Choosing a powder

[nun_hunter]

Is there a formula or guide to choosing the best (or most likely to produce best results) powder when starting load development? I did a search on here and came up with one such example but was wondering what others use assuming powder availability isn't the main driving factor.

For example RS powder data shows 4 different powders for a 50 grain bullet in .222 the only differences appearing to be pressures and velocities. Is there a way to predict (if possible) which option would be best?

From my own opinion of imagine a powder that produced the highest velocity but from the lowest pressure and filled the case as close to 100% and also achieved as close to a 100% burn in the barrel used would be a start. Without Quickload this is all a bit much to work out though. Either it's time I bought a copy or found out another way to choose a good powder to start with.

For those who use Quickload to work out new loads in advance has it been accurate in its predictions and saved you time on selecting components to start with?

 

[stubear]

The RS powders are pretty good in terms of producing good velocites but lower pressure. I've been up to 46gn of RS52 (0.4gn over their max) with no pressure signs at all in my .308, but the accuracy was pants so at the moment I'm fine tuning a 45gn load.

In terms of which to start with - Good question! My local RFD (Fultons at Bisley) only stocks RS powders, so that was the "which brand" decision taken care of.

And then in terms of the RS50 vs RS52, I went with the RS52.

My reasons for doing so were that I'm loading for a 22" barrel hunting rifle rather than a 30" barrel target rifle, so I need to get the velocity up where I want it with less barrel to play with. In my head that meant I need a hotter powder.

The second thing was I wanted to load a 165gn bullet in order to be an all rounder for boar and deer (some countries have a 10 gram minimum bullet weight), so now I'm trying to push a heavy for caliber bullet in a shorter barrel = hotter powder in my mind at least.

And then in terms of loads I wanted to focus on I knew I wanted to be close to factory ammo, so there wasnt much point in searching for accuracy nodes halfway up the powder charge scale, hence 45gn of powder. With 165gn Interbond this seems to shoot to the same POI as factory Federal 150gn soft point.

So TBH it was kinda guess work! At some point I will probably try RS50 as well because really the only way to be sure about how well a load performs is to load it up and try it.

Unfortunately I've been through the same process, searching out on loads of different forums to see if there was some piece of wisdom I was missing which would unlock a magic combo.

I'm still using factory federal at the moment because I just want to test the hell out of the home loads before I use them in the field. I've twigged not cleaning the rifle barrel now and that seems to have helped accuracy a lot, but I just want to triple check the home loads and then I'll swap over to them fully.

So yeah, short answer - pick what you think best meets what you're trying to achieve on paper with the information you have to hand and then after that just try it out and see if your rifle likes it!

 

[ChesterP]

I'd suggest reading one of the many reloading manuals, such as the ABC of reloading, the Lee reloading manual, Lyman's version or one of the others. They mostly cover this ground quite well.

When comparing powders for your calibre and bullet, you need to work out which ones give the best velocities for lower comparible pressures, and which give close to 100% burn in the barrel. Not enough burn = too slow a powder for your barrel/bullet combo, and too fast a powder can give rise to dangerous pressure spikes, so finding ones which are usually recommended and listed on the load tables is the best way to start.

If you look at Vhit's online data, there's a choice of powders for each calibre and bullet combinations and velocities for each are shown. The powders achieving best velocities are the ones generally best suited but you also have to be careful to understand the sensitivity to say 1 grain rise on pressures. Some load manuals provide the pressure differences between powders for a given bullet, such as Lyman's 49th. Even better, the Lee reloading manual offers a 1 grain factor on velocity and pressure. Why is that important? Because the powders to look for usually have more velocity gain per equivalent pressure rise per 1 grain factor. Those that don't will be more prone to exhibiting pressure spikes for no or low velocity gains as pressures rise and greater care is needed in their use.

As Stu says, powders like RS seem to give better results than some when looking at 1 grain factors and it's certainly true that in .308 for example, their RS50 and RS52 powders both exhibit higher velocites for lower observed pressures than equivalent Vhit powders for example on load data so far coming in. I did a test yesterday of RS50 with 175 grain .308 bullets and was achieving 80fps more, and with better accuracy than the Vhit powders I'd previously used with 150 and 175 bullets, but with less recoil and less in the way of pressure signs.

Whatever you choose, start low, but not too low (as this in itself can be dangerous) and work up. Never work in more than half to 3/4 a percent rise in load once you get to within 75% between min and max recommended loads and you should stay safe.

A word of warning: Do NOT trust Quickload when dealing with RS powders. Someone was kind enough to run me a whole batch of QL data for RS50 and it significantly under estimated actual pressures judging by the measured velocities and pressure signs for the load development steps done compared with QL predictions.

I believe that Laurie Holland has experienced just the exact same thing when comparing QL with RS52 loads, publishing his warning on the UKV site a while back. refer to post #23 of this thread : http://ukvarminting.com/forums/topic/39601-short-barrel-308-fast-bullet-what-powder/page-2?hl=solid

Here's similar findings for RS50 with a similar warning: http://ukvarminting.com/forums/topic/40077-switch-to-rs-powder-ql-vs-actual-results-for-308-223/

Refer to post #6 on that last link.

 

[Lateral]

There seem to be a few anomalies in the latest QL version.

RS Swiss is a good example, given the Alliant RL17, and RS Swiss RS60 are supposed to be identical, coming from the same manufacturer, but QL give lower pressures for RS60, compared to RL17 !

 

[Biathlonjimmy]

QuickLoad, although not perfect by any stretch, is by far the most comprehensive way of selecting a powder/bullet combination. As with any load dev work them up.

there are a lot of variables with quikload and if any one of them is slightly of, even seating depth by 5thou, can produce very different readings when you get close to PMax.

I found QL to be bang on with RS70. The estimated FPS was out by of 10 of the average when measured through the Magnetospeed with an ES of 23.

Pretty close QL estimates to real world in .22-250 & .308 also over a few different combinations.

It will never be exact but it's a very useful tool to cut down your options.

 

[ChesterP]

QuickLoad, although not perfect by any stretch, is by far the most comprehensive way of selecting a powder/bullet combination. As with any load dev work them up.

there are a lot of variables with quikload and if any one of them is slightly of, even seating depth by 5thou, can produce very different readings when you get close to PMax.

I found QL to be bang on with RS70. The estimated FPS was out by of 10 of the average when measured through the Magnetospeed with an ES of 23.

Pretty close QL estimates to real world in .22-250 & .308 also over a few different combinations.

It will never be exact but it's a very useful tool to cut down your options.

That's probably a fair assessment, but there are known issues with QL predictions and RS50 and RS52 powders. I have been in contact with RS about this recently and they are aware of it since I'm not the first person to raise it. Also, see Laurie's post (linked above) for his findings with RS52 and confirmation of his suspicions here. As you rightly say though, work it up, always start low, look for the pressure signs as you work up, (and that includes a deviation from linear velocity gains to steeply rising or plateauing velocities). I agree with the seating. How many people I wonder, automatically seat say 10 thou off without first batching or checking their bullets to ensure all are within a few thou base to Ogive? Not many that I've spoken with. Whilst not a problem for really well made bullets where consistency is quite good, it is certainly an issue for a lot of current production bullets that can vary by 20 thou or more! (Sierra Match Kings in 175 and 190 in .308 come to mind for example. I've measured deviations of 20 thou with those, so loading close, they certainly require batching).

 

[markyw]

....
For example RS powder data shows 4 different powders for a 50 grain bullet in .222 the only differences appearing to be pressures and velocities. Is there a way to predict (if possible) which option would be best?
....

I think that although they may give several powder options that CAN be used in the .222 (as an example),there is normally ONE recommended powder that has been developed with that particular calibre 'in mind'. In the case of the .222, I think the recommendation is RS40.

The page for RS40 gives a good indication it is the preferred for .222 : https://www.reload-swiss.com/en/rel...40_rifle_powder/rs40_rifle_powder_1/index.php

Regards

Mark

 

[nun_hunter]

Thanks Mark, I hadn't thought to look on the individual powder recommendations. I don't want to end up with loads of half used tubs of powder that haven't worked. While I appreciate what is recommended or works in another rifle may not work in mine or in the case with my 222 there may be other underlying issues.

 

[markyw]

Thanks Mark, I hadn't thought to look on the individual powder recommendations. I don't want to end up with loads of half used tubs of powder that haven't worked. While I appreciate what is recommended or works in another rifle may not work in mine or in the case with my 222 there may be other underlying issues.

Bullet incompatibilities are one thing, with twist rates and bullet weights to take into account, but not sure there are powder incompatibilities - unless you choose completely the wrong powder for the calibre.

I have loaded and shot Alliant unique, Trailboss, H322, H4198 and now looking at RS40 in my .222. 45, 50, 53 and 55 gr bullets all work (some better than others). 69 and 72 gr bullets don't.That's down to the twist rate in my CZ527 FS.

I personally use Quickload for fine tuning loads, but also if I run out of specific powder and need to load with something else I have around to ensure it is safe and will work.

Regards

Mark