Interesting find at the range today....

Hidalgo

Hidalgo

Well-known member
I took the DTech to the range today. Had an "interesting" thing happen when experimenting with loads......

I have been shooting 60 VMaxs for about a year now, with great results. Being the "tinkerer" that I am, I decided to try some Nosler Partitions out of this rifle. Here's what happened:

Same case
Same powder
Same charge
Same primer

Both bullets were 60 grain bullets.

The Nosler Partitions shot 2" higher than the VMaxs.

Now, would you consider this "rise" in trajectory simply a better, more stable bullet, or could it be a rise in velocity? Interesting to ponder...... /ubbthreads/images/graemlins/confused1.gif
 
Hidalgo
My knee jerk response is to think the Nosler has a greater bearing surface than the V Max. The result is slightly higher pressures being generated which translates to greater velocity. Your 2" rise in groups the result.

100% speculation on my part.

M
 
It could be neither, heres my take on this. It could just be harmonics, when we pull the trigger the barrel sings a song. what tune it sings we dont really know, however maybe it likes one tune better than the other so it sings a little higher note. when the bullet leaves the end of the barrel it may be a little faster down the tube or a little slower. what the barrel is doing a the instant the bullet leaves will effect the bullet down the range. if the barrel is whipping up or down or to one side or the other is what could be changing poi. thats my story and I am sticking to it.
Cracker
 
A heavier bullet recoils more. It's also slower and spends a little more time traveling down the barrel. More barrel time means the muzzle is a little higher by the time it exits.
 
I agree with Cracker,

I think the muzzle of the barrel is doing a "figure 8" (Harmonics) and the v-max may be leaving at the bottom of the "8" and the Nosler at the top of the "8". I don't think the BC or/and the velocity would be enough to raise the trajectory that much in such short a distance.
 
Quote:
A heavier bullet recoils more. It's also slower and spends a little more time traveling down the barrel. More barrel time means the muzzle is a little higher by the time it exits.



I don't think this one applies......the bullets are the same weight. /ubbthreads/images/graemlins/wink.gif

I kinda like the "bearing surface" theory..... /ubbthreads/images/graemlins/laugh.gif /ubbthreads/images/graemlins/confused1.gif

Obviously...I have NO IDEA why this happened. /ubbthreads/images/graemlins/smiliesmack.gif /ubbthreads/images/graemlins/laugh.gif
 
Hidalgo,

How did those partitions group?
My 20" DTech shoots Hornady V Max's factory loads about 1 inch low and right of everything else the same weight I tried. It shoots them into a very small group, though.
 
The Partitions are kinda stubby looking so the bearing surface is likely the reason. My T/C Contender carbine 223 prints the Partitions around 2" higher than other loads at 100 yds. My DPMS 20" AR prints them out to the left 2" or so, and didn't group very well. In a couple of weeks when our youth season opens up I'm hoping my daughters will get to see how they perform on deer.
 
Quote:
Hidalgo,

How did those partitions group?
My 20" DTech shoots Hornady V Max's factory loads about 1 inch low and right of everything else the same weight I tried. It shoots them into a very small group, though.



I just shot one 5-shot group (it got too windy) but upon initial impression, I think that I'm going to try them again. This group measured .895".....with 3 in the same hole. Veeeeery impressive initially. I have used them for 1 season in my bolt gun, and they shoot about twice as tightly as the VMaxs. BUT...they're twice the price. Not plinking bullets, to be sure. I did shoot one coyote last year with one, and hit it in the shoulder. Bullet crushed the shoulder and went out the other side behind the other shoulder. I highly doubt that a VMax would have given a good result with that shot placement.

I'll post comparisons next week when I get another calm day to shoot.
 
+1 harmonics, recoil doesn't move the muzzle before the bullet exits. You don't have enough drop at a 100 for bullet speed to account for much if anything.
 
Quote,"I did shoot one coyote last year with one, and hit it in the shoulder. Bullet crushed the shoulder and went out the other side behind the other shoulder. I highly doubt that a VMax would have given a good result with that shot placement."

You need to change bullets. A Sierra 55g BTHP or a 55g Spt would have done the same thing as the 60g partition in this case.

When you change brands of bullets, not telling where the differnt bullet will print, no sense in trying to figure it out....it is, what it is.
 
Not being an expert, I'd tend to go with the harmonics as well... especially if they are grouping reasonably well.

Depending on the charge weight used and it's relation to max. specs, I'd be inclined to test a little more with different charge weights as that will change the harmonics a little and thence, the point of impact.

I know that recently I had a major difference between the 39gr SBKs with my lighter loads and Hornady factory 40gr V-Maxs and had to play with the scope settings to get a reasonable POI...from one to the other on my .204.
 
Sometimes it just beez that way, BUT...

Did you seat them both to the same length?

If so, was this measured from the bullet's tip or ogive?

The "jump" to the lands will be different for each bullet if you seated them to the same c.o.l.
For instance, in my 7-08, a 120gr VMAX requires 2.770" c.o.l. to touch the lands.
BUT, a 120gr TSX requires only 2.730" c.o.l. to touch.

SO, if I seated the 120 Vmax same as the TSX(2.730"), they'd be jumping .040", whereas the TSX would be kissing the grooves. Obviously, this will affect p.o.i...

Get my point?

Try seating both bullets with the same jump to the lands. Then you can move along to the bearing surface theory...
 
Quote:
+1 harmonics, recoil doesn't move the muzzle before the bullet exits. You don't have enough drop at a 100 for bullet speed to account for much if anything.



Wouldn't recoil start as soon as the bullet started to move ?
 

When you change brands of bullets, not telling where the differnt bullet will print, no sense in trying to figure it out....it is, what it is.



Ackleyman nailed it. Change something, expect the results to change. /ubbthreads/images/graemlins/grinning-smiley-003.gif
 
I think more testing is needed, one group is not enough to eliminate shooter hold over, or other error. All things considered you should not see a 2" rise with the same wt. projectiles and the same loads. What your saying is 2+2 = 6 and that just don't compute
 
Fun to ponder what might cause these changes, huh? /ubbthreads/images/graemlins/laugh.gif /ubbthreads/images/graemlins/wink.gif

I don't really care what does it, it's just the fact that impact can and does change with only a bullet change....I find these things interesting and fun to observe. /ubbthreads/images/graemlins/wink.gif

The odds of me landing on the best load with the first try are very remote, but the Noslers are going to be my go-to bullet for hunting. They kill cleanly (so far) and are already showing to be more accurate than the VMaxs. Twice the cost, but I'm not going to shoot that many anyway. /ubbthreads/images/graemlins/confused1.gif
 
Quote:
I think more testing is needed, one group is not enough to eliminate shooter hold over, or other error. All things considered you should not see a 2" rise with the same wt. projectiles and the same loads. What your saying is 2+2 = 6 and that just don't compute



Sorry Blinddog, but I can shoot better than that! /ubbthreads/images/graemlins/tongue.gif

The odds of me missing 2" high for 5 shots from a bench with a Caldwell rest.....and putting all 5 in a itty bitty group.....Sorry Dude, but I DON'T miss that far at that range. /ubbthreads/images/graemlins/crazy.gif

I know what I saw, know what I did, and know that different bullets shoot differently due to bearing surface, base design, and other factors.

My shooting ability isn't the difference here. /ubbthreads/images/graemlins/wink.gif
 
Sounds like a good reason to purchase that chronograph.... At least you'd know for sure.







Scott (need an excuse...I'm married) B
 
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