Max charge of imr 4895 in .308 with 178grain amax

[alltherage]

Nosler and hornady both say around 41 grains but lyman has that as a starting load for sierra bthp. Max is around 45 i believe. That seems like a big spread. Different bullet i know. Any experiences? Im at 40 now with good accuracy but want to try to get to a higher node for velocity to 600yd

[Ryfulman]

Every rifles max pressure is different and reload manuals are now written by lawyers,so grain of salt.

When I buy a new rifle I ladder test increasing powder load by 0.3 grain til I establish max pressure in my rifle. This serves 2 purposes. Establishing max pressure with real world data and establishing the node.
Then I work within the node to find the most consistent powder load.
A reloading manual uses their test mule which isn't the same as your rifle,so they are more of a guide then set in stone.
Just my opinion.

[yobuck]

If you were loading for a wildcat cartridge there would be no published data at all other than what might trickle down from others who use that cartridge.
So why not load for factory guns the same way?
Just pick a safe load as a starting point and load one round. Then load one round with an increased powder charge of 1/2 or even a full grain.
If you have a chronagraph use it to record each round. If not shoot anyway as your main goal is to establish a max load for (that) gun.
You don't even have to shoot at a target if you choose not to. When you notice pressure signs from the gun stop shooting.
That could be bright spots on the case head from the ejector, or a sticky or heavier than normal bolt lift.
So now you know how heavy a load you can use with that powder/bullet combination.
Work backwards from that point in order to find the load you like.
Id personaly go back to the next lighter load that didn't show pressure, and play around with seating depth changes before I started looking at other charge weights.
I don't bother looking for nodes, I first look for velocity, and then try to find a way to make that work.

[bearcatrp]

What length of barrel do you have? Hornady loading book is lawyered up so its possible to go above but you have to pay attention to pressure signs if you do. I have a 24 inch barrel on my 308 and use varget. Its a slower burning powder which is good for longer barrels. Shooting 43.9 of varget with Hornady 178 ELD-X bullets with great success. Chrono at 2720 fps out of the barrel. If you don't have a chronograph, get one. A good tool to help with load development. The data in the books is based on a specific barrel and twist so if your barrel is different, won't match load data in the book.

[alltherage]

26" model 12

[bearcatrp]

If you can get your hands on some varget, do it. Allot slower burning. Look at the burn chart to see where your at vs others listed in the reload manual. You want the powder to burn just up to the bullet exiting the barrel. If you cannot, Go .2 increments up to 41 grains, watching for pressure signs, and see what happens. Are you loading OAL at 2.800? A-Max doesn't need to be close to the lands like a match round does.

[yobuck]

The question was, how much 4895 can I safely use with a 175 gr bullet in my gun?
Think about that then explain how barrel length or velocity would matter?
The velocity will be whatever it is when max load is established with that powder.
If were not happy with it then try a different powder and go thru the same thing all over again.

[Hotolds442]

Doing load work-ups is the only way you're going to find out how much your rifle will shoot safely. Don't rely on anyone else's data or estimates as every chamber is different. Add in the variances of brass, primers, seating depth, ambient temperature, and several other factors and it's all subjective. Your individual rifle will tell you how much it can withstand.

[alltherage]

i have varget. was shooting that with 168 hornady bthp match. wasn't happy with accuracy. switched to 4895 and got a little better. then tried 178 amax with 4895 and got great groups. 3/8" at 150 yards. I'm happy with the 4895 in this rifle, just interested in trying to get a bit more velocity. I understand about looking for pressure etc. Just was wondering if people were sticking around 41 or closer to 45 for max in general. thanks for the hlp

[rjtfroggy]

Hogdon list 41-45c for the 175gr. bullet I would think that some where in the middle would be a good accurate load that should be safe.
Too double check look it up on their web site, according to them you are below the starting point for that bullet.

[alltherage]

I am at 2.825 oal. .010 off lands

[bearcatrp]

I had bad luck getting close to the lands with the A-Max bullet. Once I backed them off to 2.800, tightened right up. The 178 match works great that close to the lands though.

[alltherage]

I went out and shot heavier charges today. Started seeing pressure signs at 43 grains. I was drilling nails between 41 and 42. I will reload some more and work the 41.5-42.5 interval, and then try seating depths. still at .010 off the lands currently.

[alltherage]

You were right bearcat, 2.800 tightened up. 42 grains even, with cci primers got me 1/4". Happy n ready for 600..finally

[alltherage]

My .243 axis hb with vmax likes a jump too

[RC20]

If we could also list the powder MFG?


IMR and Hogden make 4895 and AA makes a number of number matching powders that are in the vicinity but have their own characteristics as others.

[alltherage]

Imr

[bearcatrp]

You were right bearcat, 2.800 tightened up. 42 grains even, with cci primers got me 1/4". Happy n ready for 600..finally

Glad it worked out for you. Show some targets of the 600 yard shot. I wish I had a place close by to shoot that far. Will be trying my loads @1000 yards in the near future. Have to drive almost 4 hrs to do it but should be fun.

[darkker]

Let's get you some honest info about "lawyer" load garbage...

That whole notion is stupid, and untrue. Next is the "Manufacturer". IMR doesn't build powder, nor does Hodgdon. They do however blend differing lots of what they purchase, in order to get a end product that fits the burning range they want. Extruded powder isn't designed, nor built around weight and being loaded as such; that is a reloader's invention. It is built around volume, because geometry is how burning rates get controlled. Ever notice how almost all powder resellers don't list nominal Bulk Density, or Burning Rate variances?? That isn't an accident. No one reads the one caution to this point, that you should "always drop loads 10% when switching lots". Powder with the same name is NEVER identical to what you had previously. No book data lists what lots were tested, NOR who actually did the testing(in house, or calculated, or external).
Many still use Copper Crushers, which has LONG been known to not be accurate when used over around 45,000 psi. 748 as simply one example, all but dissapeared from Hodgy data a couple years back. Has nothing to do with appropriateness. Olin hasn't provided data in a VERY long time. They no longer make, nor have the capacity to make it. Hodgy has limited pressure barrels, and didn't want to fork out the money, so they reverted to last published data from Olin. Had nothing to do with Lawyers, had to do with money and marketing agreements.

So what is "The max grains", is never a single answer. Unless you use a strain gauge pressure system, the ONLY way to reliably judge if you are near max is by the velocity. Even in manuals who's grain charges vary by several grains, the velocity is almost always identical, or a measly 50fps different. All good data should be fired from SAAMI minimum spec: chambers, throats, bore and groove spec barrels. Mass produced rifles are much looser than that. So if you can match, or Beat book velocity.... It ain't because the angels like you, it's because you exceeded book velocity; regardless of the charge weight you used.

[Robinhood]

Darrker, Why do you think it is that so many Palma and F-class guys only weigh charges and do so well?