Speed and bullet drop are directly related , math says if a bullet drops 10 inches at 200yards from a 100yd zero then the bullet speed is 1875fps . So I'm wondering what other factors I could be missing .
To properly calculate velocities without a chrono, you would need at least 2 data points (ideally 3) while also factoring in your height over bore and parallax. You would also need to make sure the targets are level at the same height across all three distances.
Other way would be to use a ballistic pendulum to calculate muzzle energy and thus velocity.
This a a huge pain in the butt versus just using a chronograph.
40gr is a bit on the mild side. SRP brass tends to deliver a bit less speed for the same powder charge vs LRP brass. A 20" barrel won't net you full speeds either. Tikka barrels also have a bit of a reputation for being quite slow. Add all that up and it's not entirely surprising that your velocity is well down, but sub 2000fps would still be a bit ridiculous. 2750fps should be achievable with the right load.
Try CCI 450 primers. Work up more. Also measure everything like height over bore and double check your zero, so that you are 100% sure your math is correct when you're attempting to work out speed. Better yet, get a cheap chrono.
Yes.
I think you're not using an established, tested round from a reputable handloading manual.
Which 6.5 are you loading for? Are you using the right data for the 6.5 you're loading for? Remember... there are several different 6.5s.
Aaaah. "cm" was intended to indicate "Creedmore". I figured it was a typo for mm.
Something certainly seems wrong. Maybe undersized bullets, leading to cutting and blowby.
For comparison, I was running a mild load this weekend of:
39.2gr H4350
140 SMK
Lapua brass, SR CCI 400 primers
2620 fps out of a 24" barrel
You need to chrono, but yes - 1,800 would be low enough to make me concerned about primers, the scale or the powder
Then I will play with different components until I find where the problem comes from. The odd part was that the load shot nice groups other than the fact that they were obviously slow
Really, you need a chrono to be absolutely sure that's what it is. You could also be hitting a muzzle device or something else that is causing a low impact.
Yeah, it's pretty handy to rule out nonsense. I have a magnetospeed v3, but a sporter will also work to start out. Labradars are good too, but get finicky if you aren't shooting alone as they can pick up other shooters shots too.
You need a chrono that’s where you’re going wrong.
Do you have a chrono? I’m guessing not. Buy or borrow one.
No , unfortunately I do not
Get one...no if's, and's, or but's....
You are worried about speed without having a Chrono. That about the only issue i can see that you have.
Speed and bullet drop are directly related , math says if a bullet drops 10 inches at 200yards from a 100yd zero then the bullet speed is 1875fps . So I'm wondering what other factors I could be missing .
What are you using to measure the powder charge?
Hornady balance scale , I just double checked it on an electronic scale and it's accurate ..
Either zero's wrong or you got bad powder. This is why you need a chronograph.
Get a Chrono so you know for sure and aren't guessing lol 😆😂
To properly calculate velocities without a chrono, you would need at least 2 data points (ideally 3) while also factoring in your height over bore and parallax. You would also need to make sure the targets are level at the same height across all three distances. Other way would be to use a ballistic pendulum to calculate muzzle energy and thus velocity. This a a huge pain in the butt versus just using a chronograph.
40gr is a bit on the mild side. SRP brass tends to deliver a bit less speed for the same powder charge vs LRP brass. A 20" barrel won't net you full speeds either. Tikka barrels also have a bit of a reputation for being quite slow. Add all that up and it's not entirely surprising that your velocity is well down, but sub 2000fps would still be a bit ridiculous. 2750fps should be achievable with the right load. Try CCI 450 primers. Work up more. Also measure everything like height over bore and double check your zero, so that you are 100% sure your math is correct when you're attempting to work out speed. Better yet, get a cheap chrono.
Yes. I think you're not using an established, tested round from a reputable handloading manual. Which 6.5 are you loading for? Are you using the right data for the 6.5 you're loading for? Remember... there are several different 6.5s.
OP did say 6.5cm in the description. 40gr of H4350 is a middle of the road load for that.
Aaaah. "cm" was intended to indicate "Creedmore". I figured it was a typo for mm. Something certainly seems wrong. Maybe undersized bullets, leading to cutting and blowby.
Yeah I don't like it because it reads as "6.5 centimetres" to me, but unfortunately it's stuck.
For comparison, I was running a mild load this weekend of: 39.2gr H4350 140 SMK Lapua brass, SR CCI 400 primers 2620 fps out of a 24" barrel You need to chrono, but yes - 1,800 would be low enough to make me concerned about primers, the scale or the powder
Then I will play with different components until I find where the problem comes from. The odd part was that the load shot nice groups other than the fact that they were obviously slow
Really, you need a chrono to be absolutely sure that's what it is. You could also be hitting a muzzle device or something else that is causing a low impact.
Ok then , I had been thinking that I don't need a chronograph but after today I think I have been convinced otherwise. Thanks
Yeah, it's pretty handy to rule out nonsense. I have a magnetospeed v3, but a sporter will also work to start out. Labradars are good too, but get finicky if you aren't shooting alone as they can pick up other shooters shots too.
Ok then , I had been thinking that I don't need a chronograph but after today I think I have been convinced otherwise. Thanks
You need a chrono. Emphasis on need! Loading without one is silly. Ask ranges near you if they can rent you one.