I want a full magnum load for 158 grain, coated lead Missouri Bullet Co. SWC bullets and Bullseye powder.

My Lee Manual (2d Ed) lists loads for 158g lead bullets from 4.2 to 4.8 with a max velocity of 939 fps.

I also have a Lyman Load Data pamphlet for Popular Revolver Cartridges (2011) that lists 6.2 to 6.9 grains of Bullseye for 158gr Lead bullets with velocity from 1043 to 1096. My One Book/One Caliber booklet for the 357 (2016) lists 4.9 to 6.9 grains of Bullseye for 158gr lead Lyman bullets.

This seems strange to me. There is 2.1 gr more powder in the Lyman maximum load than in the Lee maximum load. I would like to try the higher load range in the Lyman books but this difference has me concerned. The online data for Alliant powders also has the lower range that Lee has.

Anyone have experience using the load data of Lyman for 158g lead bullets and Bullseye than can give me some advice?

My Lyman 50th shows 6.9gr max with 160gr lrn. 1119fps, 41k cup. That seems real stiff for bullseye to me. But I don’t know the cup to psi conversion.

I know this gets old hearing, but for full power, 2400 or imr 4227 would be better for velocity and possibly accuracy given the situation. Pressure with bullseye goes up like a rocket with not much more powder. Just be careful and work up.

My bullseye load in mag brass started at a max 38sp load and went from there. Didn’t go much before I found the load that was most accurate, but that’s what I was after.

The lower maximum load data is for swaged bullets to prevent leading and is not at maximum pressure for the .357. Some maximum load data for cast bullets is from Lyman and the highest I have seen with 158 gr is 7.0 grs. All Lyman data has pressure listed so you can see that all loads are within limits for the .357. I want to chronograph 7.0 grs with a 158 gr cast bullet when I get around to it. So far my highest load has been 6.1 grs with a Win mag primer and a 158 gr cast SWC for 1089 FPS out of my 4” S&W 27-2. If you look at the various loads listed with CUP and PSI pressures you will see that 35,000 psi and 42,000 cup seem to be about the same. The older actual Alliant data listed pressure with all loads in psi. All of their .357’loads used the Federal 200 SR primer and their top charge of Bulleye was around 33,000 psi. Bullseye has more upward flexibility than many might think. It’s very stable and predictable.

Get the Quick Load program and see what the chamber pressures are I have manuals from 50-60 years ago that give way different loadings tn now, I have a feeling the lawyers are involved.

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USMC 69-93 Combat Pistol Inst.

Bullseye powder is a quick burning powder better suited to target loads in 38 special or smaller calibers. I would use a medium burn rate powder like Unique or it's equivalent.

My loads for the 357 Magnum are 2400 as my favorite

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USMC 69-93 Combat Pistol Inst.

I loaded hot Bullseye loads for my 6" 357 back in the 1990's...............

I tried the 110, 125 and 158 JHP bullets and I was not a happy camper.

If that is the only powder that you have, then go for it.

Thanks for all the good advice guys.

You want a full magnum load for powder coated 158 grain LSWC bullets? Not going to happen with Bullseye. Bullseye will work well for making target wadcutter and pretty much duplicating any 38 Special or even 38 Special +P+ load with 357 Magnum brass, but way too fast burning for anything more.

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You have 3 references ...two show 6.9 grs. Bullseye as max as does my RCBS Cast Bullet Manual ... It appears safe but will be on the warm side ...we talking MAXIMUM load here ... do not go over .
Bullseye is a hot burning powder and a Gas Check would be in order here ...But , the bullets are "coated" so this might keep leading at bay .

My advice ...start low and work up, looking for sticky extraction and lead in the barrel ... when you get either of these signs ...stop and drop back a 1/10th grain or two .

I would start at 6.0 grs. Bullseye and work up and if I got to 6.5 or 6.7 grs. Bullseye ... I would stop ... I have found that best accuracy with cast bullets is usually right below the Max. charge ... and I like to leave myself some wiggle room when it comes to max. charges of fast burning powder .
Gary

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I have used Bullseye for 357 Mag. 158 gr LSWC and for 44 Mag. 240 LSWC. I cannot remember which manuals I used, but all were "book loads" (tried Bullseye in these calibers 35+ years ago). I shot a bunch of safe handloads, but there were certainly better powders, much slower than Bullseye...

(FWIW; I don't quote my powder charges, or pay any attention to powder charges, load data I see on any forum. My reloading forum viewing started in 2006 and I soon started seeing very questionable suggestions. Published manuals with a few powder manufacturer's web site data has worked quite well and safely for nearly 40 years...).

I recently shot some 158g Lswc loads, comparing 6.5g Bullseye against 6.8g Unique. The two loads felt quite similar to me.

Data is data..................
if it worked back in 1950, it will work in todays loads.

Just make sure that you follow the date correctly and don't change things.

I have noticed that the 2015 plus data is a little on the safer side but
I had rather be safe, than sorry, any day, with rolling my own.

All the loads will work...............
just that some are a little better than the others in different, uses.

When I first started loading, in 1979, I noticed that Sierra's manual listed hot loads for magnum revolvers using Bullseye and other fast powders. Speer and Hornady did not. I always wondered about that.

I'd use the fast powders for 38+P+ territory. If true magnum performance is needed, go to Blue Dot, AA#9, 2400, or H110.

Please listen to all the good advice. Bullseye is one of the fastest powders available for reloading and for sure not a good choice for full power .357 Magnum loads. You hit the pressure limits well before max performance and fast powders used in that application could be unpredictable. Slower powders will give you much better and safer results.

I use 2400 or AA#9 for all but the hottest rounds and W296/H110 for the highest performing loads. W296/H110 does not like to be downloaded.That powder works great with heavy bullets and hunting .357 Magnum ammo meant for a levergun.

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SWCA #3437

There’s nothing wrong with using Bullseye at the maximum recommended charge weights in the .357. It’s not dynamite, it’s just another powder. But you just have realize that you’re getting a lower level of performance than “full .357 magnum” loads.

One or two considerations.

Older datya, before transducers reading directly in psi was often listed as "psi" when the test method was CUP. This was because it was the only test method and trhat's what was targeted - psi. Once transducers became more common, and the differences between the measurement systems was seen, it became normal to list transducer data as psi, and crusher data as CUP. Thus, if dealing with oulder data, even if listed as psi, it's likely to actually be CUP.

A given amount of powder can only produce a given quantity of gas. Therefore, 6 grains versus 12 grains will see a decided difference in the volume of gas. Larger cases benefit from slower powders with respect to top performance at a given pressure.

The OP did ask about a "full magnum load", that's why I posted what I did. I never said Bullseye was dynamite.

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SWCA #3437

Bullseye is a great powder for low pressure rounds but the first thing you will notice when you go for magnum loads is that your cases will probably be hard to eject.

I've used very old manuals in the past to find hot loads using 158 LRN and have found Red Dot to be pretty good, Unique is better and for real fast loads 2400 or Blue dot.

Yes it's possible but why take a chance?

Bullseye loads are listed in a variety of manuals with pressure listed as CUP or PSI with original Hercules and Alliant data which is much more recent. ALL loads with Bullseye, regardless of how the pressure was listed have always been within industry standards for the .357 magnum and all other ctgs. So assuming you’re a Handloader who’s capable of only charging a case with the amount of powder you want what are you taking a chance on? And in that respect what’s the difference between Bullseye and any other powder?

I just checked in Speer 8 (oh NO , NOT That ! ) , their 357 magnum load using a 158 gr swc and Bullseye powder . The starting load is listed as 3.5 grs and max of 4.7 . Alliants current load data is 4.8 grs as a max . Like I have said before that Speer #8 is better than some give it credit for . Regards Paul

If you bother to read the ctg information in your Speer manuals instead of just looking at the load tables you might learn something. They clearly state that velocities with their 158 gr swaged SWCs are kept low to prevent leading. The so called maximum load of 4.8 grs of Bullseye reflects that. Speer # 11 lists a maximum load of 7.1 grs of Bullseye with a 158 jacketed bullet which is in line with top data in other manuals. Read your manuals folks. Don’t just look at the load data and ignore all of the “boring” information they contain.

My turn............

Bullseye will work in the 357 Magnum.
With a full maximum load, it will give you all it's got at it's maximum safe pressure.

Just that medium burn rate powders will do the same with less pressure and a little more fps.

The slowest powders will have lower pressures than Bullseye and give you the maximum fps for a 357 Magnum with safe pressures and data.

Nothing wrong with Bullseye in a 357 Magnum, for what it can do.
I just like powders that fill the case more, for safey reasons.

Well Ed as the saying goes “you pays your money and takes your choice”. For those who are satisfied with mid range loads in the .357 of around 1050-1150 FPS you pays a bit less of your money if you use Bullseye at 5.8-6.5 grs rather than reduced loads of around 12.0 grs of 2400

When I was shooting a lot of 44 Magnum loads(there was an indoor range just 5 minutes away and I'd shoot maybe 100-150 rounds per week) I could easily tell/feel the Bullseye, W231 loads from Unique, 2400, etc. by the recoil. Bullseye was a sharp "snap" in my hand,and the Unique loads were more like a "thump" (like a 6 oz plastic mallet vs a 20 oz. ball peen hammer). I got some realy good accuracy with Bullseye, mid to upper book loads, under a 240 LSWC in my Dan Wesson 44H...

Do you enjoy being argumentative, you seem to do it a lot. Not everyone can be right all the time but you seem to think you are. I'm not talking as a Mod right now, just another member. IMO you should allow for different opinions other than yours.

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SWCA #3437

Trail Boss is one of the best powders. I was surprised when I first started using it. Basic data is to load the case 3/4 fill and you have a load. Very low pressure signs and very accurate.

It may not give you the velocity you are looking for.

At one time I wanted SPEED..............

then I became a penny pincher...........

Then nothing but the best accuracy.........

In my "Silver years", I am now liking medium to low recoil loads
for 96% of my shooting needs.

It's all good.

Just glad to be able to enjoy popping primers, of any type at my age.

PS;
and I don't use 2400 for reduced loads.............
that is a wase of good full power, powder, in my mind.

However I will sacrafice some HS-6 if needed.

No I do not enjoy being argumentative, in fact I hate it. But in the reloading forum especially there is a tremendous amount of opinion posted as factual that is just plain wrong. I am not right all the time. I do however have a thing about irrational fear and try to shine a bit light into the darkness. It is common on here for people to ask a question and get ten responses expressing opinions that have no relationship to the OP’s question. If I seem to be argumentative it is that I just hate to see someone ask a question where they think the “experts” are and get a boatload of opinions and virtually no facts. I guess that does set me in opposition to other members at times. Opinions are one thing, false information is another. If I could have one wish it would be for the handloaders on here to just read their manuals to be better informed for their sake and for the sake of others.

I did the same as time went by. When way younger it was power and lots of it. Then I shot IPSC and economy as was paying for my own ammo to practice with. Now it is accuracy as I get older. But also I spend a lot of time socializing, in fact more time spent talking than shooting.

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USMC 69-93 Combat Pistol Inst.

If I remember I will check my Phillip Sharpe reloading manual to see what his loads for the .357 were. He helped Wesson develop that round in the 30's.

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USMC 69-93 Combat Pistol Inst.

You mentioned some good points and I'm in agreement. However, many today, especially those lacking a firm handloading background, search out (often dubious) shortcuts for instant and cheap results and believe that all information they would ever need is available online.

These folks unknowingly handicap themselves by not reading manuals and not examining the load data printed in them. It takes time and the books aren't free (nor are they expensive), but it's time and money well spent. There is some useful handloading information and load data online, but much of it is not available there.

A handloader can't have too many manuals.

rockquarry I agree with you 100%. Many Handloaders today, probably younger ones, think whatever you find online is the greatest and the latest and don’t want to spend the money and the time to acquire and read manuals. There is a tremendous amount of information in manuals that you can’t know just by looking up load data online.
I just checked my most recent Lyman Cast Bullet manual, #4 , which is the most recent one I believe. It was printed in 2012. It lists 7.0 grs of Bullseye with a 150 cast SWC at 36,900 CUP which is the lowest pressure of any powder listed. They also show 7.0 grs with their 158 gr gas check SWC at 39,600 CUP, again the lowest pressure of any powder used with that bullet. The CUP limit for the .357 was 46,000 CUP but most manuals stopped at around 42,000 as did Lyman. And again, you can’t have too many manuals.

As I wrote before I would look in my oldest reloading manual. This is "COMPLETE GUIDE TO HANDLOADING" by Phillip B. Sharpe. It is copyrighted 1937. Sharpe gives for the 158 grain lead 3.5 to 6.0 grains of Bullseye with velocities from 850 FPS to 1210 FPS. I myself would not use more than about 4.0 grains of Bullseye. I would prefer to use Unique or 2400 for hotter loads.

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USMC 69-93 Combat Pistol Inst.

I think the distinction here is OP talked about "full magnum" loads, which aren't achievable with Bullseye. A max load of Bullseye isn't going to achieve "full magnum" velocities.

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For those who like velocities in the 1,000 FPS range in their .357s with a 158 gr cast SWC consider the following loads chronographed out of my 4” model 27-2. Winchester brass and SPM primer, 158 gr magma style cast SWC.

5.3 grs Bullseye vel-1012 FPS , ES-14 FPS
5.7 grs : vel-1057 FPS, ES-26 FPS
6.1 grs. : vel-1089 FPS, ES-31 FPS

Great clean burning consistent loads.

Some people come on here and say they want to try the full .357 magnum loads. After they try a few they usually quickly change their minds. I don’t have any reason to load full .357 loads and I prefer loads in the 1050-1200 FPS range myself. But I have loaded the .357 to full potential in the past and for those who want to do so here’s a couple of loads that I have chronographed from my trusty 4” mod 27-2 that DO NOT exceed published data or pressure maximums.
Winchester brass and magnum primers and a 158 gr plain cast SWC, no coating or plating, firm roll crimp in the crimping groove.

14.2 grs of 2400 avg vel 1348 FPS
17.4 grs of Win 296 avg vel 1440 FPS
Recoil with the 296 load was a bit snappy even in my N frame. More than I need from my .357s these days but try them if you want.

As the OP I will clarify a few things.

I also used 110 and 2400, when I had them. I am out. But I keep looking for slow powders, just can't find any at the moment.

I do have Bullseye, hence the question.

I am like many and shoot more 38 in my 357 but also like to shoot 357 and my particular revolvers seem to be more accurate with loads just a little below max. I used to shoot a little silhouette and I used to hunt large game with a revolver so even though I am in my 70's I am not all that uncomfortable shooting strong loads.

I do not rely on the internet for my loads, I do read and use manuals, but I do enjoy increasing my understanding of loading by hearing the insights, experience and views of others. My original question was merely why there was such a difference between the manuals, and I got some good answers

I also note that responders often discuss things not actually asked about by the OP, but I happen to enjoy hearing all of the comments, and I usually learn something even by those not directly relevant to my question.

And for those who like to argue, well, I even enjoy reading those and I learn from them as well.

So, thank you to all who took the time to share your thoughts.

Yes, for full power 357 Magnum loads you need a slow powder. 2400, AA#9, and H-110/W-296 immediately come to my mind. I have quite a bit of load development with H-110/W-296 and it will wring everything possible out of the 357 Magnum cartridge. A stiff load of this powder under a 125 grain jacketed bullet is loud and the flash can make anyone on either side of you on the firing line back away or just pack up and leave. Full power 357 Magnum can be a real blast.

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I apologize for going off thread regarding your post. As for argument, a point can usually be made without it.

Many manuals do not specify the actual bullet being used. Speer uses their swagged lead bullets, but admits the other data from other companies offer made with "cast bullets" will work just fine, just expect to be a lead miner after shooting.

Lee modern reloading 2nd edition gives 148 wadcutter loads, but doesnt even specify HBWC or DEWC in the book

There is no conversion. Two different methods used, and they do not directly relate to one another.

I use Bullseye for my .38 target HBWC and WC loads, Unique and Universal for my cast SWC .38 and .357 mid-range, and 110 and 296 for my jacketed and hard cast full power loads. Each powder to each use.

I use coated Missouri Bullets for both .38 and .44 loads, but Bullseye for plinking only. Better accuracy and velocity with a higher volume of slower powder.

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Heavily armed old man.

That is correct, there is no conversion factor or formula. However, CUP will be lower than the peak PSI obtained from a piezo gauge for the same load. Just how much lower depends on a number of factors, but it is usually taken as being around 15%. Or another way to put it is that the copper crusher method does not actually indicate the true peak pressure, but gives more of an average pressure. Piezo gauges do read instantaneous peak pressure as their response time is so fast.

No ammunition manufacturer anywhere today (with the possible exception of some third world countries) uses the old copper crusher pressure measurement method as the piezo method is so vastly superior. As I have said in the past, using the copper crusher method is sort of like trying to tell time accurately by using a sundial.

The difference between CUP pressures and PSI pressures will vary depending on the ctg. If you study the manuals you will see in the case of the .357 magnum loads listed as 35,000 psi and 42,000 cup are about the same. So the top loads listed in the old manuals do not exceed current pressure limits.

Nothing wrong with bullseye in the 357mag cases. Very consistent with good velocities for the amount of powder being burned.

Top row, 2nd from left (green bullet) a 158gr fn hp/mp 640 series
Bottom row center a 158gr fn hp/cramer "hunter" bullet


Playing around on the 50yd line with a s&w 686 6" bbl sitting using a pistol rest. These are 6-shot groups using both bullets pictured above and 5.5gr of bullseye along with 6.0gr of bullseye.


That's 2 different bullets using 2 different bullseye loads with the worst group being 2 3/16" outside to outside measurements on the bullet holes/6-shot groups @ 50yds.

I personally don't mind full magnum 357 loads and I shoot them the most . I shoot them in my 19's , 2.5" and 4" barrels . My 681 gets lots of them too . My 681 wears a pair of PC Magna's . I don't find it uncomfortable to shoot any of the above mentioned firearms with magnum loads . Proper stance is key ! Regards Paul

I tried unique and bullseye in the .357 loads, but quickly changed to 2400, 296 and I think, blue dot. Using powders that will fill up a pistol case is generally a safer load, no double charges. I used to love shooting some good hot, gas checked, cast bullets in the 686, and I was pretty accurate with it. I use the manuals, both old and new, sometimes just because I can cross reference them. I DON'T get my reloading data from the internet. It's easy to be safe and have fun shooting, but you must have a plan and stick with it.

Have a blessed day,

Leon

By the way............

if those coated 158 bullets don't work out,

I had good luck with coated 125 gr bullets with Bullseye and six other powders.

Have a Happy New Year.

I read these two statements back to back and it seemed that they couldn't both be correct. So I googled up this comparison chart that lists both values for 26 different rifle cartridges.
What I'm seeing is that in all but 5 cases the CUP number is consistently lower than the PSI number. And of those 5 exceptions 2 (yellow highlights) appear to have accidentally listed the same value in both columns and the other 3 (red highlights) the CUP number is higher.

Since there are 21 where the PSI value is higher and only 5 "exceptions" I have to wonder if the exceptions are the incorrect examples. Especially when there are more than one other example in the same range of values and they consistently show the PSI number as the higher value.

EDIT: Here is a link to the article where I got the table below
https://www.shootingsoftware.com/ftp/psicuparticle2.pdf
One thing I hadn't picked up on when I started this post is that the author points out on page 5 paragraph one that vecause this data is all for RIFLE cartridges, and that since they didn't test any HANDGUN cartridges one can't assume that the same correlations exist for handgun cartridges.
Another article I found here
CUP, psi & Reloading Data - Shooting Times
explains that the difference in cartridge shapes (bottleneck rifle vs straight walled handgun) and the cartridge lengths relative to where the sensor (copper crusher vs piezo electric) have to be placed in the test barrels for handgun cartridges has a bigger and different effect on the readings making the correlation less predictable.

So I'm going to do some more searching for a table of the same type contrasting PSI and CUP in handgun cartridges. Stay tuned.

Attached Images

Hilighted CUP vs PSI.jpg (87.6 KB, 7 views)

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