Adjustable gas block question

[Bartholomew Roberts]

Originally Posted by JeepHammer

You simply can't accept facts, NATO scrapped it in 1958, US scrapped it in 1960, no amount of misconstrued BS is going to change physics.

That’s an odd statement to make coming from someone who gets so many of their basic facts wrong.

It *Might* have a niche as a PDW cartridge, but it will be substandard for that role as long as rounds like 5.7x28 in firearms like the P90 exist.

So, just to summarize your views, a 5.56x45 cartridge pushing a 62gr bullet at 3,000fps is a varmint bullet unsuitable for men. A 7.62x35 cartridge pushing a 110gr bullet at 2,200fps is also a failed concept. However, a 5.7x28 cartridge pushing a 30gr bullet at 2,350fps is the supreme personal defense weapon cartridge? Does that sum it up accurately?

By any chance, do you own a debarked chihuahua?

[Sharkbite]

So, just to summarize your views, a 5.56x45 cartridge pushing a 62gr bullet at 3,000fps is a varmint bullet unsuitable for men. A 7.62x35 cartridge pushing a 110gr bullet at 2,200fps is also a failed concept. However, a 5.7x28 cartridge pushing a 30gr bullet at 2,350fps is the supreme personal defense weapon cartridge? Does that sum it up accurately?

WINNER.....mike drop

[JeepHammer]

The concept of a PDW is useless to me, I'm not a pilot that needs a 200 yard MAXIMUM effective range firearm isn't something I'll ever need.
Failed concept for civilians.

Second, the idea of pistol volume case firing a .30-ish caliber RIFLE bullet is failed by every military.
The idea has been rolling around since circa 1900, failed for practical use in every format from Mauser to AR clones.
It's been beat to death by NATO, by the US, by the Soviet block, by every government, fails on all counts.

In field use, hog hunting in particular, I've seen first hand what the .300 BO does...
The guys flocked to .300 BO, either shoot dirt, or wound hogs, very few kills.
Hog hunting ranches are banning .300 BO right & left while they are DESPERATE to get rid of hogs.

Hornady 110 grain lists energy at 622 ft.lb. @ 300 yards, velocity @ 1,596 FPS from a 16" barrel!
The round is listed as LESS THAN 50 POUND VARMINTS.

https://www.hornady.com/ammunition/r...v-max-black#!/

You are shooting a pistol length barrel claiming velocities & ranges, with MUCH heavier bullets, that aren't listed by any reputable ammo maker...

Your arguments have been disproven by EVERY military around the world, since all have tried stretched pistol cases with pointed .30-ish bullets and found them lacking.

Like I said before, I'm happy YOU are satisfied with this failed concept, underpowered 7.62x39 round in a chopped off AR rifle action, but don't try to sell it as something useful or viable for anything other than an oddity...

Not even the Soviet block was dumb enough to make a pistol version of AK-SKS for the 7.62x39R, think about that for a minute... You are going where the Soviets wouldn't go...

I'll stick with a handgun for handgun applications, rifles for rifle applications.
I'll leave beating failed concept to the guys that like beating their heads against a wall...

Now, I've seen what a P90 in 5.7x28 will do, up close & personal, and it scares the crap out of me.
It blows through soft body armor, it shreds meat, it's light, it's ergonomic, it has a 50 round standard mag, ammo is a crap load lighter, more compact, the ammo fits in a standard handgun format, and it's used by 60 countries around the world, both police & military.

You know, the guys that lives actually matter if the firearm/round actually work or not, and have the resources & people to determine if the firearm/round actually work or not (not some internet fan boy making wild claims).

Exactly ZERO countries have adopted the .300 BO since it fails against conventional, already accepted firearms in head to head testing...
Funny, SOCOM uses P90s (5.7x28), MP7s (4.6x30), but the .300 BO is still in 'Testing'...

[Bartholomew Roberts]

Originally Posted by JeepHammer

Hornady 110 grain lists energy at 622 ft.lb. @ 300 yards, velocity @ 1,596 FPS from a 16" barrel!
The round is listed as LESS THAN 50 POUND VARMINTS.

The 110gr VMAX (Guess what the “V” stands for?) is listed for varmints under 50lbs AND “Personal Defense.” It is a round designed to fragment on impact. The 110gr GMX (https://www.hornady.com/ammunition/r...x-full-boar#!/) is an all-copper, non-fragmenting bullet listed for “Medium game 50-300lbs.” The 135gr FTX (https://www.hornady.com/ammunition/r...-135-gr-ftx#!/) is also listed in all three of those categories.

https://www.hornady.com/ammunition/r...v-max-black#!/

You are shooting a pistol length barrel claiming velocities & ranges, with MUCH heavier bullets, that aren't listed by any reputable ammo maker...

I stated that I am getting an average of 2,199fps (over five shots) for 110gr VMAX out of a 9” barrel (measured with a Magnetospeed v2 chrony). The link you posted gives a muzzle velocity of 2,375fps for the same bullet out of a 16” barrel. What exactly, do you find difficult to accept about that velocity?

I haven’t “claimed any ranges” though admittedly, I’m not even sure what that means.

The “much heavier” bullets were the 220gr Sierra MatchKing at 1,017fps avg (measured same as above). Hornady reports 1,020fps for their 208gr AMAX (https://www.hornady.com/ammunition/r...a-max-black#!/), though my own personal testing of their .300 Whisper load of the same bullet only showed 974fps in a 9” barrel.

Your arguments have been disproven by EVERY military around the world, since all have tried stretched pistol cases with pointed .30-ish bullets and found them lacking.

Which of my arguments have been disproven specifically? I ask, because I haven’t really been making arguments. I’ve just been pointing out facts you mangled in your verbose opinion sharing.

Not even the Soviet block was dumb enough to make a pistol version of AK-SKS for the 7.62x39R, think about that for a minute.

Ever heard of an AKMSU? 10.5” barrel 7.62x39. Totally different from a 9” 7.62x35 yeah?

[Sharkbite]

Hornady 110 grain lists energy at 622 ft.lb. @ 300 yards, velocity @ 1,596 FPS from a 16" barrel!
The round is listed as LESS THAN 50 POUND VARMINTS.

https://www.hornady.com/ammunition/r...v-max-black#!/

Better read your link again.

[JeepHammer]

You mean the AKMSU that has a shoulder stock and fires the 7.62x39mm round?
With shoulder stock not even Soviets pretended it was a 'Pistol'.

Not something pretending to be a 'Pistol' that shoots reduced power rounds with modified cases since it fires the full powered, standard 7.62x39mm rounds,

You mean the AKMSU the Soviets listed the maximum effective range as 150 meters?
You mean the AKMSU that was discontinued in favor of the 5.45x39mm round?

Like I said, every military in the world tried the .30 cal, pistol length barrel and crapped on it.

*IF* you were a little better informed, you would know Russia has pretty much replaced the 7.62x39mm round for the 5.45x39mm round, dumping huge stockpiles of firearms & surplus ammo on the world market... Something else you won't accept, but US military folks watch for those red & deeply ribbed mags.

Now, you are going to pull the AKS74U out of your butt,
Again, shoulder stock, full power 5.45x39mm cartridge, used as PDW by pilots, tank crews, etc.
They don't pretend it's a 'Pistol'!
No matter what you have seen on TV...

I stated that I am getting an average of 2,199fps (over five shots) for 110gr VMAX out of a 9” barrel (measured with a Magnetospeed v2 chrony). The link you posted gives a muzzle velocity of 2,375fps for the same bullet out of a 16” barrel. What exactly, do you find difficult to accept about that velocity

Virtually everything.
1. It's a 'Claim' with ZERO third party reliable source to back it up.

2. You 'Claim' the vast majority of .300 BO barrels are pistol, while every manufacturer site I checked (All the major manufacturers) have ZERO listings for pistol length barrels.
No listings for pistol length barrels = rifle round.

3. You state that DOUBLE (+/-) the barrel length only results in 176 FPS velocity increase in a RIFLE round.

4. Your own 'Claims' of 220 grain @ 1,017 FPS, while 220 grain, .45 ACP is exiting a 5" barrel @ 975 FPS, nasty hollow point included at no extra charge...
Head to Head, same weight bullet, (NOT out of a long slide/long barrel 45 which would add velocity), a whopping 42 FPS difference without a chopped up rifle firing the round...

5. AND YET, YOU CLAIM THE .300 BO is vastly superior...
I carry a 1911 (sometimes), I wouldn't carry a chopped down AR clone for 47 FPS...
Neither the size, weight, ergonomics or operation of a chopped down AR lends itself well to being a 'Personal Defense Carry Weapon'...
While a 1911 is an excellent carry weapon!

Now, *IF* I were inclined to FORCE the entire world to see/feel I was armed, I would simply carry a full power AR carbine. ( I'm not that kind of butt hole)

6. Now, we are discounting all other CONVENTIONAL pistol cartridges/firearms, up to and including .500 mag, The 100 year old .45 ACP still checks off all the boxes of a civilian short range personal defense weapon, and that's one single, well known, exhaustively tested cartridge.
A cartridge chamberings offered by virtually every major handgun maker in the US, and most outside the US. The round is ubiquitous...

7. While the .300 BO simply isn't offered by anyone but AR clone makers in 'Handguns'.
The round itself isn't 'Common', and it won't fit in conventional handguns.
Outside of some VERY specific applications (which civilians aren't included) you would have to be glutton for punishment to carry a chopped down AR clone...

8. The .300 BO, especially in 'Handgun' trim, is trying to fill a niche that doesn't exist in the civilian market. It's strictly a military/police/secret service niche, and a small one at that.
For civilians, it's STRICTLY for bragging rights, "I have something you don't, na-nana-na-na!"
Its NOT military issue, so no military collector value,
It's not practical as a handgun because of size, of weight of both firearm & ammo,
It's not a practical rifle hunting round since so many other cartridges are more powerful, more accurate & are commonly available.

A 1895 .30-30 has better ballistics, more energy at the target, and is commonly available in most parts of the world.
And by the way, some idiots put that round into 'Pistols' also, which were equally useless,
Same goes for .45-70 Govt, 12 Ga revolvers, and equally ignorant handgun chamberings.

You don't want to accept the fact it's all been done before, and it will be done again with equally useless results, that's entirely up to you. You are a fan boy, we all get that.
Geek out on your chosen round, just don't pretend it has any use other than punching paper at short ranges for bragging rights.

When you want to get serious, I'll show up with both .223 & .308 ( and we'll take cracks at 100 to 1,000 yard targets and see what the combined scores add up to...
Your 'Ultra New' .300 BO (pistol or rifle length), against 60 year old cartridge rifles.

We can also do pistol range targets, holstered to targets down, I'll use my old standby 100 year old cartridge handguns/rounds against your .300 BO 'Pistol' and see who puts down targets faster...
Say, old Navy standards of 3, 7 & 15 yards, surrender position/weapon holstered on buzzer to 3 rounds on target?

That *SHOULD* demonstrate exactly how 'Effective' the .300 BO/AR format is in the real world...

[stagpanther]

Have you ever fired one??

[Bartholomew Roberts]

Originally Posted by JeepHammer

You mean the AKMSU that has a shoulder stock and fires the 7.62x39mm round? With shoulder stock not even Soviets pretended it was a 'Pistol'.

Do you understand that AR15 pistols are only "pistols" in the technical, legal sense? Nobody is carrying them in the same role as a handgun.

Not something pretending to be a 'Pistol' that shoots reduced power rounds with modified cases since it fires the full powered, standard 7.62x39mm rounds

A 10.5" 7.62x39 fires a 123gr bullet at about 2200fps; but with more flash and blast than a 7.62x35.

*IF* you were a little better informed, you would know Russia has pretty much replaced the 7.62x39mm round for the 5.45x39mm round, dumping huge stockpiles of firearms & surplus ammo on the world market... Something else you won't accept, but US military folks watch for those red & deeply ribbed mags.

Are you serious?

2. You 'Claim' the vast majority of .300 BO barrels are pistol, while every manufacturer site I checked (All the major manufacturers) have ZERO listings for pistol length barrels. No listings for pistol length barrels = rifle round.

Where did I claim this? Please provide the exact quote that led you to believe I stated this.

3. You state that DOUBLE (+/-) the barrel length only results in 176 FPS velocity increase in a RIFLE round.

Yes, the .300 BLK is designed to burn all the powder in a 9" barrel because it was optimized for short barrels. Extending the barrel another 8" only gets you a moderate gain in velocity as a result. Here's a test through a 10.5" barrel by The Shooting Times: http://www.shootingtimes.com/ammo/ul...out-ammo-test/

4. Your own 'Claims' of 220 grain @ 1,017 FPS, while 220 grain, .45 ACP is exiting a 5" barrel @ 975 FPS, nasty hollow point included at no extra charge...Head to Head, same weight bullet, (NOT out of a long slide/long barrel 45 which would add velocity), a whopping 42 FPS difference without a chopped up rifle firing the round...

Do you understand that it is 1,017fps because I am purposely trying to keep it subsonic? Do you understand why someone would want to do this?

5. AND YET, YOU CLAIM THE .300 BO is vastly superior...
I carry a 1911 (sometimes), I wouldn't carry a chopped down AR clone for 47 FPS...Neither the size, weight, ergonomics or operation of a chopped down AR lends itself well to being a 'Personal Defense Carry Weapon'...
While a 1911 is an excellent carry weapon!

Yes, the .300 BLK is vastly superior to a .45ACP; because even its slow, subsonic loading contains about the same energy. And it's a rifle round.

I didn't address the remainder of your points because they all seem to revolve around you believing that people here are recommending AR pistols in the role of a handgun.

I think you need to take a deep breath and read what I'm actually writing instead of attributing thoughts and ideas to me that I haven't written. Your responses clearly indicate you do not understand me.

[JeepHammer]

I've built, and fired several, that's what lead me to the question 'Why?', not just a 'Want' to own one.
I process a crap load of once fired milbrass, I won't butcher a 5.56 brass, but if case necks are kinked, I cut them for .300 BO (and like).
Trust me, there is no shortage of people buying the brass. For what, I can't say...
Stockpile, shooting, just don't know & quit asking.

I do understand exactly what you are saying, you are a fan boy, you fell for the latest fad in firearms.
You can hang it up right next to your Beenie-Baby collection.

Ranks right up there with the .44 automag, the Desert Eagle .50, the .45-70 Govt revolvers, 12 Ga revolvers, the .500 Mag, the gyro-jet pistol, the list continues...
Closely to be followed by .357 Sig and other bottle necked pistol rounds.

Rifle cartridges that come to mind, since I do mostly rifles...
.224 Weatherby Magnum, .225 Winchester, .25-20 Winchester, .250 Savage, 7-30 Waters, .284 Winchester, .300 Savage, .307 Winchester, .30-40 Krag, .300 H&H Magnum, .308 Norma Magnum, .32-20 Winchester, .32 Winchester Special, .348 Winchester, .356 Winchester, .358 Winchester, .358 Norma Magnum, .375 Winchester and .38-40 Winchester, .300 Rem. SAUM...
Just to name a few of the 'Fad' rounds I can remember right off hand.

I still shoot .218 Bee, but I'm not trying to sell it as something new, wonderful or covers ALL the rolls of all handguns AND rifles!
It's old, it's slow by today's standards, its just fun to shoot and will still get a ground hog at 200 yds.
Since it's accurate at 200 yards, maybe I should try to sell it as a PDW or handgun round...
Naw, I have a brain, waste of time, so I'll just have fun with it.

This is nothing new, I've seen 50 years of fan boys with the 'Latest/Greatest' that turned into footnotes...
One of the dumbest was .30-40 Krag for nothing more than bowling pin shooting, when the surplus of bowling pins dried up, so did the revival of the .30-40 Krag.
Personally, I never hunted bowling pins, never ate a bowling pin, so I have no use for a .30-40 Krag.

Maybe you should cut down the case of a .30-40 Krag, slap it into an AR format PISTOL and start your own fad! That will give you something to do other than fan boy the .300 BO!
Win/win for you!
Makes about as much sense as .300 BO, so it should catch on like wildfire! The next 'Big Thing'!
Completely useless, so it's going to be a hit!

[Bartholomew Roberts]

So, essentially, any question I ask JeepHammer will be ignored and he'll continue to pretend he has any clue about the subjects he bloviates on?

[Sharkbite]

Ive given up on him, Brother.

He knows, so there is no explaining anything to him. Sad

[Bartholomew Roberts]

Well Sharkbite, that’s the internet in all its glory. Compounded by moderation that will slap your wee-wee for any kind of political discussion but will tolerate any amount of stupidity in technical forums.

[Sharkbite]

I dont really care if somebody likes something or not, its the dissemination of such blatantly incorrect information that annoys me.

Lots of new (or new to a subject) shooters search these forums for info, and to have to read such misleading and just plain wrong data is unfair to their learning experience.

So, anyone that wants to learn the facts about the 300AAC Blackout cartridge. Its use in the field, ballistics, strengths AND weaknesses... check out 300blktalk.com. Its another forum just like this one, devoted to that caliber. Im on it under the same screen name.

[TrueBlue711]

Well, this thread went terribly off topic. I think maybe the first 1/3 of it had to do with adjustable gas blocks.

JeepHammer, I hope you got your fill in for ranting on the 300 BLK. Now, I'm no moderator on here, but I ask that if you have more ranting on the 300 BLK to do, please start another thread about it or dig up an old thread about the Blackout. Your suggestion on simply adjusting the gas block while the can was attached was the solution, so again, thank you for that. But the other 95% of your posts didn't add anything to the topic.

[JeepHammer]

TrueBlue711, I owe you an apology, and I'm truly sorry this went off the rails.

I hope you work out any issues you have, and have fun with whatever you choose.
If you have issues with cycling, feel free to contact me and I'll try to help.

Since most don't break down the gas pulse into it's three major components, they don't understand the effects on the direct gas impengmen action. Short, and REALLY short barrels can cause issues the carbine & full length guys will never see.

Again, sorry.

[TrueBlue711]

No worries, I understand people are passionate on this site in general. Thanks again.

[JeepHammer]

It's your choice, and the choice of others.
I spent 16 years in the military, with military objectives, and military schizophrenia...
16 years of watching bullets get heavier, barrels shorter, all the while expecting 'miracles', increased velocity for increased range and knock down power.

I don't often get just going to the range for fairly short shooting for shootings sake.
I shoot targets with an OBJECTIVE, that objective being NOT missing when I hunt.
Sometimes I forget shooting targets is just plain fun... No matter what you are shooting with, sling shot or BB guns...

Kind of a military thing, you are supposed to have a driving purpose for everything...
I freely admitted I want overboard when I built my gun locker, dedicated a room, welded in steel plates, filled space with fireproof refractory cement, etc.

In my defense, I live in 'Tornado Alley', a 'Safe Room' makes sense when entire towns get removed around you every 20 years or so... (Rust Belt urban renewal)

Full disclosure, I keep a .218 Bee (grandpa's) to shoot just for fun.
Want an obsolete round, there is one for you!
Just plain fun to shoot a single shot your grandpa put food on the table during the depression & WWII rationing with! No earthy reason to shoot/hunt with it other than emotional connection, since a .17 HMR probably does a better job cheaper...

[stagpanther]

so how about that creedmoor?

[JeepHammer]

Are you having issues with gas on your 'Creedmore'?

[stagpanther]

Shouldn't have brought it up--my bad--I agree thread has veered way off the original OP's intent.

[ed308]

In defense of JeepHammer, I can understand his thoughts about the 300 BLK. The 300 BLK stirs strong emotions in people, myself included. The lies spread by Robert Silvers in comparing it to other cartridges plus seeing how it performed in the field when hunting, ended any interest or curiosity I had for the caliber. I'm ok with people liking it. Just don't make it into something it isn't.

[Sharkbite]

I'm ok with people liking it. Just don't make it into something it isn't.

That can be said of anything. The 300blk (like all things) has strengths AND weaknesses. Here are the reasons i like it. It gives me a rifle...

The size of an MP5
The ballistics of an AK
The ergos of an AR
The ability to shoot supers AND subs WITHOUT any changes (just swap ammo)
A ctg that is not hampered by short barrels (designed around 9” tubes)
Easy to make brass
Lots of bullet choices vs 7.62x39


Add all that up, and it makes a good choice in a SHORT barreled AR. Much better then a short barreled 223 gun.

If its not for you...thats ok

[JeepHammer]

I hit the same wall.
I was open minded, but unimpressed until the hog hunts.
Several people using the round in both bolt & semi-auto, and at first I thought it was just poor marksmen, but after about the third hunt I was done with the round in any format.
Shooting targets is one thing, but not even feral hogs should be wounded and allowed to run off.

There was a mixture of full power rifle rounds out there, including .30-30, and I can't remember a single hog getting away other than the .300 BO shooters, which dropped about half the shots they took...
I didn't realize it was .300BO shooters until one of the .300BO shooters said something about it the next day. I think he had enough of his rifle by that point in time.

Hogs can be tough customers, and night hunting can be tricky, but these weren't amateurs or spray & pray types, and it wasn't cheap equipment, night vision alone ruled out the $299 farm store bunch...

[Sharkbite]

There was a mixture of full power rifle rounds out there, including .30-30, and I can't remember a single hog getting away other than the .300 BO shooters, which dropped about half the shots they took...

One of the problems with the 300blk is poor ammo selection by the shooter. The ctg is NOT only for shooting subsonics. With a good Supersonic load it approaches 30-30 ballistics (especially sense its not limited to poor BC round nose bullets. The 110gn blacktip has a GREAT reputation as a hog killer.

Lots of the bad press about the 300blk is due to guys buying store bought SUBSONICS (few of which expand well) and hunting like its a full power rifle round. Sub hunting is very much like handgun hunting. Close range with excellent shot placement is needed.

If you want to hunt like its a rifle, load it with full power supers and it will do what you want

[ed308]

I've been on at least five hog hunts with other people using the BLK. In every hunt, it took multiple shoots for the BLK to drop the hogs. You can say that about any caliber with a poor shoot. But the guys using the BLK were experienced hunters. So, I group the BLK in the .223/5.56 class when it comes to hunting. It'll work, just not the best option.