Author Topic: .270 trajectory?? (Read 920 times)

sureshot2040 · « **on:** December 04, 2004, 07:08:48 AM »

i have a handi in .270 win.
my cousing shoots an encore in .270 win.
we sighted our rifles in at 25 yards
mine was dead on at 25 his was one inch low
at 100 yards both of ours is around 1 inch high
now here is where it gets confusing
at 200 yards both of ours are abt 8 and a half inches HIGH!!!
this is using remington factory 130 grain psp
so we try using hornady factory 130 balistic tips
same thing out to 100 yards as the remingtons
now at 200 yards 11inches HIGH!!!
what gives???
we already have some dies coming in from cabelas
and plan to reload but both of us ordered some 130 remington points
is this normal for this caliber to climb like that??
if so where does it level out at?
what would you guys reccomend trying to make these two guns shoot flatter??
thanks,
sureshot

Cottonwood · « **Reply #1 on:** December 04, 2004, 08:18:14 AM »

Well I wish I had the magic answer for you but this program might help you out. According to this program you should re-adjust your settings to 1.51" high at 100 yards.

http://www.remington.com/ammo/ballistics/ballistics.htm

gwhilikerz · « **Reply #2 on:** December 04, 2004, 08:23:13 AM »

I would suggest that you sight both 270s in to be about 2.5" high at 100 yds. That way you can shoot out to 300 yds or so with no holdover and your bullet should never be more than about 3 or so inches above or below the aiming point from point blank range to 300. This is with a 130 grain bullet. If you are still getting the way high shots like you said either the barrels are getting too hot or the scope is slipping. Also different brands of bullets shoot different even with the same weight. Maybe you knew all this but I thought I would offer them as Just some things to check out.

Cottonwood · « **Reply #3 on:** December 04, 2004, 08:30:10 AM »

Quote from: gwhilikerz

I would suggest that you sight both 270s in to be about 2.5" high at 100 yds. That way you can shoot out to 300 yds or so with no holdover and your bullet should never be more than about 3 or so inches above or below the aiming point from point blank range to 300. This is with a 130 grain bullet. If you are still getting the way high shots like you said either the barrels are getting too hot or the scope is slipping. Also different brands of bullets shoot different even with the same weight. Maybe you knew all this but I thought I would offer them as Just some things to check out.

According to the program for a 300 yard hold you would have to sight in at 3.86" high at 100 yards with the 130 gr PSP bullet. Now, understand that the program is set up for factory loadings with a FPS of 3,060 with a bullet coefficient of 0.336

stolivar · « **Reply #4 on:** December 04, 2004, 04:20:20 PM »

if you sight in at 2.52 inches at 100 you will only be -2.5 inches low at 300 yards.

steve

270Handiman · « **Reply #5 on:** December 05, 2004, 10:55:24 AM »

A typical 270 with factory 130's will be zero'd at 200 if it is shooting 1'5 high at 100. 11 inches high at 200 sounds real funny. I'd say something funny is going on somewhere. Better look around for something obvious.

sureshot2040 · « **Reply #6 on:** December 05, 2004, 11:21:26 AM »

think i got her figured out
took it back out today and shot it
it was all over the place no consistent grouping
took it to the work bench
rings were a tad loose
changed to a better ring locktited her down good
back to the range
set it at one inch low at 25 yards
moved back to 100 yards and she shot good the first shot then started walking downward on the target
i believe the scope is gone bad
simmons 3x9x40 eightpoint
can the recoil of a .270 with a barrel mounted scope cause the scope to loosen up inside??
only thing i can figure
sureshot

270Handiman · « **Reply #7 on:** December 05, 2004, 12:10:05 PM »

A 270 Handi Will break a weaker scope if given the opportunity. I had a cheap Tasco fall to the mercy of mine. Replaced it with a Burris FFII, 75 rounds thru it so far, and all is well.

riddleofsteel · « **Reply #8 on:** December 05, 2004, 02:01:11 PM »

I guess I am one of the old farts here. I pretty much set all my centerfires from .25 to .30 three inches high at 100 yards. This is as long as they are based on a 30-06, .308 or 7x57 case capacity. After running hundreds of sight in programs on my Pact II chrono's computer they all come out something like 2.5 high or 2.75 or 3 or 3.25 or something close to that.
I set them at 3 inches high at 100 yards and then shoot actual targets at 150, 200, 250 yards ect. to confirm what the computer is telling me.
For example my 25-06 Sendero with a 26" barrel is spitting out 117 grain Hornady SPBT's at 3150 FPS. Set 3 inches high at 100 yards it does not drop out of the kill zone on an average white tail until it reaches 385 yards. The only problem is that with this particular load the bullet rises 4 inches above the line of sight at around 180 yards or so (watch for overhanging limbs). This may not be what your particular ballistics computer tells you but in my real world it is true. When I drop the hammer on a buck at a wisker under 400 yards I know the bullet will strike the kill zone aiming dead on. I also know that at 100 yards or less the same rule applies.

stolivar · « **Reply #9 on:** December 05, 2004, 03:08:14 PM »

riddle of steel of if you are running a 10 kill zone will you be out to 385 yards and you will be 5 inchs high at 175 yards. with a 6 inch kill zone you will have this be point blank out to 316 yards with no more than 3 inch rise or fall with scope set at 1.5 inchs high. that is with the bullet and speed you allocated. ( used point blank) if you are using 8inch zone you will have till 354 inch shot. way to big of a kill zone for that range. almost every gun I have if you zero at 100 with 2.5 to 2.64 high you will have out to 250 to 316 yards. that is plenty.
download point blank, it is free.

steve

riddleofsteel · « **Reply #10 on:** December 05, 2004, 04:01:48 PM »

0 3150.0 2577.7 1.64 -2.0 -0.0 0.0 0.000
20 3097.8 2492.9 1.61 -0.7 0.0 0.0 0.019
40 3046.2 2410.5 1.58 0.5 0.0 0.0 0.039
60 2995.1 2330.4 1.56 1.5 0.0 0.0 0.059
80 2944.7 2252.6 1.53 2.4 0.0 0.0 0.079
100 2894.8 2176.9 1.50 3.1 0.0 0.0 0.099
120 2845.5 2103.4 1.48 3.6 0.0 0.0 0.120
140 2796.8 2032.0 1.45 4.0 0.0 0.0 0.142
160 2748.5 1962.5 1.43 4.2 0.0 0.0 0.163
180 2700.9 1895.0 1.40 4.2 0.0 0.0 0.185
200 2653.7 1829.5 1.38 4.0 0.0 0.0 0.208
220 2607.1 1765.8 1.35 3.6 0.0 0.0 0.231
240 2561.0 1703.9 1.33 3.0 0.0 0.0 0.254
260 2515.5 1643.8 1.31 2.3 0.0 0.0 0.277
280 2470.4 1585.4 1.28 1.2 0.0 0.0 0.301
300 2425.8 1528.7 1.26 -0.0 0.0 0.0 0.326
320 2381.8 1473.7 1.24 -1.5 0.0 0.0 0.351
340 2338.3 1420.3 1.21 -3.2 0.0 0.0 0.376
360 2295.2 1368.5 1.19 -5.2 0.0 0.0 0.402
380 2252.7 1318.3 1.17 -7.4 0.0 0.0 0.429
400 2210.5 1269.3 1.15 -10.0 0.0 0.0 0.456

pasted from my Pact II program

I am figuring a 10 inch kill zone. But as I have said what happens in the real world when I shoot my rifle is what I depend on and my true PBR is closer to 380 than 360 yards. This is based on measurements done on targets.
I had the privilige of access to a lease for many years with a tower stand and two alfalfa fields. One was 380 yards long and the other (behind the stand) was 300 yards long. I shot a deer at 380 yards about 8 years ago. I knew the distance because he was standing within 20 feet of the far corner of an alfalfa field were I had put cardboard deer and shot them many times during the summer. I had previously pulled off the distance to this points with a steel tape. I held slightly above center chest and carefully squeezed off the shot. I was resting my rifle on a pile of sandbags draped over the rail of the tower stand. When the bullet hit, the buck hunched up, stumbled, and ran about 30 yards before falling dead. When I cleaned him the bullet had hit near the bottom of the chest and took out his heart and both lungs. I never got another shot at that distance but I had decided to aim a little higher if I did. As it was knowing my PBR as shown by target work payed off.
As I have said my figures are based on real world measurements on targets and game.

stolivar · « **Reply #11 on:** December 06, 2004, 11:26:11 PM »

that was a good shot. But. with that big of a shot placement, anything that could go wrong such as wind or even a slight wabble by you would have meant a bad shot. If you don't have the privilege of sandbags and a very secure rest that shot would be foolish under most hunting conditions. a more realistic kill zone of 6 inches provides a better and safer shot. Still well done and a very good shot.

steve

gwhilikerz · « **Reply #12 on:** December 07, 2004, 07:47:17 AM »

from Montanan
"According to the program for a 300 yard hold you would have to sight in at 3.86" high at 100 yards with the 130 gr PSP bullet. Now, understand that the program is set up for factory loadings with a FPS of 3,060 with a bullet coefficient of 0.336".
I don't do a lot of reloading. Matter of fact, if I have a few empty cases I break out an old lee loader, sit in front of the tv and "fill-em-up". I know nothing about "programs" and such. I just know that all the 270s I have shot seem to perform the way I posted.

Longcruise · « **Reply #13 on:** December 07, 2004, 09:32:07 AM »

sureshot, all indications are that you have either a loose mount, a bad scope or a crappy shooting rifle. All three could occur together :eek:

Most likely you have a bad scope but OTOH, I replaced scopes three times on a Handi before I realized the reality that it was a poor shooting rifle. Two of those scopes shoot wonderfully on other rifles!

Also, if you have very high scope mounts it inreases the angle between line of sight and bullet flight path. Most ballistic programs are set up with a 1.5 inch scope height (centerline of scope to centerline of bore). Many Handi shooters have higher mounts to accomadate hammer clearance. The higher your scope is above bore centerline, the more rainbow you will have in your trajectory and thus a higher impact point a say 200 yards than if you had a low scope mount.