Pellet speed H&N 5.5mm

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Caliber 22

Caliber 22

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Nov 29, 2023
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For the H&N Baracuda 18, 5.5mm I tried different speeds but always come back to 940 fps. As soon as I lower the speed the groups start opening. I see many guys try to set at below 900fps even before group testing as if it is a rule, that is why I tried to get the speed lower but it does not work.

Is this normal for some rifles or is this an odd one?
 
I am not sure what the bc of the Baracuda 18 is but it seems higher than what I saw elsewhere which also differs from source to source. If I use those bc #'s and dail according what Strelok then give me to dail, the POI is higher at the given muzzle velocity. If I then adjust the bc in Strelok to what I see on target, the bc figure is ridiculously high for pellets. But, the calculations only then correspond to the targets at different distances.
 
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JungleShooter said:
Would you mind sharing what BC you found? 👍🏼
And mybe what steps you used to measure it, and then to calculate it?

THANKS! 😊

Matthias
Click to expand...

Go directly to https://www.hn-sport.de/en. They should have all their pellet info there.

Product detailsBaracuda 18​

CALIBRE
.22 cal.
WEIGHT
18.13 gr
MIN. MUZZLE ENERGY
12 ft.lbs
MAX. DISTANCE
50 m
BC
0.029
CONTENT OF TIN
200 pcs.
 
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DualMagMike said:
Go directly to https://www.hn-sport.de/en. They should have all their pellet info there.

Product detailsBaracuda 18​

CALIBRE
.22 cal.
WEIGHT
18.13 gr
MIN. MUZZLE ENERGY
12 ft.lbs
MAX. DISTANCE
50 m
BC
0.029
CONTENT OF TIN
200 pcs.
Click to expand...
My rifle is zeroed on 50 meter at the measured speed of 940 fps.
If I input that BC into Strelok Pro and I shoot at the 100 meter target, Strelok ask for 4.5 mildot holdover / dial. (I dial.) Then it shoot about 100mm high and I miss the target. To hit where I aim I must dial 3.5 mildot, 1 mildot less. To correct it in Strelok with the speed at 940 fps I must input in Strelok a BC of 0.055. Much more than the 0.029 BC given by H&N. Unless I change the speed in Strelok to 1120 fps which is a incorrect speed, it is measured as 940 fps.
 
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You will notice that the G1 BC is used. I saw that the difference between G1, RA4 and GA is almost non-existent in this calculation.


photo_2024-01-07_16-37-07.jpg
photo_2024-01-07_16-37-16.jpg
 
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Here is a 10 shot, 100 meter group I just shot with the 3.5 MRad dialed in the scope. (With the omni-present two flyers. :mad: ) Light wind from left to right. If I dialed to 4.5 I would have missed the 20x20cm plate altogether.

Question: BC change with circumstances, is it not because the speed is higher that the BC is higher as well? But that much?
My knowledge and experience with BP rifles obviously does not count here and I am new to PCP.



photo_2024-01-07_17-00-16.jpg
 
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The BC values for pellets, when calculated using any of the G models, is at best a rough estimate. This is because there currently does not exist a G model which accounts for the diabolo shape of pellets. G1 is generally seen as the closest model, but it is still quite a bit off since it is assuming the shape to be a flat base, ogive nose, and "smooth body" for lack of a better term. When we use pellets that have a wasp waist and high FOC, the G1 model is quite a ways off.

In some atmospheric conditions, the G1 model can be close at shorter ranges. In other atmospheric conditions, it will be very inaccurate, even when using the same pellets. This is largely due to the tremendous effect of air drag on the pellets that the G1 model just cannot account for.

@Klaas Re your original post: Speed is only one factor impacting the stability (observed accuracy down range in this instance) of the pellets. Other things like barrel length, twist rate, atmospheric conditions, specific tune, etc. will also play a part. So when people say that a certain pellet flies great at 900 fps, this may not apply to other setups. All of the tuning elements need to live in harmony, and speed is only one of those elements.
 
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DualMagMike said:
Go directly to https://www.hn-sport.de/en. They should have all their pellet info there.

Product detailsBaracuda 18​

CALIBRE
.22 cal.
WEIGHT
18.13 gr
MIN. MUZZLE ENERGY
12 ft.lbs
MAX. DISTANCE
50 m
BC
0.029
CONTENT OF TIN
200 pcs.
Click to expand...


Yeah, DualMike, I have the BC's from the manufacturer... — you just never know how they derived them. That is why I asked the specifics how the poster measured & calculated the BC they got.

Cheers,

Matthias
 
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Klaas said:
My rifle is zeroed on 50 meter at the measured speed of 940 fps.
If I input that BC into Strelok Pro and I shoot at the 100 meter target, Strelok ask for 4.5 mildot holdover / dial. (I dial.) Then it shoot about 100mm high and I miss the target. To hit where I aim I must dial 3.5 mildot, 1 mildot less. To correct it in Strelok with the speed at 940 fps I must input in Strelok a BC of 0.055. Much more than the 0.029 BC given by H&N. Unless I change the speed in Strelok to 1120 fps which is a incorrect speed, it is measured as 940 fps.
Click to expand...


Thanks for posting the details of your setup.


➊ Maybe somehow I'm misunderstanding you:
Because a higher BC will give you a higher POI (the pellet flies faster, so gravity has less effect on it per yard traveled).
Your example seems to show the opposite.


➋ Have you entered the atmospheric conditions for when you zeroed your scope/rifle — and then again when you shot the 100 yard group?
Especially a change in altitude can have a huge effect on ballistics.
At higher altitudes the air is less dense, so is causes less friction on the pellet.


Very interesting, I'm looking forward getting to the bottom of this. 👍🏼

Matthias
 
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Spartan said:
The BC values for pellets, when calculated using any of the G models, is at best a rough estimate. This is because there currently does not exist a G model which accounts for the diabolo shape of pellets. G1 is generally seen as the closest model, but it is still quite a bit off since it is assuming the shape to be a flat base, ogive nose, and "smooth body" for lack of a better term. When we use pellets that have a wasp waist and high FOC, the G1 model is quite a ways off.

In some atmospheric conditions, the G1 model can be close at shorter ranges. In other atmospheric conditions, it will be very inaccurate, even when using the same pellets. This is largely due to the tremendous effect of air drag on the pellets that the G1 model just cannot account for.

@Klaas Re your original post: Speed is only one factor impacting the stability (observed accuracy down range in this instance) of the pellets. Other things like barrel length, twist rate, atmospheric conditions, specific tune, etc. will also play a part. So when people say that a certain pellet flies great at 900 fps, this may not apply to other setups. All of the tuning elements need to live in harmony, and speed is only one of those elements.
Click to expand...
Thanks for the reply. I don't have a problem with the speed, I just try to understand why the differences.


JungleShooter said:
Thanks for posting the details of your setup.


➊ Maybe somehow I'm misunderstanding you:
Because a higher BC will give you a higher POI (the pellet flies faster, so gravity has less effect on it per yard traveled).
Your example seems to show the opposite.


➋ Have you entered the atmospheric conditions for when you zeroed your scope/rifle — and then again when you shot the 100 yard group?
Especially a change in altitude can have a huge effect on ballistics.
At higher altitudes the air is less dense, so is causes less friction on the pellet.


Very interesting, I'm looking forward getting to the bottom of this. 👍🏼

Matthias
Click to expand...
"Because a higher BC will give .... " Yes, higher BC will give higher POI, that is why with the given BC 0.029 from H&N, and others are not much different, you must dial more than for the 0.055 BC I am using in Strelok. (Edit .... The Strelok examples show the amount I must dial (or hold over) for each BC value. )

"Have you entered the atmospheric conditions .... " Yes, the atmospheric conditions as shown in the Strelok screenshots are valid for today. The temperature is the actual at home at the time of shooting and the pressure and humidity I took from https://meteotrend.com , the closest I can get since I can't measure it myself.




Thanks for all the replies.
 
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The best pellet I have tried in my P35-22 is the H&N Baracadu Match. The regular Baracuda and the Baracuda Power are both accurate too but the Match are more consistent and a little more accurate. I'm shooting it with the regulator setting it came with, I've just fine tuned the hammer spring. I'm shooting them about 835 fps in the summer and probably more like 815 fps now. I've shot a 200 on the 30 yard challenge with this gun and pellets, it is accurate.

I do not think that there is a perfect velocity for a particular pellet. I think it is the tune of the gun that makes the pellet more accurate. If that tune happens to put them out at over 900 fps, then that is their best velocity in that gun. But I haven't really tried other velocities in my P35-22. It put three into exactly the same hole at 25 yards twice when I was doing initial pellet testing. It shot JSB 18 grain well too at 25 yards but not as accurately as the H&Ns at 35 yards. They were going much faster, close to 900 fps.

Ted from Ted's holdover said in a video that he won a 100 yard benchrest competition shooting at 840 fps when most competitors were shooting much faster. It was very windy and he thought that made the high velocities unstable. My Avenger used to be tuned to about 930 fps but it didn't shoot well at 100 yards at this velocity. It did shoot well out to 35 yards. I reduced it to 900 or a little less.

If I had a gun shooting great at 930 with a 21 grain pellet I would try a 25 grain pellet. Might shoot even better. But it it holds it's accuracy to 100 yards when there is some wind I'd probably just shoot it as is.
 
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Klaas,

your shooting results defy any ballistic sense.... 😆 (Unless I somehow misread or misunderstand you! 😊)


❓ What scope height did you enter into the scope entry fields?

The Strelok screenshot shows 4.00.
➧ Is that 4.00cm, or 4.00", or what?
➠ Your scope and/or barrel must have a very small diameter to allow such a low scope mounting....

Matthias
 
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Klaas said:
It is 4cm. It is a Discovery HD 3_12x44. It just clear the barrel shroud. It is to low for the magazine so I single feed which I did even when it had high mounts on to use the magazine.
Click to expand...



Cool! 👍🏼 I have the same scope, nice.
I'd love to mount my scopes lower, but bullpup makers all seem to think that shooters can't be bothered to buy high scope rings — so they force on us bullpup users a high scope rail, even though there is no magazine to clear.... 🤦🏻‍♂️


However.... — this still doesn't solve the mystery of your unexpectedly high shots..... 🤷🏻‍♂️

Matthias
 
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OK, this is intriguing.

I replicated your Strelok Pro data — AND they match!:
I got 4.6mil up (with 0.029BC) — you got pretty much the same (4.47mil).

[EDIT: The following pararaph assumed Klaas was aiming for the bulls' eye, but he was aiming at the top left cross...., so the following paragraph is mute:]
BUT your shots are HIGH at your 100m steel target:
They are (eyeballing the group) about 2.5cm high = 0.25mil.
AND you dialed only 3.5mil (=35cm) instead of 4.5mil (=45cm).



You shot an awesome group!! Very tight!


So, here are some other things to check or test to see if they fix this error.


➊ Does your scope touch the barrel/shroud at all?
Just yesterday I installed that same scope model on a picatinny rail with low mounts, and could not squeeze a piece of paper between rail and objetive bell. Definitely a no-no, I had to change the rings for something a bit higher.
Fortunately, I didn't tighten down the rings, otherwise, I might have bent the scope tube.... 😱


➋ Do you have a barrel band installed? Or do your airtube and the shroud touch each other at some point?
If that is the case, next uestion: Do you possibly "load the bipod" when shooting (or otherwise make the gun press downward into the shooting bags or bipod)?
➠ Then, the barrel might get bent up just a fraction of a milimeter, and shoot high.


➌ Some might say that the scope you (and I) are using to dial our elevation is not expensive enough to do that reliably.
In other words, when you turn the elevation turret 5.0 mils up, the reticle does not consistently move up 5 mils, but less, or more.
You can test that (some YouTube instructionals out there), and Strelok allows you to enter a corrected click value (GPC has a turret click validator app).


Cheers,

Matthias 😊
 
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I remembered seeing some BC figures from one of Matt Dubber's videos and had to look for it. There you can see that for the JSB 18.13 the BC is not the same as what JSB themselves are giving and also it changed in flight. It start out with higher BC and decrease as the speed bleed off and / or the pellet gets unstable. That might mean that at even higher speed the BC might be higher. Together with other conditions unknown to me, the BC might reach the BC .055 number I am seeing. Unless the muzzle velocity is higher which I doubt. I don't have another chronograph to compare and confirm and I don't know somebody with one I can use. I only have the HT-X3005 unit. Steve Allan did a review on the previous model XT-X3000 and compared it to other commercial chronographs and found it to be accurate. I only use it to test the speed and then take it off when I am shooting for groups. That said, I did have the chrono on the barrel a few times when shooting groups and did not see any difference when shooting like that.


photo_2024-01-09_18-14-08.jpg



Matt Dubber JSB BC.jpg



And this is coming from his video at around 4:20 :

 
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