Duplicate mach Loads

[unclejack]

What is the best way to duplicate a match bullet like a 6.5 Creedmoor Hornady 140 grain ELD Match. Would it be wise to try to match the projectile and velocity then determine the amount of powder (H4350).

 

[Bob R]

That would be how I would start. You know what Bullet, You know what Brass, and you know the over all length.
That only leaves Powder and Primers to work with. H4350 is what the round is supposed to be loaded with. Pulling a bullet, and weighing charges will get you ball park close. However the factory powder is probably not the exact same H4350 that you will buy. So that means working up a load, and chronographing the speed.
Then we also have what exact Large Rifle Primer to use. This also can make a difference in velocity numbers as well as accuracy. You may need to experiment some. I have not read any information on what primers are used in that loading.

Years ago I was doing the exact same thing you are doing only with Federal 308, 168 grain Match Ammunition for practice ammo in a Sniper Rifle. This was long enough ago that it was loaded with IMR4064 powder. I had pulled bullets and weighed charges, and you could not get enough IMR4064 in the case to get the velocity numbers to match factory loads. I ended up using Federal Magnum Match Primers to match the velocity numbers. I am pretty sure that the factory was using Magnum Match Primers at that time, with that loading. You could not find that information doing research however.
Later when RL15 was the powder I continued using Magnum Match Primers, and I could replicate factory ammunition.

Good Luck on your Journey

Bob R

 

[Bob R]

More Information

Off an Old Box of 140 A-Max Ammunition.
Hornady Case (a given)
Hornady 140 A-Max (140 ELD-M should load the same)
Powder: H4350
Powder Charge: 41.5
Primer: Federal 210 Match
OAL: 2.810
Velocity: 2700 fps

My Hornady 11th Edition lists H4350 with a maximum load of 41.5 grains @ 2700 fps from a 24" BBL.
They list the OAL for 140 ELD-M Bullets as 2.800. The 140 A-Max is also listed with an OAL of 2.800.
I would probably go off the Box Load Data and load longer at 2.810

My advice would be to start a little under 41.5 grains of powder, and work up slowly until you get where you are happy.

Good Luck on your Journey

Bob R

 

[FrankG]

The load data given by an ammunition maker is developed and tested in accuracy and pressure and velocity test barrels.

What spec your barrels bore and groove is made to and not to mention what chamber reamer spec was used to cut your chamber could be different then the spec test barrels. This can give different pressures and velocity differences.

Lot of powders will vary from lot to lot even from the same maker.

Also for example and I’m just using this as an example and let’s say it’s 308win and the go to powder is Varget… that doesn’t mean that every lot of ammunition made by a given ammo maker is using Varget every single time.

So don’t assume if you pull a bullet and look at the powder you know exactly what it is by looking at it.

Bullets, powder, barrels. Those three things more than anything else have to work together for accuracy.

Later, Frank
Bartlein Barrels

 

[kenhwind]

I used data from Cartridges of The World for the military match load for the 7.62mm or .308 and got good results using IMR 4895.
I had some once fired Federal Match brass that the local sheriff's office had fired, the 168-grain bullet.
The data stated 42 grains, so I verified that this was okay and worked up my load.

I shot this load from a Savage Model 10 .308 Police Rifle at 200 yards and the 42 grain was dead accurate. What is interesting is that the lighter load and the next load, probably 44 grains the groups opened up.