
09-04-2010, 05:32 AM
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Beartooth Regular
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Join Date: Nov 2006
Posts: 83
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7MM-08 AI Velocities?
Took my son's Savage 7MM-08 AI out for a test drive yesterday. I tested three powders, MRP, Hunter and DP 86 with 160gr Nosler Partitions. Here are some numbers.
Hunter.
48gr---2705fps
48.5gr-2724
49gr---2766
49.5gr-2797
50gr---2820
50.5gr-2850
51gr---2884
51.5gr-2893
52gr---2894
MRP
47gr---2626
47.5gr-2722
48gr-error
48.5gr-error
49gr-error
49.5gr-error
Replace battery
50gr---2704
50.5gr-2744
51gr---2781
51.5gr-2803
52gr---2833
DP-86
47gr---2667
47.5gr-2710
48gr---2742
48.5gr-2746
49gr---2781
49.5gr-2833
50gr---2843
50.5gr-2869
51gr---2888
51.5gr-2910
This DP-86 powder/bullet combo was pretty accurate as the group from this 47-51.5gr spread was just over 2 inches.
What do ya think?
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09-04-2010, 08:20 AM
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Beartooth Regular
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Join Date: Nov 2006
Location: Missouri
Posts: 1,392
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Those are some pretty hot velocities with 160s in a 7-08. My 7mm WSM doesn't do much better than that. It does shoot better than 2" groups though. Maybe you need to try a different bullet or ratchet down the speed a little to find a load that groups under an inch? Normally Savage's will with the right load.
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09-04-2010, 09:54 AM
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Beartooth Regular
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Join Date: Sep 2009
Location: Mooresville, IN
Posts: 7,351
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The Ramshot Hunter charge looks a little excessive, but the other two seem pretty safe. I understand the DP86 is just a tad faster than 3100, but not quite as bulky. I think all three of those powders are excellent for the 7-08 AI and the velocity you're getting is nothing to sneeze at! You're getting 280 Remington performance out of that short-action job which is pretty cool. I hope your son is in his late teens or just doesn't mind recoil, because you're definitely knocking on the door of 7RM kick, there...
Looks like it's time to adjust your seating depth and find a load that impresses you from an accuracy standpoint. If you're getting 2" 5-shot groups at 100 yards, you can probably do a little better. How many rounds do you have through the barrel, at this point? Has it shot other ammunition for better groups than that, before? There was a time when 2" at 100 yards was plenty accurate, but with the Savage platform and well-made handloads, you ought to be able to cut 'em about in half.
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09-04-2010, 12:22 PM
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Beartooth Regular
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Join Date: Nov 2006
Posts: 83
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Quote:
Originally Posted by Bird Dog II
Those are some pretty hot velocities with 160s in a 7-08. My 7mm WSM doesn't do much better than that. It does shoot better than 2" groups though. Maybe you need to try a different bullet or ratchet down the speed a little to find a load that groups under an inch? Normally Savage's will with the right load.
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Yeah, but the 2 inch group was with 47gr to 51gr fired at the same target. Not bad for no fine tuning and a 4 grain spead.
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09-04-2010, 01:04 PM
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Beartooth Regular
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Location: Missouri
Posts: 1,392
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I really concentrate on 3 shot groups from a cold gun for hunting loads. (Since you're using partitions, I assume you are developing hunting loads?) What kind of accuracy are you getting with your best 3 shot groups? Also, that is a lot of different loads, have you narrowed it down to 2 or 3 to try and perfect?
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A well regulated militia being necessary to the security of a free State, the right of the People to keep and bear arms shall not be infringed.
Last edited by Bird Dog II; 09-04-2010 at 03:12 PM.
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09-04-2010, 03:09 PM
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Beartooth Regular
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Quote:
Originally Posted by Steve4102
Yeah, but the 2 inch group was with 47gr to 51gr fired at the same target. Not bad for no fine tuning and a 4 grain spead.
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Forgive me for asking, but what is the point of firing all of those rounds at the same target, if you're trying to see which is most accurate? Were you strictly testing for velocity, or something? Truth be told, hunters really don't need to worry much about velocity and have little to no need to chronograph their loads. If you have a round that's sub-MOA out to 300 yards, from a modern center-fire round, like your 7MM-08 AI, it matters very little whether they're going 2875fps at the muzzle, or 2750fps...they'll kill just as well and the difference in trajectory is truly negligible. Now, I'm one of those who just likes to know, and I'm presuming you are too, but velocity is something you check AFTER you've found a load that is consistently accurate from your gun.
Shooting a bunch of different powder charges at one, single target, such that you learn nothing about the potential accuracy of any given charge is...well, kinda dumb. It's your powder and bullets, and I'm sure it was a lot of fun, but you might as well have been throwing the lead at the target and pouring the powder on the ground, for all the good it did.
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09-04-2010, 05:03 PM
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Beartooth Regular
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Join Date: Nov 2006
Posts: 83
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Quote:
Originally Posted by broom_jm
Forgive me for asking, but what is the point of firing all of those rounds at the same target, if you're trying to see which is most accurate? Were you strictly testing for velocity, or something? Truth be told, hunters really don't need to worry much about velocity and have little to no need to chronograph their loads. If you have a round that's sub-MOA out to 300 yards, from a modern center-fire round, like your 7MM-08 AI, it matters very little whether they're going 2875fps at the muzzle, or 2750fps...they'll kill just as well and the difference in trajectory is truly negligible. Now, I'm one of those who just likes to know, and I'm presuming you are too, but velocity is something you check AFTER you've found a load that is consistently accurate from your gun.
Shooting a bunch of different powder charges at one, single target, such that you learn nothing about the potential accuracy of any given charge is...well, kinda dumb. It's your powder and bullets, and I'm sure it was a lot of fun, but you might as well have been throwing the lead at the target and pouring the powder on the ground, for all the good it did. 
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It's a new to me chamber, 7mm-08 AI and there is little or no data available. I loaded up one bullet (160gr Partition) and tested three powders for velocity and pressure. Accuracy tests will come later now that I know the charge limits of these powders.
I will post the results of my 5 shot accuracy test when I get them finished.
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09-04-2010, 07:19 PM
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The Hog Whisperer (Administrator)
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Join Date: Jan 2001
Posts: 24,114
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Have you thought about trying Dan Newberry's method for load development?
See this:
http://www.shootersforum.com/showthread.htm?t=64349
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