh.noaa.gov/epz/?n=wxcalc_speedofsound



  • @orkan said:

    Updated the original post with some load development logs. I have already launched 454rnds through this rifle. Thing is friggin fun!

    Out of curiosity, do you have any idea what the barrel life on a 300 blk would be? Other than testing is there any real way to calculate a number?
    I do however realize there are a whole myriad of variables involved.

    I looked around awhile ago, and wasn't able to find anyone who had "shot out" their barrel so nobody had a solid answer for me.

    There was some people who were saying that it could be into the 10's of thousands due to the lower pressures and velocities involved in this type of round.



  • I don't have an answer anchored in experience. I can only speculate. A 308, shooting the same bullet at 1600fps faster, and burning 4 times the powder weight, burns up a barrel in 4000-10,000rnds. So, given that... I would expect 15,000-30,000rnds to be a pretty healthy estimate of barrel life.

    At the rate I'm shooting this thing. I'll likely be able to tell you within a few years. :)



  • Have you shot it much with the can off? I am curious as to how loud it is subsonic and canless.



  • Subsonic without a can is about like a 38 special. It is loud even though it is subsonic.

    Orkan...I have a 30PSS I use on my blackout. It is a little louder than the 30P, but quite a bit shorter. However it is substantially quieter with 5cc's of water. I don't know if you want to mess with it or if it will affect your accuracy, but I bet the first round pop will be gone with a little water in the can.

    I have not done any extensive testing for accuracy or load development except to find subsonic speeds, but I use 1680 with 220's for subs. It shoots about 2 Moa which I figure is the potential of the cva rifle anyway.



  • Yeah, I've never been one to mess with adding gel or water to the can. Such a friggin mess. As you mentioned, I also don't like adding variables. I'll have to see if I can find a can without so much first round pop. When one of my ultra-9's come in, I'll see if the additional length helps.



  • Worked up a supersonic 175SMK load tonight. Boy am I tickled with it! :metal:

    https://www.gunhive.com/load-data/575620768ead0e2c5b8b4567/

    175SMK Supersonic, 1.640 to ogive, 16gr IMR4227, Lapua brass, CCI-450 primer. This is about 15 thousandths off the lands in my chamber. Getting an average of about 1715fps. What a giggle machine to shoot!!!!

    The case fill with IMR4227 is stellar. Right at the neck/shoulder junction.
    8UkNHQTl.jpg

    Velocity is what it is. I'm betting I could step on it a bit more and squeeze a few more FPS. ... though with it shooting this good, I'm not touching a damn thing. I think the SD would be better were it not for virgin lapua with headspace about .010-.015" too short. It's getting blown out nicely though, which is good. :)
    ipqjOUYl.jpg

    5 shots at 100yds. Just barely opened the hole up. I sure do enjoy when everything lands in the black.
    n6HKEzol.jpg

    5 shots at 300yds. Up 4 mils from my 100yd zero. Slightly sub-MOA at 300 in a 15mph wind with a cartridge this ballistically inferior? I'll take it. ;)
    2j3DGUhl.jpg

    I've long held the opinion that a 308 is probably one of the very best training rounds out there as it pertains to working on the fundamentals of precision rifle technique. I'd have to say that heavy bullets in a 300BLK tests your form even more than the 308 does. The recoil is significant enough and the lack of appreciable velocity gives you an eternity of dwell time. This amplifies any deficiencies in your firing position and presents them to you with clarity. Yet it is not so severe as to cloud the "learning moment" behind a scary whuppin, and it is also extremely easy on the wallet due to inexpensive components and extreme barrel life. I suppose I'm about 5 years too late to the 300BLK bandwagon, but no one ever laid out it's value as a training tool for precision rifle technique before. My primary mission with this rifle was to discover if the 300BLK did have any potential there, and at this point I can confidently state that it absolutely does!



  • @orkan said:

    I'd have to say that heavy bullets in a 300BLK tests your form even more than the 308 does. The recoil is significant enough and the lack of appreciable velocity gives you an eternity of dwell time. This amplifies any deficiencies in your firing position and presents them to you with clarity.

    Well shit. Now I want one of these too



  • @ragnarnar said:

    @orkan said:

    I'd have to say that heavy bullets in a 300BLK tests your form even more than the 308 does. The recoil is significant enough and the lack of appreciable velocity gives you an eternity of dwell time. This amplifies any deficiencies in your firing position and presents them to you with clarity.

    Well shit. Now I want one of these too

    Will it never end???LOL:laughing:



  • Maybe Howa will add a 300blk barreled action threaded 16" in the proper twist. O bet they would sell.



  • @hypo said:

    Maybe Howa will add a 300blk barreled action threaded 16" in the proper twist. O bet they would sell.

    Remington has one...but I doubt it shoots like this one.