Hello shooters I am going to be setting my rifle for 75 - 100 yards. Does distance afferct fpe? I would think it does. What is best distance for setting up with FX chronograph? I currently use 25m.
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FPE vs Distance ?
- Thread starter DJinAZ98
- Start date
@DJinAZ98 I would be inclined to agree. When considering that velocity is one of the factors in calculating the fpe it seems to be a logical conclusion. Generally I think that the further a projectile travels, the more velocity it loses. That is to say the fpe at the muzzle will likely be more than what is delivered at the point of impact. This is my basic understanding. The projectile’s weight is another factor, which also makes the ballistic coefficient relevant. Here’s where I leave the explaining to others who know a lot more than I do.
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Pellets hit with about 25-30 percent FPE at 100 yards versus the muzzle. So a 50 FPE at the muzzle should be about 13-16 FPE at 100 yard target.
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Thanks for the feedback. So, is there a right / wrong distance to try to max FPE, or just use any distance and apply formula. Currently I am at 30 FPE at 25 meters, divided by approx 4, should be approx 7-8 at 100 yards.
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i put my chono about 2' out from the muzzle, 'shooting the chrony' makes for a bad day lol ... you can figure ballistics out in an app, you need one of those .. typical drop at 100 is around 2ft, why i consider it impractical as a range to shoot at with anything other than a high power rifle .. im on at 100 the gophers and squirrels laugh at me lol ..
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My thought is to have accuracy at 100 yards. FPE matters not one iota if your projectile can not hit the target.
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And accuracy doesn't matter if your shot does have enough punch to do an ethical kill. (And around the circle we go!)
In my experience, BOTH are vitally important for hunting purposes.
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Take FX chrono readings at muzzle. 25m is a common zeroing distance, not a chrono distance. @ 100 yds remaining FPE can be 20% lighter pellets to over 50% for slugs. Don't know what your quarry is, hope it is not bear.
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This calculator will help you set up your ballistics. This is why if I know I am shooting animals further than 50 yards I use a 30 caliber. The pellet may have less FPS but the energy dump will be better at the target. It’s not always penetration that kills, it’s the shock to the nervous system of the impact also. I would much prefer no pass-through with full energy dumped into the animal. This will provide for a much more humane and quicker kill. I know we all love when we smash a critter at 70 yards with full pass-through and we get the big dust cloud in the back, but the reality is the energy dump was on the dirt after the animal not in the animal. Sure the animal dies but not as effectively as the pallet or slug mushrooming and staying within the animal, it is a delicate balance. I really think the calculator may help you.
Happy shooting
https://www.airgunsofarizona.com/Calcs.html
Happy shooting
https://www.airgunsofarizona.com/Calcs.html
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Wow, plenty to process and apply. While I have the utmost respect for ethical hunters, I do not hunt. The reason for this question is to prepare for a different kind of match than I have been in before. The Phoenix Air Gun Club is hosting a PAC Speed Steel match that includes several different types of challenges BR, XBR, FT, XFT, and since I can't find the email right now, I don't have all the particulars available. For this, I want to crank up my Benjamin Armada to at least be somewhat respectable. I have it currently shooting JSB 18.1 domed, 25 m, 30 FPE , 30 shots. I think I can get close to 40 with 15-20 shots which should be ok to run this match with. Heading out to the shop right now to play and see what I can get!!!Thanks all.
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Speed*speed*grains/450240=fpe.
Velocity squared times weight in grains / 450240. Yes, velocity has a huge impact on energy delivered. Pun intended
. FPE is measured at the barrel crown, or very close to the crown.
Velocity squared times weight in grains / 450240. Yes, velocity has a huge impact on energy delivered. Pun intended
. FPE is measured at the barrel crown, or very close to the crown. Upvote 0
I understand, I used to shoot silhouette.
And one needs enough FPE to knock the targets over.
And one needs enough FPE to knock the targets over.
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Yes. That has been an issue, they spin, wiggle like a damn webble, sometimes, luckly, they fall forward, 60 / 70 yard.
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My mistake too. Usually when someone speaks of FPE at distance it’s in reference to hunting, but I assumed and apparently wrongly. However the overall thought still applies even for knocking steal in a way. The OP didn’t mention not hunting also. Lol.
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There is a free Strelok app for Android that will figure it out for you if you have the velocity to input.
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D
Deleted member 38071
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I've had success knocking over. 22rf silhouettes with authority at 75yds with a .177 15g pellet making 25fpe at the muzzle. A 40fpe+ .22 should be fine.
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Weird that no one have said anything about momentum. It plays alot bigger role on knocking down silhouettes than FPE dose. For example 10gram bullet travelling 300m/s carries only 450joules of energy but 1gram bullet travelling 1000m/s carry 500joules. Yet larger projectile have significatly higher momentum 3m/s*kg that 1gram projectile that has momentum value of 1m/s*kg this momentum is what makes your plates fall.
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Does distance afferct fpe?
No. Everybody knows a bullet shot from a gun travels in a straight line to whatever distance it then falls straight to Earth. Consequently One can deduce from that common knowledge that projectiles carry 100% of their energy to the point at which they run out of steam and drop to Earth perpendicularly like a rock; whereupon they lose 100% of their forward energy, then carrying only a minuscule fraction of energy while falling, until they hit the ground (and stop rolling).
No. Everybody knows a bullet shot from a gun travels in a straight line to whatever distance it then falls straight to Earth. Consequently One can deduce from that common knowledge that projectiles carry 100% of their energy to the point at which they run out of steam and drop to Earth perpendicularly like a rock; whereupon they lose 100% of their forward energy, then carrying only a minuscule fraction of energy while falling, until they hit the ground (and stop rolling).
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