80g Amax in a 1:8?

[Tony.H]

I am watching this topic with great interest. I am considering a fast twist .223 myself. Currently I use my .204 for long range vermin and varminting out to 600 yards. Will I benefit from a fast twist .223 for my needs?? I can see the benefit in a fast twist .223 in shooting competition out to 1000 yrds but that's about it, plus if I was shooting out to 1000 yards I'd choose a different caliber anyhow. Out to 600 yards my.204 load is very comparable to the likes of a fast twist .223 75/80 grain A-Max, my .204 is far flatter shooting and almost identical in the the same Windage scenario out to this range...... Is it worth to me the expense and hassle of a new rifle set up plus another new scope to benefit from a possible inch or so at 600 yards.

 

What's you views guys?

 

Cheers guys

 

Steve.

i think side by side the 204 shooting a 39gr and the ,223 shooting a 75gr in the wind out 600 would show quite a difference, the 75s are by no means flat its all to do with the higher bc and how it copes with the wind.

[bradders]

Laurie,

I've no knowledge of that Wild Boar powder so can't comment.

The AA 2520 is indeed the Czech stuff.

 

As for 90's, it seems there's too much of a good thing there.

My pal in AZ, Derrick Martin gets free bullets from Sierra as he's a recognized authority on shooting matters, and used to write articles for Precision Shooting along with Barrett Tillman.

 

When the 90's came out they set up start and stop cronos at the firing point and down range at 500yds and tested them for BC and performance.

What they discovered is that the BC's do not match the quoted ones and no matter what way you looked at it, the 90's just will not out-perform an 80 from a Service length barrel as the just cant be driven fast enough

[247sniper]

i think side by side the 204 shooting a 39gr and the ,223 shooting a 75gr in the wind out 600 would show quite a difference, the 75s are by no means flat its all to do with the higher bc and how it copes with the wind.

From my ballistic data for the .204 at 600 yard with a 10mph full value wind would cause a 35 inch drift. With a .223 75 grain A-Max at these guys advised speeds would cause a 32 inch drift. That's why I don't see the point in spending money on a new set up just to for a 3 in Benefit over 600 yards, and with the .223 heavy weight you would have to be so precise with range estimation.

 

Jut don't get it.

 

 

Steve.

[Tony.H]

From my ballistic data for the .204 at 600 yard with a 10mph full value wind would cause a 35 inch drift. With a .223 75 grain A-Max at these guys advised speeds would cause a 32 inch drift. That's why I don't see the point in spending money on a new set up just to for a 3 in Benefit over 600 yards, and with the .223 heavy weight you would have to be so precise with range estimation.

 

Jut don't get it.

 

 

Steve.

yep there is prob nothing in it, and at 600y you would be dialing in anyway i would of thought

[Laurie]

Laurie, I've no knowledge of that Wild Boar powder so can't comment. The AA 2520 is indeed the Czech stuff. As for 90's, it seems there's too much of a good thing there. My pal in AZ, Derrick Martin gets free bullets from Sierra as he's a recognized authority on shooting matters, and used to write articles for Precision Shooting along with Barrett Tillman. When the 90's came out they set up start and stop cronos at the firing point and down range at 500yds and tested them for BC and performance. What they discovered is that the BC's do not match the quoted ones and no matter what way you looked at it, the 90's just will not out-perform an 80 from a Service length barrel as the just cant be driven fast enough

 

 

Mark,

 

I absolutely agree on 90s in 20-inch barrels. Bolt-actions and 28-inch barrels or more. The 90 SMK is not a success either - not very good in the long-range role, cannot be driven at much over 2,650 fps and as you say not even that great a BC. It's long barrels and Berger or JLK VLDs is you want to play that game.

 

It's more the claimed 'Wild Boar' / Western AA-2520 performance that intrigued me. If it will do this in the 223 with 80s and 90s, and perform well, it should have lots of other applications too. On reflection, the more I think about the 2.260" COALs quoted though, the more I'm convinced they're typos. Getting the 80gn SMK to 2,900 + fps with it seated that deeply simply cannot be feasible.

 

Thinking further about the Czech ball powders, steel tumbling media could change my attitudes to them completely. I had lots of good experiences with 2460 and 2520, it was just the case fouling that put me off.

 

Incidentally, anybody reading this tempted to try the Ramshot powders which I do think are going to be excellent additions to our shooting scene - only don't use them in the RCBS 1500 Chargemaster or similar. The balls are so small and run so freely, you WILL get spilt kernels on your dispenser and some WILL find their way into the electronic scale part underneath the platen. Definitely powders to dig the old mechanical measure out for. They should meter very consistently through them too.

[bradders]

I've spoken to Derrick on the phone tonight and he had given me permission to post his and Barretts Precision Shooting article on here.

It's a bit long, but worth the read

 

 

SIERRA’S HEAVY .223S

By Derrick Martin and Barrett Tillman

 

Once upon a time, well within living memory, the thought of shooting .223s in NRA Service Rifle was laughable, loony, or ludicrous. So much for alliteration. Now the really serious gravel bellies at Camp Perry and elsewhere have largely converted to M16/AR-15 systems because the heavier .223 projectiles buck the wind just as well as most .30s; or better.

But we digress.

When Sierra produced 77, 80, and 90-grain bullets it was only a matter of time until the elves in the back of Accuracy Speaks conjured up some loads for evaluation. For those of you who are so busy reloading or shooting that you don’t have time to read to the bottom of this article, here’s The Short Version:

There’s not much downrange difference in performance between properly loaded 77s and 80s. The 90s, OTOH, cannot easily be boosted to useful velocities.

Now get th’ hell back to the loading bench or to the firing line.

For the rest of you, who can actually use our hard-won knowledge for the mere pittance of a subscription to Uncle Dave’s Magazine, here’s The Rest of the Story.

BC: Not the Comic Strip

With apologies to cartoonist Johnny Hart, ballistic coefficient is the numerical value describing how well your bullet performs in flight: its aerodynamic efficiency. It’s like money and antifreeze: more is better.

For you Serious Shooters out there, here’s the lowdown:

BC is derived by dividing the mass of the object by the diameter squared that it presents to the atmosphere, divided by a dimensionless constant (i) that relates to the shape. Density is related to mass for a given cross-section, which is why bullets are filled with lead. (That’s also why tank-busting rounds use the densest material of all—depleted uranium—but unfortunately we don’t have test samples yet.)

BC is described in pounds per square inches or, for the metric part of the world, kilograms per square meter—whatever th’ hell that is.

Anyway, here’s the formula for calculating ballistic coefficient: (1)C = SD / i = w / id2

Got it?

Good.

Now let’s move on.

Where were we?

Oh, yes. Sierra BCs. Without wading through all the number crunching that follows, we’ll rush to The Bottom Line. The best of the Sierra .223s we tested were the 90s, with a BC of .506, which compares very favorably with the firm’s .30 cal. 168s, 175, and 190s. (Note: We cannot compare all three at once.)

Now you’ve heard the good news.

The bad news? Wellsir, of the three heavy .223s we evaluated, the 90s were the hardest to kick out the muzzle at a useful velocity, while BCs of the 77s and 80s were 12 to 25 percent less than the 90s.

But there’s good news to offset that fact.

Remember Sergeant Martin’s First Rule of Handloading? Repat after us: “The proof is on the target, not on the chronograph.”

Again: “The proof is on the target, not on the chronograph.”

 

Speaking of chronographs, a few words about our downrange speed measuring equipment, loaned by Middleton Tompkins Himself.

At a lasered distance of 501 yards (no querulous letters to Uncle Dave about indefinite ranges this time!), we set up Mid’s outfit, consisting of an Oehler 33 with two foot by four foot sheets of insulation material five feet apart. They were covered with aluminum foil attached to the chrono by speaker wires (one each) with alligator clips on the end. The ‘gators were clipped to the foil panels, providing start-stop readings.

We knew that the lashup worked because Mid had used the same rig for 1,000-yd tests on Palma bullets. (As an aside—a bonus for buying this magazine—we can relate that there wasn’t a lick of difference among any of the 155-grain Palma projectiles. “Irregardless” of manufacturers’ claims, they registered only about 25 fps variation.)

Oddly (or not, depending upon one’s prior inclinations) we found similar results for our .223 tests.

Basically, there ain’t enough difference to worry about. That happiness factor applies almost equally at 600 yds and at 1,000. The 80s and 90s perform very similarly, but since it’s easier to get useful velocities out of 80s than 90s, we suggest that you start your own evaluation with the former. The 77s, being lighter and with lower BCs, don’t do as well, especially at 1,000 yds.

Here’s the raw data, starting with muzzle and 500-yd data, courtesy of Accuracy’s patron reloader, Dana Beasley.

We fired two ten-round groups for each bullet, to wit:

 

77 Grainers (RL-15)

Muzzle 500 Yds Muzzle 500 Yds

Hi 2881 1881 Hi 2871 1876

Lo 2778 1793 Lo 2804 1818

Av 2829 1835 Av 2837 1852

ES 103 87 ! ES 67 58 !

 

80 Grainers (RL-15)

Muzzle 500 Yds Muzzle 500 Yds

Hi 2825 1952 2848 1962

Lo 2782 1895 2793 1893

Av 2805 1918 2832 1918

ES 43 57 55 69

 

90 Grainers (N540) Insert load data??

Muzzle 500 Yds Muzzle 500 Yds

Hi 2481 1748 2396 1676

Lo 2364 1642 2349 1620

Av 2391 1668 2374 1649

ES 117 106 47 56

 

For your notebooks, the data were compiled at Mesa, Arizona, in November 2005 c. 80 deg. F and 19% humidity. Obviously, the foregoing are not absolute values but we include atmospheric info for you number crunchers who absolutely positively have to convert everything to a Standard Day.

Note: the 77 grainers had better extreme spread at 500 yds. Go figger.

80-grain ?????? .223 Accuracy Results

Test vehicle: Remington 700 26-inch Douglas 1-8 twist

Primer: F 205 Case: Winchester OAL 2.55

A+ = ½ moa A = -1 moa B = -1 1/2 moa C = 2 moa

Powder Charge Velocity ES 200-yd grade

R15 22.0 2477 12 A

R15 22.5 2534 5 A Best

R15 23.0 2624 10 A

N540 22.0 2458 13 A Best

N540 22.5 2550 15 A

N540 23.0 2602 21 A

 

90-grain Sierra .223s

Test vehicle: Weatherby Vanguard Douglas 22-inch 1-7 twist

Primer: Winchester Case: Winchester OAL 2.42

N140 21.0 2395 9 A Best

N140 21.5 2451 10 A

N140 22.0 2497 11 B+

N140 22.5 2557 14 B 4 cookie cutters

N140 23.0 2594 14 A 5 cookie cutters

R15 21.5 2420 32 B+

R15 22.0 2464 16 B

R15 22.5 2506 23 A

R15 23.0 2570 14 A Best

N540 21.5 2383 32 A Best

N540 22.0 2477 19 A

N540 22.5 2540 23 A- 1 cookie cutter

N540 23.0 2585 11 A 1 cookie cutter

N550 21.5 2252 29 B+

N550 22.0 2325 36 B+

N550 22.5 2430 28 B+

N550 23.0 2463 26 A Best

N160 22.0 2138 7 B+

N160 22.5 2198 16 A

N160 23.0 2240 9 A+ Best of .223s

N160 23.5 2286 12 B+

AAC2700 22.0 2299 12 A Best

2700 22.5 2330 24 B-

2700 23.0 2343 19 A

2700 23.5 2411 13 B

H4895 21.5 2530 24 A Best 2 cookie cutters

H4895 22.0 2576 6 B+ 4 cookie cutters

H4895 22.5 dnf - -

IMR4320 21.0 2385 18 B

4320 22.0 2506 29 B+ 1 cookie cutter

4320 23.0 2627 10 A Best 3 cookie cutters

4320 24.0 dnf - -

We also tested a Colt factory second barrel (90-grain 223s) with R15, N150 and N540. Some would argue that the Colt’s longer throat (2.550 vs 2.420 on the Accuracy Speaks chamber0 will allow less impringement (you can look it up) into available powder volume and the ability to increase powder charges without increasing pressures. We seated the 90s to contact the logner Colt throat and fired loads we had already chronographed. There was NO reduction in velocity (translation: no additional velocity was gained with the added powder volume and primers cratered at the same rate.) Therefore, no velocity increase would be realized with the longer seating depth and greater powder capacity. Sorry.

Calculating the Numbers

Here’s how the BCs were derived. All were Sierra Match Kings. Wind values are full deflection (inches) at 10 mph.

Bullet Wt. BC Muzzle 600 Yds 1000 yds 600 1000

Wind Wind

77/223 .402 2850 1691 1169 33.5 111.3

80/223 .449 2850 1789 1279 29.0 95.1

90/223 .506 2500 1622 1203 30.9 98.7

Calculations were done in “Ballistic Calculator 4.10”, corrected to STP (standard temperature and pressure).

A few things stand out: in .223 rifles, 90s use more wind than 80s, so save yoru money on the new short-twist barrel because it ain’t in improvement!

Also, note the identical wind values for 175-gr. .30s and 90-gr. .223s. But that’s to be expected, given the same BC for each projectile. However, as we noted, it’s hard to get the 90-gr. pills to achieve 2,500 foot-seconds at the muzzle. Pressure signs and some blown primers tell us that we don’t want to go there. Additionally, 90s need a fast-twist barrel, but there’s no need to take that route. (As Yogi Berra reportedly said, “When you come to the fork of a road, take it.” Makes sense to us.)

Let’s take a closer look at the numbers.

At 600 yds the windage difference between the 80 and the 175 is only two inches, or 1/3 moa. At 1,000 it’s barely 3 ½ inches, again 1/3 moa. Can you hold one-third minute at 1,000 yds? If so, you’re a Rifle God and you don’t need to read this article because you have the knowledge imprinted in your DNA. Go climb a mountain, swim in the ocean, make love to your spouse.

Lesser mortals, read on.

As we were saying before we so rudely interrupted ourselves, there is no functional difference in the amount of wind used by the 80/223 and the 175/308. Zero. Zip. Nada. So…you might as well gain the benefits of shooting a .223 (preferably one crafted to your own requirements in Our Shop.)

Remember: we are not comparing .30s and .223s; we are comparing 80s and 90s of the .223 persuasion.

About Barrels

Our tried & true test barrel is a Douglas 7-twist affixed to Dana’s Weatherby action, the same one that’s done such sterling service lo, these many years. Precision Shooting could hardly exist without it, let alone Accuracy Speaks.

We used a standard chamber in the Douglas tube with 90-grainers contacting the rifling at 2.440 inches. The 80s have a similar ogive so the fit is very close to that.

Howsomever: we also tried a Colt 7-twist tube and found some astonishing (nay, dismaying!) results. While zeroing on a 25-meter target we found all the rounds punching thru the paper (nowhere near the X ring) in profile. That’s right, boys & girls: at only 25m the rounds were turning sideways.

What’s going on?

Short answer: danged if we know.

Colt barrels have a much longer throat, with the 80s contacting at 2.550 inches. Would we get more velocity if we seated the bullets longer? We’re not sure, and may redo the load development to see if it helps.

Meanwhile, be aware: in Douglas barrels, 1-in-7 twists are both hunky and dory, and under some conditions 90s can be fired through 1-8 twist barrels as seen by our .22BR and .22-250 data.

Notice: with the same ammo, our Weatherby action produced “cookie cutter” primers sooner than the AR lashup. You can probably use comparable loads in your AR-15 but that is not—repeat NOT—license to increase powder charges in your service rifle fodder.

Squirrel Shooters Unite!

It will be immediately apparent to varmint assassins that Sierra’s new products lend themselves to prairie rodent depopulation. Toward that audience we address the following .22-250 dope.

Our .22-250 barrel was a 1-8 twist that worked alright with 90-grainers. We suspect that much like 80s in a 9-twist tube, it only works during a test and might turn around and bite you in a match.

But you knew that.

The most we got out of the .22-250 was 2,900 fps. The amount of degredation relative to 80s was negligible since the 80s bucked the wind better in service rifles.

From the following, you can use our measured BCs in your computer’s program for whatever velocity you choose for your rifle. Both .22-250 and .22 BR should benefit from the 90s but we still can’t push ‘em fast enough for utility in the .223.

Test vehicle: Remington 700 .22-250 from a 25-inch Douglas 1-8 twist.

A+ = ½ moa A = -1 moa B = -1 1/2 moa C = 2 moa

80-Grain Sierras

Primer: F210 Case: R-P OAL 2.72

 

Powder Charge Velocity ES 200-yd grade

R15 26.5 2553 29 A

R15 27.0 2621 17 A+ Best

R15 27.5 2648 15 A

R15 28.0 2696 12 A

R15 28.5 2707 8 A

R19 33.0 2718 11 A

R19 33.5 2773 17 A Best

R19 34.0 2811 19 A Best

R19 34.5 2863 23 A

N160 33.5 2729 42 A Best

N160 34.0 2734 28 A

N160 34.5 2831 30 B

N160 35.0 2903 -- B+

4831 33.0 2698 28 A

4831 33.5 2772 27 A

4831 34.0 2816 25 A+ Best of .22-250s

4831 34.5 2867 16 A

4831 35.0 3891 24 A-

4831 35.6 2953 12 A Note: 35.6

.22 BR 90s

We stuffed the Sierra 90s onto the .22 BR case and gained the following results.

 

Powder Charge Velocity ES 200-yd grade

RL-15 27.5 2723 6 B

RL-15 28.0 2777 39 A

RL-15 28.5 2802 14 B

RL-15 29.0 2875 28 A Best

 

AC2700 30.0 2707 34 B

AC2700 31.0 2795 12 A-

AC2700 32.0 2889 22 A-

AC2700 33.0 2969 18 A Cratered Primer

 

.30 cal. Comparison

For those of the .30 cal. persuasion, here’s the Sierra Match King figures for comparison with the firm’s .223s (noted previously).

Bullet Wt. BC Muzzle 600 Yds 1000 yds. 600 1000

Wind Wind

168/30 .462 2700 1667 1188 32.3 105.6

175/30 .505 2600 1667 1218 30.9 98.7

190/30 .513 2500 1603 1184 31.9 102

[Tony.H]

there are three powders that ive been looking at to use with the 75gr amax,

varget,

reloader 15

h BL-c2

have any of you used these powders.

Ive also read that the 75 amax needs to be pushed so also which powder of the three would suit that?