Hammer ballistic coefficients

[Don Titus]

I have had good success with 181 Hammer Hunters. I recently replaced my REM 700 in 300 WM with a Tikka T3X in the same caliber with a 1:10" twist and a magazine length of 3.370". Steve Davis recommended the 174 gr. which is designed to shoot well in rifles with short magazines. The scope is a Sig Sierra 3x18 BDX which can be programmed with ballistic data to establish holds at up to five specific distances based on bullet type, weight, FPS and ballistic coefficient. The problem is Hammer doesn't publish BC data. I have searched the internet and found two different G7 BC's referenced for the 174: .208 and .247.

Can anyone verify what the true G7 is for this bullet?

Thanks

 

[ButterBean]

You will need to verify it yourself at distance, BC is not a static number and can be changed by many variables

 

[Don Titus]

You will need to verify it yourself at distance, BC is not a static number and can be changed by many variables

When BC's are published by manufacturers, how do they do it? Is there a standard method? Of so, where is it published?

 

[Don Titus]

When BC's are published by manufacturers, how do they do it? Is there a standard method? Of so, where is it published?

 

[ButterBean]

When BC's are published by manufacturers, how do they do it? Is there a standard method? Of so, where is it published?

Estimated BC's are on the Hammer website listed with every bullet

 

[T3ninja]

I had to change mine quite a bit for the 196 out of my .300W. I don't remember what the website says but I ended up with "G7 .229" This put me on the money out to 740 yards with first round hits inside a 3ish" target at 4 and 500 yards.

I didn't do an actual "drop" test, I just used my dialed dope from a very good 100 yard zero. Scope used was a new NX8, velocity was obtained with labradar AND magneto speed in unison. I did a tracking test with the NX8 at a (tape) measured 100 yards, from a fixed rest. ( a scope based drilled/tapped into a 700 LB tractor weight, so I can attach a ringed optic) the scope passed with perfection from what I could do.



EDIT: Estimated G7 BC IS .268 by HAMMER.
MY, verified BC is .229

 

[ButterBean]

I had to change mine quite a bit for the 196 out of my .300W. I don't remember what the website says but I ended up with "G7 .229" This put me on the money out to 740 yards with first round hits inside a 3ish" target at 4 and 500 yards.

I didn't do an actual "drop" test, I just used my dialed dope from a very good 100 yard zero. Scope used was a new NX8, velocity was obtained with labradar AND magneto speed in unison. I did a tracking test with the NX8 at a (tape) measured 100 yards, from a fixed rest. ( a scope based drilled/tapped into a 700 LB tractor weight, so I can attach a ringed optic) the scope passed with perfection from what I could do.



EDIT: Estimated G7 BC IS .268 by HAMMER.
MY, verified BC is .229

I do the same thing

 

[dflyfish]

The 169 hammer hunters I worked up for a 7 LRM we're very close to published numbers. Verified drops to 800 and they shot well to 1050 on steel

 

[Doc88]

Verify drops out to as much distance as you can. Play with the BC in your ballistic calculator until the drops match. I usually adjust the middle number as needed. I find this the best way to match Hammer Bullet results with ballistic calculator rather than adjusting velocity. The rule of thumb is to adjust velocity out to 600 yards and BC past 600. Best results have been from only adjusting the BC. I us the AB mobile app and live at sea level. By doing this I'm able to get first round hits out to 750 yards (as far as my little range goes) with several different Hammers

 

[naja302]

In the ones I've shot it's been significantly lower than advertised

 

[7070yshot]

Estimated BC's are on the Hammer website listed with every bullet

They either use a mathematical guess or have bullets shot and measured with a Doppler radar like what applied ballistics lab uses. These are 100kplus$ machines.
also you are given an average and for 600y shot and under it will very close. After that things can fall off IMO and certainly ones the bullet hits 1250fps (transonic) the BC changes then again at 1100-1050.

Even the AB Labs Doppler system only goes out to 2000y from there data is extrapolated (mathematical guess)

my advice is use the box BC or Your App bullet library. Adjust velocity to match actual come up in MOA/Mils out to 600-900. Then have a second table or do a BC calibration for wherever you hit transonic. Meaning if BC is .425 but you hit 2MOA low at 1000y adjust BC until the come up matches impact

 

[ButterBean]

They either use a mathematical guess or have bullets shot and measured with a Doppler radar like what applied ballistics lab uses. These are 100kplus$ machines.
also you are given an average and for 600y shot and under it will very close. After that things can fall off IMO and certainly ones the bullet hits 1250fps (transonic) the BC changes then again at 1100-1050.

Even the AB Labs Doppler system only goes out to 2000y from there data is extrapolated (mathematical guess)

my advice is use the box BC or Your App bullet library. Adjust velocity to match actual come up in MOA/Mils out to 600-900. Then have a second table or do a BC calibration for wherever you hit transonic. Meaning if BC is .425 but you hit 2MOA low at 1000y adjust BC until the come up matches impact

X-2 , That goes for every bullet, Not just Hammers

 

[dougduey]

I have had good success with 181 Hammer Hunters. I recently replaced my REM 700 in 300 WM with a Tikka T3X in the same caliber with a 1:10" twist and a magazine length of 3.370". Steve Davis recommended the 174 gr. which is designed to shoot well in rifles with short magazines. The scope is a Sig Sierra 3x18 BDX which can be programmed with ballistic data to establish holds at up to five specific distances based on bullet type, weight, FPS and ballistic coefficient. The problem is Hammer doesn't publish BC data. I have searched the internet and found two different G7 BC's referenced for the 174: .208 and .247.

Can anyone verify what the true G7 is for this bullet?

Thanks

My Kestrel lists the 181 at a G7 of .232, while Litz has it listed at .272. So, you see there can be a difference. I've tended to go by what my Kestrel says the number is, but it makes very little difference from 500 yards or less. Only way you'll find out is to get actual drop data at longer distances.
Also, check the twist on your Tikka, for it should be 1:11 not 1:10.

 

[Don Titus]

In the ones I've shot it's been significantly lower than advertised

Yep, that's what I've heard from other sources...

My Kestrel lists the 181 at a G7 of .232, while Litz has it listed at .272. So, you see there can be a difference. I've tended to go by what my Kestrel says the number is, but it makes very little difference from 500 yards or less. Only way you'll find out is to get actual drop data at longer distances.
Also, check the twist on your Tikka, for it should be 1:11 not 1:10.

Tikka changed the twist for the 300 WM last February to 1:10, in recognition of where the market was headed with long, higher BC bullet designs. I was lucky to get one of the first of these when they became available.