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Gentlemen: I've made the jump and started reloading. Lots of fun, with first good results. Question is the following:

I have three recipes, all with different max powder charges.
1) 60.5gr (24"barrel)
2) 57.5 (26")
3) 62 (24")

Corresponding velocity is 3000fps. I have a 22" barrel, no pressure signs and average velocity at 2940fps with a sub-MOA group at 60.2gr.

60.5 and 60.8 produced comparable, but not quite as good groups, and velocity crept up to 2980.

Given my shorter-than-recipe barrel, should I make 60.2gr/2940fps the point to fine-tune around? Meaning, is it correct that a shorter barrel will cost fps-per-inch? I think I've read that somewhere, but can't recall -- any suggestions would be much appreciated.

I have no interest in pushing the envelope in terms of pressure.
 

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Gentlemen: I've made the jump and started reloading. Lots of fun, with first good results. Question is the following:

I have three recipes, all with different max powder charges.
1) 60.5gr (24"barrel)
2) 57.5 (26")
3) 62 (24")

Corresponding velocity is 3000fps. I have a 22" barrel, no pressure signs and average velocity at 2940fps with a sub-MOA group at 60.2gr.

60.5 and 60.8 produced comparable, but not quite as good groups, and velocity crept up to 2980.

Given my shorter-than-recipe barrel, should I make 60.2gr/2940fps the point to fine-tune around? Meaning, is it correct that a shorter barrel will cost fps-per-inch? I think I've read that somewhere, but can't recall -- any suggestions would be much appreciated.

I have no interest in pushing the envelope in terms of pressure.
Whole lot of info missing. Caliber? Gun? Powder? Projectile?
 
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If you are happy with the results at 60.2gr, then I would say go with it! Sounds like a load I'd be happy with, good work.

Make your seating depth tweaks and such and see if you can get it to where you like it more.
 

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Yes a shorter barrel is slower than a longer one, generally. Twist can also affect velocity as can the surface of the bore and other factors.

I cant find it right now, but there was a article where a barrel builder took a single barrel with a known load, and started cutting 1" off the end and recording the velocity differences. I remember it falling within the widely accepted 25-50fps per inch figure talked about often.


-DallanC
 

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Here is some info on it from Chuck Hawks:

The 45th Edition of the Lyman Reloading Handbook also has a table showing Center Fire Rifle Velocity Vs. Barrel Length. Their figures apply to barrels between 20 and 26 inches in length and agree with the Remington figures. The Lyman table shows the following approximate velocity changes:

  • For rifles with muzzle velocities in the 1000-2000 fps range, the change in velocity for each 1" change in barrel length is 5 fps.
    For rifles with muzzle velocities in the 2001-2500 fps range, the change in velocity for each 1" change in barrel length is 10 fps.
    For rifles with muzzle velocities in the 2501-3000 fps range, the change in velocity for each 1" change in barrel length is 20 fps.
    For rifles with muzzle velocities in the 3001-3500 fps range, the change in velocity for each 1" change in barrel length is 30 fps.
    For rifles with muzzle velocities in the 3501-4000 fps range, the change in velocity for each 1" change in barrel length is 40 fps.
The 43rd edition of the Lyman reloading Handbook gave some concrete examples of velocity loss for specific calibers and loads. The Lyman technicians chronographed some high velocity cartridges in rifles with barrels ranging in length from 26 inches down to 22 inches with the following results:

  • The average loss for the .243 Win./100 grain bullet was 29 fps per inch.
    The average loss for the .264 Win. Mag./140 grain bullet was 32 fps per inch.
    The average loss for the .300 H&H Mag./220 grain bullet was 25 fps per inch.
For standard high intensity cartridges in the same test, the Lyman technicians chronographed the cartridges in barrel lengths ranging in length from 24 inches down to 20 inches with the following results:

  • The average loss for the .270 Win./130 grain bullet was 37 fps per inch.
    The average loss for the .270 Win./150 grain bullet was 32 fps per inch.
    The average loss for the .300 Sav./180 grain bullet was 17 fps per inch.
    The average loss for the .30-06/180 grain bullet was 15 fps per inch.
    The average loss for the .35 Rem./200 grain bullet was 11 fps per inch.
So caliber matters as well as to the velocity loss with shorter barrels.

-DallanC
 

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Discussion Starter #10

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Tikka T3 30-06 22" barrel 11 twist
Boyds laminate stock pillar/glass bedded
H4350 CCI primer Berger 155.5gr Hybrid
Have you tried the 175 gr Bergers? I haven't reloaded a lot yet for my .30-06 but am looking into the heavier bullets for it. I know the 175 gr Bergers are recommended as replacements for the highly accurate 7.5x55 rounds used in my Swiss K31's.
 

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Have you tried the 175 gr Bergers? I haven't reloaded a lot yet for my .30-06 but am looking into the heavier bullets for it. I know the 175 gr Bergers are recommended as replacements for the highly accurate 7.5x55 rounds used in my Swiss K31's.
No haven't! This is the first bullet I'm trying ... I'd probably go with a Nosler Accubond 165 if this one doesn't pan out before I go to 175.
 

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Have you tried the 175 gr Bergers? I haven't reloaded a lot yet for my .30-06 but am looking into the heavier bullets for it. I know the 175 gr Bergers are recommended as replacements for the highly accurate 7.5x55 rounds used in my Swiss K31's.
I wouldn't look at the BC of a particular bullet and think it will work in any gun without looking at what the bullet manufacture reccomend on twist rate of the rifle. I dont think 1/11 will stabalize the 175's.
 

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I wouldn't look at the BC of a particular bullet and think it will work in any gun without looking at what the bullet manufacture reccomend on twist rate of the rifle. I dont think 1/11 will stabalize the 175's.
Berger (http://www.bergerbullets.com/products/hunting-bullets/) says that only the 210gr 30 cal bullet requires 11 twist, all smaller bullets can do with slower twist ...

What reasons would there be to expect a heavier bullet to be more accurate? I like the velocity and hence flat(ter) trajectory of the 155gr.
 

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The 210 grain bullet matches the rifle twist. It also has a better bc. BC is all about slipping the wind long range. Do you want a perfect spiral when throwing a football? Yes and you want your bullets to stabalize as well. Matching reccomended twist rate gets you close.

If you dont care to shoot past 400 yards it probably doesn't matter with half inch groups like the op is getting with one of his loads.

Heavier bullets also retain their energy and speed longer. you can also match any buller to turret so verticle drop is one of the last things I'd look at unless you don't care to shoot past 400 yards
 

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Berger (http://www.bergerbullets.com/products/hunting-bullets/) says that only the 210gr 30 cal bullet requires 11 twist, all smaller bullets can do with slower twist ...

What reasons would there be to expect a heavier bullet to be more accurate? I like the velocity and hence flat(ter) trajectory of the 155gr.
It all just depends on your intended use for your rifle - If you're planning on shooting long range with it, I'd try to go with the heaviest bullets your twist rate will stabilize.

If you're just looking for a great deer load, anything from 150's to the 180's are fine. I really don't think you need a 210 to take a deer down with. Plus, the T3 magazine limits how far out you can seat those long heavies.

Those groups look great as they are. I'd try tweaking the seating depth to see if that helps tighten it up even more.
 
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