Matching a factory load

[mbohuntr]

Well, I finally made it to the range yesterday, Hornady whitetail 150 in .308 shot excellent in my rifle, so I put a chrony on it... they average almost right at 2900 fps 3' from the muzzle. I have read they are interlocks, but what powder??

If I am shooting that close to max loads in the cold, what happens when it's hot out?? I wouldn't want to load them that hot with H4895, or IMR4064.... :o

[bigedp51]

IMR-4895, IMR-4166, IMR-4064, IMR-4320, Varget. and CFE 223 will all break 2900 fps at Hodgdon's with a max load.
And the max load of Varget 47.0C grains, 2,937 fps at 50,300 cup is the lowest chamber pressure.
NOTE, Varget is a extreme powder and the least temp sensitive.

http://www.hodgdonreloading.com/data/rifle

http://i.imgur.com/33XPgx3.jpg

[mbohuntr]

Thank-you very much!!

[Zero333]

Even if you know what powder and primer to use (and of course the brass), to duplicate the factory load it's just as crucial to size the cases to the same point as the factory ammo and have the same neck tension.

You can pull one of the bullets and weight the powder from the case. This will give you a better idea as to what it might be. Very few powders are identical looking, and the factory charge weight can help narrow it down.

[bearcatrp]

Remember, Hornady reload book used a 1:12 twist for there testing. If you have a 1:10, your readings may be different.

[RC20]

As re-loaders, who would have ever thunk we would be trying to match up to factory ammo for accuracy?

[m12lrs]

As re-loaders, who would have ever thunk we would be trying to match up to factory ammo for accuracy?

Crazy isn't it.

Much better to find the load for you rifle. That is what it is all about.

If not why not just buy the factory ammo

[Deadshot2]

Well, I finally made it to the range yesterday, Hornady whitetail 150 in .308 shot excellent in my rifle, so I put a chrony on it... they average almost right at 2900 fps 3' from the muzzle. I have read they are interlocks, but what powder??

If I am shooting that close to max loads in the cold, what happens when it's hot out?? I wouldn't want to load them that hot with H4895, or IMR4064.... :o

The IMR 4064 wouldn't be so bad. Why not try some of IMR's Enduron powders? Supposed to be relatively temperature insensitive so you won't run into pressure issues with wide temperature swings.

I'm starting to develop loads using IMR-4451 in place of H-4350 in my 6.5 Creedmoor and IMR-4166 instead of Varget or IMR-4064. So far so good. Just takes patience while working up the loads.

As for what powder the factory is using? Pretty much different stuff than we can buy "on the street" unless you want to buy 75# "barrels". We can buy powders that are "Like" factory powders but not the "SAME". Just lot size/number differences are enough to cause variations.

[bearcatrp]

If not why not just buy the factory ammo

Because its cheaper to reload it. Have shot superformance out of my 308. Dam accurate. Fairly hot too. I used that to strive for but to exceed when possible. Am able to go a little higher and keep the same accuracy.

[bearcatrp]

I tried IMR 4166 with 208 ELD-M. Varget got me only so far before case swipes started. Getting a little further with IMR 4166. But for my 178 ELD-X, varget really shines. I keep an abundance of varget on hand. Using 43.9 gr @2720 fps with varget.

[mbohuntr]

Because its cheaper to reload it. Have shot superformance out of my 308. Dam accurate. Fairly hot too. I used that to strive for but to exceed when possible. Am able to go a little higher and keep the same accuracy.

Exactly!! I have tried several different factory combos out of it now, and nothing came close to the bug holes I shot with that ammo... If I roll my own, I estimated it would cost about half as much, and I would never have to worry about being out of stock, or buying and keeping ammo in storage for years... Thanks for the excellent ideas!!

[Deadshot2]

IMR-4895, IMR-4166, IMR-4064, IMR-4320, Varget. and CFE 223 will all break 2900 fps at Hodgdon's with a max load.
And the max load of Varget 47.0C grains, 2,937 fps at 50,300 cup is the lowest chamber pressure.
NOTE, Varget is a extreme powder and the least temp sensitive.


http://i.imgur.com/33XPgx3.jpg


If you read Hodgdon's product sheets you'll find that the Enduron offering that matches Varget pretty well is also very temperature insensitive. From 0 degrees to 125 degrees it varies (according to Hodgdon) only 25 fps. (~0.8 %) The chart in your post does not show temp sensitivity for the IMR Enduron Powders. As a bonus, the Enduron line also includes a copper fouling reducer.

Since most of us more likely than not do our load development somewhere around the 60 degree day that means only a 12-13 fps change when getting cold or hot. Most chronographs, according to a recognized expert, have half that much error built in due to their electronics and sensor types.

At first I resisted using Enduron powders. Then H-4350 became as scarce as Varget was so I tried some IMR-4451. Let's just say I no longer worry about the scarcity of H-4350.;)