Range Report Range Time with 168 AMAX versus 178 AMAX

[JSTARSZ]

I went to the Range this morning with my normal load:
Atmospherics: 70 Degrees, 80% humidity, wind 7 MPH from right to left on range - full value.
Rifle: GAP M40A3 - 25" Barrel
Scope - Leupold MK4 M1 Turret - 6.5. x 20 Mil-Dot
Ammo: 168 GR AMAX 44.2 GR Winchester 748 - 2.850 OAL .20 to the lands - 2650 FPS

That load requires 5 MOA up to get to 350 yards (my testing distance) and I was using 1.25 MOA right windage to compensate for the wind. It was dead nuts on.

I am trying out my 178 AMAX load so I can use it a 1000 yard training event that I have coming up in June.

LOAD: 178 GR AMAX - 44.5- 45 GR was my trial points at .2 -.3 grain increments - COAL = 2.865 - .20 off the lands

The chrony said they were:
44.5 AVG = 2640
44.7 AVG = 2660
45.0 AVG = 2675

What I found interesting was that when I changed the loads from 168 to 178 the 178's were almost three inches lower than the 168's. Now I know it will change some but I never would have thought 3" low.

I am going to work up some more loads at 44.7 and see how accurate I can get them as there was no signs of pressure at any powder charge range.

By JBM ballistics the loads should be really close but they are not. And, I am not sure why. It will require some more investigation but if anyone has seen this before please chime in. Especially the Hornady guys on the site.

 

[Rob01]

Re: Range Time with 168 AMAX versus 178 AMAX

Did you rezero at 100 when you went to the 178 from the 168? 3" is less than 1 MOA at 350 yards so it might just be that it needs to be rezeroed at 100 as the POI might be different. I know my 168 and 178 AMAX 100 yard zero is different.

Also Varget might give you some more velocity. My 20" barrel gets 2690fps with 45grns of Varget and the 178 AMAX, which is the max so don't start there obviously.

 

[JSTARSZ]

Re: Range Time with 168 AMAX versus 178 AMAX

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Rob01</div><div class="ubbcode-body">Did you rezero at 100 when you went to the 178 from the 168? 3" is less than 1 MOA at 350 yards so it might just be that it needs to be rezeroed at 100 as the POI might be different. I know my 168 and 178 AMAX 100 yard zero is different.

Also Varget might give you some more velocity. My 20" barrel gets 2690fps with 45grns of Varget and the 178 AMAX, which is the max so don't start there obviously.</div></div>

I have several pounds of 748 so I am going to use that up before I try Varget or RE15. That is the cheap in me I guess.

I didn't re-zero and you are probably right I should have but I was just a tad perplexed that it would be that different being that most everything was the same vice 10 more grains of bullet and a .3 grains of powder. Interesting though and it does add just one more piece of information on understanding ballistics and how to use it to your advantage.

 

[81sfo]

Re: Range Time with 168 AMAX versus 178 AMAX

For my w748 loads i used 43-44 grains on the 178 amax,and 44-45 on the 168amax,but that was my load ,start a bit lower just in case.
The heavy bullet will almost always have lower point of impact using the same zero.The 155 scenars are always alot higher since they are lighter and faster.Good luck on your load Tim.

 

[JSTARSZ]

Re: Range Time with 168 AMAX versus 178 AMAX

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 81sfo</div><div class="ubbcode-body">For my w748 loads i used 43-44 grains on the 178 amax,and 44-45 on the 168amax,but that was my load ,start a bit lower just in case.
The heavy bullet will almost always have lower point of impact using the same zero.The 155 scenars are always alot higher since they are lighter and faster.Good luck on your load Tim.</div></div>
Jose, can you stay supersonic to a 1000 with the 178 GR at the 43-44 grain level? I am assuming that would be about 2550 or so?

Also, I was checking the rifle I just bought from you...man that is a short throat. I can see why you said it liked 2.80 With a 178 I was hitting the lands at 2.818. I can see why it would like 2.8's as that is little less than .20 from the lands.

 

[mdesign]

Re: Range Time with 168 AMAX versus 178 AMAX

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Rob01</div><div class="ubbcode-body">Did you rezero at 100 when you went to the 178 from the 168?......</div></div>

+1, sometimes its much different than you think and will change the way you look at the performance of a load.

 

[JSTARSZ]

Re: Range Time with 168 AMAX versus 178 AMAX

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: mdesign</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Rob01</div><div class="ubbcode-body">Did you rezero at 100 when you went to the 178 from the 168?......</div></div>

+1, sometimes its much different than you think and will change the way you look at the performance of a load.</div></div>

when I go back to rezero at a 100 yards I am going to see how much difference it is between the 168 and 178 zero's. I will be interested to see what the difference is.

 

[ReaperDriver]

Re: Range Time with 168 AMAX versus 178 AMAX

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Rob01</div><div class="ubbcode-body">
Also Varget might give you some more velocity. My 20" barrel gets 2690fps with 45grns of Varget and the 178 AMAX, which is the max so don't start there obviously. </div></div>

2690 with a 20"??? What kind of chamber? My pet 178 AMAX load for my 20" SPS-T is 45grns Varget and I'm only getting 2580 fps. Granted, those were chrono'd when the temps were in the 50's. But I can't imagine you can get another 100 fps unless its a tight match chamber. What depth (COAL) are you seating the 178's?

 

[Hellbender]

Re: Range Time with 168 AMAX versus 178 AMAX


I run 2670fps with 44.0 gr. Varget, 178 Amax, LC99LR cases at 2.84" OAL, 70 deg F. in a 24" bbl Rem.

 

[TCA4570]

Re: Range Time with 168 AMAX versus 178 AMAX

Trying to get down to 2800 FPS with 44.5 Varget and 168 A-Max.
(Barrel is a little long)
45.0 can show preasure and not much gain in velocity.(Varget and RL-15)
Acuracy suffers more.
Depends more on proper load for gun, not load from book.
That's why we load.

 

[Rob01]

Re: Range Time with 168 AMAX versus 178 AMAX

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: ReaperDriver</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Rob01</div><div class="ubbcode-body">
Also Varget might give you some more velocity. My 20" barrel gets 2690fps with 45grns of Varget and the 178 AMAX, which is the max so don't start there obviously. </div></div>

2690 with a 20"??? What kind of chamber? My pet 178 AMAX load for my 20" SPS-T is 45grns Varget and I'm only getting 2580 fps. Granted, those were chrono'd when the temps were in the 50's. But I can't imagine you can get another 100 fps unless its a tight match chamber. What depth (COAL) are you seating the 178's?</div></div>

Standard chamber and Broughton 10 twist barrel using Win brass. 44.2grns in Lapua gives the same velocity. Factory barrels can be slower. I am seating them .010" off the lands at the ogive. I think they are at about 2.840" or so but fit fine in AICS mags.

 

[Hellbender]

Re: Range Time with 168 AMAX versus 178 AMAX

JSTARZ...

You understand that because your new 178gr load hits 3" lower without rezeroing does NOT mean the trajectory of the load is dropping 3" more than the old 168gr load?

You will have to rezero, THEN compare the trajectory of the loads.

One load may be exiting at the bottom of the barrels vibration pattern, and the other may be exiting at the top.

 

[M25BeastShooter]

Re: Range Time with 168 AMAX versus 178 AMAX

I'm shooting 43.5 RL15 with the 178 AMAX from a Rem PSS at 300 yds I need 1/4 up to put it where my 175 SMK load with the same 43.5 RL15 load.

I put 5 shots at 300 into 1.54" from that rifle last week the bullet is a performer

I haven't had a chance to Chrono the load yet as my chrony bit the dust. I expect it should be runninhg about 2630