Producing Ammo with Low SD's

Brandon Biwer · Mar 2, 2024

Perhaps some more experienced reloaders can comment.

What is the biggest indicator of producing low SD's in ammo? Is it bullet selection, powder selection(powder burn rate), primers, case fill, consistency of brass, or some combination of the above?

I have a new 6gt competition barrel which is shooting really tight groups on paper, but the SD's have been around 20 for a 25 shot sample size. This is with virgin Alpha brass and a barrel round count around 100. Running 112 Matchburners with 37GN of H4350 behind them and cci 450's. I'm hoping the SD's will drop once the barrel is fully broken in, I'll start load development at that point and perhaps experiment with some faster burning powders behind 109 Bergers.

KnowNothing256 · Mar 2, 2024

The bullet is what I'd change out of what you listed. Everything else looks like you're using quality components.

Case fill I don't personally believe is much of a factor unless you're well outside the typical ranges (assuming you have an appropriate powder for the cartridge and bullet weight). Are you getting the MV you'd expect from it?

Brandon Biwer · Mar 2, 2024

KnowNothing256 said:
The bullet is what I'd change out of what you listed. Everything else looks like you're using quality components.

Case fill I don't personally believe is much of a factor unless you're well outside the typical ranges (assuming you have an appropriate powder for the cartridge and bullet weight). Are you getting the MV you'd expect from it?

Muzzle velocity is at 2,880fps, so its right where I would expect. I'm just using the 112's for barrel break and and practice ammo. They shoot really well on paper at 100 yards although the bc consistency downrange doesn't compare to the Bergers. I've always placed more weight on powder and primer selection, but perhaps bullets have more of an influence on SD's then I've realized.

I have noticed that I can put the same ammo in two different rifles and get very different SD's so perhaps how precisely the camber has been cut has more of an influence than anything.

I am curious in general though what has the biggest impact on SD's for most people? This is a question I've had since I started reloading a couple years ago but have never really been able to pin down.

I recently bought a Garmin chronograph so perhaps I can finally start to collect enough data to get an idea.

ARShooter91 · Mar 2, 2024

Good components and consistent neck tension.

semperfireloading · Mar 2, 2024

I would say brass consistency. Without it, low SD is just luck. Using brass with similar internal capacity, I would say is #1, or the foundation. Then you have a list such as consistent neck tension, seating depth....

LR1845 · Mar 2, 2024

Numbers will improve with the next loads, I wouldn't worry about virgin brass numbers.

Jefe's Dope · Mar 2, 2024

So consistent powder weight/case fill has little effect on SDs? That's what I'm getting reading the replies.

Otherwise I wouldn't worry too much about it until you get past one firing on all the brass.

I was under the impression that consistent powder weights, consistent brass sizing, and neck tension have the most effect on SDs.

LR1845 · Mar 2, 2024

Jefe's Dope said:
So consistent powder weight/case fill has little effect on SDs? That's what I'm getting reading the replies.

Otherwise I wouldn't worry too much about it until you get past one firing on all the brass.

I was under the impression that consistent powder weights, consistent brass sizing, and neck tension have the most effect on SDs.

With virgin brass...yes its the wrong time to be worried about numbers after brass has been fired is the time to start looking at numbers.
And yes you are correct....consistent powder weights, sizing and neck tension effect SD's.

Ledzep · Mar 2, 2024

What scale are you using? What chronograph?

ma smith · Mar 2, 2024

The main thing is going to be the powder...unless you are willing to entertain new brass or a new chamber. The bullets and the primers will also matter, but in general, the powder move the needle the most assuming you are using top-tier bullets/primers/brass and are locked into a chambering.

If you want the lowest possible SDs from a clean sheet of Paper, the BR and X47 chambers seem to offer the lowest SD potential.

Mxridr · Mar 2, 2024

Agreed I have been shooting a lot of 22lr lately and messed with my 6.5 x47 and know why I have loved this caliber. Messed with some new bullets and brass from a different gun and had sd from 3-4. One ladder was sd of 1

straightshooter1 · Mar 2, 2024

Brandon Biwer said:
Muzzle velocity is at 2,880fps, so its right where I would expect. I'm just using the 112's for barrel break and and practice ammo. They shoot really well on paper at 100 yards although the bc consistency downrange doesn't compare to the Bergers. I've always placed more weight on powder and primer selection, but perhaps bullets have more of an influence on SD's then I've realized.

I have noticed that I can put the same ammo in two different rifles and get very different SD's so perhaps how precisely the camber has been cut has more of an influence than anything.

I am curious in general though what has the biggest impact on SD's for most people? This is a question I've had since I started reloading a couple years ago but have never really been able to pin down.

I recently bought a Garmin chronograph so perhaps I can finally start to collect enough data to get an idea.

The "biggest impact on SD's for most people" is consistent powder weight. And the two other things that follow is consistent case volumes and consistent seating depths.

A couple weeks ago I fired 50 rounds with my 6.5 PRC with an SD of 7.4 and an ES of 26 and last week firing my .308 I recorded and 8.2 SD with an ES of 28 for 30 shots. I use an FX-120i for measuring my powder and use Lapua brass in both instances as Lapua is pretty consistent. To help with consistent seating depths, I anneal my brass after every firing. I do other things that I've been told doesn't make that much difference, but I do it anyway. . . like uniforming pocket depths and seating primers to a consistent depth for consistent ignition.

Brandon Biwer · Mar 2, 2024

Ledzep said:
What scale are you using? What chronograph?

RCBS charge master and Garmin chronograph. I consistently get single digit SD’s on my competition 6.5 Creedmoor using the charge master( I know it’s a cheap unit and I will likely upgrade at some point).

XP1K · Mar 2, 2024

I've probably done more "precision" reloading myself for 300winmag than any other cartridge I shoot. The single biggest contributer to consistent sd's that I have experienced has been consistent neck tension. If my annealing is off I tend to see it go wild.

Next would be powder. I hand throw using a harrels br measure and weigh every charge. I've burned a lot of 7828 in a winmag and can consistently get an SD under 5 without much fuss. I've actually seen 0 for 3-5 shots a couple different times. Currently working my way through a jug of magpro and I'm having a hard time staying under 10. Ball powder thing maybe?

Primers. I seem to get a consistent sd with whatever primer but that may be consistently high. If I have a load that's close to where I want to be but has a high sd I change primers. Usually I end up with standard Winchester lr or rem 9½ being the best. Yet I always start with the 215m or cci 250.

Brandon Biwer · Mar 2, 2024

I just fired my 200th round through this barrel this morning using the same loads with virgin brass.

I recorded the last 10 with my Garmin. It was only a 10 round sample size but the SD was 7, so big improvement.

I’m suspicious the high SD’s were due to the barrel not being fully broke in. I’ll try a larger sample size next time and hopefully get single digit numbers. .

I typically use h4350 with my Creedmoor and will allow .2 tenths variation in charge weight (I shoot a lot and hate taking the extra time to get every charge perfect). I get single digit SD’s on 30 rd sample sizes every time with these loads. If I switch to 6.5 Staball at max pressure and weigh every round perfect my SD’s double regardless, so the powder type had been the biggest indicator in my limited experience.

I’ve also noticed I can go abou 2GN under max charge weight with H5350 in 6.5 Creed after which SD’s fall off a steep cliff, so there is a certain point at which case fill makes a difference.

Sometime I’d like to have an experiment using the same load with premium vs cheap brass to see how much of a difference it makes.

Thanks for the feedback!

straightshooter1 · Mar 2, 2024

XP1K said:
I've probably done more "precision" reloading myself for 300winmag than any other cartridge I shoot. The single biggest contributer to consistent sd's that I have experienced has been consistent neck tension. If my annealing is off I tend to see it go wild.

Next would be powder. I hand throw using a harrels br measure and weigh every charge. I've burned a lot of 7828 in a winmag and can consistently get an SD under 5 without much fuss. I've actually seen 0 for 3-5 shots a couple different times. Currently working my way through a jug of magpro and I'm having a hard time staying under 10. Ball powder thing maybe?

Primers. I seem to get a consistent sd with whatever primer but that may be consistently high. If I have a load that's close to where I want to be but has a high sd I change primers. Usually I end up with standard Winchester lr or rem 9½ being the best. Yet I always start with the 215m or cci 250.

I've also got a jug of MagPro that I got a couple years ago (when I couldn't get the powder I wanted) and it did OK for me and was able to get single digit SD's. But I do think heat can be a factor with it that can effect the SD's.

XP1K · Mar 2, 2024

straightshooter1 said:
I've also got a jug of MagPro that I got a couple years ago (when I couldn't get the powder I wanted) and it did OK for me and was able to get single digit SD's. But I do think heat can be a factor with it that can effect the SD's.

I've done the majority of my shooting with it in warmer conditions on the Texas gulf coast and in south Texas.

straightshooter1 · Mar 2, 2024

Brandon Biwer said:
I just fired my 200th round through this barrel this morning using the same loads with virgin brass.

I recorded the last 10 with my Garmin. It was only a 10 round sample size but the SD was 7, so big improvement.

I’m suspicious the high SD’s were due to the barrel not being fully broke in. I’ll try a larger sample size next time and hopefully get single digit numbers. .

I typically use h4350 with my Creedmoor and will allow .2 tenths variation in charge weight (I shoot a lot and hate taking the extra time to get every charge perfect). I get single digit SD’s on 30 rd sample sizes every time with these loads. If I switch to 6.5 Staball at max pressure and weigh every round perfect my SD’s double regardless, so the powder type had been the biggest indicator in my limited experience.

I’ve also noticed I can go abou 2GN under max charge weight with H5350 in 6.5 Creed after which SD’s fall off a steep cliff, so there is a certain point at which case fill makes a difference.

Sometime I’d like to have an experiment using the same load with premium vs cheap brass to see how much of a difference it makes.

Thanks for the feedback!

Having used a number of different powders over the years with my .308 and 6.5 PRC, there can be a difference is SD's that I get, but nothing significant I can attribute to powder alone. I've had rare occasions where I got a crazy SD and I can only think that it had something to do with a mistake I probably made in reloading, like . . . maybe jarring my loading block some how and knocking some kernels of out of some cases. Sometimes after charging cases I'll find a few kernels on my loading table that makes me wonder where they come from.

BTW: I also have a ChargeMaster, though I haven't used it since I got my FX-120-i. When I got the FX, I was curious how much of a difference I would get, taking charges weight on the CM and seeing what those weights were on the FX. And while at it, I tried a couple other scales I had to see what they showed. Here's the results (in case you haven't see this where I've posted in other threads):

XP1K · Mar 2, 2024

straightshooter1 said:
Having used a number of different powders over the years with my .308 and 6.5 PRC, there can be a difference is SD's that I get, but nothing significant I can attribute to powder alone. I've had rare occasions where I got a crazy SD and I can only think that it had something to do with a mistake I probably made in reloading, like . . . maybe jarring my loading block some how and knocking some kernels of out of some cases. Sometimes after charging cases I'll find a few kernels on my loading table that makes me wonder where they come from.

BTW: I also have a ChargeMaster, though I haven't used it since I got my FX-120-i. When I got the FX, I was curious how much of a difference I would get, taking charges weight on the CM and seeing what those weights were on the FX. And while at it, I tried a couple other scales I had to see what they showed. Here's the results (in case you haven't see this where I've posted in other threads):
View attachment 8362854

View attachment 8362856

I've watched a lot of the videos from Mark and sam after work on his reloading practices. He uses the rcbs chargemaster and for big cases he only loads in 1gr increments and mostly uses standard large rifle primers. Almost exclusively uses berger bullets. Quite often he's. 050-.060" off the lands. But he's pretty meticulous on case prep.

In videos where he puts up chrono data his es is always pretty tight and if you watch his groups at elr they look pretty good to me. But what do I know. Im just getting into lr. Much less elr.

BenE · Mar 2, 2024

Brandon Biwer said:
Perhaps some more experienced reloaders can comment.

What is the biggest indicator of producing low SD's in ammo? Is it bullet selection, powder selection(powder burn rate), primers, case fill, consistency of brass, or some combination of the above?

I have a new 6gt competition barrel which is shooting really tight groups on paper, but the SD's have been around 20 for a 25 shot sample size. This is with virgin Alpha brass and a barrel round count around 100. Running 112 Matchburners with 37GN of H4350 behind them and cci 450's. I'm hoping the SD's will drop once the barrel is fully broken in, I'll start load development at that point and perhaps experiment with some faster burning powders behind 109 Bergers.

I would assume the barrel is still speeding up with only 100 down the pipe.

Maurygold · Mar 2, 2024

Zero load development or looking at sd until 100 shots in. This is very normal example of why the fouling of a barrel isn’t the time to evaluate accuracy and you will see mc rise over the next 100 as well but significantly less dramatically.

Halfnutz · Mar 2, 2024

Have you tried annealing? Sorry if I missed it in the above.
Use mandrel?
Graphite necks before seating?

Right or wrong, after my intial attempt at loading a few, I annealed and trimmed new Lapua right out of the box. Followed by a mandrel and Redding Graphite on the neck before seating.
I seat with a K&M arbor press with the force gage. Watching the force gage and your technique will show the initial spike in seating, then your seating pressure until it spikes upon bottoming out. Technique and the gage got me to a consistant pressure. SD's were much improved over the virgin unannealed (factory annealed) brass. Fired and annealed brass has powder fouling even after a light tumble that seems to be different again.

I think the concensus is neck tension and powder measurement.

straightshooter1 · Mar 2, 2024

Halfnutz said:
Have you tried annealing? Sorry if I missed it in the above.
Use mandrel?
Graphite necks before seating?

Right or wrong, after my intial attempt at loading a few, I annealed and trimmed new Lapua right out of the box. Followed by a mandrel and Redding Graphite on the neck before seating.
I seat with a K&M arbor press with the force gage. Watching the force gage and your technique will show the initial spike in seating, then your seating pressure until it spikes upon bottoming out. Technique and the gage got me to a consistant pressure. SD's were much improved over the virgin unannealed (factory annealed) brass. Fired and annealed brass has powder fouling even after a light tumble that seems to be different again.

I think the concensus is neck tension and powder measurement.

That variations in neck tension along with seating force can effect seating depth, which the later is what I've found to be most important of them. The more force it takes to seat a bullet the less consisted one's seating depth will be. Where there's a lot of neck tension lubing the inside of the necks helps reduce the amount of force to seat the bullets leading to more consistent seating depth.

With the Lapua plastic box of cases I used to get, I'd always run them through my Lee collet die, not only to be sure dents were removed, but also to get the neck tension I want. With their new cardboard packaging, it doesn't seem there'll be any issue about denting as before. I recently got some new Lapua brass (see pic below) and using pin gauges I measured neck tension and for the .308 cases, the neck tension ran .004 to .005". I've found that much neck tension on virgin brass really gives me a lot of variation in seating depth, especially if no lube is used. And that has resulted in higher SD's than I typically get.

CK1.0 · Mar 2, 2024

Good shit is good, but I can get the same single-digit SDs using Match Burners as I get with Berger's.

I recommend putting ~200rds through a barrel before really starting to look too hard at anything. Sometimes it can even take longer than that for a barrel to settle in and stop speeding up.

IME, in order to get repeatable low SDs using good components matters, but once you reach a certain echelon where you're using decent stuff, the components don't matter anymore and then it becomes more about one's process. It becomes a question of craftsmanship, not how much one can spend.

For me it became about looking at the order in which I do things, and why... more so than anything that can be bought.

I don't believe in ladders, "nodes" or any of that fairytale nonsense... it's ridiculous that some guys still think that a couple/few tenths more or less of powder has anything to do with any of it. If one's processs is sound and one preps each and every case as exactly the same as possible, puts the same amount of powder in each case to the kernel, and then seats bullets to within a couple/few thou of each other, good numbers will follow.

A couple of the biggest epiphanies I've had for getting low SDs are: wet tumbling is kryptonite for precision loads and good numbers, save the wet-tumbling for blaster stuff, and, most guys who dry tumble their lube off after sizing would be surprised how much the tumbling fucks up their newly sized cases... using a mandrel after the brass comes out of the tumbler is worth the squeeze (it fixes most of the damage, not to mention helping with consistent neck tension).

Doom · Mar 2, 2024

@straightshooter1 mentioned consistent case fill but what is really required is high case fill which keeps the powder in the case in a consistent position so that ignition and burn are consistent. Obviously charge weight needs to be consistent also.

straightshooter1 · Mar 2, 2024

Doom said:
@straightshooter1 mentioned consistent case fill but what is really required is high case fill which keeps the powder in the case in a consistent position so that ignition and burn are consistent. Obviously charge weight needs to be consistent also.

That's a good point. I do keep my cases fills above 93% and the closer to 100% the better.

schmi015 · Mar 2, 2024

Charge weight, neck tension and weight sorting your bullets will impact your groups the most. For bullets throw set aside the outliers. Make it look like a bell curve and cull the far left and right. Use those to get on paper.

ARShooter91 · Mar 2, 2024

I sorted a couple boxes of Hornady 140elds and found 139.6-140.4 extreme. Only 2 of the low and one of the high. Shot all 3 with a couple right at 140g at 1011yds and all hit less than .2mil difference in elevation. So outside of bench rest or shooting a mile or something I don't think that variance mattered.

Edit: I'd probably need to do this 10 more times to have conclusive data.

schmi015 · Mar 2, 2024

ARShooter91 said:
I sorted a couple boxes of Hornady 140elds and found 139.6-140.4 extreme. Only 2 of the low and one of the high. Shot all 3 with a couple right at 140g at 1011yds and all hit less than .2mil difference in elevation. So outside of bench rest or shooting a mile or something I don't think that variance mattered.

I had a box of 500 145grn match burners and there was some variance, cant remember what the low/highs were but culled 75 or so.

CK1.0 · Mar 2, 2024

I think case-fill ratio is sort of important for low SDs and maybe not talked about enough. That said, over the last couple of years, I've been rethinking it a little depending on the powder and/or the case...

For me, it seems like with smaller cases (like Dasher up to 6GT) and with faster-burning powders like Varget/SWPR, charges near/around 80% powder capacity work great. But with medium burn-rate stuff like H4350, 80% is more like the minimum, and ideally, I want more case-fill for the best results with that stuff, especially as the cases get bigger (like with 6CM).

As an aside, when talking case-fill ratios, I wish there was a better way to figure out case capacity beyond just using H2O capacity, as actual powder capacity with a bullet seated is less... anyone got anything? I usually just guestimate by lopping off ~5-10% off of the H2O capacity and use that number as being closer to actual powder capacity with a projectile seated.

straightshooter1 · Mar 2, 2024

CK1.0 said:
<snip>

As an aside, when talking case-fill ratios, I wish there was a better way to figure out case capacity beyond just using H2O capacity, as actual powder capacity with a bullet seated is less... anyone got anything? I usually just guestimate by lopping off ~5-10% off of the H2O capacity and use that number as being closer to actual powder capacity with a projectile seated.

This is where one of the QuickLoad's useful calculations comes in. When the H2O case "volume" is entered, it'll calculate available case "capacity" based on the particular bullet's dimensions, case OAL and seating depth. Then of course, it takes that available case "capacity" (not case volume) and calculates the case fill based on the type and amount of powder being used.

PS: Gordons Reloading Tool, which is very similar to QuickLoad, but free download, does the same kind of thing.

ma smith · Mar 2, 2024

CK1.0 said:
As an aside, when talking case-fill ratios, I wish there was a better way to figure out case capacity beyond just using H2O capacity, as actual powder capacity with a bullet seated is less... anyone got anything? I usually just guestimate by lopping off ~5-10% off of the H2O capacity and use that number as being closer to actual powder capacity with a projectile seated.

Berger bullets have a detailed load data page for bullets, you can probably work out the volume of the boat-tail if your want.

I typically use that data to calculate min COAL for each bullet/cartridge combo, since it lets you locate the start of the boat-tail so precisely, you can figure out seating depth in relation to that, ie start of the boat tail vs the start of the neck, and then how much bullet will be forward of the neck.

Rocketmandb · Mar 2, 2024

Lots of things matter in getting good SDs. First off, others have mentioned it, but I'll reiterate it: doing any sort of measurement in the first 100 rounds down the barrel or with virgin brass is an exercise in futility.

Here are some screen shots from my Garmin app while doing load development on my 300 PRC last weekend.

Now, these are only 5-shot groups, so one might say that the sample size is too small. I don't expect to get 2.7 or 3.1 fps SDs going forward, but I do expect them to be low - my expectation is to get consistently in the 6-7 fps range. As to the sample size, notice that the SDs remain low across all 3 groups (15 shots). I'll be validating a load against 50 shots on Wednesday.

What I've found matters in getting low SDs:

Brass neck thickness consistency:
Lapua is the best here outside of RWS, which is hard to get in the US. If you don't use Lapua, it's best to neck turn. Before Lapua came out with 300 PRC brass, I was using ADG. I dropped a decent amount of SD when I switched. I also neck turned the ADG and got similar results to Lapua. The best I've ever gotten in my 300 was when I used RWS 8x68S and remade it into 300 PRC.

Charge weight consistency:
Should be obvious as to why, and it's the easiest to control.

Use of a mandrel:
Helps ensure inside neck size consistency. You might ask why, if you use a mandrel, neck thickness consistency matters as I mentioned above. The reason is that you will get different spring back with different neck thicknesses, as the brass will need to expand more or less based on that. This is also why I use a bushing that is just small enough to ensure that every case _barely_ engages the mandrel. Less movement in the brass leads to more consistency as well.

Use of a neck lube:
I've done a fair amount of testing here and I've found that cases with molybdenum disulfide (moly) works the best here. This doesn't make a huge difference, but it certainly does contribute.

Annealing:
I anneal every time. There's enough chatter out there as to why it matters. Suffice to say it does.

All that said, here is the data from my 6 BRA last weekend:

Depending on your point of view, you might think this is either good or bad. I happen to think it's pretty bad. So, after all I mentioned above, why did I get such bad (in my opinion) SDs????

Well, these 25 shots were rounds 6-30 down my new barrel. I was also fire forming from virgin 6 BR to 6 BRA, and I didn't mandrel or use neck lube (because for some reason Lapua 6 BR doesn't absolutely require a mandrel to load forming round like other of their cases do, and no need for neck lube if I'm just forming and speeding up the barrel anyway). When everything is said and done, I will expect 4-5 fps SDs from this rifle.

SmileMaker · Mar 3, 2024

Granted the sample size in each of these are not large enough to be statistically significant. Each are different rounds (300NM, 6.5x284, 338 Snipetac, 6XC) but all are single digit SD and sub 1/2 MOA in my rifles. My procedures regardless of caliber or brass manufacturer.
1) I neck turn all my match brass
2) I anneal brass after each firing
3) Body sized, neck sized (both die and mandrel), length trimmed, case mouth chamfered, Inside neck dry lubed, match primers
4) Powder measured to 0.04 grain (AutoTrickler)
5) Bullet seated. Usually a Berger (Although I am using up my 140 gr SMKs in 6.5)

Not an endorsement, but I use Forster body dies, LE Wilson neck dies and bullet seaters and case trimmer.

Rocketmandb · Mar 3, 2024

SmileMaker said:
1) I neck turn all my match brass
2) I anneal brass after each firing
3) Body sized, neck sized (both die and mandrel), length trimmed, case mouth chamfered, Inside neck dry lubed, match primers
4) Powder measured to 0.04 grain (AutoTrickler)
5) Bullet seated. Usually a Berger (Although I am using up my 140 gr SMKs in 6.5)

This is pretty close to my process except:

- If I'm using Lapua brass, I've found that neck turning delivers little to no benefit. For non-Lapua, neck turning has a noticeable effect. Note: I hate neck turning.
- I FL size using either Whidden or LE Wilson dies, and don't do a body size then a neck size.
- For powder measure, I get right on the money for smaller powders like Varget, and +.02/-0.0 for my magnum powders.

Are you using an arbor press and LE Wilson seaters?

Maurygold · Mar 3, 2024

I don't turn neck, anneal, seat on in-line, neck lube, or use a separate mandrel for expansion and I regularly am shooting under 7-8SD.

Don't get caught up in overcomplicating your procedure for diminished returns. Good brass, powder, bullet, primer, and fundamentals will get you tremendously far.

Brandon Biwer · Mar 3, 2024

Maurygold said:
I don't turn neck, anneal, seat on in-line, neck lube, or use a separate mandrel for expansion and I regularly am shooting under 7-8SD.

Don't get caught up in overcomplicating your procedure for diminished returns. Good brass, powder, bullet, primer, and fundamentals will get you tremendously far.

View attachment 8363629

View attachment 8363632

Although I bought an annealeeze this year (more to extend brass life than anything), I quit using an expander mandrel and weighing every charge to the exact tenth of a GN because I wasn’t seeing significant gains in performance for the amount of time invested.

It’s my goal to shoot 100 practice rounds a week this season plus competitions, and time at the reloading bench is the limiting factor. If I can get single digit SD’s from a faster process, that is good enough for me.

Does anyone have any numbers to compare for reloading on a progressive press vs single stage? I’ve considered purchasing a Dillion 750 for making practice ammo using ball powder. I would probably use a single stage to size brass still, so I’m not sure if the time savings is worth the investment or not.

I’ve appreciated the feedback from everyone regardless. Thanks all!

Maurygold · Mar 3, 2024

Brandon Biwer said:
Although I bought an annealeeze this year (more to extend brass life than anything), I quit using an expander mandrel and weighing every charge to the exact tenth of a GN because I wasn’t seeing significant gains in performance for the amount of time invested.

It’s my goal to shoot 100 practice rounds a week this season plus competitions, and time at the reloading bench is the limiting factor. If I can get single digit SD’s from a faster process, that is good enough for me.

Does anyone have any numbers to compare for reloading on a progressive press vs single stage? I’ve considered purchasing a Dillion 750 for making practice ammo using ball powder. I would probably use a single stage to size brass still, so I’m not sure if the time savings is worth the investment or not.

I’ve appreciated the feedback from everyone regardless. Thanks all!

Check out some f class John videos. He won sw nationals last years using a Dillon 750 in f open.

LR1845 · Mar 3, 2024

Brandon Biwer said:
Although I bought an annealeeze this year (more to extend brass life than anything), I quit using an expander mandrel and weighing every charge to the exact tenth of a GN because I wasn’t seeing significant gains in performance for the amount of time invested.

It’s my goal to shoot 100 practice rounds a week this season plus competitions, and time at the reloading bench is the limiting factor. If I can get single digit SD’s from a faster process, that is good enough for me.

Does anyone have any numbers to compare for reloading on a progressive press vs single stage? I’ve considered purchasing a Dillion 750 for making practice ammo using ball powder. I would probably use a single stage to size brass still, so I’m not sure if the time savings is worth the investment or not.

I’ve appreciated the feedback from everyone regardless. Thanks all!

I run a 550 and 750...I can size 300 pieces of brass on the 750 in about 15 minutes and yes they are consistent .002 shoulder bump. De-prime on station 1, full length sizer no expander in station 2, mandrel in station 3. I hand prime and then load on the Dillon, I weigh powder on a V4 and dump charge on station 2 through a powder through die and seat on station 3.

So yes a Dillon will save you a bunch of time.

MarkyMark007 · Mar 5, 2024

CK1.0 said:
I think case-fill ratio is sort of important for low SDs and maybe not talked about enough. That said, over the last couple of years, I've been rethinking it a little depending on the powder and/or the case...

For me, it seems like with smaller cases (like Dasher up to 6GT) and with faster-burning powders like Varget/SWPR, charges near/around 80% powder capacity work great. But with medium burn-rate stuff like H4350, 80% is more like the minimum, and ideally, I want more case-fill for the best results with that stuff, especially as the cases get bigger (like with 6CM).

As an aside, when talking case-fill ratios, I wish there was a better way to figure out case capacity beyond just using H2O capacity, as actual powder capacity with a bullet seated is less... anyone got anything? I usually just guestimate by lopping off ~5-10% off of the H2O capacity and use that number as being closer to actual powder capacity with a projectile seated.

NO. Bryan Litz shows that case fill ratio is NOT important for low ES/SD.

And for the group size low ES/SD is important at long range. For short range this is NOT important, and that's why you cant test at 100yard if your barrel is not shooting good at 1000y.
If your barrel is deforming bullets so they get inconsistant BC and big groups at 1000y, your group can still be good at 100y (B.Litz).

XP1K · Mar 5, 2024

MarkyMark007 said:
NO. Bryan Litz shows that case fill ratio is NOT important for low ES/SD.

And for the group size low ES/SD is important at long range. For short range this is NOT important, and that's why you cant test at 100yard if your barrel is not shooting good at 1000y.
If your barrel is deforming bullets so they get inconsistant BC and big groups at 1000y, your group can still be good at 100y (B.Litz).

Interesting. I had a 308 that would shoot .2's and .3's or better at 100 but it went nuts around 750. I guess that explains that.

Gunfighter14e2 · Mar 5, 2024

MarkyMark007 said:
NO. Bryan Litz shows that case fill ratio is NOT important for low ES/SD.

Correct, as if it were many of us would not be getting the numbers we are with our subs. Most of us use gas checked cast bullets with pistol & shotgun powders, & they run single digits. Sub reloading will quickly tell you where you're are lacking, once you get past 300 yds. Its much easier to reload for 1K yds than 500-600 yds with a sub.

ARShooter91 · Mar 5, 2024

XP1K said:
Interesting. I had a 308 that would shoot .2's and .3's or better at 100 but it went nuts around 750. I guess that explains that.

168smks will do that

Gunfighter14e2 · Mar 5, 2024

ARShooter91 said:
168smks will do that

As well bad barrels marking the bullets. Scratch the nose of the bullet, and shoot a group of 5 at 400yds, then the same but bearing surface , then again the same at the transition between the bearing surface, an boat tail.

XP1K · Mar 5, 2024

ARShooter91 said:
168smks will do that

It did it with everything. 155's, 168 eldm/amax,smk, 175smk, and 178's.

I stored it improperly for a out 5 years and the bore rusted. I always suspected maybe the rust pits were damaging the jackets somehow. It has a 1:9 lilja now but it's currently in pieces. Again.

ARShooter91 · Mar 5, 2024

Try JBing the bore? Pits too deep to smooth out?

Rocketmandb · Mar 5, 2024

ARShooter91 said:
Try JBing the bore? Pits too deep to smooth out?

If JB is enough to smooth out pitting, it's enough to screw up the rest of the barrel. I've had issues with JB and the like (e.g. Iosso) in that they will slow down barrels. In more than one case, I also saw slight accuracy degradation after using for an extensive cleaning. Those products no longer find their way into my barrels.

ARShooter91 · Mar 5, 2024

Yeah it's a last resort and I don't use the red label stuff. Also use it sparingly and then back to boretech. I haven't seen adverse effects using in moderation.

I don't mean completely removing the pitting with JB, rather smooth the bore out a bit.

CK1.0 · Mar 5, 2024

MarkyMark007 said:
NO. Bryan Litz shows that case fill ratio is NOT important for low ES/SD.

And for the group size low ES/SD is important at long range. For short range this is NOT important, and that's why you cant test at 100yard if your barrel is not shooting good at 1000y.
If your barrel is deforming bullets so they get inconsistant BC and big groups at 1000y, your group can still be good at 100y (B.Litz).

IDK, I don’t think Litz is the ballistic Jesus some of y’all act like he is and I base my opinions off my own experience.

Since I shoot out to 1250 yards regularly, I don’t really care about or spend too much time shooting groups at 100 like some guys do either.

Do you, but I haven’t had an SD that wasn’t single-digits in 3+ years and I’m not that lucky and don’t believe in coincidence, so I must be doing something right.

CK1.0 · Mar 5, 2024

I also use Iosso and at least one brand new bronze brush every time I clean my barrels… it works awesome.

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