Frustration @ 100 yards today

[ivanthesane]

Sent kid #1 to grandmas, kid #2 stayed home with mommy to make cookies (yum - oatmeal with cranberries, raisins, chocolate and walnuts), and went to the range.

Started at 25 yards wtih my Savage Mk II BTV in 22lr to try some new ammo, and confirm zero wtih what I had been shooting. New ammo did OK, zero was confirmed. My "old" stuff is CCI Blazer, gives one ragged hole groups for me at 25 and the one other time I shot it at 100 it gave me an honest 2" group for 25 shots.

After having fun for a while at 25, I moved over to the 100 yard range. Set targets up, went to work. Nice and calm, what wind there was was coming from straight behind me.

Couldn't really get a group, more of a pattern, and my zero kept shifting left to right to left by 6-8 inches.

Very frustrating.

Went back to the 25 yard range, shot a few 5 shot groups to confirm zero, good tight groups right where they should have been.

Ideas? Using a bipod up front, my fist under buttstock to help control elevation.

Help?

 

[clmayfield]

Re: Frustration @ 100 yards today

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: ivanthesane</div><div class="ubbcode-body">Nice and calm, what wind there was was coming from straight behind me.
</div></div>

0 value wind from behind is the toughest kind of wind to group in, IMO. Here is why... wind never comes from exactly one direction. It might come from 11 o'clock and 1 o'clock... with a 22 at 100, that makes a difference. The problem that I have in this type of wind is getting the hold right. Wind magnitude is easy to read, but if you are holding 1" left when you should be holding 1" right... you can really screw it up. Or at least I can screw it up.

Further, as a simplification, we tend not to make correction for verticals. With zero value wind, your verticals will be affected if the wind is on and off... and during low winds, the variation can happen quite a bit.

So low zero value winds can be very, very tough.

Now that aside... CCI Blazer is supposed to give MV's of around 1,250 fps. At 1,100 fps, it goes transonic. In colder temps, the speed of sound actually gets a little faster, which means that it will go transonic sooner. So there is a possibility that in warmer temps, you were able to get better groups because of a lower transonic threshold.

Just some stuff to consider. If it is working at 25 yards and not 100, I don't think the cleanliness of the bore is an issue. This looks like an external ballistics, not an internal ballistics issue.

 

[ivanthesane]

Re: Frustration @ 100 yards today

Working out of the bulk box of Blazer that gave me 2" at 100 on last trip, and was giving one ragged hole groups at 25 that day.

Didn't try any others at 100 since all I had left was giving patterns at 25 (already shot up my box of Wolf and 2 boxes of Rem Sub Sonic HPs at 25).

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: DFOOSKING</div><div class="ubbcode-body">Try running a snake thru the bore, take out some of the fouling, no solvent just the snake or patch.

once in while its good to give a little run thru, I'm no cleaning preacher, sometimes though it's worth a try.

without being there I can't say if its form, but other than a bad batch of ammo, its hard to say. Did you try any other kinds of ammo? I try to keep a little batch of rounds laying around just to test this kind of stuff in case there turns out to be a mechanical reason for it. </div></div>

 

[clodhopper]

Re: Frustration @ 100 yards today

Im with Carter on this, A fishtailing wind from 5 oclock to 7 oclock feels like it is straight from shooter to target, It gives me shifting zeros.
Tie a peice of yarn up near by to judge wind direction.

 

[DBohn]

Re: Frustration @ 100 yards today

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Carter Mayfield</div><div class="ubbcode-body">

In colder temps, the speed of sound actually gets a little faster, which means that it will go transonic sooner. So there is a possibility that in warmer temps, you were able to get better groups because of a lower transonic threshold. </div></div>

This is wrong. The speed of sound in an ideal gas, which air basically is, depends only on temperature and not on pressure or density. In an ideal gas pressure and density change in lockstep with a given temperature and cancel each other out.

The speed of sound at 0 deg. C is 331 m/s and at 20 deg. C is 343 m/s.

Speed of sound is slower in cold air and faster in hot air.

 

[Mag 300]

Re: Frustration @ 100 yards today

+2

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: clodhopper</div><div class="ubbcode-body">Im with Carter on this, A fishtailing wind from 5 oclock to 7 oclock feels like it is straight from shooter to target, It gives me shifting zeros.
Tie a peice of yarn up near by to judge wind direction. </div></div>

 

[SmallBoreSnipers]

Re: Frustration @ 100 yards today

I'm with Carter also. If I'm shooting at 200 or 300 I'll put up windage flags both near me and down range by the target. The wind you're feeling can often be different than the wind at the target. This will help you sight in better.

 

[clmayfield]

Re: Frustration @ 100 yards today

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: DBohn</div><div class="ubbcode-body">
This is wrong. The speed of sound in an ideal gas, which air basically is, depends only on temperature and not on pressure or density. In an ideal gas pressure and density change in lockstep with a given temperature and cancel each other out.

The speed of sound at 0 deg. C is 331 m/s and at 20 deg. C is 343 m/s.

Speed of sound is slower in cold air and faster in hot air.</div></div>

Interesting. You're right. I was wrong on that. I always thought that the speed of sound was density-dependent, which is why sound travels faster in water. It is dependent not only on density, but also compressibility, so my short-hand way of remembering it is wrong. Thanks for pointing that out.

 

[ida83704]

Re: Frustration @ 100 yards today

Here is a cut and paste of a table for speed of sound.

Letf column is temp in F
Right column is speed f sound in feet per second


0F-----1051 FPS
10F-----1062 FPS
20F-----1074 FPS
30F-----1085 FPS
40F-----1096 FPS
50F-----1106 FPS
60F-----1117 FPS
70F-----1128 FPS
80F-----1138 FPS
90F-----1149 FPS
100F-----1159 FPS

 

[DBohn]

Re: Frustration @ 100 yards today

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Carter Mayfield</div><div class="ubbcode-body">
Interesting. You're right. I was wrong on that. I always thought that the speed of sound was density-dependent, which is why sound travels faster in water. It is dependent not only on density, but also compressibility, so my short-hand way of remembering it is wrong. Thanks for pointing that out. </div></div>

You bet. Glad I could help.