Desire- build an upper for an AR platform suitable for deer-size game. Two routes include changing out for the larger diameter case, which would solve the small powder capacity problem, but if the case was to be kept the same- just expanding the neck; IS THERE A BORE SIZE that maximizes the performance of the 223 case? The options run from: leaving bore as is, shooting big game style .224" bullets to the .30 BLK with big/slow bullets. For deer size game, is there a best size bore for balancing bullet diameter & weight with velocity?

If I were to make a .223 based AR for deer only, I would look at the .25-45 sharps case. I doubt the quarter bore has any advantages over the others though. I'm basing my opinion on the fact that it produces enough energy to ethically do the job. Plus, the cartridge sounds "classy".

Ray B that is an excellent question and more than likely you will get quite a few opinions and very few backed up by any kind of statistical analysis.
As you already know I played with the 6x45 for awhile and am very pleased with the results, some day I may try the .257 x 45 and the 6.5x45.
(For some reason I have not much interest in the 300 Blackout)I have a gut feeling that the 6mm or .257 variant will be about the max for the little .223 case in my perspective. The thought of trying 6.8mm (.277") and 7mm (.284") isn't thrilling to me. I have seen one AR member that used to post here that developed a .338" on a .223 case and I believe it headspaced on the case mouth like a pistol cartridge.
Another option I will pursue is the 7.62x39 on an AR which will require a different bolt or bolt face, barrel and different magazines but no other specialty items.
Good luck on your search, your ultimate satisfaction depends on so many variables you must remember that what makes one guy happy may not work for your style of hunting or area you hunt. (cover, distances, animal size, disposition, shot angles......)
Do remember that the .223 with monometal bullets is a solid performer however pedestrian.

There are already several excellent 223 AR based calibers out there, excellent for deer...ready-to-buy or ready-to-build...that are already well thought out. There are built in problems with the AR platform that bolt guns don't have to contend with that have been dealt with so why get into that POS when you don't have to...bolt velocity, gas pressure, gas bleed off point, correct pressure curve/powder type etc.

AS far as your question is concerned...I don't thing there is such a thing...ARGUMENTATIVELY SPEAKING...just lots of opinion and conjecture, some backed up with excellent theory and some that do work and some just hot air....but it is a good question and many shooters are always looking for Valhalla.

If your real about wanting that kind of information you will need to contact people who work with the AR platform and build those rifles ...SPECIFICALLY...many are here on AR...I've "built" two, one 223 and one 308, each with an additional barrel, 450 Bushmaster and 6.5 Creedmoor(and a couple of wild hairs keeping me up at night)..."built" basically means I've bought a bunch of pieces and parts and assembled them...the accuracy of my knockoff lathe isn't up to doing the necessary barrel/receiver work.

I guarantee BOTH extra barrels calibers AND the original calibers will deal with a deer and with a whole lot of larger animals to boot. Calibers out to 30 on the 223 case and 375 on the 308 case have been around for MANY years and adapted to the AR platform and are basically nothing more than resize, load and shoot propositions.

Brownells is a good place to look for available barrel/parts and caliber choices...McGowen, Douglas, Pac-Nor and most of the other barrel makers for drop-in barrels...you just have to do your own research.

In addition to Snellstroms observations, I think there is an aftermarket bolt or conversion for the x39 available...I seem to have read about it while I was playing with my toys. Lots of plains game have been taken with the TCU case in various calibers on the XP platform and in rifles along with MANY steel chickens, pigs and other metallic critters.

There is very little new under the Sun by this time in history, that hasn't been at least tried by someone, somewhere at sometime...the only reason everyone seems to know what-the-hell-and-why is because of the net and our need to sing our praises...most of the really good stuff never made it into the gun rags of yesteryear, so therefore all this "new stuff" on the net may or may not be new after all...just on the news now.

I think that is great.

LUCK

Why not a 6mm Hagar? It is not a .223 derivative (6.8 SPC) but it works great in an AR. I have one with a Krieger bbl and it shoot great.

You could get a 7mmTCU chambered barrel. That is a 223Rem necked up to .284" diameter projectiles. I don't have an AR in that cartridge but do have a Contender 10" pistol barrel and it is plenty accurate for deer and the 120gr bullets will put a deer down easily. They (the creators of this cartridge disign, which is Thompson Center) say to not use 5.56 brass to reload this cartridge but I had a bunch of it on hand and it works fine in my set-up.

6.5 Grendel---job done

THOMPSON CENTER (WES)UGALDE...TCU...that admonition probably refers to the variation in case dimensions between a 223 case and a TCU case and the case shoulder needing to be blown forward a bit. If done correctly no problems occur...if not who knows....I never had any problems fire forming TCU cases for my T/C's in ANY caliber or cartridge profile...low end load, bullet into the lands and T/C stiff to lock-up.

If the 7 mm TCU can knock over a heavy steel ram way the heck out there then a poor 4 legged critter has NO chance...even my little 10" 256 Win never has any trouble with deer...within ~75-100 yds and correct bullet placement, and that 85 gr Nosler's only going about 2050-2075 fs MV.

Grendel work and even a 25/6/6.5/7 Fireball (or Whisper) if you REALLY want to go small.

LUCK

358 Gremlin is a fun one.
Might want to stay with the 223 and up the lethality by using 40 grain cutting edge raptor bullets.

Neat thread, Ray. I have shot the 6, 6.5 and 7mm TCUs in Contenders. Never could find a .25 TCU. They are capable little cartridges and should be even more so out of an AR barrel. Let us know what you decide!

I found a 25 TCU, NOT on a T/C chassis but on a XP-100, at a metal match in Nevada. The gunsmith was testing it on rams to see how it performed...iffy at best with the loads he was using that day. He did all the work himself using home made hand dies...several cuts to get the chamber right...etc...only live one I ever came across. I think it would be a very neat toy to play with...kinda like a 256 Win on steroids, a 256 Win "Maximum" and similar to a 25-35 Win.

I tried the Leigh X-Pens in my 450 Bushmaster(on a 223 AR platform). While they were narly BAAAADDDDD looking they just wouldn't feed because the bullet X nose would hang up the in bolt locking rings. They worked OK single feeding(most of the time) and would probably work OK in a bolt gun.

Raptors are totally neat but a bit pricey for my taste...there are several other brands with similar performance parameters that will suffice for my needs...Barnes has several I still use when I can find them on sale...the .451-2" have shot very accurately in my 450 Bush, from ~200 gr to 325 gr.

LUCK

Raptors are more expensive but the performance is the best imho. If you are hunting or self defense I want Raptors. If you are just plinking almost any bullet will do. I would love to have a 270-223 to use the lighter 6.8SPC bullets. The issue is BC for shots over 250 yards where the 223 takes over but I am fine with shooting under 300 yards.

6x45 will maximize performance from a 223 case.

2800FPS with 85gr bullets and a tiny pinch of H4895

Got about a dozen one shot kills on Whitetails with my son’s 6x45 and that load

If i’m Looking for deer with an AR, I will always defer to more case capacity. Have seen good results with the 6x45 and those 85gr Sierra HP’s but the reason for using that bullet is there isn’t any room for a longer heavier bullet. That’s the problem with using the 223. Go to the Grendel for all-around deer round or something like the 458 SOCOM for 150 yards on in for pretty impressive game performance.

DTech makes 243 WSSM chambered uppers. About 100 fps faster than the 234 Win in an AR15 package.

quote:

If i’m Looking for deer with an AR, I will always defer to more case capacity.

Matt: Here are some water case capacities:
6x45 26.9
7mm TCU 33.0
6.5 Grendel 35.0
6.8 SPC 35.0
22 Nosler 36.0

quote:

Originally posted by matt salm:
If i’m Looking for deer with an AR, I will always defer to more case capacity. Have seen good results with the 6x45 and those 85gr Sierra HP’s but the reason for using that bullet is there isn’t any room for a longer heavier bullet. That’s the problem with using the 223. Go to the Grendel for all-around deer round or something like the 458 SOCOM for 150 yards on in for pretty impressive game performance.

The 6.8 SPC is a nice non wildcat fish/fowl cart that should meet most deer hunting needs and I agree that more boom room is better going up in diameter but he asked about the 223 case. If I wanted to go wildcat, there are a few options that rotates my shaft like the 358 Gremlin based on the larger Grendel case. The main issues I see are;
Range and BC needs
A variety of bullets that meet range criteria within functional impact velocity.
COAL
Boom boom room
Desired case
Feeding from magazine


What are the range needs for 90% of shots?
Is the 223 case a foregone conclusion?
What cartridge maximum dimensions will feed in your mags?

You should be able to neck the 223 up to 257 without and feeding issues or Mag mods. Larger than that you may need specific mags or mods.
How far down the financial rabbit hole is he willing to go?


If keeping the 223 case and wanting to go bigger on diameter I think starting with formed 222 case and necking up to 6.8 and trimming the neck back to get a 1.65"ish case is one way to skin that wildcat.

Oh...Yeah...we ALL have our fav's and ways to prove/defend them...it's all good. I'm glad we, here in the USA, can tickle our fancy no matter which way or make something new-to-us.

I'm not a big fan of the 6.8/.277, or hair spitting on case size/volume and would rather go 6.5 or 7 and a case I DON'T have to futz with, all the nit picks and hair splitting arguments aside, but I'm also VERY happy those nit pics are available to chew on...changing the barrel length +/- 1" will negate all the hair splitting in a New York second, or going with a bolt gun over the 223 AR size receiver OR going to the 308 AR receiver or even a plain old single shot stomps the HE** out of most hair ball arguments.

To me it's mostly arguments-in-the-mind and whatever the argument, for/against, it can be turned around and used in the opposite roll.

But...HEY..IT'S ALL GOOD...I do what I want when wildcatting irregardless of what anyone else thinks. I did the 450 Bushmaster on the AR 223 platform instead of the AR 308 platform for many reasons, most of which were it's availability and it's shorter range performance...I could have done a 450 Marlin on the AR 308 instead...I already have one of those in a BLR...and the Creedmoor on the AR 308, instead of the Grendel on the AR 223 platform for basically the same reasons...MUCH higher pressure ranges on the AR 308...HIGHER long range potential.

I've killed more deer with a 22 LR or 22 Mag than I ever did with larger calibers. Carrying a 22 LR during deer season in most states can get the law dogs in a different frame of mind if you're stopped so I carry something larger or just cull the deer in my yard, no need to get run over by all the ATV's haulin' azz chasing air.

The more the merrier...Hey

Luck

My personal AR hunting cartridges are the 6.8 and 458 socom. Both have performed well on both deer and hogs. I feel sure that the grendel and 450 bushmaster would have served me just as well, had I chosen them.

Sweet spot for a 223 case is .224. If you want more cowbell in an AR15, get a Grendel or a 6.8 SPC.

Well you could also neck the 30 RAR (Remington AR) that is a Bushmaster parent case down to 6.5 or leave it as is.

quote:

Originally posted by bobmn:

Matt: Here are some water case capacities:
6x45 26.9
7mm TCU 33.0
6.5 Grendel 35.0
6.8 SPC 35.0
22 Nosler 36.0

Surprised the TCU is that close, but due to OAL issues which it doesn't have in the Contender platform it's pretty much unusable in an AR with any type of game bullet I would think. I JUST started shooting a 6.5TCU and they are loaded long and still not touching the TC Contender barrel throat.

I'm a fan of the Grendel, but would use the 6x45 in a pinch with those 85gr Sierra bullets.

Matt: Don't forget the 7 mm TCU case is "improved" which increases the case capacity compared to a .223 case. When 7mm bullets are seated to an OAL to fit in an AR magazine some case capacity is lost compared to a Contender barrel. A .284 bullet displaces 16.02 grains per inch. This is offset by the larger bore which acts as increased case capacity in the first few inches of barrel. You can get a 120 grain bullet to 2600 fps in a 21" barrel at an OAL of 2.26" the same OAL as a .223. Handloader 264 page 60 has a good article on the 7mm TCU in rifles.

In the real world, I doubt you'll do much better in terms of field performance than a .223. On paper the 6x45 is better, but I seriously doubt the deer will notice.

I killed a deer with mine (bolt gun not AR) this year. Got complete penetration, and the deer dropped within 20 feet. Nothing to complain about. I was actually surprised by how much damage it did. Entered behind the shoulder, broke on rib, blew off the top of the heart, broke 3-4 ribs on the way out, and clipped the offside shoulder. The exit hole was bigger than I get with my .30-06.

That 30 RAR would be a COOL case to wildcat up and down...~44 gr H2O case volume...OR the 450 Bushmaster, whose parent case is the 284 Win at ~60 gr H2O. I have a AR 375 "Bushmaster" in the back of my mind...wanted to do a Sav 99 but never found that round toit to doit. Both would be more powerful on the larger receiver but they would be plenty powerful on the small receiver loaded to the lower pressure/velo not to mention about 1 1/2 lb lighter.

A perusal of the latest cases gives an infinite variety of possibilities WITHOUT resorting to mucking about with the case other than necking...AND...being able to use bushing type dies for more than one cartridge..one of my economy measures when selecting wildcats...SAVE A BUCK WHENEVER POSSIBLE.

But...AGAIN...there are already a bucket full of already developed calibers for BOTH AR size receivers that will fill your venison plate 10 times over with commercially available ammo...WHY would anyone want to go to all the trouble of doing a wildcat unless you are sado-masochistic and just LIKE to get whacked around??? or just want to do a wildcat. ...Yeah me too.

So many cases, so many calibers, so little time.

LUCK

If your going to use the 6x45 or deer use the Speer bullet (80 or 85 grs.)its a decent bullet but a tad soft IMO.

The vert best deer bullet for the 6x45 is the 80 gr. GS Customs of Gerards who posts here, Ive killed deer, my kids and grand kids killed deer, Ive culled whitetail, Impala, Springbok, Kudu with it, not to mention Mule Deer and Pronghorn antelope with it..of the large number of animals killed only a few ran 25 yards, most died on the spot, and none were wounded and escaped, most all were heart/lung shots. The exception was mostly in culling wherein we used head and neck shots.

Based on what I have witnessed many times, the only reason I could see for expanding from a .223 would be if .22 centerfire not legal in your state. If it aint broke don't fix it. 55 grain bullet plenty heavy. All the different options and theories are very interesting and on paper probably support the presented opinions. In actual hunting, those theories are mostly fiction.

I have AR uppers in 5.56, 6 x 45, (just bought a 25-45 barrel but have not assembled it yet), 300 Blackout, 458 SOCOM and 308 in an AR10. Of the AR15 rounds I'm confident of any of them on deer as long as I know the bullet construction and stay within a range I like for that particular round. Even that point is subjective. Point being I don't think you can go wrong whichever you decide.

I'm waiting for some more info on the 22 Valkyrie on the AR15 platform from Federal. I really like 22 caliber rounds and this one seems very well balanced from little varmints to medium game. It sounds like they succeeded where the 22 Nosler fell just a hair short.

quote:

Originally posted by Ray B:
IS THERE A BORE SIZE that maximizes the performance of the 223 case?

I had a similar question about the optimum bore size in a short action. So given a short action, a WSM type case maximizes the powder volume. Given this volume and a maximum cartridge length, what is the best bore size. This is what I came up with using quickload and jbm:



This is showing wind drift at 500 and 1000 yards, which was my measure of performance. You can see that the optimum is around 7mm.

However you seem to be talking about hunting performance, which is harder to quantify and has a lot of different aspects that could be considered as part of "performance." You could almost as easily ask, "what is the best food." If you can narrow the field a bit it would help. i.e. "what is the best food to take into space?" Or, "what is the best food you can buy for a dollar?"

So can you be more specific about what "performance" means to you?

I've shot deer with the 6.5 Grendel, .450 Bushmaster, and the .458 SOCOM, all from an AR with great success. Of the three, the .450 seems to drop them where they stand more often than the other two, though I have a feeling it has more to do with the 45 caliber Hornady FTX than anything. I shoot a Nosler ballistic tip from the Grendel and a Barnes TTSX from the SOCOM.

quote:

Originally posted by jpl:

So can you be more specific about what "performance" means to you?

What I was asking regarding a sweet-spot was to compare the bore sizes for cartridges based on the .223 case. So the variations would be .17" to about .30". As the bore increases the surface area on the base of the bullet allows for more efficient pressure and increased velocity, however the increased diameter of the bullet causes increased resistance once the bullet leaves the bore. The increased diameter also requires increased bullet weight to gain a more aerodynamic shape, so the increased weight reduces the velocity of the bullet but there is an offset by a more streamlined shape.
So put in less theoretical terms, if three bullet diameter cartridges based on the 223 case were used: a .224", .277", and .308" and bullets of similar shape (so the weight would increase as diameter increased), how would the three cartridges compare and could any conclusions be drawn regarding which bore size obtained the most performance with regard to trajectory and downrange energy.

Ray,

I'm not sure you're not overthinking the question.

I think you could do that kind of theoretical study using quick load. But you first need to define your criteria of sweet spot. Is it flat trajectory, energy, momentum, the ability to use a cartridge in a certain platform, or something else?

But, you can also draw on other families of cartridges, like the .308 family. Clearly overbore at .22, flat-shooting at .243 and .257, good moderate range hunting and also very useful target loads at .260, .270, 7mm-08, and .308, useful shorter-range hunting loads at .338 and .358. Probably a wide sweet spot between .243 and .308, depending on your criteria.

Obviously, a .30-.223 would be a workable moderate range deer rifle, but I question the wisdom of building one when one can purchase a .308 in the same length action and have significantly more capability along with commercial ammunition availability. In the same vein, a .223-based cartridge in .24, .25, or .26 is limited as to usable bullet weights if the magazine length of the AR platform is a criteria.

So, the criteria must be carefully defined in order to allow a search for a sweet spot.

Clarence

quote:

Originally posted by Ray B:
...could any conclusions be drawn regarding which bore size obtained the most performance with regard to trajectory and downrange energy.

Right, so that is what I did with the WSM. I made a 22WSM in quickload, which showed how fast it could theoretically push various 22 bullets. Even though there would be other problems with a WSM necked to 22 cal quickload is able to estimate how it would work. Then I did the same for 6mm, etc. all the way to a 510WSM. Doing the same process for each caliber using the same parameters in quickload (like barrel length) should create a level playing field for comparison. Then to compare their "performance" I used jbm to calculate the different wind drift for each one, which is what the plot above is showing. Like you would expect, the 22WSM has a higher muzzle velocity than the 510, but the bullets have a lower BC. So as you can see above, the "sweet spot" for the WSM case with regard to wind drift is around 7mm. This is the best trade off between muzzle velocity and BC given the limitations mentioned. Make sense?

You could do the same with the 223 case, and in fact you can use real data for a lot of it (instead of quickload) because the 223 has actually been necked down to 17 and 20, and up to 30, etc. So you can compare these for yourself and rank them based on what your version of "performance" means.

In general, a given cartridge will be capable of the same muzzle engergy based on the amount of powder it can hold. With this amount of powder you can push a light bullet fast or a heavy bullet slow, each with about the same muzzle energy. Pushing slow heavy bullets is actually slightly more efficient, but then the case capacity starts to get reduced. So as an estimate, you can pick whatever bullet you're interested in and give it a muzzle velocity such that it has the same kinetic energy as other known loads. Then you can use a trajectory calculator to see what it would do.

So again, there are ways to calculate or estimate what would happen with a 223 case necked to something else and tipped with whatever bullet--but when you want to then rank them by "performance" you need to be more specific about what that is. You say "trajectory and downrange energy," but even then are you talking drop? drift? and at what range? At a far enough range BC will be dominant so the biggest/heaviest/highest BC bullet you can fit in there (300gr .338 perhaps) will have the best trajectory and most energy. At short range the .17-233 would have the least drop, if that's the part of "trajectory" you're interested in.

You started off talking about hunting. For hunting "performance" the bullet construction may be more important than trajectory or energy. In this case, there are probably more good hunting bullets in 6mm than in 22, for example.

The 6.8SPC is actually a great deer cartridge. We have killed a lot of deer with more than acceptable performance from several different bullets. We have Rock River and Barret versions that are "minute of chipmunk" at 150 yards with sierra and nosler bullets. From 15 to just under 200 yards we have had very decisive results on deer in the 125 to 200 pound range. Not "intriguing" but very effective. if you are looking for reliability beyond 200 yards use a more reliable CLASS of cartridge.

quote:

Originally posted by Von Gruff:
6.5 Grendel---job done

Von Gruff knows what he is talking about!

Harvests a lot of game.

To best inform one's decision when the question goes beyond the notion of "That cartridge looks sexy", one should ask a few questions:

First, what is the largest medium game animal one plans to take with the cartridge? The answer will set the minimum recommended bullet weight (http://shootersnotes.com/ideal-bullet-weight/).

Second, what is the longest range one plans to attempt taking the animal at? The answer combined with ballistic performance of the desired bullet will set the muzzle velocity.

The bullet weight and muzzle velocity will set the case volume.

From there, it's easy.

Back to Von Gruff's answer:

quote:

Originally posted by Von Gruff:
6.5 Grendel---job done

quote:

Originally posted by JASmith:
[QUOTE]
From there, it's easy.

Actually not easy- I think swaging the base of a 5.56 case (.377") out to that of the 6.5 Grendel (.439") would be a significant problem, but since you claim it is such a slam-dunk, maybe you could enlighten me.

quote:

Originally posted by Ray B:

quote:

Originally posted by JASmith:
[QUOTE]
From there, it's easy.

Actually not easy- I think swaging the base of a 5.56 case (.377") out to that of the 6.5 Grendel (.439") would be a significant problem, but since you claim it is such a slam-dunk, maybe you could enlighten me.

One starts with 6.5 Grendel brass from any of several sources.

Of, course if one really wants to go through the trouble, there's any of the 7.62x39 and daughter cartridges one could start with.

The point is the lead sentence in the OP has "build an upper for an AR platform suitable for deer-size game." Several posts have already responded in that spirit.

quote:

Good luck on your search, your ultimate satisfaction depends on so many variables you must remember that what makes one guy happy may not work for your style of hunting or area you hunt. (cover, distances, animal size, disposition, shot angles......)Do remember that the .223 with monometal bullets is a solid performer however pedestrian.

I think I said it best, second post from the top.
Go back and read it....

In the original post I stated that keeping with the AR lower, it is stipulated that I could go with the larger diameter case and use the Gendel or such; however I went on to pose the question of the thread that if I wanted to stay with the 223 case, was there an optimum bore size where graphing the increase in velocity due to bore size intersects the decreasing velocity function of due to drag. Apparently there is no significant difference in the reasonable range performance for the smaller bore 223 based cartridges, eg 223, 6x223, 25x223. So as noted, I'll limit it's use to those state where I can hunt those states smaller deer using a 223 loaded with bonded bullets.

After shooting a few deer with the .300 Blackout...I will just say it is a very capable moderate range deer killer and seems to be a very accurate little cartridge.

My sons Ruger American will sometimes shoot a dime sized ragged hole group off a bench at 100 with cheap factory ammo.

Every broadside shot exited some taking a chunk of rib out.