AR15 Gas Key Staking Tests - You Don’t Need Expensive Tools! 

Personally i would keep the 6.25 barrel. Recently ive been delving into improving the efficiency for subs and encountered/resolved other issues from running supers. However, i have now sorted them and its been 100% so far with both subs and supers. Biggest takeaway from my findings is that an adjustable gas block is not worth the trouble with 300blk. The benefits dont outweigh the cons Im not running any gas adjustment with mine anymore. So my suggestion would be to run a standard gas block, use a bcg with sprinco extractor and ejector springs. Both of these will fix the issues with high velocities from running supers on a system gassed for subs. There is way more to this but i dont want to give it all away before my next video. My suggestion is to simply invest in an efficient bcg (chrome lined, or full chrome) And use sprinco ejector and extractor springs. These are an absolute must. Tune for subs, run supers through it without gas adjustment. And use a gas busting charging handle of course. I just drill the side of my radian raptors to create a vent hole and i dont get any gas to face with supers or subs this way.

@@eitrisenhancementsllc wow that’s some good information and that kind of blew my mind you don’t have an adjustable gas block. I guess it’s not that important. I will get the BCM Bolt Carrier Group and replace the extractor and ejector Springs from Sprinco. For the extractor from Sprinco, there’s an option on the website for the (extra power 5 coil), or you can get (enhanced power 4 coil). which one did you get? I’ll also get a busting charging handle. 👍🏻. Did you do anything unique with the buffer tube and the buffer tube spring? You mentioned that to have the gun tuned for subsonics, besides doing the things you mentioned in the notes how else do you tune it for subsonics if your just using a normal gas block?

@sloth1490 if you are willing, the solgw bcg is essentially identical to the bcm, except it comes with the sprinco springs in it already. Plus the solgw bcg are on sale at primary arms right now But otherwise, get the 5 coil extractor, thats the one you need. Currently im running a sprinco yellow reduced power spring. Then i just reduce buffer mass to tune for subs. Less mass will require less energy to cycle, so thats how i tune. But this is mainly because gas is lacking and not in excess

@@eitrisenhancementsllc ok cool. I will buy the Solgw today and the yellow buffer spring. So you don’t have any issues shooting supersonics with the softer yellow spring? Do you have to change the buffer tube weights to go from subsonics to supersonics? Or is there a sweet spot. What buffer tube with weights do you use to tune? Thanks for the information.

@sloth1490 i currently experience no issues with supers. But no, i dont swap buffer weights between them. Just 1 setup for all. My current weight setup is a law folder extension (2.2oz) with an empty buffer (1oz) So technically its a 3.2oz buffer. Or slightly heavier than a standard carbine buffer (3oz) If you dont plan on using the law folder then there is no need to pull the weights out of the buffer. Only thing to watch out for is to avoid heavy bolt catches like the pdq or maritime bolt catch. These are slower to actuate and the increased bcg velocity with supers may cause issues locking back So stick to a standard bolt catch too. Also, 100% use 300blk pmags. They are made to feed the heavier bullets, so they are an absolute must for 300blk to keep up with bolt velocity. Happy to help!

As far as penetration goes there will definitely be a difference with the longer barrel, purely due to the velocity difference. Realistically though, i dont believe the 1:5 will offer any more accuracy on supersonics. The primary goal of the 1:5 was for subsonic accuracy since they are such long projectiles with slow velocities that they really do need a faster spin to achieve stability. Basically, if you have 2 barrels with the same twist rate, one a 6” and the other a 10” As long as the bullet leaves both the barrels at 1000fps, the rpm will be the same. And therefore there should be no difference. That said, super short barrels sometimes struggle getting to 1000fps so the 1:5 definitely helps with having the bullet at minimum leave the barrel stable. For supersonics its where it gets tricky Because now you are overspinning the bullet. Which can be harmful for accuracy and bullet integrity. Its hard to really quantify unless you really analyze a ton of data. Which can be done. But its just time consuming. But most, if not all 300blk projectiles are .308 So to really seek similar accuracy for this bullet, velocity and rpm must be similar. Which maybe in rpm it might be simply by the faster twist. But velocity plays a factor on the bullet’s ballistic coefficient. And typically the slower it travels the worse it is. (Sierra matchking shows their BC based on velocity) So long story short. Yes, i do believe a longer barrel may offer better accuracy. But i cant prove it. I can only hypothesize because of the bullets accuracy being related to speed and rpm. So in other words. The closer you can get to 308 velocity and rpm. The better (in theory) the accuracy should be. HOWEVER: This may all go out the window based on barrel profile alone, and many other factors. I can do a bit more research on rpm differences between 308 and 300blk if you are interested. I may just have a delayed response till i get things straightened out. Hope this wasnt too long lol

@@eitrisenhancementsllc Not long at all, thanks for the reply. I guess that since I have a 10.5" already. I might just get the 6" and a suppressor in the near/not-so-near future. Also those are very fair points. Thinking the build and what you said and demonstrated in your videos. it makes more sense for me to go for that one. Your channel is very interesting, keep it up!

Thank you! I also wanted to mention i did research on barrel twist and rpm and compared bullet velocities of the same grain between 300blk and 308 in their respective barrel lengths. I found that out of the 6” barrel, with supers, it would be ideal to use a 1:6 twist. This would closely match the rpm of the same bullet with the velocity difference from a 1:10 308 long barrel and the 300blk 6” This only applies to the 6” barrel velocities though Basically the 1:5 is definitely over-spinning supers, not a dealbreaker in a 6” barrel but it may be on a 10-16” barrel However, since barrel length is almost irrelevant for subs at 1000fps The 1:5 twist matches the rpm almost exactly to that of a 220gr pill being shot out of a 308 chambered rifle with a 1:10 twist barrel. As the velocity is about 2000fps So yes, the 1:5 is definitely there for subsonic stability and accuracy. However, even though we are achieving the spin. We are harming the ballistic coefficient due to the lack of velocity. Considering the bullet was designed for double the velocity. So basically. Unless the bullet is designed from the ground up for subsonic ballistic coefficient. Its gonna be a little hard to really be supremely accurate with subs. But at least the stability aspect is no longer playing a part in messing with accuracy and or baffle strikes. Because, yknow. A bullet flying straight will always be more consistent than a bullet flying sideways lol

@@eitrisenhancementsllc VERY interesting, Thanks for looking it up! The reason this question came to my mind is because a new caliber being developed, the 8.6 Which is essentially a .308 caliber version of the 300BLK. But in that case they increased twist rate to 1:3 and a longer barrel, particularly for subsonic ammunition. Ballistic gel testing has demonstrated impressive penetration characteristics, taking me to consider if a similar approach could be applied to the 300BLK. I imagined this would have a similar effect on 300blk, especially with a barrel twist rate close to 1:3. But I didn't think that drift could have a noticeable effect at the shorter distances for which the 300BLK is intended to be used.

@@argg.x ive looked into 8.6blk too and i dont see why we couldnt apply the same logic to 300blk However its hard to know wether the 1:3 was because of them needing to stabilize such a long bullet, especially since rpm is directly related to velocity of the bullet. Since the bullet is designed to be expelled at 1000fps. You are kinda limiting the rpm to stabilize the projectile. Personally i think the 1:3 was simply to stabilize effectively. The penetration is more than likely just due to the sheer mass. And the way it cuts a corkscrew in the target could simply be a way to disperse the amount of kinetic energy in such a large projectile. Its hard to really say without knowing which came first, the chicken or the egg, or in this case, the rpm requirements or the damage goal on target as far as the reason for the 1:3 twist. All i know, is the combination, wether accident or on purpose, is VERY effective. But it does have limitations. You absolutely should not shoot supers that are not solid copper. Or they may explode as soon as it leaves the barrel. Because well, rpm is directly related to velocity of course