.300 blk pistol for 9 year old hunting

[ARTrooper]

So I have decided to build a .300 blackout pistol for my oldest child’s first hunting rifle. Funny enough, he is born on opening day of Wisconsin hun season. He will be 10 when he first gets to hunt with this rifle but he is a very small child for his age.
 

I looked at youth hunting rifles but decided on a ar15 pistol due to length of pull with brace fully in. not to mention the lower recoil that an ARs buffer system creates. 
 

So for wisconsin deer with a low recoiling rounds in an ar15 I would go no less than a 6mm arc or .300 blk. I have now taken 3 deer with my 16” 6mm arc but I am less than confident in the 103 gr ELD-X bullets. They are extremely accurate but they don’t usually give a full pass through, which for the terrain I hunt in, I like a nice blood trail. Barnes has 95 gr LRX bullets that I would love to try on deer in a 12” 6mm arc in the future, just not sure I want to try that out for a child’s first hunting round/platform. 
 

So I plan on building a .300 blackout pistol from a Aero Precision M4E1 upper and lower. Looking at either a 7.5” faxon barrel with a 1:5 twist or ballistic advantage (or faxon) barrels with 1:7 twist that are either 8” or 9”. 

It will also have a 7.3” aero precision atlas s-one handguard and a a tactical sba3 brace. Will probably go straight to heavybuffers for a heavier than standard buffer and spring due to running is suppressed a lot of the time with my rugged micro30.  

[shooterrex]

Sounds like a plan. Just remember all the stupid rules on braced pistols they are getting ready to jam down our throats.

Edited December 12, 2022 by shooterrex

[ARTrooper]

4 minutes ago, shooterrex said:

Sounds like a plan. Just remember all the stupid rules on braced pistols they are getting ready to jam down our throats.

They are trying but there are a lot of lawsuits against the ATF right now that are going our way. I am not worried because besides Madison and milwaukee, my state is pretty right wing and pro 2a, and my county is a 2nd amendment sanctuary county where the Sherrif and DAs office will not prosecute.

[BrianK]

Sounds good. Also sounds like an excellent 1st deer gun. An AR pistol was beyond my vision (300Whisper) when I was hunting, and I can no longer hunt, but a 300BLK or Whisper pistol is exactly what I wanted 20 years ago. 

Just an off the wall question, Your build will be fine, but BA also makes a 10.3" barrel. I wouldn't want a 16" barrel, but an additional 1" of barrel might be worth having for less blast and a hair more velocity at peak pressure. Of course either will work and the cartridge was designed for a  complete powder burn in 9" of barrel. I have the 10.3" barrel and while I wouldn't want a 16" barrel, I do look longingly at the velocities they achieve that I just can't hope to get. I doubt you'd see any appreciable difference in handling with an extra inch of barrel from 9-10". To help your son and further reduce blast near the face an inexpensive "blast forwarder" can be screwed on the end. They can be bought as such or if the "oil trap" people still exist online that would work and maybe be less $. All that's required is a female thread at one end and a hollow tube to get the blast out in front.

He'll need to pick his shot, but I would write that no matter what he was shooting. Plus he would have the advantage of subsonic loads to reduce meat damage, again, picking the shot. Over on 300BLKTalk.com there is an incredible amount of data for loads and such and people using it effectively. Not all bullets expand at the velocity we can achieve and they've tested lots of them. Of course there are folks here doing the same in the 300BLK section.

If ATF does get around to completing brandons evil on arm braces you could SBR it and then put a real stock on it. Yes, I know that not everyone wants to be in the register and it's just plain wrong, but it had to be mentioned as a possibility.  

[jtallen83]

6 hours ago, ARTrooper said:

Will probably go straight to heavybuffers for a heavier than standard buffer and spring due to running is suppressed a lot of the time with my rugged micro30.

Give it a try with standard buffers first, I never had a reason to change out the regular H buffer in mine, 10.5in barrel. It pretty much runs suppressed all the time, functions fine with supersonics.

[dpete]

1 hour ago, jtallen83 said:

Give it a try with standard buffers first, I never had a reason to change out the regular H buffer in mine, 10.5in barrel. It pretty much runs suppressed all the time, functions fine with supersonics.

^^This. 

[ARTrooper]

1 hour ago, jtallen83 said:

Give it a try with standard buffers first, I never had a reason to change out the regular H buffer in mine, 10.5in barrel. It pretty much runs suppressed all the time, functions fine with supersonics.

Yeah I have never had a problem with any of my buffer setups, but was thinking about doing it just to have a buffer combination I don’t have already to experiment with in many of my rifles. Lol. 

[ARTrooper]

@BrianK a lot of people say the powder fully burns at 9 inches, but I have watched a lot of videos comparing 5.5” barrels going up to 10.5” with different twist rates. From what I have seen going down to 7” isn’t that big of a change for each inch, especially since I will mostly be shooting subsonics. There was a noticeable difference on the wound channels created by faster twist rates. Faster twist rates is really what I am looking for with a barrel, otherwise 9 inches would be the length I would choose. Shooting subs I am not as worried about the muzzle blast, especially if I do put my suppressor on it. 
 

What I will be loading for the hunting loads will be Maker REX bullets that seem to open amazingly in soft tissue. and I have seen many videos of them expanding really well on pigs. Basically it will be like a flatter shooting and more accurate arrow broadleaf with how it expands. 

[Rsquared]

Sounds like you've got the plan down dude.

I'd jump in on the 10" barrel camp. I built my SBR with a 10.3 Noveske barrel. And just using an EOTech HWS, that thing is deadly accurate out to a couple hundred yards. Either suppressed subs, or regular supers. If you throw a LPVO on something like that, it's only going to get more deadly for those pesky 4 leggers.

That's great that you're getting your boy involved at that age.

[BrianK]

Yeah, it'll work fine.  👍

I load 85 grain Trex Makers for my HD load. 1k ft/lbs and 2300fps, pretty good accuracy out to 50 yards only because I haven't shot them further. The tests I've seen in gel convinced me of the bullet at that velocity. In a 16" they can go faster, but I wanted 2300ish and it just so happened that that's what the barrel gave me and was happiest.

[dpete]

12 hours ago, ARTrooper said:

 

What I will be loading for the hunting loads will be Maker REX bullets that seem to open amazingly in soft tissue. and I have seen many videos of them expanding really well on pigs. Basically it will be like a flatter shooting and more accurate arrow broadleaf with how it expands. 

As long as you realize hunting with subs is pretty much like archery with a firearm.  I have all the confidence in the world of hitting what I am aiming at with a 200 grain Maker if its 50 yards and in (4 deer so far at about 30 yards).  At a target they will shoot 1" groups at 50 yards, but stretch that to 100 yards and that group opens up to over twice that and drops 6".  Same 8" barrel with supressor and 110gr Barnes is pretty much dead nuts at 50 and 100 yards.  Same impact point but bullet rising at 50 and dropping through the same point at 100.  For your son on his first hunts I would load up some 110 grain Tac-TX supres to let him gain some confidence on hitting what he is aiming at.  Recoil with or without a supressor is minimal.

[unforgiven]

22 hours ago, ARTrooper said:

So I have decided to build a .300 blackout pistol for my oldest child’s first hunting rifle. Funny enough, he is born on opening day of Wisconsin hun season. He will be 10 when he first gets to hunt with this rifle but he is a very small child for his age.
 

I looked at youth hunting rifles but decided on a ar15 pistol due to length of pull with brace fully in. not to mention the lower recoil that an ARs buffer system creates. 
 

So for wisconsin deer with a low recoiling rounds in an ar15 I would go no less than a 6mm arc or .300 blk. I have now taken 3 deer with my 16” 6mm arc but I am less than confident in the 103 gr ELD-X bullets. They are extremely accurate but they don’t usually give a full pass through, which for the terrain I hunt in, I like a nice blood trail. Barnes has 95 gr LRX bullets that I would love to try on deer in a 12” 6mm arc in the future, just not sure I want to try that out for a child’s first hunting round/platform. 
 

So I plan on building a .300 blackout pistol from a Aero Precision M4E1 upper and lower. Looking at either a 7.5” faxon barrel with a 1:5 twist or ballistic advantage (or faxon) barrels with 1:7 twist that are either 8” or 9”. 

It will also have a 7.3” aero precision atlas s-one handguard and a a tactical sba3 brace. Will probably go straight to heavybuffers for a heavier than standard buffer and spring due to running is suppressed a lot of the time with my rugged micro30.  

I assume you took him to Hunter's Ed course , youngest has been 8 yrs old.

[dpete]

Something I thought of after making the last post.  In my experience and others with subsonic hunting, you don't end up tracking a deer using its bloodtrail, you look for a dead deer because there isn't any bloodtrail.  A sub doesn't have any hydrostatic shock that pulverizes internals like a super.  The Maker expanding bullets peel open beautifully but they then tear through rather than slicing through like a broadhead.  The best shot with a sub is CNS, head or neck. 

The 4 deer I've taken with Makers, all shots 30 yards or less.

Head on with head up. Hit in chest and bullet recovered in the stomach, went 30 yards.  Ground blind.

Broadside through both lungs, ran 100 yards in snow.  Ground blind.

Broadside through at least one lung and possibly heart, went 20 yards.  Tree stand, shot was downward angle.

Head on with head down.  Hit in the top of the neck in front of shoulder, bullet blew out the top of the heart.  DRT.  Ground blind

None of them left any bloodtrail at all.  The last one had a pond under it but that was from having the heart taken out and a drain hole at the bottom of the chest.  Short shots in the neck or head for me from now on, DRT and no tracking is good for my bad knee.

 

[dpete]

9 hours ago, unforgiven said:

I assume you took him to Hunter's Ed course , youngest has been 8 yrs old.

@unforgiven  Wisconsin has a hunting Mentor program. 

https://dnr.wisconsin.gov/Education/OutdoorSkills/mentor

[ARTrooper]

1 hour ago, dpete said:

Something I thought of after making the last post.  In my experience and others with subsonic hunting, you don't end up tracking a deer using its bloodtrail, you look for a dead deer because there isn't any bloodtrail.  A sub doesn't have any hydrostatic shock that pulverizes internals like a super.  The Maker expanding bullets peel open beautifully but they then tear through rather than slicing through like a broadhead.  The best shot with a sub is CNS, head or neck. 

The 4 deer I've taken with Makers, all shots 30 yards or less.

Head on with head up. Hit in chest and bullet recovered in the stomach, went 30 yards.  Ground blind.

Broadside through both lungs, ran 100 yards in snow.  Ground blind.

Broadside through at least one lung and possibly heart, went 20 yards.  Tree stand, shot was downward angle.

Head on with head down.  Hit in the top of the neck in front of shoulder, bullet blew out the top of the heart.  DRT.  Ground blind

None of them left any bloodtrail at all.  The last one had a pond under it but that was from having the heart taken out and a drain hole at the bottom of the chest.  Short shots in the neck or head for me from now on, DRT and no tracking is good for my bad knee.

 

Interesting, I expected a maker 200 or 220 to act a lot more like a broadhead after impact, creating a nice blood trail of hit in the bleedy bits. I don’t see why it wouldn’t cause a blood trail like a nicely placed broadhead shot. What factor am I missing here? I am a science nerd and want to know. Lol. 
 

well I just bought a tool craft nickel boron bcg yesterday, so I am building something. Lol. 
 

@unforgiven I will be hunting with him using the hunting mentorship program. Once he is 11 he will be taking hunter’s safety probably. 

[dpete]

29 minutes ago, ARTrooper said:

Interesting, I expected a maker 200 or 220 to act a lot more like a broadhead after impact, creating a nice blood trail of hit in the bleedy bits. I don’t see why it wouldn’t cause a blood trail like a nicely placed broadhead shot. What factor am I missing here? I am a science nerd and want to know. Lol. 
 

 

@ARTrooperProbably the biggest factor in the lack of bloodtrail is the speed of the bullet.  Your typical 30-06 bullet is 3/4 or slightly more in weight compared to a subsonic, but its going over twice as fast in the supersonic range.  That mass plus the speed makes for a huge energy dump into the target.  The energy dump is what makes the huge wound channel, turns the internals to mush and blows the huge exit hole out the other side.  A subsonic bullet has the mass but not the speed.  There is no comparable hydrostatic shock from a sub like you see when a normal rifle bullet hits ballistic gell.  The huge wound cavity just isn't there.  The Makers are designed to open at low speeds to increase wounding potential, but they shred through flesh and organs rather than slicing like a razor sharp broadhead, or blasting through like a super.

The other factor I am sure is shot angle.  With a tree stand shot you have a high entry and low exit.  ( I sub hunt out of my bow stands and shots are 20-30 yards)  That low exit makes a good drain hole for blood out of the chest, but the blood inside the chest has to get up to the level of the hole before it comes out.  If a deer doesn't drop almost immediately it goes into overdrive and takes off.  A double lung shot with a sub punches holes in them, but how far can a deer run barely breathing on pure adreniline before the blood in its chest gets to the exit hole?   Damn far with no blood trail to show for it.  (The one that went 100 yards)

Edited December 14, 2022 by dpete

[unforgiven]

3 hours ago, dpete said:

@unforgiven  Wisconsin has a hunting Mentor program. 

https://dnr.wisconsin.gov/Education/OutdoorSkills/mentor

That's great 👍

[BrianK]

1 hour ago, dpete said:

There is no comparable hydrostatic shock from a sub

dpete, As Elmer Keith once wrote about lack of hydrostatic shock, "You can eat all the way to the hole.". Meaning the bullet hole. Do you find that?

The shots you describe if well taken could be just as deadly (CNS, head, neck) with a non-expanding bullet but of course for a .30 to go to 1" makes for more opportunity to hit something critical if one is slightly off. 

[dpete]

1 hour ago, BrianK said:

dpete, As Elmer Keith once wrote about lack of hydrostatic shock, "You can eat all the way to the hole.". Meaning the bullet hole. Do you find that?

The shots you describe if well taken could be just as deadly (CNS, head, neck) with a non-expanding bullet but of course for a .30 to go to 1" makes for more opportunity to hit something critical if one is slightly off. 

I can't really speak to "eating all the way to the hole" because I haven't really looked too hard for the holes.  But yes there is far less collateral damage to meat with the subs.  Its also true that a non expanding bullet would be just as deadly in a CNS shot situation if placed perfectly.  But most of the time perfect shots are hard to come by, you take what you can get.  Plenty of people used 220gr Sierra Match Kings as sub hunting bullets before specialized expanding sub bullets were developed.  If they hit bone the thought was that they would tumble on through for the kill.  They did that, but if they didn't hit something to cause the tumble they would pencil right on through leaving just the 30 caliber hole in anything it touched.  The deer would be dead if it was a vital hit, but it would be dead in the next township without leaving any trace of where it went.

Put one of these Makers into a chest cavity and its going down a whole lot faster.

                        

The last deer I shot with one of these looked as if someone pushed a spinning 3/4" holesaw bit through the top of its heart.  That was after it went through the spine and neck from the top down

[ARTrooper]

11 hours ago, dpete said:

@ARTrooperProbably the biggest factor in the lack of bloodtrail is the speed of the bullet.  Your typical 30-06 bullet is 3/4 or slightly more in weight compared to a subsonic, but its going over twice as fast in the supersonic range.  That mass plus the speed makes for a huge energy dump into the target.  The energy dump is what makes the huge wound channel, turns the internals to mush and blows the huge exit hole out the other side.  A subsonic bullet has the mass but not the speed.  There is no comparable hydrostatic shock from a sub like you see when a normal rifle bullet hits ballistic gell.  The huge wound cavity just isn't there.  The Makers are designed to open at low speeds to increase wounding potential, but they shred through flesh and organs rather than slicing like a razor sharp broadhead, or blasting through like a super.

The other factor I am sure is shot angle.  With a tree stand shot you have a high entry and low exit.  ( I sub hunt out of my bow stands and shots are 20-30 yards)  That low exit makes a good drain hole for blood out of the chest, but the blood inside the chest has to get up to the level of the hole before it comes out.  If a deer doesn't drop almost immediately it goes into overdrive and takes off.  A double lung shot with a sub punches holes in them, but how far can a deer run barely breathing on pure adreniline before the blood in its chest gets to the exit hole?   Damn far with no blood trail to show for it.  (The one that went 100 yards)

I completely understand the extra damage hydrostatic shock creates. I meant comparing it more to archery broadheads. But I think I get what you mean, lower exit wounds have a better chance of creating a blood trail due to a the lower position of the whole. Kinda a “which cup is going to overflow first” type scenario. I almost always am shooting down at deer which helps with that lower exit wound and some of my best blood trails have been from archery. 

[dpete]

2 hours ago, ARTrooper said:

I completely understand the extra damage hydrostatic shock creates. I meant comparing it more to archery broadheads. But I think I get what you mean, lower exit wounds have a better chance of creating a blood trail due to a the lower position of the whole. Kinda a “which cup is going to overflow first” type scenario. I almost always am shooting down at deer which helps with that lower exit wound and some of my best blood trails have been from archery. 

Comparing an archery broadhead to an expanding subsonic bullet is apples to oranges. 

An archery broadhead has 3 sometimes 4 razor sharp edges that follow a similarly razor sharp tip into an animal.  The tip slices in then the blades continue the slicing as the entire arrow slowly rotates (arrow vanes produce a spin in flight).  The resulting cut areas can be up to 2 inches across with an expandable head.  The exit hole is also a gaping triangle with sharp clean edges

An expanding sub even though its travelling roughly 3 times faster than the broadhead, plows into the deer (I've heard it, it sounds like someone slapping two leather mitts together).  Once it hits, the petals open but unlike a broadhead there is no tip to lead the way and begin cutting and no mass of arrow pushing it from behind.  It begins to tumble and the edges of the petals tear their way through. 

A clean cut from a razor blade will bleed a whole lot more than a slip of a hacksaw blade.  One does more damage faster than the other.

A blood trail is a matter of getting as much blood out of the body as possible in the shortest amount of time.  Archery broadheads are razor sharp to do that as efficiently as possible at slow speeds.  Expanding subs open in order to increase the bleeding potential over one that would pencil through.  They still aren't as efficient a cutter compared to a broadhead and even though they may cut better than a supersonic bullet the collateral damage from hydrostatic shock isn't there to blow a giant exit hole open

[dpete]

Back to bullets.   All three of these came out of a Blackout.  The two smaller ones were shot at 150 yards into gallon milk jugs of water.  The third is the Maker I recovered from a deer, head on shot into chest and lodged in the stomach.

L to R

130gr Speer Varmint                110 gr Barnes Tac-Tx                     200 grain Maker

 

Edited December 14, 2022 by dpete

[BrianK]

That Maker mushroom is exactly why I chose the 85 gr Makers for HD, similar look to the expansion, much different velocity. Oddly, and I know you've run across this info dpete since you're also over on 300blktalk, the 85s have a sweet spot for velocity. Too little v and expansion suffers, too much and the petals peel back "too much" and expansion suffers. There is a Goldilocks zone for velocity. But that's the 85s. I lucked out and got what I wanted right in the Goldilocks zone. 

Clearly that v consideration doesn't exist for the 200s. Nice looking performance.

ARTrooper, the reason I suggested a blast forwarder is because I don't know Wisconsin law and wasn't going to research it. Some states don't allow cans at all for hunting, some allow them, some only with a special permit. If I were to ever hunt with my 300BLK it's much simpler for me to just remove it (they're allowed for hunting with permit) and since I must have something there to get the blast out from under the handguard I'd put a blast forwarder on the end of the barrel. It would also have the positive effect of making the gun at least a pound lighter. The can that is almost always found on mine is a blast can for CQB and isn't hearing safe.

[dpete]

@BrianK  ARTrooper and I are both in Wisconsin.  Thankfully it is still a free state compared to some.  If you can legally possess a SBR or a supressor you can legally hunt with it.  Only requirement is that the rifle be larger than .22 caliber.  The deer I spoke of were taken with an 8" barrelled SBR with my form 1 can attached. 

[ARTrooper]

Hmmm thanks guys. Lots of thinking to do. I do believe it will still be a good 100 yard hun for my son, might go with something supersonic for him though until I myself can be confident with how subsonic work on deer.