Faster powders for shorter barrels - say 1680 for a 16 inch 308

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I don't know why the OP doesn't do his own experimentation and then report the loads, velocities, actual observed pressures, and measured recoil impulses.
It is his theory, he could be doing the actual testing.


Whats that old saying? Never let reality get in the way of a good idea....
 
I don't know why the OP doesn't do his own experimentation and then report the loads, velocities, actual observed pressures, and measured recoil impulses.
It is his theory, he could be doing the actual testing.

Whilst i agree, i can only assume he doesnt have old parts rifles sitting around that he doesnt mind running the chance of ruining it. Nor a 28" barrel that can be cut to 18" for the test, also the land to do it on. 50k with 1680 probably shouldnt be done at a public range.

And i like shooting and testing thing. Also some people are talkers and some are doers, i like doing stuff.

It will be 40 rounds of ammo to do the test
 
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Remember the #44 powder sold by Ammomart? Apparently it had been rejected and sold off as surplus because the anti-flash coating was off spec. I loaded some ammunition for my .22-.250AI with it. Very accurate, no pressure signs (case head expansion, etc.). But the muzzle flash and muzzle blast were dramatic. Bright fireball in broad daylight! The muzzle blast was almost a concussion.
I recall a .270 I picked up with the barrel badly bulged near the muzzle. Cutting and crowning to 18" solved the bulge problem, but it was not a pleasant rifle to fire.
But you're right. Centerfire rifles are loud, and good hearing protection is important.
 
There was some Russian 7.62x54 heavy ball (200gr, yellow tip) around a decade or more ago, it was ridiculous shooting it in an M44, surprised the grass didn't get set on fire shooting that stuff prone, massive 🔥 ball. The thing I remember most about it though was the sound...it was more like the binary target booms...very low and deep BOOM when you shot that stuff. Not the typical centerfire crack from regular ammo.
It was pretty miserable for recoil too.
 
Remember the #44 powder sold by Ammomart? Apparently it had been rejected and sold off as surplus because the anti-flash coating was off spec. I loaded some ammunition for my .22-.250AI with it. Very accurate, no pressure signs (case head expansion, etc.). But the muzzle flash and muzzle blast were dramatic. Bright fireball in broad daylight! The muzzle blast was almost a concussion.

I remember that Ammomart #44, shot up quite a bit of it. Had a burn rate close to IMR 3031.
In any rifle you loaded it, the muzzle flash was impressive!! And it certainly did not need to be
a short barrel. Think I paid about $4.00/lb for it in 7 lb containers. Dave.
 
Are you the same guy on FB last week that was arguing the 7.62x39 round was superior in every way (including terminal performance at long range 300-600M) to the 5.56?
 
I remember that Ammomart #44, shot up quite a bit of it. Had a burn rate close to IMR 3031.
In any rifle you loaded it, the muzzle flash was impressive!! And it certainly did not need to be
a short barrel. Think I paid about $4.00/lb for it in 7 lb containers. Dave.

Dave....did you consult quick load between the first and second truckload? Everyone blew their face off before quick load, don't you know.
 
This reminds me of a poster a couple of years ago who was continually bragging about the very high velocities he obtained with his superior reloading techniques( more than 200 fps over published loads). He posted nearly weekly & argued with everyone because he was more intelligent. Then he suddenly stopped 2 years ago. Ive often wondered how badly he blew himself up.
 
It's been alleged that this was being done back in the day by ammo companies, 5 grains less powder in millions of rounds equals $$$. And few if any people would notice the difference before chrongraphs.
 
This reminds me of a poster a couple of years ago who was continually bragging about the very high velocities he obtained with his superior reloading techniques( more than 200 fps over published loads). He posted nearly weekly & argued with everyone because he was more intelligent. Then he suddenly stopped 2 years ago. Ive often wondered how badly he blew himself up.

I remember that guy but can't remember his username. I used to shake my head because he was convinced everyone else were the dumb ones. He's probably missing some body parts be now.

I like to remind myself that people have been reloading for several hundred years and that billions (if not trillions) of handloads have been fired. It's unlikely that I'm going to come up with a magic load that everyone else has missed
 
This reminds me of a poster a couple of years ago who was continually bragging about the very high velocities he obtained with his superior reloading techniques( more than 200 fps over published loads). He posted nearly weekly & argued with everyone because he was more intelligent. Then he suddenly stopped 2 years ago. Ive often wondered how badly he blew himself up.

I remember that guy but can't remember his username. I used to shake my head because he was convinced everyone else were the dumb ones. He's probably missing some body parts be now.

I like to remind myself that people have been reloading for several hundred years and that billions (if not trillions) of handloads have been fired. It's unlikely that I'm going to come up with a magic load that everyone else has missed

Probably CFBMI. Knowledgeable with tons of experience but very crotchety.
 
I remember that guy but can't remember his username. I used to shake my head because he was convinced everyone else were the dumb ones. He's probably missing some body parts be now.

I like to remind myself that people have been reloading for several hundred years and that billions (if not trillions) of handloads have been fired. It's unlikely that I'm going to come up with a magic load that everyone else has missed

Maybe this is the same guy with a new username & a prosthetic hand.
 
Some time ago, there was a fellow here who, if he showed at the range, myself and a couple of others
just packed up and went home. He would beat his bolt open with a piece of wood, and then shoot another
of the same load, beat it open again......He reportedly blew up 3 rifles before he quit reloading.

Takes a while for some to learn, and some never "get" it. Dave.
 
The one load that I can recall having unusually large muzzle flash was one I shot last winter in my 16.1" Ruger 223. H335 under Nosler's 35gr BT. According to Quickload, 86% powder burn in 16.1", 26" would still be only 92%

for conversation, Some powder burn specs for common loads :

22-250, 55gr bullet, 38.0grs H380 = 97% powder consumed @ 26"
243 Win, 100gr bullet, 42.0grs IMR 4350 = 98% powder burn 22"
270 Win, 130gr bullet, 59.0grs H4831 = 94% powder burn 22"
7mm Rem Mag, 160gr bullet 65.0grs RL22 = 99% powder burn 24"
30-30 Win, 150gr bullet, 31.0grs IMR 3031 = 97% powder burn 20"
308 Win, 150gr bullet, 46.0grs IMR 4895 = 98% powder burn 22"
30-06, 165gr bullet, 57.0grs IMR 4350 = 95% powder burn 22"
300 Win Mag, 180gr bullet, 74.0grs IMR 7828 = 98% powder burn 24"
338 Win Mag, 250gr bullet, 66.0grs H4350 = 99% powder burn 24"
375 H&H, 300gr bullet, 73.0grs Win760 = 98% powder burn 24"
 
Muzzle flash and the concussion is not caused by unburned powder.

It is caused by gasses igniting when they hit the air. The fireball forms about a foot or two in front of the muzzle.

Military powders add anti-flash to the mix to prevent it. Some commercial powders do not. Such a powder in a short barrel can produce what I call a "bark" that is very painful if your are not wearing protection.

If you want more velocity, you want the pressure curve to drop less quickly. The peak of the curve for a slow and a fast powder will be the same.

The slower powder will drop more slowly and give more velocity. It does not matter if some of the powder is blown out the muzzle.

Yes, a faster powder will burn 100%, but you would use less of it, to keep the peak pressure at the limit, and then the curve would drop faster.

Trust me, us old farts are familiar with shot barrels. One common thing that I think every generation has done (starting round 1900) is to take a barrel and test it in 2" increments.

Hatcher has a good write up of his test in his book.

And on the wall of Fulton's, at Bisley, is a plaque with some barrel bits and the bullet that came out of them. The shortest barrel was about 3". The tip of the chambered bullet would be visible at the muzzle. The base of the bullet is mushroomed from the unsupported pressure when the bullet exited. Peak pressure is reached very quickly. I don't know how quickly, but I am guessing within the first 4 inches.

The idea they 1680 would produce more velocity than 4895 is ludicrous. By all means experiment, but be very careful you don't make a 1680 pipe bomb looking for that velocity.

You may recall that Hornady, a few years ago, offered a "Magnum" version of 308 and a few other calibers. The 308 I tested delivered an honest 200 fps increase. Made the 308 into a good 3006.

As you know, a 308 case holds about 48 gr of powder.

Before they case was neck down, they inserted 54 gr of slow powder in the straight walled case. Then, the case was put in a supporting, to hold the case walls in place, and a ram came down and compressed the powder into a solid mass. Then the case was necked into a 308.

I still have some of that ammo. I should dig it out and see what it does in a 20" Hog Hunter.

Some info on barrel length and velocity.

hCskzg4.jpg


I have lots of 1680 and 4895. I could run the test in 303 or 308, but have no way here at home to adjust to the same peak pressure. I recently sold my 308 that had a pressure strain gauge on it.
 
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Some time ago, there was a fellow here who, if he showed at the range, myself and a couple of others
just packed up and went home. He would beat his bolt open with a piece of wood, and then shoot another
of the same load, beat it open again......He reportedly blew up 3 rifles before he quit reloading.

Takes a while for some to learn, and some never "get" it. Dave.

Your Sig line is perfect.
 
The one load that I can recall having unusually large muzzle flash was one I shot last winter in my 16.1" Ruger 223. H335 under Nosler's 35gr BT. According to Quickload, 86% powder burn in 16.1", 26" would still be only 92%

for conversation, Some powder burn specs for common loads :

22-250, 55gr bullet, 38.0grs H380 = 97% powder consumed @ 26"
243 Win, 100gr bullet, 42.0grs IMR 4350 = 98% powder burn 22"
270 Win, 130gr bullet, 59.0grs H4831 = 94% powder burn 22"
7mm Rem Mag, 160gr bullet 65.0grs RL22 = 99% powder burn 24"
30-30 Win, 150gr bullet, 31.0grs IMR 3031 = 97% powder burn 20"
308 Win, 150gr bullet, 46.0grs IMR 4895 = 98% powder burn 22"
30-06, 165gr bullet, 57.0grs IMR 4350 = 95% powder burn 22"
300 Win Mag, 180gr bullet, 74.0grs IMR 7828 = 98% powder burn 24"
338 Win Mag, 250gr bullet, 66.0grs H4350 = 99% powder burn 24"
375 H&H, 300gr bullet, 73.0grs Win760 = 98% powder burn 24"

I've shot Barnaul (or maybe it was MFS) 308 in an 18" Ruger that produced a fireball that obscured the sight picture with an orange blast through an optic in full sunlight! It was the only factory loading that would do that.

My 16" Ruger 5.56 is an obnoxious gun to shoot with most 55 grain factory loads, producing massive blast and muzzle flip that is miserable after a few shots. Accuracy is dismal with these loads. 75 grain factory and handloads are so pleasant (and accurate) that all i shoot now are these loads (and 62 grain at slightly reduced velocity) out of all my 5.56 guns.
 
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Ganderite, there is no real reason to even do the test other then to prove to the OP what you already know. So if hes ok with using quick loads estimate, i say we use that for the test, probably not ideal but hes the one using quick load to make all these claims. So we might as well use it too to assume the peak pressure. The normal powder can kind of be verified by looking at other sources and getting an idea.

If you want to do it by all means go ahead, but id gladly do it if you weren't interested. I did make the offer to test the OP claim for him.

All i want for the test is the little quick load print out that has all the charge, % burned, time, pressure info for whatever powder, bullet and case is picked.

Wheb the OP gets his quickload id like it for
174gr pulled ww2 bullet h4895 3.075 oal
123gr pulled x39 bullet h4895 2.910 oal

And

174gr pulled ww2 bullet 1680 3.075 oal
123gr pulled x39 bullet 1680 2.910 oal

id even just use a quick load prediction as simple as this
49391706302_766a9039d8_k.jpg
 
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