Opinion/Advice Needed

[cornchuck]

I am planning on doing the OCW version of load testing. What I want to test is 178gr. A-Max being pushed by a load of IMR 4064 and a load of Varget. These are being shot out of a Rem 700P in .308 with factory barrel with virgin brass.

As Dan Newberry stated for the work up for this type of testing, is to consult at least 3 loading manuals to get a max load. I checked 5 manuals with Hodgdon's website as being one of them. Here is what I came up with:

IMR 4064 Varget
Lyman 48th edition 44.3 max 44.0 max
Sierra 42.8 " 41.7 "
Hornady 41.3 " 43.2 "
Nosler (180gr. load) 44.0 " N/A
Hodgdon (180gr. load) 45.2 compressed 45.0 compressed

43.5 grs. for an average for both powders. So I rounded it up to 44.0 grs. of both powders to be my max load. And I'm following Dan's instructions for this test. Starting low and working up ( as anyone testing new loads should do). 44.0 grs. is where I stopped. Even though the instructions say to go 1 gr. higher than max.

For some reason, my gut is saying that once I get to the higher loads, I'm going to get into some trouble. My load for this gun now is 175 SMK, 42.5 grs. of Varget, and CCI-BR2 primers. I have shot up to 44.5 grs of Varget with this bullet but it didn't group as well as the smaller charge. I have seen other guys post some of their loads for the 178 A-Max to be around 42.0-43.0 grs, of IMR 4064. I just wanted to try something differnet.

I have already loaded them up but haven't tested them.
What do you guys think? Do I need to pull some bullets or am I good to go?

Opinions/Advice will be appreciated.

Jason

 

[Canadian Bushman]

There are a bunch of things i dont like about dan's OCW method and his opinion on max charges is one of them.

Some guns will have a vastly different max charge than others, and i believe in finding the max for each rifle and load.

Instead of trying to determine the max by resources i determine a safe starting place by resources and work up to the max letting my rifle tell me whats too much.

 

[FearNoWind]

... I have shot up to 44.5 grs of Varget with this bullet but it didn't group as well as the smaller charge. ...

Jason, that statement hits the nail on the head. You'll find some shooters that believe faster is better. To some extent, that's a valid argument. But the higher velocity serves little purpose beyond making any fight with the wind a little easier and slightly extending the effective range.
I'm currently shooting 180 Bergers with 53 grains of H4831 at 2650 fps and enjoying .25 MOA accuracy. They group beautifully and don't go sub sonic until well after 1000 yards. I spent some time at the range yesterday working up to 55 grains. I was able to gain 100 fps but my groups blew up and the best I could get was 1 MOA.
As a result, I'll be shooting the 53 grain load at the match this Saturday.

 

[cornchuck]

Thank you for the replies fellas. I am not looking to make this a speed
gun. Would like to get around 2600. I guess what I was worried about is when I loaded these rounds up, and seating the bullet, it looked like they all were going to
be compressed loads. Yes the 178 A-max is longer than the 175 SMK, which I'm more familiar with. After seating the bullet I don't hear the powder shake in the case. I am also seating the A-max at 2.200 from the ogive. And being virgin brass, the stouter loads might give me some stuck cases.

Should I pull these bullets and have a lower max load?

Jason

 

[Canadian Bushman]

I loaded 45 gns of varget and 44 gns of 4064 with a 185 berger and a .02" jump for years. I believe i was somewhere around 2.9 coal, this was not a compressed load.

 

[Bigeclipse]

Thank you for the replies fellas. I am not looking to make this a speed
gun. Would like to get around 2600. I guess what I was worried about is when I loaded these rounds up, and seating the bullet, it looked like they all were going to
be compressed loads. Yes the 178 A-max is longer than the 175 SMK, which I'm more familiar with. After seating the bullet I don't hear the powder shake in the case. I am also seating the A-max at 2.200 from the ogive. And being virgin brass, the stouter loads might give me some stuck cases.

Should I pull these bullets and have a lower max load?

Jason

compressed loads are not as bad as some may say. What I would do to check your compressed loads is to measure the bullet oal right after seating them and then let them sit over night and then measure the overall length again and see if it moved. If it didn't move, you are good to go as far as the compression is concerned. However, as far as using higher end loads from a book it is ALWAYS recommended to start lower from max (typically 10% is recommended) and then work your way up. before I do an OCW test I will always look for my max load. For example...lets say book values gave me a low of 50 grains and a high of 60. I will pick somewhere in the middle OR 10% lower than the highest charge and load it. I will then proceed to load bullets in .5 grain increments until I get to the max charge. Then go to the range and shoot these over a chrono graph if you have one. You can use these shots to check for brass pressure signs, but also to sight your scope in which you will need for your OCW test anyways. Make sure you shoot 2-3 fouling shots first...you can use over the counter ammo for these or load up an additional 3 rounds of the lowest charge weight. Now, once you reach book max, stop there and then run OCW test.
The chronograph is useful in that it will give you velocities AND it will show you if anything funky is going on.
P.S. you should run this pressure test on whatever seating depth you intend on using in your rifle.

 

[benchracer]

I am planning on doing the OCW version of load testing. What I want to test is 178gr. A-Max being pushed by a load of IMR 4064 and a load of Varget. These are being shot out of a Rem 700P in .308 with factory barrel with virgin brass.

As Dan Newberry stated for the work up for this type of testing, is to consult at least 3 loading manuals to get a max load. I checked 5 manuals with Hodgdon's website as being one of them. Here is what I came up with:

IMR 4064 Varget
Lyman 48th edition 44.3 max 44.0 max
Sierra 42.8 " 41.7 "
Hornady 41.3 " 43.2 "
Nosler (180gr. load) 44.0 " N/A
Hodgdon (180gr. load) 45.2 compressed 45.0 compressed

43.5 grs. for an average for both powders. So I rounded it up to 44.0 grs. of both powders to be my max load. And I'm following Dan's instructions for this test. Starting low and working up ( as anyone testing new loads should do). 44.0 grs. is where I stopped. Even though the instructions say to go 1 gr. higher than max.

For some reason, my gut is saying that once I get to the higher loads, I'm going to get into some trouble. My load for this gun now is 175 SMK, 42.5 grs. of Varget, and CCI-BR2 primers. I have shot up to 44.5 grs of Varget with this bullet but it didn't group as well as the smaller charge. I have seen other guys post some of their loads for the 178 A-Max to be around 42.0-43.0 grs, of IMR 4064. I just wanted to try something differnet.

I have already loaded them up but haven't tested them.
What do you guys think? Do I need to pull some bullets or am I good to go?

Opinions/Advice will be appreciated.

Jason

As you go through your powder charge workup, you should be in the habit of checking each fired case for pressure signs. If you see signs of excessive pressure before you reach your max load, stop. Worrying about pulling bullets before you have seen any results is silly.

I was doing an OCW, not too long ago, that consisted of 7 different powder charges over and above the first three sighters. I started getting cratered primers and ejector marks by the third powder charge and terminated the test.

With that particular combination, I started getting pressure signs much sooner than expected. I will have to back my charges down and recalculate my OCW. THAT is why we work up carefully and pay attention to each step in the process.

 

[benchracer]

I guess what I was worried about is when I loaded these rounds up, and seating the bullet, it looked like they all were going to
be compressed loads.

And being virgin brass, the stouter loads might give me some stuck cases.

Should I pull these bullets and have a lower max load?

Jason

If you are bothered by the compressed loads, use a drop tube. That will buy you some case volume.

You will get pressure signs long before you end up with a stuck case. Work up carefully, watching for pressure signs, and you will be fine.