Powder to bullet comparison

[GetReel]

First off let me say I know every rifle is different and results vary but…

Do guys/gals find better luck with a faster than normal powder paired to a heavy for caliber bullet or a slower than normal powder paired with a heavy for caliber bullet?
Same question with light for caliber bullets.?
Or is there no real thought process here?

 

[Tank308]

I don't know if it's right or wrong. But I've always tried to pair slow with heavy and fast with lite.

 

[lancetkenyon]

Totally depends on cartridge, bullet type, and barrel length in my opinion. And, your definition of "fast" or "slow" powder burn rates.
Generally speaking, faster burn rate for lighter bullets, slower burn rate for heavier bullets. But getting the right burn rate for the barrel length might take some playing. I have a 20" and 26" in the same chambering. With the same bullet, they like different powder choices. 26" like a slower burn rate powder, 20" likes a faster burn rate powder to maximize velocity. Even though the 20" is actually heavier, the recoil impulse is different, a bit sharper with the faster burn rate powder. And definitely noticeable.

 

[243winxb]

Accuracy better with fast burn rate powders @ reduced charges, (below maximums) for heavy or light for caliber bullets. Published load data.

Different story if looking for maximum velocity. Slower burn rate, produces higher maximum velocity. Length of barrel doesnt make any difference in chamber pressure.

The amount of unburnt powder exiting the muzzle is a higher % with slow burn rate powders & short barrel.

First off let me say I know every rifle is different and results vary

Agreed.

 

[rustyshackleford]

I'd say you get better results with "slower" powders with bigger heavier bullets just because typically the goal with bigger heavier bullets is to shoot further and further and you need as much velocity up front as you can get. Kinda like the previous poster said, a guy who shoots benchrest told me that the majority of the powder used was quicker than what was expected and not necessarily top charges. But in BR you need a 0.1" group and for hunting or action rifle shooting that just isn't necessary. If I'm picking btw a 0.1" load be a 0.6" load, and the 0.6" load is going 150 ft/sec faster or more I'll choose it every time and top velocity loads typically happen with "slower" powders for a given cartridge.

 

[spladi]

First off let me say I know every rifle is different and results vary but…

Do guys/gals find better luck with a faster than normal powder paired to a heavy for caliber bullet or a slower than normal powder paired with a heavy for caliber bullet?
Same question with light for caliber bullets.?
Or is there no real thought process here?

I have in my 06 with 3031 and the 168's

 

[BallisticsGuy]

Heavy for caliber bullets need slower powders lest bad things happen. That said, within the slower burning powder options there is usually some window of very slightly faster vs. very slightly slower and that's religious stuff right there.

I know people that will go toward the faster side for more consistent burn at the cost of a higher peak pressure and others that go for the slowest end for a longer burn with less peak pressure and higher average pressure. Since not one of those people actually has any pressure testing equipment at their disposal and QuickLoad is helpful but not authoritative and easy to make mistakes with anyway, their stated preferences are by definition entirely speculative and thence can be discarded as apocrypha at best. I like to stay with the slowest options that still deliver the velocities I'm looking for partly because I bias toward extremely long barrels. If my barrels were on the short side then I'd probably slide my powder selection toward the very slightly faster side of the appropriate powders.

 

[Mikecr]

QuickLoad guy here. I run what ifs for:
-fastest powder
-that fills the case w/bullet bearing half in neck
-that predicts SAAMI max pressure with bullet off the lands.

So far it works, and my best load has always been near SAAMI max per QL.
My predicted MVs have been close as well.

 

[CONatureBoy]

First off let me say I know every rifle is different and results vary but…

Do guys/gals find better luck with a faster than normal powder paired to a heavy for caliber bullet or a slower than normal powder paired with a heavy for caliber bullet?
Same question with light for caliber bullets.?
Or is there no real thought process here?

Light bullets need faster powders; heavy bullets, slower. Example using QuickLoad estimates: 300 RUM at SAAMI-spec COAL with 26" barrel.

Bullet Powder Max Charge Fill Ratio Peak Pressure Muzzle Velocity
(grains) (%) (at/below SAAMI limit) (fps)

Nosler Ballistic Tip 150 grain Reloder 22 92.5 96.6 at limit 3,361
Reloder 33 102.8 100.0 13 kpsi under 3,185

Berger Hybrid OTM 230 grain Reloder 22 81.2 81.2 at limit 2,809
Reloder 33 95.7 98.4 at limit 2,897

The "wrong" powder costs you 100-200 fps in this example. In one case your fill ratio is likely unsafe with the wrong powder. Try to keep your fill ratio above 90%. See https://www.shootersforum.com/threads/loading-density-secondary-explosion.13083/ for the reasoning.

 

[MagnumManiac]

What Mikecr is implying here is efficiency, which I agree with 100% within reason.
Certain small bore cartridges with large cases will actually perform much better with an even slower powder than what is generally recommended.
Example; 264WM has very little testing with new powders, the companies just don't see the need when they are promoting their new stuff…
So, when powders like Retumbo and N570 aren't filling the case above 85-90%, to get better fps per grain of powder, you need to look to powders like H50BMG, US869 and RE33.
When I switched to RE33 and US869, the cartridge really opened up the realm of high velocity and made the cartridge more efficient.
Disclaimer! This testing was done on a custom rifle, with a custom match grade minimum chamber, custom throat length at .220" long and different experimental leade angles in a 8" twist 29" barrel.
A standard throated rifle will most likely NOT get the velocities this rifle did with these powders as the expansion ratio is too small.
The most efficient powder is the one that gains the highest velocities at or just under max pressure without causing an overbore situation. Which is to say that a lot of powder is being burned outside of the barrel.
The top 3 powders listed across several manuals for whichever bullet weight are generally the most efficient.
Their fps per grain of powder is highest in most applications, Nosler had a good write up on this subject in one of their manuals, just can't remember which one.

Cheers.

 

[Plinker147]

A lot of it depends on this question. Most what everyone is saying does followsuite, slow powders for heavies, faster powder for lighter bullets. Doesn't always ring true though. You will see a lot of short mags that operate just as good if not better with faster powders. Like R17 will often be as good as R22-thru 25 in short mags. Finding the perfect balance with case capacity, but rate, barrel length, and individuals chambers can vary a lot . I haven't found a hard fast rule other than trying and seeing for each individual gun.