APC223 Non restricted whos getting one ?

mikethebike said:
whats wrong with a 1/9 barrel, it shoots better than he 1/7 if you shoot 55 grain... The fact that this gun has a 1/9 lothar walther is actually what convinced me to buy
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Well Mike... This story starts back in the 80s when I bought a Sako varmint rifle in 223 with a 1:12 twist. It was 0.3 MOA accurate and I tested several loads and settled on a 55 grain Sierra soft point. In those days I was self employed and had the time to go shooting ground hogs on a regular basis. It was typical to shoot upwards of 30 ground hogs per day, so you might say I got the hang of it.

Well a pattern started to form where I could hear the womp of the round hit but the ground hog would still run for his hole and disappear. I knew he would die, but he was not pegged there on the spot if it wasn't hit right in the chest.

One day I bought a new rifle. It was an AR15A2 Delta HBAR which was the top AR15 available from Colt. You can google that if you want... but the A2 gun was the product of about 2 billion dollars spent by the US military to replace the M16 and they came up with a few small tweaks to the rifle deemed the M16A2.

Well one of the changes was to the barrel twist rate from 1:12 to 1:7 with a corresponding shift to heavier bullets... So after the US spent all that money on R&D... who are we to second guess that decision.... So I bought the AR15A2 rifle and got to work on load development.

Well for an expensive rifle it did not shoot very well with 55 grain bullets... one day the gun store owner recommended that I try hevier bullets... so I did.

Well that's when the lights came on and that rifle really came to life. Accuracy was about 5/8" at 100 yards and as for ground hogs... it was a game changer.

I have come to the undeniable conclusion that spin rate is a critical factor to terminal performance... and nobody ever talks about it.

Ever use a blender? Well it mixes better on high than low right?

There's centrifugal force stored as explosive energy as a byproduct of spin rate.

Well ground hog shot with 69 grain SMKs from that 1:7 would be blown to pieces. They looked like they were hit with a 308... which I also used on occasion. You could not tell the difference.

>>>>>>>>>>>>>>>

Ok... its raining out so... one more story.... I shot many deer with that same AR15A2 Delta HBAR with 69 grain SMKs and never saw one run more than 10 yards after getting hit.

I shot 2 deer with a mini 14 with a 1:9 twist. One deer was shot with 55 grain soft points at least 3 times from inside 10 yards and that deer was never recovered.

The second deer I shot with a mini 14 was shot in the heart with 69 grain SMKs and ran about 20 yards.

So on deer hunting and ground hogs I have come to insist upon a 1:7 and with ammo no lighter than 69 grains for terminal performance that is nothing like what most people think of from a 223.

Even further... I have a box full of awards that I won in long range F Class competitions from 300 to 1000 yards that were won with the 223 with 80 grain SMKs and 1:7 on a more recent custom Sako rifle.

For long range shooting in F Class nobody who wins anything uses a 1:9... everyone is using at least a 1:8 and some even at 1:6.5.

Nobody in long range competitions shoots anything lighter that 75 grains in 223....

In the end, a 1:7 can shoot 55s ok or 80s really well, but a 1:9 can only shoot 55-69 accurately, but does not have that blender effect of the 1:7, and the 1:9 can never be accurate with heavies.

With a muzzle velocity of 2800 FPS and a spin rate of 1:9 the bullet is spinning 224,000 RPMs.
With a muzzle velocity of 2800 FPS and a spin rate of 1:7 the bullet is spinning 288,000 RPMs.
 
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K so without going into exploding gophers and hyberbolas:
You can over spin a bullet, also known as turbulence
You can also under spin a bullet, also known as instability
There is a nice little table here: http://info.stagarms.com/blog/bid/371861/How-Barrel-Twist-Rate-Affects-Ammunition-Choice
1/7 55-85 grains
1/8 50-80 grains
1/9 45-75 grains

For prs:
smk 77 grain ammo would in theory function in 1/7, 1/8, and at the very edge of 1/9 77grain is the max you can load in a magazine. So if you plan to shoot exclusively 77grain ammo sure you might have an issue with 1/9, but then why not just choose a 69gr smk?

You'll have more of a problem mounting optics or scopes on the APC than what the barrel twist represents. I don't see this platform in PRS, sorry, that's just not what this thing is. You could run it, sure, but why?

For regular competition shooting using <70gr bullets:
m16a1 started with 1in14 which had some observed tumbling, then they went to 1in12 which proved to be ideal for m193
Current 1in7 is due to modern ss109 bullet, models built to use both m193 and m855 are 1in9

Do you shoot ss109 bullets? ss109 is usually in the m855 (green tip) it is 61.5 grain steel core

I have a bunch of ss109 m855, but I shoot that crap with my tavor which is 1/7. It is not accurate ammo, it is meant to punch more than to group, i get about 4 moa from the beast and from my cc barrels firing that stuff.
 
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I expect the APC to work like this:
laviiiup-980x428.jpg


Not like this:
16PHX1MT1212.jpg
 
mikethebike said:
K so without going into exploding gophers and hyberbolas:
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Yes I do shoot SS109s but that’s just fun blaster ammo and I agree that’s no accuracy or hunting load. I also have little need for armor piecing as nothing I anticipate shooting at is running with ballistic plates.

For hunting, the SS109s are terrible. (that's another story) The reason for this is consistent with complaints from soldiers in the middle east. These rounds just poke straight through and do surprisingly little damage, because they do not destabilize and dump energy within the thickness of a human body, which is similar to a deer. They might, if not spinning so quickly… which was the point of the early M16 with 1:14.

So really we have two choices… we can under stabilize the round so that it goes squirrely at first contact with flesh, or using non-AP rounds... we can spin the bullet so fast that its on the verge of self destruction from centrifugal force so that it explodes on first contact with flesh. Anywhere in between I think is less effective.

The main point is that I like to spin heavy high BC hollow point bullets quickly for improved terminal performance with a side benefit of reduced wind drift.
Since we are limited to 2.25 OAL with an AR mag, we are in practical terms limited to 77 grain loads. We can run 80s but not very fast.

While to achieve gyroscopic stability with bullets in the 69 to even 75 grain range can happen with a 1:9 and you do not require a 1:7 twist, I have found… and many fellow long range competitors agree.. that a little extra spin is always better at long range than a little less.

I did blow up a bunch of 40 grainers during some load experimenting with a 1:7 because they spun too fast for the jacket to withstand the outward force. Just little specs appeared on the target. I figure just under that ragged edge of self destruction is the sweet spot and 1:9 just isn't there, but it is more accurate with cheap light ammo which is also that much less useful at long range.

If none of the above is a factor in your plans, then by all means disregard the points, but it is at the very least valid and worth consideration.

My thinking is that I'd rather live with 4 inch groups with cheap ammo that is useless past 300 yards anyway, but have the option of running match grade stuff at longer ranges if lucky enough to get decent accuracy out of it. even of not more accurate, the 1:7 is more effective for hunting at moderate ranges.
 
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That short QD grip was so expensive...lol... But the grip included looks like crap so I had to upgrade. At least the 2 port comp was only 115$ ...lol...
 
One of my friends told me once that that 1:7 twist in 5.56mm was standardized due to Minimi SAW's need to stabilize M856 tracer bullet. So US army decided to give 1:7 to rifles too.

Also, AFAIK, it's not the mass, it's the length of the bullet which dictates the twist, so the above opinion kind of makes sense.
 
best thing i did in regard to the APC. was pay the deposit, and then completely ignore all discussion or mention of this rifle and forget about it until i was emailed that it had landed and was ready to ship. worst thing i did was now fully paying for it. i dont think my body can handle the shock from 0 to OMG i have to have this now!.
 
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