Inconsistent bc

[blacktailcentral]

Hello fellow roksliders,

Have yall experienced inconsistent bcs before, I live in the great state of commiefornia, and must use non lead ammo. I have been hand loading for my 25 saum with the 110 hammer hunters and it seems the bc at 300-400 is much much different than extended ranges.

 

[Fire_9]

Tune you bc to match up with your actual drops. Not uncommon for the advertised be to be wrong

 

[blacktailcentral]

Tune you bc to match up with your actual drops. Not uncommon for the advertised be to be wrong

Yes unfortunately that’s not the issue, my bc at 300 yards is spot on then go to 400 yards and is almost a full moa off.

 

[wapitibob]

Yes unfortunately that’s not the issue, my bc at 300 yards is spot on then go to 400 yards and is almost a full moa off.

that's likely an app and data input issue

 

[Bluefish]

Hello fellow roksliders,

Have yall experienced inconsistent bcs before, I live in the great state of commiefornia, and must use non lead ammo. I have been hand loading for my 25 saum with the 110 hammer hunters and it seems the bc at 300-400 is much much different than extended ranges.

Bc is not a single number. It changes with velocity. I have also found non tipped hammers were lower than advertised.

 

[Fire_9]

Yes unfortunately that’s not the issue, my bc at 300 yards is spot on then go to 400 yards and is almost a full moa off.

Using a bubble level?

 

[Wrench]

Have you tall target tested? Shot at extended ranges? Monitored MV with a reliable chronograph?

I ask because it takes a pretty substantial scrub in bc to show up that close.

You're more likely missing something on your data input.

 

[blacktailcentral]

Bc is not a single number. It changes with velocity. I have also found non tipped hammers were lower than advertised.

Definitely this rifle is going fast so bc is higher out the muzzle but degrades as velocity slows

 

[blacktailcentral]

Have you tall target tested? Shot at extended ranges? Monitored MV with a reliable chronograph?

I ask because it takes a pretty substantial scrub in bc to show up that close.

You're more likely missing something on your data input.

Using a garmin xero, no tall test but have shot out past 1000

 

[blacktailcentral]

Using a bubble level?

Yes

 

[Fire_9]

So are drops lining up at further distances? Using the correct pressure input?

 

[blacktailcentral]

At further distances they have been lining up

 

[SloppyJ]

Yes unfortunately that’s not the issue, my bc at 300 yards is spot on then go to 400 yards and is almost a full moa off.

That's a bigger issue with your zero, velocity, BC or rifle. How'd you zero your rifle? Let's start there.

 

[JFK]

So I assume you have a solid 100 yard zero?

At 300 yards it’s on. At 400 yards it’s off. High or low?

Then further than 400 it’s on?

I’d reconfirm zero with at least 10 shots. More is better. Then shoot at a waterline at 200, 300, 400 and beyond.

 

[blacktailcentral]

That's a bigger issue with your zero, velocity, BC or rifle. How'd you zero your rifle? Let's start there.

Zeroed with a 5 shot group, zero is on

 

[Wrench]

At 400 you could use virtually any BC you can dream of and be within 1 MOA. It's not a BC issue ESPECIALLY if you're tracking beyond 600.

 

[blacktailcentral]

Going to check zero again this week, might be slightly off and have the bc slightly off and the stacked tolerances are creating the discrepancy

 

[schmidty3]

You've gotta be pushing 3400+ fps right?

How off are we talking?

Taking a stab at it based on my 25 prc experience....

.2 mil at 200
.7 at 300
~1.2 at 400
~2 at 500?

Should be a pretty flat sucker.

 

[blacktailcentral]

You've gotta be pushing 3400+ fps right?

How off are we talking?

Taking a stab at it based on my 25 prc experience....

.2 mil at 200
.7 at 300
~1.2 at 400
~2 at 500?

Should be a pretty flat sucker.

It’s a 21” barrel so I’m right at 3300, the drop at 400 was 3 moa so essentially right at 1.2 mil. But all the ballistic calculators are calling for 4.5 moa at that distance

 

[schmidty3]

It’s a 21” barrel so I’m right at 3300, the drop at 400 was 3 moa so essentially right at 1.2 mil. But all the ballistic calculators are calling for 4.5 moa at that distance

Well your first problem is right in your face....whats all this MOA stuff?

What is it at 500? Thats like your 500 number

For it to be that far off something is whack and its not the BC you are putting in.

What calculator? Go through the inputs it again