Increased ES with increased velocity

[LCazador]

I’m wondering if there is a simple explanation as to why my ES/SD increases as my velocities increase. Loading for a 7PRC with h1000. I should mention this is virgin ADG brass. I would stick with the lower velocities but it’s a little slow. Factory ammo runs about 2750 in my gun and these are shooting about 2715. At 2715 my ES is about 10 with a great group size and with each powder increase my ES increases to where at 2850ish my ES is 50 with terrible groups. I know there are many factors at play but maybe there is a common issue that creates this situation.

I had the same issue with 7PRC and switched to Retumbo. Great ES and velocity. Like mentioned above don't start load work until after you fire form your new cases. You may also want to try N560 or N570 powder.

 

[Old Navy]

You are both correct I have dispatched elk with a 22 Rimfire, not much energy there!… a broad head makes a huge wound channel placed in the correct spot. At say 200 yards and you miss your mark and hit it directly in the front shoulder……. Probably not. I realize 200 is a ridiculous distance for a bow but so is say 1200 yds with a 168 gr .284 bullet,.. why?…. Not enough energy in both cases!… it’s long been known that most std hunting,…. Once again HUNTING bullets needs about 1800 ft lbs of remaining energy for the bullet to reliably expand to dispatch an elk , does it need that if you hit it in the spine or heart?… no of course not, can you for certain on your first shot at 1000+ yards hit one in the neck?..
one last thought…… if a 2000 lb car traveling at 1 mph hits you is the probability that your going to die high or low?…..now at 65 mph the same car hits you what’s your probability of death now?…… wait!….. your already typing it was the velocity that killed you….. really?…. If the car was made of styrofoam that weighed 5 lbs at the same speed would your survival rate increase?…..energy does play a factor.
Wayne

You are both correct I have dispatched elk with a 22 Rimfire.
After it was down to finish it off I take it?

 

[bozo699]

You are both correct I have dispatched elk with a 22 Rimfire.
After it was down to finish it off I take it?

No!… during general rifle season some Rambo decided to take a head shot,…. Missed and blew bottom jaw off!… a couple weeks later I was driving on my property and in the middle of the creek trying to drink with no bottom jaw ,…. All I had was a 22
Wayne

 

[kyreloader]

You are both correct I have dispatched elk with a 22 Rimfire, not much energy there!… a broad head makes a huge wound channel placed in the correct spot. At say 200 yards and you miss your mark and hit it directly in the front shoulder……. Probably not. I realize 200 is a ridiculous distance for a bow but so is say 1200 yds with a 168 gr .284 bullet,.. why?…. Not enough energy in both cases!… it’s long been known that most std hunting,…. Once again HUNTING bullets needs about 1800 ft lbs of remaining energy for the bullet to reliably expand to dispatch an elk , does it need that if you hit it in the spine or heart?… no of course not, can you for certain on your first shot at 1000+ yards hit one in the neck?..
one last thought…… if a 2000 lb car traveling at 1 mph hits you is the probability that your going to die high or low?…..now at 65 mph the same car hits you what’s your probability of death now?…… wait!….. your already typing it was the velocity that killed you….. really?…. If the car was made of styrofoam that weighed 5 lbs at the same speed would your survival rate increase?…..energy does play a factor.
Wayne

What is so special about 1800 ft-lbs? I have never seen a study that looks at remaining energy as a marker for terminal performance of bullets.

Minimum impact velocity of bullets is what is needed to reliably expand the bullet "to dispatch" an animal, not terminal energy.

For example:
Berger bullets maintain that a minimum velocity of 1800 fps is needed to reliably expand their hunting bullets. In a 7PRC with Hornady load data, RL26 max load will get a velocity of 3150 fps with 162-166g bullets (will use 168g Berger in this example). 168g Berger at 3150 fps (using standard conditions and JBM calculator), reaches 1809 fps at 975 yards. The remaining energy at that distance is 1221 ft-lbs.

If 1800 ft-lbs is needed "to dispatch an elk", with the above example, a hunter would only be able to shoot an elk at less that 650 yards (1826 ft-lbs).

That is a 325 yard difference.

How have the guys from Gunwerks (and others) been killing elk for multiple decades with the 7 LRM and the 168g Bergers at longer ranges than 650 yards if 1800 ft-lbs of energy is needed "to dispatch an elk"?

Again, where did that magic 1800 ft-lbs threshold come from?

(Sorry to derail the original thread and question)

 

[Homerange]

Here in NZ the considered minimum magic figures are 2000fps and 1000ft/lbs for all deer species here.

Yet projectile terminal performance in game overrules all....select the right pill for the job !

A link to the authority on these matters:

Extensive Field-Tested Rifle & Cartridge Research - BallisticStudies.com

Expert rifle & cartridge research, carefully compiled through extensive field-testing & freely offered to the firearms community.

www.ballisticstudies.com

 

[jelenko]

a hunter would only be able to shoot an elk at less that 650 yards

Sounds like a good idea.

 

[Doom]

What is so special about 1800 ft-lbs? I have never seen a study that looks at remaining energy as a marker for terminal performance of bullets.

Minimum impact velocity of bullets is what is needed to reliably expand the bullet "to dispatch" an animal, not terminal energy.

For example:
Berger bullets maintain that a minimum velocity of 1800 fps is needed to reliably expand their hunting bullets. In a 7PRC with Hornady load data, RL26 max load will get a velocity of 3150 fps with 162-166g bullets (will use 168g Berger in this example). 168g Berger at 3150 fps (using standard conditions and JBM calculator), reaches 1809 fps at 975 yards. The remaining energy at that distance is 1221 ft-lbs.

If 1800 ft-lbs is needed "to dispatch an elk", with the above example, a hunter would only be able to shoot an elk at less that 650 yards (1826 ft-lbs).

That is a 325 yard difference.

How have the guys from Gunwerks (and others) been killing elk for multiple decades with the 7 LRM and the 168g Bergers at longer ranges than 650 yards if 1800 ft-lbs of energy is needed "to dispatch an elk"?

Again, where did that magic 1800 ft-lbs threshold come from?

(Sorry to derail the original thread and question)

I think Jeff meant 1800 fps not ft-lbs which is what many hunting bullets list as minimum velocity for expansion.

 

[Old Navy]

No!… during general rifle season some Rambo decided to take a head shot,…. Missed and blew bottom jaw off!… a couple weeks later I was driving on my property and in the middle of the creek trying to drink with no bottom jaw ,…. All I had was a 22
Wayne

To bad when they don't where to shoot and how to track a wounded animal. I found a dog in our local gravel pit years ago. Some one tried to put it down and missed the first shot. What a mess there was there. Wish I could un-see that.

 

[bozo699]

To bad when they don't where to shoot and how to track a wounded animal. I found a dog in our local gravel pit years ago. Some one tried to put it down and missed the first shot. What a mess there was there. Wish I could un-see that.

Understand my friend
Wayne

 

[shoot4fun]

I’m wondering if there is a simple explanation as to why my ES/SD increases as my velocities increase. Loading for a 7PRC with h1000. I should mention this is virgin ADG brass. I would stick with the lower velocities but it’s a little slow. Factory ammo runs about 2750 in my gun and these are shooting about 2715. At 2715 my ES is about 10 with a great group size and with each powder increase my ES increases to where at 2850ish my ES is 50 with terrible groups. I know there are many factors at play but maybe there is a common issue that creates this situation.

To me it seems your story is incomplete.
What bullet brand and weight are you experimenting with?
H1000 should be (and is highly recommended) for 7PRC.
As for the factory ammo you are using for comparison.
What kind of groups and Chronograph data did you compile?
There is much more to the quest for an "ideal load" than velocity or SD.

 

[atombaum]

It is not uncommon for reloads to be slower than factory ammo. I think maybe the ammo manufacturers have some kind of fairy dust or something that they blend in with the powder and get more velocity than us reloaders get. I have seen that many (most? never really kept track or measured myself against factory ammo velocities much in 30+ years of reloading) times oves the years. Accuracy is where it's at. It sounds like you are in the right place with your load.