Bullet Drop

[newskate9]

Hi all,

I don’t post here often but read quite a bit. I’ve started my journey into longer range shooting and have a question I could use some help with.

I have a Savage Rifle – nice one – bought some Hornady ammo, 150 gr, 3000 ft/sec (on the box). I sited in the rifle and can basically shoot holes at 100 yards. The rifle and scope are sweet. I went to the gun show, and bought some ammo from a “vet owned” ammo dealer. I bought some to go bang, and I bought some of the “good stuff” to hit holes. The good stuff was 168 gr. No speed rating was listed.

I went to range and loaded the Hornady – and shot 3 rounds that basically touched each other. I then put 3 rounds of the “good stuff” down range. The grouping was about 2 inches wide and about 6 inches below (but in line with) the Hornady grouping. I duplicated this – 3 more Hornady, 3 more good stuff. Same result.

I did some calculations for drop and the velocity would have to be about HALF to explain the drop. I can see the larger grain being a bit slower, but half? Makes no sense to me. But, given the pattern was also about 2 inches, I suspect the ammo may be odd.

So, am I thinking about this right? What else could explain this drop? Could this ammo be that weak?

Also – no feedback please on the ammo purchase. I was trying to do a good thing and supporting a smaller business. I realize now that, for this purpose, only better ammo should see this gun. My bad. Behavior corrected.

[frankski]

The 168g factory ammo is likely in the range of 2600 to 2700 fps. The different point of impact may be related to either velocity or the harmonics of your barrel, or both. As to the accuracy issue with the 168s, I'd need more info.

BTW, I load for a .308, and the variation in POI between 125g bullets loaded to run 2650 vs 3000 fps with two different powders is a couple of inches vertically and horizontally. Accuracy with both though, is under MOA.

Bullets of 125, 150, and 168 loaded to the same velocity of about 2650 have the same POI for me.

[cephas]

I generally find reduced loads, especially with heavier bullets, hitting the target higher at a given range. This is due to the bullet being in the barrel longer and the effect of recoil.
A chronograph reading would be interesting. There a quite a few variables in play.
Was the ammo in question a commercial brand, remanufactured or just reloaded in a garage somewhere?

edit: given range = close up to 100 yd.

[RenoV8]

Different Loads, even amongst manufacturers can and will have a differnt POI. There are so many aspects which could affect your shooting conditions/results.

I have a Savage Rifle too, with a 24 inch barrel. I thought the rifle did well with 168gr bullets...try 175 gr SMK's. I only shot one brank of ammo from my rifle for a couple years. Even within that brand, I had significant enough results to start reloading my own.

I would suggest you start reloading...buy a chronogragh and do so load development for your rifle. Only then will you be able to eliminate certain variables affecting your outcome and work on others which are more within your control, which will in turn, give you even better results.

Have fun with it...

[newskate9]

Thank you for your responses. The one ammo is Hornady brand of course. The other is "reloaded" brass, Hornady bullets. The company is well known and is always at shows and has on line site. I don't want to bash them - the feedback on them was why I bought in the first place.

Net - it seems like there are quite a few reasons this could be happening. I think I need to stick with the better, brand name, ammo for this beast as a starting point. AND - reloading appears to be in my future as well!

[MedicCop]

As everyone has said, there are a lot of variables. The listed muzzle velocity on commercial ammo is only valid for the same barrel length that it was tested in. If your barrel isn't the same length, the velocity rating won't be accurate. Then, there is the difference between the projectiles. Besides 150gr VS 168gr, there is potentially the difference in BC and projectile design. Then there is the variable of powder used. Then there is the variable that certain rifles just 'like' certain projectiles/loadings better than others. My suggestion would be to buy a few different loads and figure out which one your rifle likes best.

[Gripsafety]

Thank you for your responses. The one ammo is Hornady brand of course. The other is "reloaded" brass, Hornady bullets. The company is well known and is always at shows and has on line site. I don't want to bash them - the feedback on them was why I bought in the first place.

Net - it seems like there are quite a few reasons this could be happening. I think I need to stick with the better, brand name, ammo for this beast as a starting point. AND - reloading appears to be in my future as well!

For store bought ammo, I use match grade BTHP from Federal for long range shooting, with excellent results. I've also been able to dial in Indian Hills ammo with good results. Both use Sierra Match King 175 grain BTHP bullets, which is what my barrel likes. If the best you can do with a given ammo at 100 yds is 2" groups, it is useless at longer ranges.

If I ever get to shoot more than I do now again, I will learn to load my own.

I have never had good results with factory reloads.

[A/C guy]

As said before, there are a lot of variables. Reduced loads change the trajectory (drop), but they also change barrel harmonics. I once made reduced loads for 22-250. Same bullet in both, but went from 3500 ft/sec to about 2500 ft/sec. At 100 yards, POI was shifted down about 7" and 3" to the left. Group size remained about the same, around 0.6".

[CMP703006]

I have learned that the heavier bullet does not always hit lower. For example my .458 shoots about 6" higher with the 500gr compared to the 300gr bullets going 600 fps faster. I was also testing the 225gr ELD-M, per the ballistics program it should be only .12" lower however it was actually 1.5" low, it is simply how the harmonics are in the barrel when the bullet leaves.

As for the group sizes it depends entirely on the gun as each one is different. My .300 shoots the 212gr ELD-X better than the 215 Berger Hybrid even though the Berger bullets are almost twice the price and many people shoot tiny groups with them. Unfortunately smaller shops don't have the resources to test their loads across a wide array of rifles like Federal has with their Gold Medal Match ammo. It could be that their ammo shoots lights out in Remington 700's but the slightly different chamber of your Savage favors the Hornady Superformance ammo. We have a 25-06 that shoots 120gr green boxes under an inch but won't put any 117gr Hornady ammo under 2 inches.

Once you get into reloading you will really get a chance to see how minute changes can bring drastically different results. I was just reloading for a friend's rifle 52.8gr and 53.2gr were 1.5" but 53gr was sub 3/4 MOA. Same with seating depth, powder lots, bullet choice and so on. My advise would be to pick several different ammos that meet your needs and find the ones that your rifle shoots best.