Ammo way slower (FPS) then advertised??

[huntsd]

Would love some feedback/help! I’m going hunting next week so, all this timing is pretty unfortunate! I am shooting Nosler e tip 180 out of a tikka 300 win mag (that usually shoots lights out with other ammo, just couldn’t find other ammo)

I dialed in at 100 then 300. I couldn’t hit a giant card board box at 500. The box says it’s 2950 FPS. I finally dialed my moa clicks to reflect 2700 fps I shoot pretty good groups at 3,4,5 and 600. I went back to 200 it hit high and then high again at 400. I’m not the best shot in the world but can usually put a good group down range with other ammo to 600.

I’d really appreciate feedback/thoughts!!

 

[SDHNTR]

You are spinning your wheels without a chronograph. Imo, anyone who wants to shoot past 300-400 yards needs one.

 

[huntsd]

You are spinning your wheels without a chronograph. Imo, anyone who wants to shoot past 300-400 yards needs one.

I’ve always been able to shoot pretty good groups to 600 and have never used one (just do math on hitting high/low and adjusting moa speed in ballistic calculations accordingly)

 

[SDHNTR]

That’s still guessing, due to the margin of human error. They aren’t that expensive nowadays anyhow. $100 and you’re in business. You’ll burn that up in ammo trying to figure out your drops.

 

[Vandy321]

You are spinning your wheels without a chronograph. Imo, anyone who wants to shoot past 300-400 yards needs one.

I disagree, dope is dope, it's all ballistics.

Pick a calm day and shoot, plug that drop into AB calc...math is never wrong.

Shooting a mile, sure, grab a chrono. Shooting at ethical big game ranges, not required for accurate dope.

Also, OP...my tikka bbl is 145fps slower than the box, and I'm at 5800ft ASL

 

[huntsd]

I disagree, dope is dope, it's all ballistics.

Pick a calm day and shoot, plug that drop into AB calc...math is never wrong.

Ya the strange part of all this is 2700 fps and moa clicks accordingly was dialed at 3-600 yards. Then I stepped back up to 2 and 400 and it was shooting high again

 

[Vandy321]

Ya the strange part of all this is 2700 fps and moa clicks accordingly was dialed at 3-600 yards. Then I stepped back up to 2 and 400 and it was shooting high again

You lost me, have no idea what you're saying.

Take your verified drop at 600 yards...plug that bullet into applied ballistics or hornady 4dof. Adjust speed until your AB apps drop at 600 until they sync up. Ensure the appropriate sight height, zero offset, environmental, barrel twist, length, etc entered...and then verify that dope again out to your max range. The further out you can start, the more accurate that # will be.

Just like any other calculation with respect to the data...garbage in = garbage out.

 

[huntsd]

You lost me, have no idea what you're saying.

Take your verified drop at 600 yards...plug that bullet into applied ballistics or hornady 4dof. Adjust speed until your AB apps drop at 600 matches your verified results, with the appropriate sight height, zero offset, environmental, barrel twist, length, etc entered...and then verify that dope again put to your max range. The further out you can start, the more accurate that # will be.

Just like any other calculation with respect to the data...garbage in = garbage out.

I used the speed of 2700 and moa clicks based of that speed. Good groups at 3,4,5,600. All verified that 2700 fps should be correct. Using the same speed of 2700 and moa clicks I shoot at 200 and 400 again (after I just verified at 3-600). Both distances provided very high groups

 

[Vandy321]

I used the speed of 2700 and moa clicks based of that speed. Good groups at 3,4,5,600. All verified that 2700 fps should be correct. Using the same speed of 2700 and moa clicks I shoot at 200 and 400 again (after I just verified at 3-600). Both distances provided very high groups

Not sure what to tell ya...assuming the data input is 100% correct at 600, the ballistic app is just doing the math. I'd start by double checking your inputs and shooting it again.

Warm barrel maybe? Did it warm up outside? Wind change? All can have an effect. So can changes in form/fundamentals...there is human error involved, bit I'll take verified/true'd dope anytime...chrono numbers are just a starting point.

My opinion, i'm not a pro, far from it.

 

[chaser_2332]

Best thing to do if u have access to the ranges is to shoot and verify, no need to use a calculator. As some has said the math is never wrong however it’s only as good as the input and there is a lot more input needed than speed. The speeds on the boxes are had best guesses anyway. I had a few guns built almost identical in barrel lengths and chambers and with the same load run diffent speeds that’s just the nature of the beast. You did have access to a chrono you could take that variable out of the equation, next i would tweak the BC for your bullet. Once a bullet if fired the BC isn’t going to be the exact same as the published data in some circumstances.

 

[Rob5589]

I used the speed of 2700 and moa clicks based of that speed. Good groups at 3,4,5,600. All verified that 2700 fps should be correct. Using the same speed of 2700 and moa clicks I shoot at 200 and 400 again (after I just verified at 3-600). Both distances provided very high groups

Scope, shooter, environmental changes?

 

[huntsd]

Scope, shooter, environmental changes?

I had a great rest. I really don’t think I pulled any of the shots. Maybe a little less right to left wind and a few degrees colder but that is all I can think of

 

[MidGAHunter]

So you zeroed at 100 then established your drops up to 600, then dialed back down to a previously verified drop and it didn't hit where it previously was hitting, correct? . If I'm reading that correctly, you may have a scope issue. Using ballistic calculators will get you close but ultimately truing up your setup to establish verified drops (like you did) is best. Since you did that and it didn't return when you dialed back, I'd worry about your scope.

 

[tdot]

If you're first attempt at 300, 400, 500 and 600 were good and then your second attempt at 400 was bad, and you used the same number of clicks for each group then something else has changed. Were both groups at 400 the same size? Just different locations on the target? Could be scope or just a mistake made while dialing. Do you dial back to zero each time or do you just add the difference between range adjustment? That could easily be an addition error. Lots of other things could be going on, I wouldn't solely focus on velocity.

For what its worth, I've just started load development for a friends Tikka. Factory ammo was 300-400fps slower then the box. Handloads today were right in the ballpark that load data said it should be. So it may not be the Tikka, it could be the Ammo.

 

[huntsd]

If you're first attempt at 300, 400, 500 and 600 were good and then your second attempt at 400 was bad, and you used the same number of clicks for each group then something else has changed. Were both groups at 400 the same size? Just different locations on the target? Could be scope or just a mistake made while dialing. Do you dial back to zero each time or do you just add the difference between range adjustment? That could easily be an addition error. Lots of other things could be going on, I wouldn't solely focus on velocity.

For what its worth, I've just started load development for a friends Tikka. Factory ammo was 300-400fps slower then the box. Handloads today were right in the ballpark that load data said it should be. So it may not be the Tikka, it could be the Ammo.

No i did not dial back to 0. For example of 300 was 4 moa and 400 was 6 moa I would just click up to 6 moa when I was ready to shoot at 400. Group sizes were all the same, about 1 moa.

 

[Rob5589]

I would dial back to zero, dial for elevation at the various yardages, and see where you're at. The way you describe it, sounds like a scope issue.

 

[Spoonman]

Just find a chrono and use it. Be sure of what you are shooting. Some bullets drop off faster than others.

 

[JPeters218]

Any chance when you went back to 200 and 400 you were using a new box of ammo? If it was different lot than what you zeroed with it could possibly be a little faster, causing you to be high now.

 

[davsco]

are you going to hunt in the same region in which you are sighting in? then a chrono and ballistic program isn't needed if (as it seems) you are actually shooting at 1,2,3,4,500 etc and getting your actuals drops/dials. you just want to go out and back a few times to make sure you, your scope, rifle and ammo are working and results are repeatable.

but yeah for $100 get a chrono or borrow a friend's or hang out at the range until someone shows up with one. make sure all your inputs (ballistic coefficient etc) are accurate.

sounds like you're shooting some pretty decent groups, so something else is going on with scope tracking or your data inputs.

 

[huntsd]

Any chance when you went back to 200 and 400 you were using a new box of ammo? If it was different lot than what you zeroed with it could possibly be a little faster, causing you to be high now.

It was same kind of ammo but thinking back now yes it could have been for my last shoot at 200 and 400