Group size at different ranges and zero

Dawgdad

clembob wrote:

Will be for fox using a .243 55gn heads range 100 to 300 yards.
Was thinking about a .204 for the job.

Fox present a small kill zone and a flat trajectory is necessary.

If you can push the ,243 55BT at 3800 fps you can get a 300 yard 4" Point Blank Zero with a true zero at 260 yards.

That means if you zero at 260 the bullet will be within 2" of the crosshairs out to 300.

.204 will do the job too If you get a 32 grain bullet to 4000 fps your 4" PBZ is 327 yards with a 280 true zero.

Might be less fur damage with the .204 if you are going to sell the fur.

I shot a fox with a 110 grain V-max from a 30-06 at 250 yards last winter.. left a 4" exit wound...

clembob · Member Joined: Jul 10, 2011 Posts: 28 Location: UK

Whats happening then ?

Touching group at 87 yards then a 3/4inch at 100 yards.
Rifle Savage 16FCSS .243
55gn Sierra Blitz King
42gn Vit 140
COL 2.630
Shot 5mins after the first group
Gave the rifle to my friend an he shot exactly the same groups!

stovepipe

Some variables come to mind in this order. Hold, trigger, barrel whip and temp (resonates diff at diff temps), wobble, wind, humidity. If I'm really on that day and conditions are perfect (5 million variables) I can get 3 shot groups to touch @ 100y. Dont sweat it. Run some paper or a gong with a dot out to 200y, try it again. Take some flat black spray paint for quick touch up's. Have some fun with it and track your results, data for consistent testing and stay HAPPY. Happy trigger fingers work better than sad ones. I keep telling myself that today even factory loads in most firearms are light years more consistent and accurate than they used to be/I can hold most of the time. Short of using a machine rest I couldnt even come close to what some BR's do. If i was devolping a hunting load I'd go for the most consistent 3 shot group load @ 200y zero from a cold fouled bore and call it good when I got one that did it over a broad temp range within reason but I try to over simplify things so that jsut my .02.

Ominivision1

I agree with Stovey, there is just too many variables when working up a load, example is on my 243 I use varget with excellent results and accuracy. But using imr 3031 with the same col, I had better luck turning the rifle around and using the butt end as a tack driver. Very Happy

This is one of the things with developing your own loads, chances are you will not get lucky developing that ultimate tack driver load on the 1st try even following the books because each rifle has it's own individual personality.

It takes time to develop loads and thats where record keeping is a must. Even thou the distance was only 39' between the above 2 targets, you would be surprised at how different bullets, col, crimp, primer, case length, powder all weigh in on the final determination.

HayCreek · Member Joined: Sep 10, 2011 Posts: 36 Location: Central ND

Clembob -

What scope are you using?

Stovepipe has a good suggestion. Zero at 200 yds and see what it looks like at 100, 200 and 300. I'm curious as to the reason this is happening and data from longer ranges may tell the story.

44marty

The key is to keep your shooting consistent. Allow the barrel to cool between rounds. Make sure to support the rifle stock at the same point for each shot. If you know exactly when the shot will fire, you have to work on your trigger technique. Pay close attention to the wind.

Something may have changed between shooting the two groups. It could even be just that the light changed. You would be surprised how much difference this can make in the appearance of a bullseye type target through your scope. Maybe try printing out some solid black squares on white paper. Line the crosshairs up so they lie along two edges of the square (so you are aiming at one corner).

SingleShotLover

Since you state that you and your friend shot identical groups, I'm wondering about your scope. You might be right at the edge of parallax problems at 87 yards and it is showing up at 100. There shouldn't be that much difference in only 13 yards. Make sure your focus is crisp and clear before making any other adjustments(this doesn't eliminate parallax, but it isn't going to help you if the focus is blurred). Point the scope at a white wall and move your focus ring (not the objective) so that the cross-hairs stand out sharp and clear. Lock it down and don't move it again.

If you have an adjustable objective scope, adjust the objective so that the target is crisp (only after you made the above focus adjustment). Do not depend on the markings on the objective; they are only for reference and not accurate enough for real-world use.

If your scope doesn't have an adjustable objective, you can check for parallax by firmly resting the rifle on a support and moving your head behind the scope. If parallax is present, the cross-hairs will appear to wander over the target. If this is the case you are better off looking for a new scope.

Just a thought...let us know how you make out.

Vince

Gidday Clembob...I wouldn't get too "wrapped around the axles" with those groups mate... 3/4" at 100 yds is still well under MOA.

A five minute cool down between 3 shot groups should be adequate, however I found in my Weatherby .243 that 55gn bullets were usually a pretty "hot" load and they would really put some heat into the barrel. May well be that you need to allow more time for your barrel to cool between groups. How long was the break between your last group and your friend's first? I'll lay odds that it was more than five minutes, which allowed that barrel to cool down then return the same results as yours. If nothing else, it shows a certain amount of consistency.

Remember, when out hunting the first shot is from a cold barrel, and is the one that you want exactly on target. From what I can see your rifle is delivering good accuracy with the first three shots. Unless you get amongst a pack of foxes (is there any such thing) chances are you will only fire one shot every hour or so anyway, so it is that first one you want on the money mate.

As a couple of the others have said...have a look at your scope and mounts...could be that there is a minor problem there, although with your friend getting the same results as you, it leads me to think that there isn't any problems with the scope or the mounts. As SSS says, the problem may be parallax.

Cheers, Vince

chambered221

Shoot your first group at 100 with the cold bore .......might just be heat !!!

Just curious ....... why you shooting at 87 when you obviously have 100 ???

clembob · Member Joined: Jul 10, 2011 Posts: 28 Location: UK

Hi All
Thanks for all the comments
Scope is a Leupold VX-III 4.5x14 x 50 LR
My friend has two ranges it easier on the 87 that the 100 so we always shoot the 87.
We tried this load with the ranges of 100 150 200 and 225 and that what started this forum up my results below. (attached are placements done in pointblank)
Agaign the barrel was left to cool between each group,load was exactly the same as above. no wind on the day, we tried the above ranges to see what happed after the 3 bullet group at 87 so disapointed went back to 87 and great 3 bullet group as per example agaign.
Bullet 0 at 200 was a pulled shot
At 87 42 gn of Vit 140 was the best grouping of three bullets acorss the range of V140 loads from min to max in 1gn jumps

Elvis

was the scope set on the same magnification???
why such a light weight projectile in .243 would not a slightly heavier one give less pelt damage but hold up better at range??I know my .270 gave huge damage with 110grns but is not so messy with 130s on a wallaby whick must be comparable for size. I use the .223 for them now its easier all round.

Elvis

why is it easier at 87? do you have a better bench type hold versus damped prone at 100?

stovepipe

Nothing wrong with the groups. Keep practicing till YOU get them smaller. Borrow a lead sled and try it again. Take's the shooter out of the equation.

HayCreek · Member Joined: Sep 10, 2011 Posts: 36 Location: Central ND

Hmmm...Ok, a SWAG. That particular bullet my not be stabilized well in your rifle. As the velocity increases, the instability will spread your groups.

The reason I say this is that I shoot a Savage in .204. A whole passel of guys love the Sierra bullets and shoot great groups. However, for some reason, my rifle just doesn't like them. 32gr or 39gr...both keyhole no matter what the load.

I can shoot the 32s and 40s from Nosler or Hornady and they work just peachy.

Might just be your barrel doesn't like that particular bullet.

Just saw Stovepipe's post. Good point, too. Are you able to shoot MOA at longer ranges with other rounds?

Ominivision1

Something is really amuck, 39' more should not make that drastic of a difference since you are using the same loads for all targets. Try the same targets at 100 yards period with the barrel cooling off as you did before and see what happens and post your results. Do not change yardage for targets as this will help us to help you to find out whats going on here.