[ROMANS]

I am looking at having Gun doc do some work to my Mini in the spring time can anyone give me the advantages of cutting a barrel down to 16 of shorter. I do know the laws concerning a shorter than 16 inch barrel. At what point do I get no return and where does it starts to affect long range accuracy.

Thanks
ROMANS

 

[Holmes375]

A shorter barrel is a stiffer barrel and will often group tighter. The shorter tube also affords a bit of improved portability.

The shorter barrel will yield a loss in bullet speed and a shorter sight radius with irons. Usually not an issue for tactical usage. The shorter barrel will also exhibit a more dramatic muzzle flash which can be mitigated with a flash hider and by using ammunition designed to minimize flash.

I don't think you'll truly realise a real world loss in long range performance cutting down to the legal length limit considering the ballistics of the cartridge itself.

I'd cut the barrel and enjoy the tighter and more consistent groups you'll get at all practical distances within the limitations of the cardtridge.

 

[old grump]

Agree with Holmes, a shorter barrel is a stiffer barrel and it could be a plus for your accuracy, advantage to 16 is better handling in brush and inhouse use. Disadvantage is you will lose about 100 fps if shooting 45 gr bullets and about 40 fps if shooting 55 gr bullets so the difference in performance is minimal unless you are taking 600 yard shots at something shooting back at you. You get much shorter than 16 and you could lose functions like ejecting and feeding so I would not go shorter.

 

[Pet-Rock]

Look at these data points.

The Effects Of Reducing The Barrel Length On Velocity And Accuracy In The 223 Remington

The next thing to do would be to find at what velocity does the .223 need to yaw or "tumble" ie. above 2800 fps? 2700? etc.

If you are using hollow points I guess it doesn't much matter, they will expand.

 

[tri70]

Cutting the barrel down does not hurt the gun, like others said you loose a little velocity but not much. What size of bushing are you using in your gas block? If you have the stock bushing you will be fine, if the bushing is too small you may have problems cycling lighter loads or cheap loads. Gundoc will be a great choice!

 

[bluzman]

I am looking at having Gun doc do some work to my Mini in the spring time can anyone give me the advantages of cutting a barrel down to 16 of shorter. I do know the laws concerning a shorter than 16 inch barrel. At what point do I get no return and where does it starts to affect long range accuracy.

Thanks
ROMANS

Beware of the Nannies if you're in CA.

Barrel length less than 16" (measured from bolt face to the end of the barrel or a permanently installed muzzle device) = ILLEGAL

 

[jgodwin2]

I bought my Mini-tactical expressly to get the 16" barrel.
Being in a wheelchair it is very handy and fast to aim.

 

[Mr. Snuffalupagus]

Look at these data points.

The Effects Of Reducing The Barrel Length On Velocity And Accuracy In The 223 Remington

The next thing to do would be to find at what velocity does the .223 need to yaw or "tumble" ie. above 2800 fps? 2700? etc.

If you are using hollow points I guess it doesn't much matter, they will expand.

IIRC,
2000 fps at the target for the 55 grain FMJ as used in the M193 round.
I'll see if I can find the data on that later... but 2000 fps seems to stick in my mind as the terminal velocity where the 55 grain round will (almost) always yaw and frag at the cannalure in a flesh target. the 62 grain Penetrator as used in M855 does this less reliably though.

 

[Pet-Rock]

Alright yeah if you could find a link to it thatd be awesome.

I searched for about an hour but couldn't come up with anything concrete

 

[40nascar]

Beware of the Nannies if you're in CA.

Barrel length less than 16" (measured from bolt face to the end of the barrel or a permanently installed muzzle device) = ILLEGAL

You must also get an NFA stamp to be legal with the Feds, even if you live in a gun friendly state.

 

[Mr. Snuffalupagus]

Alright yeah if you could find a link to it thatd be awesome.

I searched for about an hour but couldn't come up with anything concrete

here you go:
http://ammo.ar15.com/project/Fackler_Articles/wounding_patterns_military_rifles.pdf

page 62 is most pertinent, however all of it is a good read.
Dr. Facklers research in wound ballistics is fascinating and pretty informative to say the least - the attached is only the tip of the iceberg.

when it comes to wound ballistics Martin Fackler MD. is the man - I'll put my faith in his research over everything else out there.
fancy that... using scientific method, Battlefield and ER medicine and lots of fired bullets to determine what bullets do to bodies...

instead of anecdotal evidence from soldiers,hunters, and self appointed experts.

anyway - memory is a fuzzy thing :beer: I was thinking 2000fps was the magic number... I was close 2500-2300 fps is a more reliable velocity for M193 to yaw/frag, basically under 200m out of a 20" barrel

that being said 5.56 M193 is my goto stockpile round. my mini likes the winchester flavor of it, it's cheap enough to buy in large lots and under 200m out of my 18" mini it'll do what needs to be done.

 

[Pet-Rock]

Ah ha!

Thank ya very much

I'm assuming the damage would only worsen if the round was a hollow point, yeah?

 

[Mr. Snuffalupagus]

Ah ha!

Thank ya very much

I'm assuming the damage would only worsen if the round was a hollow point, yeah?

I haven't seen anything that would indicate that - however logic dictates that this would be so.

the downside to Fackler's research (the bits of it I have read- it's extensive as hell- so if he ever experimented heavily with expanding 5.56, I haven't come across it yet. I've seen some commentary from him on expanding 5.56 -but no wound diagrams or extensive narrative on it.) is it primarily focuses on military rifle and pistol (FMJ) or law enforcement expanding pistol calibers and bullet construction - and predates the now prolific usage of the .223/5.56 in a law enforcement setting where HP/expanding ammo would be commonplace. (back before the late 90s the rage in LE for long guns... besides the venerable 12 gauge shotgun - was for pistol caliber carbines like the Colt SMG or HK MP-5.
As far as I know - the only HP bullets that are approved for use by the US military are the Open Tip Match (OTM) bullet as loaded in the M118LR, MK316 mod 0 and the M852. all of which are .30 cal

however a safe assumption is an expanding 5.56 cruising at the velocities the round is known for would be a real nasty customer, and probably would be more effective beyond 200m than FMJ of equal grain
I do have a few boxes of 45 grain Winchester Varmint HP .223, which I keep for home defense based on some interesting stuff I've come across on the net about how lightly constructed high velocity .223 has a tendency to self destruct after hitting 2-4 layers of drywall and turn into lead and copper confetti that may wound - but probably not kill. counter intuitive, yes - but the experiments I've seen seem to be well run and free of any glaring mistakes in method. From personal experience - 9mm and .45ACP can and will punch through most of a house from the street (I did an inspection on an apartment that had been hosed in a drive by - there were bullet holes that went from the facade of the building all the way through the home and exited out the back wall. the police said they found a ****load of 9x19mm, .380, and 45 casings in the street, and the rounds that got lodged in the walls were of those two calibers) this was around the time I started to re think my HD firearm choice which was a 9x19mm pistol.

however the expense for such premium .223 rounds for me is pretty prohibitive - at least in any kind of bulk. and the likely hood of having to defend myself beyond 200m is very very low. (and if it ever came to that - my 270 bolt gun flinging a 130 grain Hornady Superformance Ballistic tip or even a Winchester whitebox powerpoint would be a better way to deal with such things IMHO)

 

[Pet-Rock]

Wow! All the way through the house?! I wold have bet my money on a 223 doing that, not the pistol calibers. That said, I still am going to grab my 45acp (185 JHP at 1000 fps) in HD situations. Something about not making my ears bleed when things go bump in the night is very appealing lol

Im right there with you, 223 in my mind is a 300 yard or less round. The reason I brought up the tumbling effect was because I was unsure if the OP was going to hunt with the rifle or not.

Thanks for all the great info Snuff!

 

[Mr. Snuffalupagus]

Wow! All the way through the house?! I wold have bet my money on a 223 doing that, not the pistol calibers. That said, I still am going to grab my 45acp (185 JHP at 1000 fps) in HD situations. Something about not making my ears bleed when things go bump in the night is very appealing lol

Im right there with you, 223 in my mind is a 300 yard or less round. The reason I brought up the tumbling effect was because I was unsure if the OP was going to hunt with the rifle or not.

Thanks for all the great info Snuff!

mind you the building was a "project" apartment in petrero hill SF,

so it wasn't a very big apartment - and construction quality was not very robust... but yes, several of the rounds of both calibers did in fact punch through a layer of siding, and 5-6 layers of drywall (through living room through bedroom) and out another layer of siding on the back porch.

the spent rounds likely petered out someplace over the Mythbusters shop - which is below that particular building :lol:

I was there working for PG and E, to do in a weatherization inspection for a low income program back in 2003 this was. We footed the bill on several small "exterior wall repairs" at that unit. aka "bullet holes"

 

[jwb47]

you could go 14.5 inches and have a 1.5 in flash hider permnantly attached and be ok .
shoot something like 64 grain winchester power points or barnes 62 grain ttsx bullets for hunting and what ever trips your trigger for fun times. I like cabelas 62 grain fmj or hollow point for cheap stuff to blow down the range .

 

[ROMANS]

Op is back

All,
The mini I have is a 187xxxxx, it is a 1 in 7 twist.
It is going to be 1 of my shtf weapons. What ever the situation dictates. I do intend on coyote hunting with it also. I know there are better weapons for such.

Butgol darn it I love my mini. I like to carry it around the property and hunt whatever is legal at the time , as well as the old henry 22 mag
I am just trying to get it to a place where it will out shoot me. I do have old eyes. Bad thing is I still love irons. Just put on a tech sight. (love it).
Thanks
romans