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I picked up some Perfecta brand ammo from walmart for my 308 Tikka t3. I thought it would be good for some basic target shooting and for sighting in the scope.

I have my rifle sighted in at 100 yrds. It was sighted in on a make shift rest of rifle cases and an old towel. No lead sled or solid rest.

The Perfecta grouping is freaking touching at 100 yrds. Pretty impressive.

I have been using Federal Fusion for my deer hunting round. The Fusions are hitting within a 1" in group at 100.

Just for fun I thought I would see how the group looks at 200 yrds. The Fusion box stated at 200 yrds I should be about 3.8" low. The perfecta box did not have any bullet drop info.

The Fusion shoot pretty much as stated. The Perfecta was closer to 9" low. There is only a 3 grain difference in the bullet weight.

Is there less powder in the Perfecta ammo which would account for droppage? I know the ammo was about $5 less a box. It just seems odd they can be so accurate at 100 but so far off at 200.


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Posts: 3879 | Location: Pittsburgh, PA, USA | Registered: February 27, 2001Reply With QuoteReport This Post
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With a scope over bore height of around 2", a 308 zeroed at 100 yards will generally see a POI of 3.5" to 4" low at 200 yards. I suspect this is the first time you've shot past 100 yards, so you don't have drop charts to 200. I suspect you also may not have chronograph data on either load.

So....we must back into things.
- What's your barrel length?
- What weights are the bullets? I'm guessing 150 on the Fusion and 147 on the Perfecta.
- Do the ammo boxes list expected muzzle velocities?
- Did anyone else shoot your rifle to confirm POI at 100 and 200 yards?
- What group sizes did you get at 200 yards? What kind of shape were they -- concentric, random, vertical stringing, horizontal stringing, or something else?
- Could you feel a difference in recoil between the two rounds?
- What type of bullet is used in the Perfect ammo? I'm guessing some kind of FMJ.
- What scope do you have and what magnification was used at 200 yards?
- Describe your targets at 100 and 200 yards. Shape, size, color, etc.
 
Posts: 5609 | Location: Colorado | Registered: January 26, 2008Reply With QuoteReport This Post
Freethinker
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quote:
Originally posted by gpbst3:
Is there less powder in the Perfecta ammo which would account for droppage?


Possibly, but in addition to the questions fritz raises, the ballistic coefficients of the bullets in the two loads are probably different, and that affects trajectories as well.
Bullets with more drag will lose velocity faster and therefore drop faster than those with less.




“Most men … can seldom accept the simplest and most obvious truth if it … would oblige them to admit the falsity of conclusions … which they have woven, thread by thread, into the fabrics of their lives.”
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Posts: 38766 | Location: 10,150 Feet Above Sea Level in Colorado | Registered: April 04, 2002Reply With QuoteReport This Post
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quote:
Originally posted by fritz:
With a scope over bore height of around 2", a 308 zeroed at 100 yards will generally see a POI of 3.5" to 4" low at 200 yards. I suspect this is the first time you've shot past 100 yards, so you don't have drop charts to 200. I suspect you also may not have chronograph data on either load.

So....we must back into things.
- What's your barrel length? 22 in
- What weights are the bullets? I'm guessing 150 on the Fusion and 147 on the Perfecta. Yes. You are good.
- Do the ammo boxes list expected muzzle velocities? Perfecta did not. Federal did but I do not have that info on hand
- Did anyone else shoot your rifle to confirm POI at 100 and 200 yards? no
- What group sizes did you get at 200 yards? What kind of shape were they -- concentric, random, vertical stringing, horizontal stringing, or something else? I really did not shoot enough to gather grouping data. It was more of a oh wow those shoot really low.
- Could you feel a difference in recoil between the two rounds? no
- What type of bullet is used in the Perfect ammo? I'm guessing some kind of FMJ. unknown
- What scope do you have and what magnification was used at 200 yards? leupold vx1 3x9 and used on 9 power
- Describe your targets at 100 and 200 yards. Shape, size, color, etc.
orange diamond approx 3 in on white backing


Wow. Lol. I was hoping this question was easily answered. I had no clue there can be this many variables.


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Posts: 3879 | Location: Pittsburgh, PA, USA | Registered: February 27, 2001Reply With QuoteReport This Post
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I ran best guess numbers through JBM ballistics. I assumed 3,000' Density Altitude, 100 yard zero, and 2" sight-over-bore height. Fusion with a muzzle velocity of 2800 fps, Perfecta with an MV of 2700 fps. Fusion lists its G1 BC at .414, which is in the ballpark for such a bullet. Fusion isn't listed in JBM's drop-down list of bullets. Perfecta's 147 also isn't in JBM's bullet list, but a 147 grain FMJ is listed under S&B (G1 BC of .402) and Winchester -- both of which produced similar flight results.

JBM predicts the Fusion 150 will drop 3.1" at 200 yards and 12.3" at 300 yards.
JBM predicts the Perfecta 147 will drop 3.6" at 200 yards and 13.7" at 300 yards.

As I expected, there is very little difference in flight ballistics between the two loads over close distances. Unless something is really wonky with your Perfecta ammo, the data suggests it's a shooter issue, not an ammo issue.
 
Posts: 5609 | Location: Colorado | Registered: January 26, 2008Reply With QuoteReport This Post
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Interesting. Thank you. I believe perfecta ammo has been discontinued. I think I only have about 20 rounds left so I dont think I will get too far with further testing.


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Posts: 3879 | Location: Pittsburgh, PA, USA | Registered: February 27, 2001Reply With QuoteReport This Post
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