100% powder burn... does it matter?

[Pony Soldier]

When I started reloading I was using a bolt action (7RM).I chose a slow powder that gave high velocities. When I switched to a BAR, it would spit cases out with 3" of flames from unburned powder. I had forest fire concerns and potential for tearing the casing apart on ejection.

Upon suggestion of a gunsmith I changed to H4350 and have been reloading it since the very early 80s. My accuracy is llimited to 2 grain variance. I double check my scale readings and find the variance of the electronic trickler is 3-5 grains.

 

[Harvey_NW]

I am planning to test H4831sc first, only because that is the only one I have on hand. I am trying to figure out which powder I would test next if the H4831 is not giving the results I can live with.

H4831SC with 162 ELD-X shot absolutely lights out in my 280AI, and there was plenty of room to scoot out and get enough in there to hit pressure before compression, at .050" off the lands, IIRC. Highly recommend starting with that, and the VV powders have been great for me in a couple other cartridges.

 

[streamerfish]

Mine is a 30-06, and I had tried several factory loads, and a couple different bullets previously, and nothing shot even acceptable groups. I started hand loading and was using H4350 with 178 gr ELD-m bullets, in lapua brass. I always heard H4350 was the gold standard for 160-180 grain bullets in the 30-06, so I did not try any other powders. After extensive load testing and seating depth testing, I was able to get about .6-.7" groups with the seat depth around 0.060 off the lands. That was best in a couple different tests I did, so I thought it was the load for me... until I kept using it and the groups became as bad as everything else. Running all of my actual numbers through GRT I discovered that I was not likely getting complete burnt powder, and I have read that having less than 100% burn could potentially lead to inconsistency... since inconsistency is exactly what I was seeing, It lead me down this rabbit hole of how to find more optimal powders. I have seen several reloader articles and videos that will only consider powders that get 100% burn.

Now I have ordered a new barrel for it, and decided to switch it to a 280 AI, just to get a little better wind management with a slightly faster bullet with a better BC.... that and I just have always wanted a 280 AI... I already have accumulated some Peterson Brass (supposed to be the highest quality brass made in 280 AI), a good pile of Berger Classic hunter bullets (so they should be very consistent and forgiving), and both CCI & Federal primers (I'll test those after finding the best powder). So my components are good enough to avoid blaming them. Now I really just need to find the right powder. I am willing to test enough to find the one that works best, I just don't want to waste time on ones that are unlikely to give good performance, and I would like to narrow it down to what look like the best options first. Right now I have found the Range of powders to run from H4350 on the fast end, to H4831 and N560 on the slower end. H4350 would likely only give me around 86-87% case fill, but would burn 100%. H4831 I would have to compress to around 103-104% case fill to get to the right pressure range, however it would only get around 90% burnt powder... Between those two extreems, there are some options that look good, like N555, N160, Ramshot Hunter, IMR 4831, and AA4350. I've seen alot of people get great results with N560, but it will be around 95% burnt powder... which brings me back to the original question... does that matter? and if it does, at what point does it matter? Every powder I have listed is worth a try, plus probably a few others, but it would cost me an arm and a leg just to test them all. I am planning to test H4831sc first, only because that is the only one I have on hand. I am trying to figure out which powder I would test next if the H4831 is not giving the results I can live with.

What are the results you can live with/ the results your looking for?

 

[z987k]

I would think that as well. I have just noticed that some of the most used powders in bith 280 Ai & in 30-06 are not 100% burnt, yet people must be getting decent results. I have read that having less than 100% burnt can increase inconsistency, but am curious if anyone kbow that to be true or untrue. I am curious, if you can get consistency with less than 100% burnt, how much mess than 100% will still give very good results? and how accurate is GRT when it comes to the % powder burn?

If it's a popular powder, couple things. 1) a lot of people actually have no idea what they're doing, they just load something and shoot and say looks good.
2) You're bullet weight is too light. Try simulating a heavier bullet.
3) Your pressure is too low. Pressure effects burn rate.
4) You're running a rather short barrel.

For H4350 in GRT- I see pretty big differences with 30-06 and 6.5CM with real data over what it models. For example, in an 18" 6.5 CM, I am 2638fps with real life data, but it shows I should only expect 2548. This means the GRT pressure data is not accurate, and therefore the burn rate is also off. As you get higher pressure, you burn more of the powder charge. So don't put too much stock in what that software says, just believe the target.

Are you measuring your fired brass for capacity? If you're using defaults, expect it to be wrong, those are just something to kind of give you ideas and into the ballpark. You need to be putting in real case capacities, your actual seating length, the primer, the pressure from the bullet material and then adjust the powder for your actual results.

 

[Colorado Cowboy]

Many, many years ago (about 50) when I got my first .300 Wby, it took me about 3 months to get a load that shot as good as factory loads. I tried probably 10 or 12 different powders. About 5 years ago I got a new Ruger #1 .300 Wby and it took only about 4 sessions of range time to get a great load. I only used RE 25 & 26 and 180 gr Nosler Partition bullets.

 

[nm.otter]

A full case can help with SD/ES but you and your system need to be at a high level to realize that on target, especially when you shoot higher round count groups.

Challenging to get to that level when shooting .30-06 from a light-ish rifle in a sporter stock.

 

[jesco88]

Mine is a 30-06, and I had tried several factory loads, and a couple different bullets previously, and nothing shot even acceptable groups. I started hand loading and was using H4350 with 178 gr ELD-m bullets, in lapua brass. I always heard H4350 was the gold standard for 160-180 grain bullets in the 30-06, so I did not try any other powders. After extensive load testing and seating depth testing, I was able to get about .6-.7" groups with the seat depth around 0.060 off the lands. That was best in a couple different tests I did, so I thought it was the load for me... until I kept using it and the groups became as bad as everything else. Running all of my actual numbers through GRT I discovered that I was not likely getting complete burnt powder, and I have read that having less than 100% burn could potentially lead to inconsistency... since inconsistency is exactly what I was seeing, It lead me down this rabbit hole of how to find more optimal powders. I have seen several reloader articles and videos that will only consider powders that get 100% burn.

Now I have ordered a new barrel for it, and decided to switch it to a 280 AI, just to get a little better wind management with a slightly faster bullet with a better BC.... that and I just have always wanted a 280 AI... I already have accumulated some Peterson Brass (supposed to be the highest quality brass made in 280 AI), a good pile of Berger Classic hunter bullets (so they should be very consistent and forgiving), and both CCI & Federal primers (I'll test those after finding the best powder). So my components are good enough to avoid blaming them. Now I really just need to find the right powder. I am willing to test enough to find the one that works best, I just don't want to waste time on ones that are unlikely to give good performance, and I would like to narrow it down to what look like the best options first. Right now I have found the Range of powders to run from H4350 on the fast end, to H4831 and N560 on the slower end. H4350 would likely only give me around 86-87% case fill, but would burn 100%. H4831 I would have to compress to around 103-104% case fill to get to the right pressure range, however it would only get around 90% burnt powder... Between those two extreems, there are some options that look good, like N555, N160, Ramshot Hunter, IMR 4831, and AA4350. I've seen alot of people get great results with N560, but it will be around 95% burnt powder... which brings me back to the original question... does that matter? and if it does, at what point does it matter? Every powder I have listed is worth a try, plus probably a few others, but it would cost me an arm and a leg just to test them all. I am planning to test H4831sc first, only because that is the only one I have on hand. I am trying to figure out which powder I would test next if the H4831 is not giving the results I can live with.

To answer your question- don’t worry about burn rate. I shoot a lot of 223 with Varget from an AR, according to GRT it’s like 88% burn rate. I’m getting sub moa 20 round groups. Besides, the only thing you and me can measure is velocity and group size. That’s the only things that really matter in my book.

Congrats on the 280AI! I’ve always wanted try go that route with my Tikka 30-06, but I’ll likely be building a 22GT or 22ARC for my son with my 30-06. Sounds like your factory barrel was just not up to snuff.

If it's a popular powder, couple things. 1) a lot of people actually have no idea what they're doing, they just load something and shoot and say looks good.
2) You're bullet weight is too light. Try simulating a heavier bullet.
3) Your pressure is too low. Pressure effects burn rate.
4) You're running a rather short barrel.


Are you measuring your fired brass for capacity? If you're using defaults, expect it to be wrong, those are just something to kind of give you ideas and into the ballpark. You need to be putting in real case capacities, your actual seating length, the primer, the pressure from the bullet material and then adjust the powder for your actual results.

Yep, putting actual case capacity from 5 fired cases. I’ve seen this with a number of cartridges that I’ve loaded too. It’s a fun tool to play with but it’s just another tool to have, it’s not gospel.

 

[Brad1974]

If it's a popular powder, couple things. 1) a lot of people actually have no idea what they're doing, they just load something and shoot and say looks good.
2) You're bullet weight is too light. Try simulating a heavier bullet.
3) Your pressure is too low. Pressure effects burn rate.
4) You're running a rather short barrel.


Are you measuring your fired brass for capacity? If you're using defaults, expect it to be wrong, those are just something to kind of give you ideas and into the ballpark. You need to be putting in real case capacities, your actual seating length, the primer, the pressure from the bullet material and then adjust the powder for your actual results.

I was measuring fired case capacity. I now have unfired cases that I will use when my new barrel comes in, and have measured those already. Again, this is part of why I asked this question in the first place. Some of the slower burning powders that I have seen many people say they get good results using, looked like they might work when using the defaults. My unfired brass has much lower case volumes than default setting, and even after fire formed they will be lower, so the faster burning powders that get 100% burn look even better... at least on paper. I just wanted to see if anyone has been able to correlate real world accuracy and low SD/ES with having 100% burnt powder or if people have used loads that are not burning 100% and still have great results.

 

[Brad1974]

(per reloading software) To answer your question- don’t worry about burn rate. I shoot a lot of 223 with Varget from an AR, according to GRT it’s like 88% burn rate. I’m getting sub moa 20 round groups. Besides, the only thing you and me can measure is velocity and group size. That’s the only things that really matter in my book.

Congrats on the 280AI! I’ve always wanted try go that route with my Tikka 30-06, but I’ll likely be building a 22GT or 22ARC for my son with my 30-06. Sounds like your factory barrel was just not up to snuff.


Yep, putting actual case capacity from 5 fired cases. I’ve seen this with a number of cartridges that I’ve loaded too. It’s a fun tool to play with but it’s just another tool to have, it’s not gospel.

Yea, I've been wanting the 280 AI for years, and it's finally going to happen.
My brass is unfired currently, and I am getting 70.8 grains water case volume, which is exactly what the Peterson brass website says my lot should be, so that's pretty cool. It's thick brass, so I would expect even after fire formed it will remain 72 grains or less, but I'll find out after that happens.
Group size and velocity are not the ONLY thing we can measure... we also have SD or ES, which when shooting at distance will be important as well. My question was about finding what powders are more likely to give me good SD/ES, on top of having good accuracy and velocity. There are a dozen or more powders that could work according to most people or reloading manuals, but I am curious if anyone has ever been able to correlate good performance, specifically group sizes and SD/ES, with whether or not the powder is burning completely as shown on reloading software. I am just trying to figure out which powders I would test first, without it being just a random guess. I think I've got it pretty close to narrowed down between about 3-4 powders.

 

[jesco88]

Yea, I've been wanting the 280 AI for years, and it's finally going to happen.
My brass is unfired currently, and I am getting 70.8 grains water case volume, which is exactly what the Peterson brass website says my lot should be, so that's pretty cool. It's thick brass, so I would expect even after fire formed it will remain 72 grains or less, but I'll find out after that happens.
Group size and velocity are not the ONLY thing we can measure... we also have SD or ES, which when shooting at distance will be important as well. My question was about finding what powders are more likely to give me good SD/ES, on top of having good accuracy and velocity. There are a dozen or more powders that could work according to most people or reloading manuals, but I am curious if anyone has ever been able to correlate good performance, specifically group sizes and SD/ES, with whether or not the powder is burning completely as shown on reloading software. I am just trying to figure out which powders I would test first, without it being just a random guess. I think I've got it pretty close to narrowed down between about 3-4 powders.

If you can get 10rounds under 1.5" @ 100yds, the accuracy of the rifle is no longer an issue out to like 800 yards. Your wind calling abilities and shooting abilities are the larger piece of the puzzle. For me, I certainly take note of my SD and ES. But I don't really care if I'm nailing 10" plates out to 700yards. If you're using good components, and have good reloading techniques, generally SD and ES are good enough to not be concerned with them. Stick with known good powders, Hodgdon Extreme Series, Vihtavouri powders, and Alliant powders. Go with CCI200/Federal 210s, hell I've had good luck with cheap Remington 9 1/2 from my 308 practice rifle.