Range math?
06-22-2007, 04:45 PM
#1
Thread Starter
Join Date: Jan 2007
Posts: 426
Range math?
I am going to the range tomorrow and have a question for the range rats. I am zeroed in at 100 yards with a 300g xtp with 100g 777 2F loose. I am going to play with 250g speers tomorrow. Assuming that bullet will be in the 4 inch high range, give or take, how much reduced powder charge will it take to get it to zero? 70-75g?
06-22-2007, 05:19 PM
#2
Giant Nontypical
Join Date: Nov 2004
Posts: 5,425
RE: Range math?
If I'm reading your question right, you are assuming that the 250s will hit higher than the 300s with the same powder charge....
First, you are going to have to shoot the gun to see what is happening....But I would bet that the 250s actually
hit LOWER than the 300s, with the same powder charge and no change in scope adjustment....
I have seen this in pistols and muzzleloaders...Here is why I think it happens...
A 300 grain bullet spends more time in the barrel than a 250, so recoil has more time to effect the bullet, sending the heavier bullet higher than the lighter bullet...In other words, recoil kicks the bullet higher...This isn't usually noticable in a centerfire because velocities are higher...
First, you are going to have to shoot the gun to see what is happening....But I would bet that the 250s actually
hit LOWER than the 300s, with the same powder charge and no change in scope adjustment....
I have seen this in pistols and muzzleloaders...Here is why I think it happens...
A 300 grain bullet spends more time in the barrel than a 250, so recoil has more time to effect the bullet, sending the heavier bullet higher than the lighter bullet...In other words, recoil kicks the bullet higher...This isn't usually noticable in a centerfire because velocities are higher...
06-22-2007, 05:47 PM
#3
Thread Starter
Join Date: Jan 2007
Posts: 426
RE: Range math?
ORIGINAL: nchawkeye
If I'm reading your question right, you are assuming that the 250s will hit higher than the 300s with the same powder charge....
First, you are going to have to shoot the gun to see what is happening....But I would bet that the 250s actually
hit LOWER than the 300s, with the same powder charge and no change in scope adjustment....
I have seen this in pistols and muzzleloaders...Here is why I think it happens...
A 300 grain bullet spends more time in the barrel than a 250, so recoil has more time to effect the bullet, sending the heavier bullet higher than the lighter bullet...In other words, recoil kicks the bullet higher...This isn't usually noticable in a centerfire because velocities are higher...
If I'm reading your question right, you are assuming that the 250s will hit higher than the 300s with the same powder charge....
First, you are going to have to shoot the gun to see what is happening....But I would bet that the 250s actually
hit LOWER than the 300s, with the same powder charge and no change in scope adjustment....
I have seen this in pistols and muzzleloaders...Here is why I think it happens...
A 300 grain bullet spends more time in the barrel than a 250, so recoil has more time to effect the bullet, sending the heavier bullet higher than the lighter bullet...In other words, recoil kicks the bullet higher...This isn't usually noticable in a centerfire because velocities are higher...
Your saying it should be somewhere around zero and not as high as I am guessing.
06-22-2007, 06:40 PM
#5
Boone & Crockett
Join Date: Aug 2004
Location: Idaho
Posts: 11,703
RE: Range math?
oldrookie
I shoot both bullets from my Ultra Mag, an Omega and 2 Remingtons, I do shoot 110 grains of T7 though and @ 100 yards i would be surprised if you saw dramatic difference. Maybe a couple of inches. The bigger problem might be left and right. The lighter bullet may set up different harmonic in the barrel causing the bullet to drift & then again nothing may change much you will not know untill you shoot it.
Look at this target shot with an Ultra-Mag... especially the lower left target shot after the gun was sighted in. The top 2 target were sight in targets....
I shoot both bullets from my Ultra Mag, an Omega and 2 Remingtons, I do shoot 110 grains of T7 though and @ 100 yards i would be surprised if you saw dramatic difference. Maybe a couple of inches. The bigger problem might be left and right. The lighter bullet may set up different harmonic in the barrel causing the bullet to drift & then again nothing may change much you will not know untill you shoot it.
Look at this target shot with an Ultra-Mag... especially the lower left target shot after the gun was sighted in. The top 2 target were sight in targets....
06-22-2007, 07:27 PM
#8
Thread Starter
Join Date: Jan 2007
Posts: 426
RE: Range math?
Interesting.....I will setup 2 targets one for the 250g speer and one for 300g xtp both will be in same frame. same charge of 100g 777 loose. Will start with 300g and will alternate loads every other shot. I will shoot five each and adjust accordingly.
06-22-2007, 08:03 PM
#9
Boone & Crockett
Join Date: Aug 2004
Location: Idaho
Posts: 11,703
RE: Range math?
oldrookie
Which gun are ya shooting... should be and interesting experiment...
Here a couple of BC charts for Speers...
BC for a 250 Gold Dot-> .165
BC for a 300 Gold Dot -> .233
BC for a 300 XTP -> .200
Indicating that the 45 cal 300 grain Speer Gold Dot should fly better and flatter than the 300 XTP, which might make the difference between the two POI's even less....
Which gun are ya shooting... should be and interesting experiment...
Here a couple of BC charts for Speers...
BC for a 250 Gold Dot-> .165
BC for a 300 Gold Dot -> .233
BC for a 300 XTP -> .200
Indicating that the 45 cal 300 grain Speer Gold Dot should fly better and flatter than the 300 XTP, which might make the difference between the two POI's even less....
06-22-2007, 08:12 PM
#10
Thread Starter
Join Date: Jan 2007
Posts: 426
RE: Range math?
I'll shoot a cva optima with shorter barrel (26"). I figured it would be best to alternate each shot vs shooting 5 of one and then the other. Probably will have cooler temps 8:30am tomorrow so the barrel temp should stay consistant. I'll use 777 primer and crushed ribbed sabot.
I guess I figured 25% difference in weight would make a bigger difference. I am looking forward to the experience. On your recommendation of the speer, is why I ordered them. I meant to order the speers in 300g but had a senior moment and didn't pay attention. I do have some 300g on order.
I guess I figured 25% difference in weight would make a bigger difference. I am looking forward to the experience. On your recommendation of the speer, is why I ordered them. I meant to order the speers in 300g but had a senior moment and didn't pay attention. I do have some 300g on order.