Slow burning powder and a 23" barrel

[analog_peninsula]

This is what happens when you shoot 120 grains of IMR 4350 out of your .500 A2 with a 23" barrel.

 

[hoytcanon]

Great... how does it shoot?

 

[analog_peninsula]

Surprisingly well. Some say the A2 stock looks like a club, but it does what it’s designed to do, which is absorb recoil. Note the forward, scout style scope as well.

 

[Hunter-Habib]

This is what happens when you shoot 120 grains of IMR 4350 out of your .500 A2 with a 23" barrel.

View attachment 598793

Good one. Is that a Hannibal model ?

 

[Riflecrank]

Cut my teeth on a 500 A2 also before learning torque control from Mitch Carter's .577 Tyrannosaur.
That fire snake reaches 20 feet or more down the 100-yard tunnel:

 

[analog_peninsula]

Yes, it’s a Hannibal. I’ve never been brave enough to shoot it from the bench.

 

[Albert Penselldiche]

This is what happens when you shoot 120 grains of IMR 4350 out of your .500 A2 with a 23" barrel.

View attachment 598793

Looks like a great load for followup shots on dangerous game. Sure to give that charging buffalo second thoughts even if the shot is missed. Even an angry hurt animal is bound to give serious consideration before running into a flame thrower. Mega noisy too I'll bet.

 

[D.M.V]

Blue dot in a 40 s+w or 10mm gives a pretty good flame on the upper end of the loading schedule as well

 

[Nhoro]

Pretty impressive. Just a random question for experienced reloaders, does faster powder reduce the fireball and give you more velocity for less powder ? Just spitballing here and thinking less of a faster powder might make more velocity with less unburnt powder ?

 

[analog_peninsula]

IMR4350 is really too slow for optimum use in the A2. The cartridge itself is very forgiving, and I’ve found acceptable loads with RL15, H4895, Varget, Benchmark, H335, and RL17. With 570 and 600 grain loads, recoil doesn't really get ugly until you approach 2400 fps. Max is somewhere around 2475 and 2500 fps. All that said, I don’t see any real need to go faster than 2300 fps, but many people do and seem to enjoy the punishment. There’s much less of a fireball with the faster powders.

 

[Mark A Ouellette]

Pretty impressive. Just a random question for experienced reloaders, does faster powder reduce the fireball and give you more velocity for less powder ? Just spitballing here and thinking less of a faster powder might make more velocity with less unburnt powder ?

You are on the right track. Yes, up to the pressure limit is reached.

Less weight of faster powders will provide X velocity but will also reach the maximum mean pressure faster for a given cartridge and bullet weight.

To achieve a higher velocity within safe mean pressure, select a slower powder. The slower powder will require more weight to match the velocity of the previous faster powder. Then, even more weight is required to achieve a higher velocity. Sometimes this results in a compressed powder charge.

 

[cmk]

Pretty impressive. Just a random question for experienced reloaders, does faster powder reduce the fireball and give you more velocity for less powder ? Just spitballing here and thinking less of a faster powder might make more velocity with less unburnt powder ?

Yes it does. Ish. But the pressure curve is different as the peak pressure is reached sooner. And it could get into dangerously high pressures if too much of a too fast powder is used.

If you load e.g. a 7mm RM with a pistol powder (i.e. fast) you could only load the case to so full before it will be dangerous. And even then the total gas volume generated by the burning fast powder would be less than with a slower powder that burns just until the bullet leaves the barrel.

So there is a sweet spot/range of powders that work well for a particular cartridge/bullet weight/barrel length.

 

[375 Ruger Fan]

Kills them and cooks them, I like it.

Serious question though: Is all that powder doing anything for you if it's burning beyond the end of the barrel?

 

[Nhoro]

And then I guess a big fireball indicates unburnt powder. So the velocity ladder of that round would have flattened out before the 120 grains ie 115 to 120 would show little if any increase in velocity ?

 

[analog_peninsula]

IMR4350 is really a reduced load powder in the A2. I don’t believe you can stuff enough powder in the case to hit max pressure with 570-600 grain bullets, but that’s from memory, so verify. With the fast twist of the A2 barrels (1:12), I’ve seen references to shooting bmg bullets for plinking, but I’ve never tried it myself. From memory again, I think those loads used H870

 

[cmk]

I see that @Mark A Ouellette was faster than me in replying. Typing on the phone is sloooow

And then I guess a big fireball indicates unburnt powder. So the velocity ladder of that round would have flattened out before the 120 grains ie 115 to 120 would show little if any increase in velocity ?

Yes, it would probably not do much difference, but it will do some, even if the majority of the extra powder burns after the bullet has left the barrel.

The extra powder takes up space, which means that there is is less space available for the expanding gas as the powder burns. And that leads to higher pressure, which in turn increases the burn rate of the powder, leading to more gas being produced. This is easily illustrated by pouring a little powder on the ground and setting fire to it. It will burn, but not so dramatically, since there is no pressure build-up.

There are complex relationships to take into account when calculating what amount of which powder is the 'best' for a cartridge. Case volume vs bore area is another one, Consider a small case with a large diameter bullet (e.g. 45-70) and a larger case with a smaller diameter bullet (e.g. 300 Wby). The 45-70 will need a faster powder, since the pressure is working on larger portion of the internal surface of the combustion chamber (the case walls and the bottom of the bullet), compared to the 300 Wby. This means that the 45-70 bullet will accellerate fast, and the volume behind the (now moving) bullet increases faster. When a 45-70 bullet has travelled an inch into the barrel, the volume behind it approximately doubled, thus the need for a powder that will burn fast and therefore maintain the high pressure that accellerates the bullet.

A 300 Wby bullet that has moved an inch has not seen the same volume increase behind it, and thus it is not needed to build up pressure as fast. That is the reason 'magnum' cartridges normally benefit from slower powders and longer barrels.

Bullet weight also comes into play, since a heavier/longer bullet both occupies more space initially, and also has more inertia. So for any given cartridge, a ligher bullet can use a faster powder, because it starts to move easier.

Luckily we have reloading manuals, and don't have to do the calculations by ourselves.

 

[Riflecrank]

I used 110 grains of RL-15 with the 570-gr bullets (GSC FN and Barnes XLC, olde-style blue-coated)
in a 23" barreled .500 A2 for my hunting load.
Gave about 2450 fps MV (McGowen 1:10" twist, stainless, on a BRNO ZKK 602 in a McMillan stock).
Today I would choose Varget for better ThermoBallisticIndependence.

That was iron-sighted and with the muzzle brake removed, just to be kind to my ears.
The 570-gr XLC broke an offside shoulder and the 5-1/2 y.o. bull turned to run on three legs.
Then the 570-gr GSC FN entered his rump and came out his throat, tail to tonsils, exited.
He dropped after two impacts at about 50 yards for each shot.

For my target load in a Ruger No. 1 .500 A2 with 27" barrel that I throated a little longer for the heavier 50 BMG bullets (McGowen 1:10" twist, stainless also)
IMR-4350 worked a charm.

705-gr AAA Harlow bullet with 110 grains of that did about 2125 fps and
would put 3 bullets into 0.170" at 100 yards when I got lucky.

A 5-mil holdover with that powder charge and the 750-gr Hornady A-Max would get me on paper at 942 yards, in a cow pasture.
I would choose H4350 for such plinking nowadays.

 

[Riflecrank]

Finding that the Texas Heart Shot had exited bison's throat, I shot him again post-mortem in the other ham from only 25 yards, and X-ed him long ways with the GSC FN. By golly that exited too.
Both expanding bullets were recovered under the offside hide in chest. The more shortened one from 25 yard impact and the less shortened one (on right above) from 50-yard initial shot.
FN solids exited 8 to 10 feet of bison, from both 50-yard and 25-yard impact.
Bilateral Texas Tonsilectomy.

 

[Albert Penselldiche]

I used 110 grains of RL-15 with the 570-gr bullets (GSC FN and Barnes XLC, olde-style blue-coated)
in a 23" barreled .500 A2 for my hunting load.
Gave about 2450 fps MV (McGowen 1:10" twist, stainless, on a BRNO ZKK 602 in a McMillan stock).
Today I would choose Varget for better ThermoBallisticIndependence.

View attachment 598968
That was iron-sighted and with the muzzle brake removed, just to be kind to my ears.
The 570-gr XLC broke an offside shoulder and the 5-1/2 y.o. bull turned to run on three legs.
Then the 570-gr GSC FN entered his rump and came out his throat, tail to tonsils, exited.
He dropped after two impacts at about 50 yards for each shot.

For my target load in a Ruger No. 1 .500 A2 with 27" barrel that I throated a little longer for the heavier 50 BMG bullets (McGowen 1:10" twist, stainless also)
IMR-4350 worked a charm.

View attachment 598969
705-gr AAA Harlow bullet with 110 grains of that did about 2125 fps and
would put 3 bullets into 0.170" at 100 yards when I got lucky.

View attachment 598970
A 5-mil holdover with that powder charge and the 750-gr Hornady A-Max would get me on paper at 942 yards, in a cow pasture.
I would choose H4350 for such plinking nowadays.

View attachment 598971


View attachment 598972

570 gr @ 2450 fps and muzzle brake removed. Wow! Who's shoulder broke? Yours or the bison's?

 

[meritman]

Won

This is what happens when you shoot 120 grains of IMR 4350 out of your .500 A2 with a 23" barrel.

View attachment 598793

Wonderful site and grate combination lol