3000 FPS plus with 140 grain in the 7mm-08

yodave

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I've looked at the StaBall 6.5 load data more then once and all it left me was confused and intrigued, and here is why...
For 139 grain bullets, they list a max charge of 51 grains with a velocity of over 3050 FPS, and yet they list a max of 48.5 grains for a 140 grain bullet and 2975 FPS. Now from my experience, there are not many powders that will break 2900 FPS with the 140 grain bullets in the 7mm-08, nevermind 3000 FPS......

A couple of years ago I saw Federal Fusion bullets for reloading, and with enough luck I managed to find 3 boxes of 100 in stock a couple weeks ago, so I sought out some StaBall 6.5 powder and brand new Winchester brass, so why Winchester?? well because I have always had good luck with it, and it has always seemed to have more internal case capacity then any other brand of case, and when playing with such a slow powder, it might be what is needed.

I did a primer test, shot 3 round groups with 47.0 grains of StaBall with different primers, speeds were close, far from advertised but between remington, federal, winchester and CCI primers what stood out at that test would later be contradicted, so the matter of importance here is that CCI 250 primers won during round 3 testing.

So let's back up a bit, the federal fusion 140 grain bullet makes contact with the rifling in my stainless T3 rifle at a COAL of 2.930, that's awesome, except the magazine limits me to 2.840 but feeds with no issues at a max COAL of 2.828, so 28 thou over the book COAL of 2.800, could this be the reason my speed was so much slower then that listed on hogdgons website?? A max load of 51.0 grains of powder had me just breaking 2900 FPS, okay my barrel is about an inch and a half shorter then their test barrel, my math says I should lose about 90 FPS due to barrel length, but I am almost double that, with no pressure signs......so I am moving to the dark side, straying from the book and relying on experience and the fact I still own 8 fingers and 2 thumbs, proceed with caution as this is my rifle, my data, and my loading skills, I do not endorse anyone follow in my footsteps unless qualified or confident to do so......

We're going about the suggested, starting at 50.6 grains of powder I loaded up 2 tenths of a grain until I got to 51.8 grains and shot a ladder test at 100 yards, meant to do it at 200 but there was other testing going on with the same rifle. I wrote the numbers down from the Labradar following every shot, and numbered them on the target where they landed

#1 50.6 grains..2882 fps
#2 50.8 grains..2903 fps
#3 51.0 grains..2910 fps
#4 51.2 grains..2939 fps
#5 51.4 grains..2930 fps
#6 51.6 grains..2956 fps
#7 51.8 grains..2990 fps



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the brass and primer of the 51.8 grain charge.......

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no flattening of the primer, no hard bolt lift, no weird sounding retort when I fired it.....it appears it could take more pressure safely, at 51.0 grains I had to start using a 3 inch drop tube but the powder is down halfway up the shoulder, so there is room for more without heavy compression

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I want to see the first number a 30XX so I am going to work up slowly from this point again, starting at 31.4 to confirm earlier findings of both speed and the apparent accuracy node I am walking into at this speed node......

so......did winchester just take the 7mm-08 into 284 win and 280 rem territory???
 
I'd be interested to know when you shot again, what's the ES and SD for your 51.8?

I just shot 1 of each looking at speed and pressure, will work up a load once we know where either speed or pressure maxes out.......in my rifle...do so at your own risk
 
Not at all unrealistic in a modern action with modern powders.

I've seen those numbers and greater in 7/08 without pressure signs.

Carry on until you see pressure signs.

I will say that you will likely find your best accuracy node between 2800 and 2900 ft/sec with 140's and a factory twist barrel.
 
Tried StaBall in my 24" barreled 7mm/08 with the 145 Speer SBT. Worked up to 50 grs with no pressure signs what so ever and got 3012 ft/sec with MOA accuracy. Also got 2992 ft/sec with 49 grs of H-100V.
 
There are a lot of reloading books that "undercharge" loads due to safety and lawsuit concerns. All loading data should be taken as a guideline. All rifles and hand loads should be brought up from the bottom with known safe loads a bit at a time until you see problems. You may run out of nerve before you see problems, you may see problems before you hit book max (theoretically) but that would be rare.
 
Following this thread. I've achieved ~3050 fps in my 7-08AI with other Varget (started to see very slight pressure signs), but have backed it down to about 2925 fps for an accuracy node. That's out of a 22" barrel. I'm curious to find some StaBall 6.5 to see what I could get out of it.
 
Shot same loads in a tikka and a Remington, tikka no pressure signs, rem very hard bolt lift, same reamer on both rifles, same distance to lands. Tikka handled it, not sure why the Remington wouldn't. Big fan of the tikka.
 
Not knocking anybody, but why the concern about getting a minute percentage increase in velocity?
So long as bullet does it's job, my main concern is not wearing the barrel and throat prematurely.
 
Not knocking anybody, but why the concern about getting a minute percentage increase in velocity?
So long as bullet does it's job, my main concern is not wearing the barrel and throat prematurely.

I wouldn't consider 100 plus FPS a minute percentage
 
Not knocking anybody, but why the concern about getting a minute percentage increase in velocity?
So long as bullet does it's job, my main concern is not wearing the barrel and throat prematurely.

For what it's worth, I don't consider it a minute increase in velocity. 100 FPS is considerable, especially if pressures remain below upper thresholds. Besides, maybe trying StaBall 6.5 will also provide a better overall load. The fun is in trying.

If nobody cared about a (few) hundred fps, why on earth would anyone go for a .30-06 over a .308 win?
 
for what it's worth, and this information may be a shock to you, but a 140 grain bullet sheds just over 200 fps in the first 100 yards, now if you can get that back by increasing your muzzle velocity to 3020-3040, think in terms of down range energy and what this does for shots out at 250 yards, dead is always dead, but at 250 yards there is always more risk of hitting a shoulder bone.......and, if the 7mm-08 will now do what the 284 used to do, there is no real reason to have my 7-08 chamber cut to 284 specs.
do you put 94 octane in your car?? why?? 88 octane will still get you to work.........and we're talking hunting rifle here......you know one of those 14 shots a year kind of useful collectible items we all own, the outside of the rifle is going to erode from carrying it long before the inside of the barrel erodes from shooting it
 
100fps is 3.333% of 3000fps.
A 100fps increase from 2900fps to 3000fps is a 3.445% increase.

160grs retain their velocity better.
 
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Excellent, wondering what the real world results are. Big fan of running 162 eld-x, even with that its a pretty decent jump in velocity if the numbers hold true, about 150-175fps faster than my Varget load. May have to test it!
 
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