30-06 Handload Ballistics

[Shooter14]

I've been working on some loads using Sierra 165 BTSP bullets in my Howa 1500. Through this process I've noticed that my gun consistently shoots better groups with powder charges toward the max end of the scale. Have not noticed any pressure signs as I've moved up to and slightly beyond the max loading data in the Sierra manual. So last weekend I loaded and shot some with IMR 4350, IMR 4064, and H4831SC. The IMR 4350 and 4064 did well, but with 59 grains of H4831SC I got three shots in a half inch group at 100 yards (which is good for me). Next best was 51 gr 4064 at about one inch, and then about 1.25" with 56 gr 4350. Next, I shot two rounds at 200 yards. The two H4831SC rounds were touching (lucky), but dropped more than the other two loads at 200 yards. I thought, when I came up with these three powder charges, that my three loads would have been in the ballpark of 2900 fps. I am curious about my velocity with the H4831SC, but don't have a chronograph (YET!). The two IMR powders hit about 1.5 inches high at 100 yards, and the H4831SC hit about 0.5" low (but with better grouping) Is there anyone out there with ballistics software that could give me the pressure and velocity for the following load? And possibly the other two mentioned above as well?

59 gr 4831SC
CCI 200
3.330" OAL
Howa 1500, 30-06, 22" barrel

 

[minnesota]

Every gun is different, the only way to know for sure is to use a chrony.

 

[ArchAngelCD]

I have the same Howa rifle in 30-06 and I get my best groups with a 168gr SMK bullet over 58.0gr H4350. I don't have my notes handy so I can't give you the exact velocities. @100 yards I was able to produce a .314" group backed up by a .320" group. @200 yards the group was just over 1".

When shooting a 26" barrel Model 1917 I can actually get the same velocities with 57.0gr H4350 and I do with 58.0gr H4350. Off the top of my head the velocities are in the 2870/2880 fps range. The Max charge listed on the Hodgdon Load Data Site is 59.0gr H4350.

 

[gamestalker]

Every gun is different, but so are powders in this respect. I load a lot of 7mm RM and my powder of choice is RL22. I've found that with that cartridge, my rifles will group much better when the charge is up above the mid range, and that the pressures begin to not only come down slightly, but the velocities will get more consistent. And with bullets of 120 grs. and lighter, compressed charges produce the most consistent performance.

For my .270 win. and 30-06 actions, RL19 and IMR-4350 have been the best performers when loaded at or near maximum charges. 4831sc is a very good powder for this kind of loading too.

 

[GooseGestapo]

Those powder charges closely match what I've seen through the years with numerous .30/06's.
FWIW (each gun/bbl is different) I've gotten 2,775fps with 56.5gr of IMR4350 (accuracy load) and 165gr Sierra BtHpt. With a different gun (both w/24"bbl) I've gotten best accuracy w/57.0gr and 165gr bullet (both Sierra 165gr BtSpt and Nosler B.T.) for 2,820fps, or closely to what I'd expect.

H4350 will run a little faster with 58.0gr as suggested max, and RL17 (my current darling '06 powder) at 57.0gr for near 3,000fps but not quite as accurate as IMR4350.

With a 22" Savage M110LH I was getting approx 70-90fps less velocity. It was a "slow" bbl and it showed max pressures (hard bolt lift and burnished case heads) at 1-1.5gr below what a MkX Mauser or Colt Lt. Rifle gave, so I sent it "down the road"....... It found a new home via a local gunsmith.....

I will "guess" that your Howa is getting about 2,750fps with your IMR4350 load and H4831 loads. The IMR4064 will be a little bit slower at around 2,700fps. But, only a chrono will tell for sure.

FWIW; the powders are engineered to operate optimally at or near the max published data, so that explains your observations. The lower published data is for the "low" end of average due to manufacturing tolerances... both powder lot#'s and rifles... and other components....

Additonally, the difference between the H4831SC may not be velocity difference but "harmonics" with regard to barrel vibration and when the bullet exits the bore. The barrel vibrates like a "tuning fork" when fired and if the bullets exit at the low point, they shoot/impact lower, though the actual velocity may be higher...!

 

[Shooter14]

I posted the same question on another forum and got the following info. from one of the forum moderators that seems to always have good answers.

[What I have found without fail ... the listed powder charge that gets you closest to factor ammo velocity will be quite accurate. Maybe not the most accurate but close. Factory 30-'06 with 165 gr bullets are loaded to 2800 fps so you are a little light on two of these loads. I would actually chronograph your loads to confirm. Max SAAMI chamber pressure for a 30-'06 is 58,750 psi.
Using QuickLOAD, your above load of 59 gr 4831SC shows a chamber pressure of 44,278 psi and a velocity of 2587 fps from a 22" barrel using the same Sierra 165 gr bullet. That tells me the powder is a bit too slow burning for this bullet weight and case combination.
59 gr of IMR 4350 shows CP @ 57,923 psi and a velocity of 2825 fps from a 22" barrel.
51 gr of IMR 4064 shows CP @ 53,847 psi and a velocity of 2727 fps from a 22" barrel.] End Quote

This seems to accurately describe what I was seeing at the range, that is, the H4831SC loads were shooting approximately 2 inches lower on the target out of the same Howa 1500, thus lower velocity.
Also, I have my gun zeroed to shoot about 1.5 inches high at 100 yards with factory ammo, so to hit about the same with my reloads seems to imply a near factory load equivalent velocity.

Goosegestapo, your info follows closely what was generated above using Quickload software.
Thanks for all you guys comments. I've got some more rounds loaded and am about to head to the range.