Sleuthing the Federal Gold Medal match load... Mk 316 Mod 0?

#4
sib1948 said:
Hope I can do as well in my reloading endeavors. Have over 2000 once fired Federal 175 SMK cases I plan to start working on in the next few months.
Click to expand...

If you're using 4064, you should just be able to go straight to the 41.7 grain charge. Or round it up to 41.8 grains. Hodgdon's starting load is 41.5 grains...

Let us know how this works if you try it. I don't believe 4064 varies much from lot to lot, so velocity ought to be very close to the factory loading.

Dan
 
#6
Here's a copy of that build sheet... note that IMR 4064 is the powder listed. And it would be counter-intuitive to think that the best load possible load for our military would be any different than the best load to be offered to the general public (pressure tolerances withstanding, of course). Velocity is probably going to vary between 2550 and 2625 fps depending on how close the lands are, and how long the barrel is. The batch we pulled apart here was running a bit over 2600 fps from a factory Savage heavy barreled gun.

 
#10
Do you have a data card for the 168 smk load?

Dan Newberry said:
Here's a copy of that build sheet... note that IMR 4064 is the powder listed. And it would be counter-intuitive to think that the best load possible load for our military would be any different than the best load to be offered to the general public (pressure tolerances withstanding, of course). Velocity is probably going to vary between 2550 and 2625 fps depending on how close the lands are, and how long the barrel is. The batch we pulled apart here was running a bit over 2600 fps from a factory Savage heavy barreled gun.

Click to expand...
 
#13
Thank you for the video. Saves a lot of work, and gives me a good starting point.
This may sounds really dumb, but have you seen a difference in the brass Federal is using for their 168 load and their 175 load (case volume wise)? I can't imagine two different product lines.
 
#14
I can't say that I've measured case weights between 168 and 175's... but that would be an interesting thing, if true.

I don't know where Federal is making the Mk316 stuff... it might make economic sense to run it on the same line that they're making the commercial 175 grain GMM on. I have not as of yet weighed and compared any Mk316 brass to the commercial GMM brass. Maybe we'll turn up some case weight and/or volume comparisons in the near future.

Dan
 
#32
I use 43 grains of reloader 15 in Lapua and LC LR brass. Get the same velocity. The one thing I would like to say is that this is by no way the best load for all 308 rifles. The replica load doesnt make it to 1000 yards breaking the sound barrier. My current load is supersonic to 1400 yards-ish. 208 amax at 2650 in my 22" long action at 3.1" mag loaded. Doesnt mean it will work for anyone else...thats the joy of making YOUR OWN load
 
#33
I am confused. Are you saying that you get the same muzzle velocity from both powders but at distance one powder is faster? It seems to me that once the bullet has left the barrel, under the same conditions, with the same bullet and the same velocity they should exhibit similar, or even the same performance. Or are you saying that the replica load and the rl 15 load don't stay supersonic past 1000, but your current load does?
 
#36
Matching velocity in hopes of achieving the same level of accuracy does not work because barrel time can vary, even with the same MV. Think about two drag race cars... one accelerates faster, and hit top speed sooner than the other... it finishes with a faster 1/4 mile time... even though the other car crossed the finish line at the same speed.

Barrel time, not per se muzzle velocity, is what you're after as you search for a good, accurate, repeatable load.

Dan
 
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#39
The lot that Steve Williams and I pulled down didn't vary at all... the charges were spot on. Even the loaded cartridges barely varied, as mentioned in the video.

That doesn't speak for all of the lots... it may be they have Monday ammo... and Friday ammo... I don't know. But I would expect that this whole process is so automated that bad lots should not be created, or escape the factory if they do... :) I did recently see a lot of FGMM 260 Remington match ammo (with the 142 SMK's) that was marked "seconds". I didn't get a chance to pull any of that down though.

Dan
 
#40
Dan Newberry said:
The lot that Steve Williams and I pulled down didn't vary at all... the charges were spot on. Even the loaded cartridges barely varied, as mentioned in the video.

That doesn't speak for all of the lots... it may be they have Monday ammo... and Friday ammo... I don't know. But I would expect that this whole process is so automated that bad lots should not be created, or escape the factory if they do... :) I did recently see a lot of FGMM 260 Remington match ammo (with the 142 SMK's) that was marked "seconds". I didn't get a chance to pull any of that down though.

Dan
Click to expand...

The extreme closeness of the loaded cartridge weights is what prompted me to contact
Dan about the FGMM 175 I had in my possession.

I'm of the opinion (only my opinion !)the softness of the brass responds favorably to any pressure variances
that might be present in this mass produced ammo (lower pressure-less expansion, more pressure...
you get the idea). Which leads to barrel times remaining consistent, and allows this ammo shoot accurately across
a wide variety of firearm configurations, mfg's, etc.
 
#41
Steve... I do think the softer case necks is a plus for accuracy. New Winchester brass is kinda soft in the necks (they're actually just thinner than some other makes) so this helps... and annealing any brass, if you do it right seems to help accuracy as well. So yes, the FC cases deliver great accuracy on the first, and usually the second firings... then they seem to work harder a little faster than average, and need annealing.

I've gotten good results by annealing them after two firings (two counting the factory firing, that is).

Dan
 
#42
Dan Newberry said:
Steve... I do think the softer case necks is a plus for accuracy. New Winchester brass is kinda soft in the necks (they're actually just thinner than some other makes) so this helps... and annealing any brass, if you do it right seems to help accuracy as well. So yes, the FC cases deliver great accuracy on the first, and usually the second firings... then they seem to work harder a little faster than average, and need annealing.

I've gotten good results by annealing them after two firings (two counting the factory firing, that is).

Dan
Click to expand...

:cool:
 
#43
Dan, for these different brass you said

Federal from FGMM for 175: If you're using 4064, you should just be able to go straight to the 41.7 grain charge. Or round it up to 41.8 grains.
I don't have a sheet for that (168 gr), but from pulling recent lots down, they show to have 42.8 grains (42.75?) of IMR 4064, in Federal brass with of course the 168 Sierra.
With Lapua probably about 41.9 grains would be on the node... maybe 42.0. Try both.
With Winchester brass, look around 42.1 to 42.2 grains...
Click to expand...

But when it came to Lake City?
So does 42.0 grns 4064, 175SMK in a LC case sound right?
Click to expand...

You said,
Matching velocity in hopes of achieving the same level of accuracy does not work because barrel time can vary, even with the same MV. Think about two drag race cars... one accelerates faster, and hit top speed sooner than the other... it finishes with a faster 1/4 mile time... even though the other car crossed the finish line at the same speed.

Barrel time, not per se muzzle velocity, is what you're after as you search for a good, accurate, repeatable load.
Click to expand...

:confused: ;) What?! No love for Lake City? LOL :p

Seriously, I love this thread and really appreciate the information I've gained from it and the video.

thanks

Seekers

ETA: Good idea with the Lee case trimmer and I've given my wife a bolt/nut to help her with her scope. :cool:
 
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#44
Dan Newberry said:
The lot that Steve Williams and I pulled down didn't vary at all... the charges were spot on. Even the loaded cartridges barely varied, as mentioned in the video.

Dan
Click to expand...

This is intriguing. I am really wondering how Federal manages the charge weights so precisely on an automated line. I have always been puzzled about how/why FGMM performance got to be, and stayed, so excellent. I concluded that they paid extra diligence to the very basic parts of the loading process, and have tried to emulate this in my own handloading process.

Steve... I do think the softer case necks is a plus for accuracy. New Winchester brass is kinda soft in the necks (they're actually just thinner than some other makes) so this helps... and annealing any brass, if you do it right seems to help accuracy as well. So yes, the FC cases deliver great accuracy on the first, and usually the second firings... then they seem to work harder a little faster than average, and need annealing.

I've gotten good results by annealing them after two firings (two counting the factory firing, that is).
Click to expand...

Then, there's the softer brass issue. This idea has been kicking around this forum for as long as I've been a member, well over a decade. If this was a problem for Federal, I'd have expected they would have changed that, yet they have never been seen to take the hint. Ergo, I take that as some sort of confirmation about softer brass and factory ammo accuracy, for which FGMM is the standard. I do believe I may need to take another (and closer) look at annealing.

My research appears to suggest that Nosler brass is made by Federal, with deburred flash holes and chamfered necks; something to consider further.

Greg
 
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#46
Greg,

I wondered that too about the FC cases. I even thought for a while that they deliberately made their brass soft so you wouldn't be able to get too many reloads from it, and then have to buy more ammo... :) But maybe they just didn't want to mess with what was working so well.

The newest FGMM seems even better than stuff made some years ago, and their brass is better than it used to be also. I've gotten the third reload off some factory FGMM brass and so far, so good...

As to how they're making the stuff so consistent... maybe they do drop the ball every now and again. Someone posted recently that they found some variance in the powder charges. We didn't check many of the charges, so we may have missed some that were off a bit. But with the depth of a good accuracy node, the variance won't be off too bad as far as POI.

Then the 4064 doesn't meter well at all either... so they've obviously got some trick going for them, making that work. Remington uses a lot of extrudes, like IMR 4350, and their charge weights are all over the map in a single box of CoreLokt.
 
#47
My thoughts have been quite similar. But then again, factory ammo doesn't (or shouldn't) be in any way dependent on any further usage beyond the first firing (from the point of view of the business plan).

The reference to newer FC brass being somewhat harder, yet the FGMM ammo better, leaves me with even more question marks.

Dropping the ball aside, I'm not concerned about figuring out what happens when charge weight management goes awry, that's fairly simple to discern. My real interest is in about how they get things so right when things go right.

My guess is that there is some sort of QC process being applied to charges just prior to their insertion into the case. Again, this is why I check/adjust charges when they are dropped.

Up until now, I've been fumbling around with various iterations of partial length neck resizing. But results are not as I had hoped, and I believe I am done with that technique.

Greg
 
#48
Dan Newberry said:
Matching velocity in hopes of achieving the same level of accuracy does not work because barrel time can vary, even with the same MV. Think about two drag race cars... one accelerates faster, and hit top speed sooner than the other... it finishes with a faster 1/4 mile time... even though the other car crossed the finish line at the same speed.

Barrel time, not per se muzzle velocity, is what you're after as you search for a good, accurate, repeatable load.

Dan
Click to expand...

Hello, I'm a newbie with barrel time. What is barrel time and how do you find it and setup for it? You are the man that knows!!!!
 
#49
Use Dan's OCW method. The nodes are based on barrel time.

Most of us cannot actually measure barrel time.

Quickload will give you an estimated barrel time, but you just need to shoot and see where the nodes are.
 
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