Page 1 of 1
Reloading impact question ❓
Posted: Thu Oct 26, 2023 5:28 pm
by Diver43
OK, to make a long story short. Loading .308 167 gr ELD-M bullets over 40 grains, 41 grains and 42 grains of powder. 40 grains impact wad approx 5 inches high. 41 grains 3 inches and 42 grains was an inch high.
I am not an experienced reloader nor a roçket scientist. But, my thinking says it should have been the opposite
Can anyone make me a little smarter ?-
Re: Reloading impact question ❓
Posted: Thu Oct 26, 2023 5:37 pm
by PFD45
Might be due to higher velocity = lower dwell time for the bullet in the barrel.
The bullet gets out of the barrel before it rises more.
Or sun spots?
Re: Reloading impact question ❓
Posted: Thu Oct 26, 2023 7:22 pm
by Wambli Ska
Harmonics, I’ll call you. Can’t type that much…
Re: Reloading impact question ❓
Posted: Thu Oct 26, 2023 9:00 pm
by GrapeApe
Wambli Ska wrote: ↑Thu Oct 26, 2023 7:22 pm
Harmonics, I’ll call you. Can’t type that much…
Yep, it takes something like 0.01" or 0.001" (I forget which) of movement at the muzzle to move the POI 1" @ 100 yards. and if you get a chance to see a CF rifle being shot on a super slow motion camera, the muzzle whips around like you wouldn't believe. Where the muzzle is when the bullet leaves is a HUGE thing
Re: Reloading impact question ❓
Posted: Thu Oct 26, 2023 9:59 pm
by GrapeApe
Re: Reloading impact question ❓
Posted: Thu Oct 26, 2023 11:38 pm
by Diver43
Amazing. I have heard of barrel harmonics, but thought it was vibration, not actual movement
Re: Reloading impact question ❓
Posted: Thu Oct 26, 2023 11:39 pm
by Diver43
Amazing. I have heard of barrel harmonics, but thought it was vibration, not actual movement
Re: Reloading impact question ❓
Posted: Thu Oct 26, 2023 11:52 pm
by Linefinder
Simple answer....the longer your bullet stays in the barrel, the higher it's going to hit.
Mike
Re: Reloading impact question ❓
Posted: Fri Oct 27, 2023 1:31 am
by Freezer
This may sound overly simple but work your load up one grain at a time. When you find the most accurate, change it by one quarter and a half grain up and down till you find the most accurate load. Use the load charts to determine the trajectory and be happy.
If you really want a good book on the subject, get "Understanding Firearms Ballistics". It is written in three levels, so everyone can understand it. For the novice it has simple explanations, and for the expert and mathematician it has the formulas.
Needless to say, I failed math but was engrossed with the book. I don't have it anymore, but now that I'm reloading and shooting more, I may have to find it on kindle.
Re: Reloading impact question ❓
Posted: Fri Oct 27, 2023 1:34 am
by GrapeApe
Yep Robert A. Rinker's book is a GREAT resource
Re: Reloading impact question ❓
Posted: Fri Oct 27, 2023 1:39 am
by Diver43
Freezer wrote: ↑Fri Oct 27, 2023 1:31 am
This may sound overly simple but work your load up one grain at a time. When you find the most accurate, change it by one quarter and a half grain up and down till you find the most accurate load. Use the load charts to determine the trajectory and be happy.
If you really want a good book on the subject, get "Understanding Firearms Ballistics". It is written in three levels, so everyone can understand it. For the novice it has simple explanations, and for the expert and mathematician it has the formulas.
Needless to say, I failed math but was engrossed with the book. I don't have it anymore, but now that I'm reloading and shooting more, I may have to find it on kindle.
I did work my way up to max load. Each step closed the group and brought it closer to POA.
Re: Reloading impact question ❓
Posted: Fri Oct 27, 2023 10:57 am
by GrapeApe
POA is a variable, and a load hitting close to the existing POA is fairly irrelevant since you can adjust POA for the chosen load.
In my 6.5 Grendel, EVERY load I've tried with Nosler Ballistic tips shoots considerably left (3-4") of the established POA of both Hornady Amaxes and Speer Gold Dots
Re: Reloading impact question ❓
Posted: Fri Oct 27, 2023 4:01 pm
by Diver43
GrapeApe wrote: ↑Fri Oct 27, 2023 10:57 am
POA is a variable, and a load hitting close to the existing POA is fairly irrelevant since you can adjust POA for the chosen load.
In my 6.5 Grendel, EVERY load I've tried with Nosler Ballistic tips shoots considerably left (3-4") of the established POA of both Hornady Amaxes and Speer Gold Dots
Understand, just an observation that with each increase of powder, the group closed up and moved closer to POA. The target looked like I was making scope adjustments. I wish I had gotten a photo, but it was a public range and I didn't want to wait for a ceasefire
Re: Reloading impact question ❓
Posted: Fri Oct 27, 2023 7:44 pm
by Bigslug
You witness this phenomenon a lot with light loads in magnum-rated revolvers. The gun has a high bore axis which causes them to pivot on their axis of recoil-rotation to a greater degree. The gun starts recoiling as soon as the bullet starts moving forward, and a slower bullet takes longer to get out of the gun - ergo, the muzzle has climbed more off the POA at the point the bullet exits with the slower load.
This will likewise be more pronounced with something like a '94 Winchester or other low stock comb that was designed for iron sights than it will with something like an inline-recoiling AR-15, or a good straight-comb, scope-ready bolt gun like a Ruger M77.
Re: Reloading impact question ❓
Posted: Fri Oct 27, 2023 7:59 pm
by PFD45
Well I'll be...
Re: Reloading impact question ❓
Posted: Sat Oct 28, 2023 4:43 pm
by jwv2023
where did the 2nd and 3rd shot hit at each of those loads? Whichever was the best group, load that. Then sight in for the range your going to shoot. Accuracy is the only thing that matters as a handloader. Don't get excited by velocity, only get excited about how close you can get to the point of aim.
Re: Reloading impact question ❓
Posted: Sat Oct 28, 2023 5:04 pm
by Diver43
jwv2023 wrote: ↑Sat Oct 28, 2023 4:43 pm
where did the 2nd and 3rd shot hit at each of those loads? Whichever was the best group, load that. Then sight in for the range your going to shoot. Accuracy is the only thing that matters as a handloader. Don't get excited by velocity, only get excited about how close you can get to the point of aim.
With each increase in powder, the group closed and also got closer to POA. I stopped at book max
