280 Remington reload data help

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dragon32

Inactive
Hello I'm new to reloading. Just started reloading for my Thompson center venture 280 Remington 24 inch barrel. I'm trying to understand what my velocity should be I don't own a chronograph yet but plan on buying one in the future. Here's what I have loaded up Remington core lokt Ultra bonded 140 grain with 57.5 grains of r19. My OAL is 3.28. I'm trying to achieve 2950-3000 muzzle velocity. The load data I got with my Lee die set and Alliant said with 59 grains of r19 (max load) should be around 2960. But other people are claiming they are getting near and over 3000 with 57 grains of r19 with a 22 inch barrel. So can anyone help me figure out what my muzzle velocity is??? Very frustrating. Thanks for all your help.

Will
 
While there are other ways to calculate your bullet's velocity, a chronograph is the easiest way, and they are pretty cheap today, compared to what they used to cost.

However, it doesn't really matter all that much. Your rifle and load combination are going to deliver what they deliver, and it may be more, or less velocity than other people get with their rifles and loads.

Every barrel and bullet combination is slightly different, and sometimes these differences stack up to deliver results at either end of the bell curve.

Sometimes, a given 22" barrel shoots a given load faster than a 24" barrel. Its not impossible, and not really all that unusual. "identical" barrels can show a difference in velocity, shooting the same ammunition. As much as 100fps is not unheard of. Not common, but not unheard of.
 
I don't go for the very last FPS. Accurate is more important.
And any game you hunt isn't going to notice 50fps.
 
Forget FPS, it really doesn't matter. Useful for computing MPBR if you sight in that way, but not necessary. No dhronographs around when I was shooting a 7mm mag. Worked up a safe load just under max and sighted it in 3" high ay 100yds and good to go for 300yds! The difference between 2950 and 2960 fps won't amount to squat.
 
Buy a $100 chronograph. The difference in 50 fps isn't important, but your fingers and eye sight are.

Worked up a safe load just under max and sighted it in 3" high ay 100yds and good to go for 300yds
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Without a chronograph you have no idea what a safe load is. Your chronograph will tell you what is a safe load. If your load manual says 2960 fps is supposed to be a max load with 57 gr of powder then 2960 fps your max load, NOT 57 GR powder. It is relatively common for you to hit 3000+ fps in individual rifles with 55 gr of powder. You THINK you are just under a max load, when in fact you are already over loaded in that individual rifle. In my rifle I may not be. The only way to know is with a chronograph. Without one I'd never venture over mid level loads. And in my experience I've seen this happen more often with the Reloader powder more often than other brands.

Zeroing a rifle 3" high at 100 yards was thought to be good advice 50 years ago, but no serious shooters fool with that nonsense anymore. With a +3" 100 yard zero you can easily shoot OVER a deer at 200 yards because you'll be 5-6" high. With almost all cartridges and bullets you can zero at 100, be -2" at 200 yards and still make hits at 300 without any hold over. Simply hold on the top of an animals back and the bullet will still be in the kill zone.

At 400 yards you'll have about about 22-25" of bullet drop with a 100 yard zero. With a +3" zero you'll still have over 12" of bullet drop. If someone can account for 12" of drop it is just as easy to account for 24".

Beyond 300 you need to be using a rangefinder and BDC type scope anyway. Those scopes are designed to work with a 100 yard zero, not some random amount over at 100 yards.
 
Without a chronograph you have no idea what a safe load is. Your chronograph will tell you what is a safe load.
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I have to disagree with this. Your chronograph will NOT tell you what a safe load is. ALL your chronograph can tell you is your bullet's velocity.

If your load manual says 2960 fps is supposed to be a max load with 57 gr of powder then 2960 fps your max load, NOT 57 GR powder.
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Again, this is incorrect. Manuals do not list "max velocity" they list the velocity of their "maximum loads", which are the loads where the loading company decided to stop. And, while this is usually dependent on the load pressure, pressure alone might not be the reason.

There is a relationship between pressure and velocity, but it is NOT a straight linear relationship. A chronograph cannot tell you a thing about pressure, other than that there was enough to drive the bullet through the chronograph, at the speed recorded.

A Chronograph cannot tell you if they pressure was high, low, within, or exceeding SAAMI specs. Nor can it tell you if it was safe in your rifle. ALL a chronograph does is measure speed.

A speedometer cannot tell you if your brakes are bad, or if the road is icy, or that your tires are bald, or that you are going too fast to make that sharp curve ahead, or anything else, it can only tell you what speed it is registering.

period.

A chronograph can show you if your velocity is above or below what you EXPECT, but it cannot, and does not tell you WHY. That, you have to figure our for yourself, and the reason MAY not be excess pressure.
 
With 140gr NBT, my best accuracy was 55gr of RL19. In my 26" barrel, I got 3027, with 1/2" groups. I went to 56gr and started showing pressure with only 30fps more. In a second rifle with 24" barrel, 55gr produces 2987.
 
Accuracy is far more important than velocity.
MAX loads of RL19 don't produce 3000 FPS with a 140. Alliant shows 59 grains gave them 2962 FPS out of a 24" barrel.
"...other people are claiming..." They're confused. However, your Venture has 1 in 10 rifling. Typical .280 Rem rifles are 1 in 9.25. That might make a difference.
"...Without a chronograph you have no idea what a safe load is..." A chronograph is 100% unnecessary. Determining what load is safe is what manuals are for.
 
A chronograph is 100% unnecessary. Determining what load is safe is what manuals are for.
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I used to have a chronograph, I think I still do, but I haven't used it in decades.

Back when I was using one, in the prehistoric, pre-Internet days, I shot a lot of different loads in quite a few calibers, and comparing the numbers I got against what was in the published manuals taught me something.

It taught me that my loads were all delivering exactly what the books said they would, allowing for the expected variations because I was using my guns, not the guns they used for their testing.

If the books says barrel length X load xyz = 2987fps. You shoot the exact same load (as close as you can get) in a rifle with the same barrel length, and you get 2923fps on your chronograph. You shoot the same ammo in a different rifle with the same barrel length and get 3026fps.

THEY ARE ALL CORRECT.

The manuals won't tell you what is safe in your rifle. The tell you what was safe in the test gun(s) they used, and there is a really high probability that will also be safe in your gun, but its not a 100% guarantee, which is why the manuals are GUIDELINES, and careful load testing and workup in necessary and important.

Everything has a range of tolerances, and when they line up just the right way, you end up with results on either end of the bell curve, instead of in the middle.

There are guns that show pressure signs (sticky extraction, flattened primers, etc.,) at or sometimes even below the listed starting loads. Some will do it with factory ammo.

There are also guns that can shoot loads well above the listed "maximums" with no observable pressure signs or ill effects.

Any combination of things is possible, and it is prudent to proceed assuming a worst case, until your testing shows you otherwise.
 
"I have to disagree with this. Your chronograph will NOT tell you what a safe load is. ALL your chronograph can tell you is your bullet's velocity."

Not necessarily correct. Each powder works within certain pressure parameters, regardless of burning rate. Starting with the start load and working up to the "published" maximum load usually with show a velocity increase that runs in a linear rate, sat 50 FPS plus or minus maybe 10 FPS. When you reach the max load for that particular powder in that particular firearm. velocity will do one of several things. Either a big jump in speed, no increase in speed or even a drop in speed. That's the time to drop back a grain or two of powder as you have hit the max load for that firearm.
Case in point, I have a custom Mauser in 7x57 that I needed to work up a load for an elk hunt. Max load in the Speer manual for the 160 gr. Grand Slam says 45.0 gr. of H4350 for 2580 FPS. (The starting load is 41.0 gr. for 2354 FPS FWIW) I got 2550 FPS average for three shots from the starting load. That rifle has always shown higher pressure signs, even with the underloaded factory ammo.

I did have two sets of loads made up for the tests as I wanted to determine whether to use the custom rifle or a Winchester M70 FWT I have in 7x57. The M70 digested every one of the loads up to the max and indications are I can still go a bit higher as velocity increase was still in the proper linear range. I haven't decided whether to continue on or call it good. Shots in the m70 only barely reach 2500 FPS and some shots where I hunt run as far as 350 yards. I'd like to at least be comfortable to about 200 to 250 yards as most shots will fall into that range.


I do believe the use of a chronograph will be an aid when approaching max loads for the rifle in question. It's worked for me for a very long time.
Paul B.
 
Perhaps I'm being to literal to be clear...:o

All a chronograph does is measure the bullet speed. It can show you a change in the expected velocity, (or show you no change if there isn't one) but its up to you figure out WHY. And additionally if the why is a safe, or unsafe condition.

You need more than just a chronograph reading to determine that.

I'm not saying a chronograph doesn't give you useful information, just saying that the chronograph alone doesn't tell you all you need to know it determine if a load is safe, or not.
 
Zeroing a rifle 3" high at 100 yards was thought to be good advice 50 years ago, but no serious shooters fool with that nonsense anymore. With a +3" 100 yard zero you can easily shoot OVER a deer at 200 yards because you'll be 5-6" high. With almost all cartridges and bullets you can zero at 100, be -2" at 200 yards and still make hits at 300 without any hold over. Simply hold on the top of an animals back and the bullet will still be in the kill zone.
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I don't own the first rifle that shoots high at 200 with a 100 yd zero.
 
My Oehler also gives Extreme Spread and Standard Deviation, which has been important for me. When I get to the upper limits, I stop when the ES goes above 30fps and the SD goes above 10. I have found that going further decreases accuracy with the increased pressure.
 
When I get to the upper limits, I stop when the ES goes above 30fps and the SD goes above 10. I have found that going further decreases accuracy with the increased pressure.
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I have found that usually this is cyclical. Keep pushing higher charge and the numbers will eventually move back together.
 
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