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December 29, 2019, 11:38 AM | #26 | |
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What's the conditions and standards used to establish that? |
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December 29, 2019, 12:15 PM | #27 |
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December 29, 2019, 03:41 PM | #28 |
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I have a Rem model 742 carbine. !8" tube and caliber 06 Springfield. Factory ammo is awesomely bright after dark and muzzle jump will garner any shooters attention.
So since I do not like muzzle flash or muzzle jump. The choice of re-load powder does make a difference. Since the rifle is Semi-auto IMR 3031 functions the action nicely with far less flash. Although muzzle jump is still a tiny problem my having to deal with. |
December 29, 2019, 03:59 PM | #29 |
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Reynolds357,
1.5 is a commonly cited optimal stability number, not a minimum stability number. If Berger said otherwise, they are wrong, but I would be surprised to learn Bryan Litz let them publish that basic a mistake. 1.0 is the minimum for stability because that is how the gyroscopic stability factor is defined. Under 1.0 is unstable, over 1.0 is stable. It is true for all projectiles. It's just that being barely over 1.0, while stable, does not produce best accuracy and allows enough sustained coning motion in a spin-stabilized projectile to degrade BC some by adding to drag. The best value depends upon what authority you listen to. Spinning faster increases stability, but it also increases wobble due to any imperfections in the mass symmetry of the projectile all the way up until the thing spins so fast it flies apart. Where the best compromise between minimum spin and excessive spin occurs depends on the authority you are listening to. Harold Vaughn liked 1.4, Don Miller liked 1.5; Sierra told me long ago that 1.3 to 3.0 was good for hunting accuracy and 1.4 to 1.7 was for match accuracy.
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December 29, 2019, 04:23 PM | #30 |
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"But for what you want to do it wont matter. Even from a 20" barrel a 30-06 is faster than a 308."
Using factory ammo, t'ain't necessarily so. A few years back I ran Winchester Power Point 180 gr. loads from a .308 Win. 22" barrel and the same ammo in 30-06 through three different rifles with 22, 24 and 26" barrels. Both cartridges ran almost the same with about 1o to 20 FPS advantage to the 30-06 Velocity was 2610 from the .308 and 2630 IIRC from the 06. Speed picked up a bit in the 24" barreled 06 but the only rifle that came close to advertised velocity for the 30-06 was the Ruger #1B with 26" barrel. FWIW, I have run 180 gr. Hornady Spire Points in a 22" 30-06 at 2820 FPS with a stiff load of H4350. Pressure appeared just fine and temperature was in the low 90's the day I ran them over the chronograph. "I'd get a 1:12 twist 22" barrel for bullets up to 180 grains if best accuracy is important." I'm not so sure about that. I have a 30-06 custom on a Mauser action with 24" 1 in 12" twist that will put five 165 gr. Nosler Accubonds into slightly over half an inch fairly regularly. I have never found a 180 gr. load that will shoot better than two inches from that rifle and that includes round nose bullets. Never have figured that one out. Granted a sample of one doesn't mean much statistically but it might cause one to thiunk about it. Paul B.
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December 29, 2019, 04:25 PM | #31 |
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Bart B. So?
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December 29, 2019, 05:55 PM | #32 | |
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January 4, 2020, 12:25 PM | #33 |
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I ordered a 10 twist. Thanks all.
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January 4, 2020, 06:05 PM | #34 |
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In the heyday of the 30-06 in NRA high power disciplines, match winners and record setters rebarreled at 2000 to 2500 rounds. The most accurate ones tested about 5 to 6 inches at 600 for 20 shots. Good enough with the target's 12" V ring inside the 20 inch 5 ring.
Of course, some went 2 to 4 times as many rounds. But they weren't producing the highest scores. Again.... What's the standards and conditions for 4000 to 5000 rounds you referenced? Last edited by Bart B.; January 4, 2020 at 07:51 PM. |
January 5, 2020, 11:00 PM | #35 |
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Bart B. OP posting about hunting rifle.
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January 6, 2020, 05:24 PM | #36 | |
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I think your issue with 180's was not the case nor barrel. 24" 1:12 twist 308 Win barrels have shot 190's near half MOA through 600 yards. 22" barrels in M14NM rifles shot 180's winning matches and setting records with 1:12 twists. Last edited by Bart B.; January 6, 2020 at 06:27 PM. |
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January 6, 2020, 06:57 PM | #37 |
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16.1" ... a Shuff's Mini-G in .30-06.
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January 8, 2020, 09:00 AM | #38 |
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When comparing two 30 caliber cartridges in different barrels for muzzle velocity, ensure both barrels have the same bore and groove dimensions. Their pressure should be at SAAMI specs and both rifles held and fired the same way. The same bullet should be used in both cartridges.
The best source of data comparing two rifle cartridges is SAAMI's documents listing pressure and velocity values. The "Rifle" link in: https://saami.org/technical-informat...mber-drawings/ Last edited by Bart B.; January 8, 2020 at 09:20 AM. |
January 9, 2020, 11:26 AM | #39 |
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Many '06s used to be 22", but everyone seems to want 24's today. I never heard a deer complain about a short barrel's lack of killing power.
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January 9, 2020, 02:49 PM | #40 | |
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Nor have deer, hogs, elk, moose, caribou, or bears ever voiced a complaint about being killed by '06s out of barrels as short as 20, 18, or 16.1 inches. Of course, it's also true that as these barrels get shorter, the practical hunting ranges also get shorter. |
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January 12, 2020, 02:20 AM | #41 |
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For a .30-06 class hunting rifle - would need a good reason not to get it w/ a 24" Bbl.
...and there are a few, but that is your call. Red |
January 12, 2020, 04:10 PM | #42 |
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IMO, its not a bad idea to use multiple criteria to make a decision.
Back in WW1 they used long bayonets. I assume by the same logic,a long barrel was a longer handle for a bayonet. Part of why the M-4 is the standard rather than the M-16 is getting in and out of a Hum Vee. Some brush and vine or stand situations,or thin air at 9000 ft,might favor shorter,handier barrels,as might hunting on horseback The "hang" or inertia of a longer barrel might be better for steady holding ,whether offhand or prone... If I preferred a shorter barrel and was concerned about flash and blast,I might help a little by loding 4895 or Varget. Or if I had a 24 in bbl and I wanted velocity 4350 works pretty well. A fat 20 in bbl will be rigid,and MIGHT be more accurate than a 26 in # 3 contour...or maybe not. Thing is,often its wide open spaces where a longer barrel might be handy for longer shots...slight velocity and "hold" advantage. The same conditions that favor o shorter ,handier rifle usually present shorter shots. I might start with the 26 in + blank,then saw off an inch or so at a time till the rifle jus feels "right" for what I want. I typically end up around 21 to 23 in. . And IMO,nothing says a rifle bbl length has to be evenly divided by 2. A 23 or 21 or 25 !/2 bbl is just as good as a 20,22,or 24 in bbl. I have no need for a tape measure regarding barrel length,except for BATF minimums |
January 14, 2020, 04:18 PM | #43 |
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I recall a time when a 24" barrel was standard for sporting rifles. IIRC, I was Jack O'Connor who did a lot of stumping for lighter weight barrels and 22" in length. I never saw where 2" more barrel increased weight all that much and never saw a 24" barrel to be all that big a problem even in thick brush.
Paul B.
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January 14, 2020, 05:52 PM | #44 |
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IIRC, Ballistics by the Inch showed that in bbl lengths shorter than 19" [remember, that's with the chamber, so really only 16.5" of bullet travel] the rate of velocity sacrificed to the God of Noise grew progressively worse for .30-'06. So that would be my lower bound for a .30-'06 "carbine." To put it in perspective, the M1 Garand is considered to have a 22" bbl, so that would lop 3" off the end of one, and I've never considered the M1 to be conspicuously "unhandy." Mmmm, a Tanker M1 w/o all the sturm und drang: Tasty!
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January 16, 2020, 05:58 PM | #45 |
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Rifle barrel lengths are always measured from bolt face to muzzle regardless of their cartridge.
I don't think sound pressure levels across all typical barrel lengths for a given load are much different. It varies with pressure upon bullet exit. Faster burning powders have less pressure at the muzzle than slower ones for a given peak chamber pressure. I'll try to find some test data. Last edited by Bart B.; January 16, 2020 at 08:48 PM. |
January 16, 2020, 07:10 PM | #46 | |
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Perhaps you were thinking of the M14. Which is not .30-06. |
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January 22, 2020, 09:36 PM | #47 |
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I used to have only 22" barrels on my hunting rifles, but now my two .270s have 24" barrels. Both .243 Rems are 24", but my Rem 700 Light Varmint .223 is only 22" and it's my favorite walk-about varmint rifle.
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January 23, 2020, 06:37 AM | #48 |
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a 165 gr .308 at 2800 fps at the muzzle gets to 500 yrds at over 1800 fps and with over 1200 fpe and with a 200 yrds zero drops 46", a 7mm 162 gr bullet at 2800 fps gets to 500 yrds with over 1900 fps with over 1400 fpe and with a 200 yrs zero drops 43". with the .270 and a 150 gr at 2800 fps the 500 yrds fps is over 1800 and fpe 1200 and the drop 45". info from Hornady vol 2 handbook of cartridge reloading. so the old 3006 does pretty good with other calibers when compared at 500 yards.
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January 23, 2020, 07:52 AM | #49 | |
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Yes, I'm in agreement here! 24" should be the standard for an "all around" 30-06. But I would purposely build it for the primary planned hunting conditions: If its stalking deer 150 yards or less might go shorter, however I've not found a 24" to be any hindrance. If its longer ranges for Elk, I would go 26".
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