357 Cast Slugs

[caliusoptimus]

This thread is for all of the slugs I've cast and tested. Maybe I'll find a few good combinations to recommend for others.

Left to right. Weights listed are from casting with 40:1 lead/tin.

1. Lee 90316 107 grain
2. An alteros inspired mold I made
3. MP Molds 10929 120 grain
4. MP Molds 10860 130 grain
5. Lee 90574 130 grain
6. MP Molds 10094 130-135 grain

 

[caliusoptimus]

Testing 1-6 in a Western Rattler.

This was with a 1:20" twist TJ barrel. I also tried these with the stock 1:26" barrel and results were about the same or worse. Slug 1 did not do well in the 1:26".

50yds, 15 shot groups. Groups left to right, top to bottom.


1st group, slug 1, 950fps
Best of the day. I shot 100yds with this one and 5 shot groups varried from 1.5" to 3.5". I'm wondering if better consistency in casting will tighted up the fliers.

2nd group, slug 2, 880fps
This one didn't go all the way into the mag. Had to jam in in there and I think the base was deformed in the process. Not a fair test... I may redesign the slug and try again in the rattler.

3rd group, slug 3, 900fps
A good little group with wild fliers. Might try this one again.

4th group, slug 4, 870fps
Not great. Nuf said.

5th group, slug 5, 880fps
Not too shabby. Will try this one again.

6th group, slug 6, 865fps
I used the blank pins for these so they were not hollow point. I've tried the hollow points on several occasions and results are about the same.

7th group
I don't remember what this was.

 

[Firewalker]

Nice lineup! I'm fond of Elmer Keith profiles myself.

 

[sonnysan]

Stick with the TJ barrel for slugs. Stock 1:26 is too slow. What is the groove diameter of the TJ, and what did you size them to?

 

[caliusoptimus]

Stick with the TJ barrel for slugs. Stock 1:26 is too slow. What is the groove diameter of the TJ, and what did you size them to?

Glad you asked because I forgot to mention that... both barrels have .358 grooves, and slugs were sized to .358. Thinking it would pick up some fps if sized to 357. I'll test this idea eventually.

 

[sonnysan]

You are on the right path with the Lee mold. I wonder if the EPP-UG design will work well in .358. I was supposed to get one of these molds just like the one in .458, but biglube ran out and subbed a 38 slim in its place.

Bullet Design Details | Accurate Molds

www.accuratemolds.com

Oh well, I can always get another mold.
The 38 slim mold looks promising. It will be the first slug I test in my Recluse.

 

[caliusoptimus]

You are on the right path with the Lee mold. I wonder if the EPP-UG design will work well in .358. I was supposed to get one of these molds just like the one in .458, but biglube ran out and subbed a 38 slim in its place.

Bullet Design Details | Accurate Molds

www.accuratemolds.com

Oh well, I can always get another mold.
The 38 slim mold looks promising. It will be the first slug I test in my Recluse.

View attachment 471554

View attachment 471555

Extra deep groove on that one. Let me know how it goes.

I've had some generally bad results with lighter slugs in both my rattler and my AEA. NSAs under 110gr go from meh to horrible missing the paper at 50yds. I got a Lee 90305 hoping it would be decent... misses the paper at 50 in both rifles no matter what. I'm suprised the lee SWC above was so good.

Also having bad results from boat tails in any caliber. Sticking to flat base from now on.

Just picked up this mold based on hopes and dreams... https://www.mp-molds.com/product/358-640-hollow-point-plain-base-4cavity-mold/

 

[sonnysan]

Extra deep groove on that one. Let me know how it goes.

I've had some generally bad results with lighter slugs in both my rattler and my AEA. NSAs under 110gr go from meh to horrible missing the paper at 50yds. I got a Lee 90305 hoping it would be decent... misses the paper at 50 in both rifles no matter what. I'm suprised the lee SWC above was so good.

Also having bad results from boat tails in any caliber. Sticking to flat base from now on.

Just picked up this mold based on hopes and dreams... https://www.mp-molds.com/product/358-640-hollow-point-plain-base-4cavity-mold/

That's the risk with these molds. You'll know if it's a keeper within 15 rounds. Most of the time they do not work out. I hope your new MP mold shoots well. That is an expensive experiment.

 

[caliusoptimus]

Some more slugs for testing.

Left to right.

7. Lee 90305 106gr

8. MP Mold 11032, Solid 172gr

9. MP Mold 11032, Large HP 161gr

10. MP Mold 10904, Large HP 87gr

11. A NSA inspired mold I made, solid, 129gr

Notes-

7 has had horrible accuracy. Hit or miss on a 12"x18" target at 50yds. I've tried it in 3 different 1:20" twist barrels and a 1:26" barrel. Avoid this one.

8 and 9 come with a few different hollow point pins. 8 is the solid pin and 9 is the largest hollow point pin.

10 comes with a few different pins. This one is the largest hollow point pin.

11 nearly the same shape as a NSA 125gr, but without the hollow point. One of my 357's likes the NSA 125gr so I made this mold to plink for cheap.

 

[sonnysan]

Some more slugs for testing.

View attachment 472519

Left to right.

7. Lee 90305 106gr

8. MP Mold 11032, Solid 172gr

9. MP Mold 11032, Large HP 161gr

10. MP Mold 10904, Large HP 87gr

11. A NSA inspired mold I made, solid, 129gr

Notes-

7 has had horrible accuracy. Hit or miss on a 12"x18" target at 50yds. I've tried it in 3 different 1:20" twist barrels and a 1:26" barrel. Avoid this one.

8 and 9 come with a few different hollow point pins. 8 is the solid pin and 9 is the largest hollow point pin.

10 comes with a few different pins. This one is the largest hollow point pin.

11 nearly the same shape as a NSA 125gr, but without the hollow point. One of my 357's likes the NSA 125gr so I made this mold to plink for cheap.

Please let us know how this group of slugs compare to the 90316 Lee mold. I'm interested in acquiring the Keith design further down the road.

 

[caliusoptimus]

50yds. Groups left to right, top to bottom. 15 shot groups. Western rattler, 36" long 1:20" twist TJ barrel. No moderator.

1. Slug 8, 835fps average

2. Slug 9, 858fps average

3. Slug 11? I didnt take notes for this one.
Edit: This was Slug 10 at 1030fps

4. Slug 10 960fps average. Started this one over 1000fps and it was wild. Slowed down to mid 900s and it was much better.

5. Slug 5, 930fps average

6. Slug 1, 1000fps average. Too fast.

This one is a bit messy.... 50yds. 15 shot groups. Western rattler, 36" long barrel. No moderator.

1. Slug 1, 938fps average. Mid 900s doing pretty well.

2. I changed barrels here. For the rest of the groups I used a 1:26" twist barrel. Same length, same manufacturer. The two on the left were because of the barrel change. Scope adjust for the rest of the group. Slug 8, 840fps average.

3. Slug 9, 860fps average

4. Slug 10, 960fps average

5. Slug 5, 936fps average

6. Slug 11, 925fps average


Slug 1 still doing great. A keeper for sure, will probably pick up the 6 cavity version of this mold.

Slug 5 doing great. Shoots well in my AEA too, stock and custom barrels. Overall a great slug.

Slug 9 seems to be slightly better that slug 8. Need to find the perfect speed for this.

Slug 10 is also great. I'll bet it tightens up at the perfect speed.

 

[sonnysan]

1 and 5 are here:

Lee 2-Cavity Bullet Mold 358-105-SWC 38 Special, 357 Mag, 38 Colt New

Lee Bullet Molds are a great choice for reloaders looking for a quality mold at an affordable price. Lee machines their mold blocks from aluminum making...

www.midwayusa.com

Lee 2-Cavity Bullet Mold 358-125-RF 38 Special, 357 Mag, 38 Colt New

Lee Bullet Molds are a great choice for reloaders looking for a quality mold at an affordable price. Lee machines their mold blocks from aluminum making...

www.midwayusa.com

Thank you for trying out all of your molds and reporting the results. This takes an awfully long time that is appreciated.
You also spent several hundred dollars in the process for our benefit.
Now anyone who has this gun and wants to get into casting has a great starting point. I added your discovery to my notes for future reference.


View attachment Sonnyslugs_1.1.xlsx

 

[caliusoptimus]

1 and 5 are here:

Lee 2-Cavity Bullet Mold 358-105-SWC 38 Special, 357 Mag, 38 Colt New

Lee Bullet Molds are a great choice for reloaders looking for a quality mold at an affordable price. Lee machines their mold blocks from aluminum making...

www.midwayusa.com

Lee 2-Cavity Bullet Mold 358-125-RF 38 Special, 357 Mag, 38 Colt New

Lee Bullet Molds are a great choice for reloaders looking for a quality mold at an affordable price. Lee machines their mold blocks from aluminum making...

www.midwayusa.com

Thank you for trying out all of your molds and reporting the results. This takes an awfully long time that is appreciated.
You also spent several hundred dollars in the process for our benefit.
Now anyone who has this gun and wants to get into casting has a great starting point. I added your discovery to my notes for future reference.


View attachment 472714

I see you've got the lee 90388 mold. Any comments or experience with it? Thinking about giving it a try since the BC is good.

 

[sonnysan]

I see you've got the lee 90388 mold. Any comments or experience with it? Thinking about giving it a try since the BC is good.

I haven't tried any of the .358 molds yet even though I have three guns in this caliber. I know this design works well in the .401 version.

 

[caliusoptimus]

2 more slugs to try this weekend.

12. (Left) Modified Lee 90449 182gr

13. (Right) Lee 90388 160gr

Notes-

Slug 12 is a modified mold. The original mold had a gas check section but it was too long to fit in the rattler mag. I milled the mold down to remove that portion.

Based on the results so far I think that slug 1 or 5 is going to become my go-to plinking ammo. I'm not ruling out slug 10 either, but I need to try these at 100yds and find the sweet spot velocity for each, then I can make a final comparison.

I've been testing the heavier slugs to find one that performs accurately with high-ish BC for shooting past 100yds. Still need to test 12 and 13 before I move out to longer ranges.

If I decide to go hunting slug 9 will be my go-to. With the 36" barrel and the reg at 180bar this slug will do 300fpe. I could squeeze out at least another 10-20fpe by going heavier but... that's a pretty small percentage increase and probably not worth the effort. If I need more I'll grab a bigger caliber.

 

[caliusoptimus]

I spent about an hour and a half today tuning in slug 9 and I think it has 1moa potential.

I was having some significant flyers... not sure why but my suspicion is scope related. May also be the barrel leading up or casting inconsistencies. Once I was satisfied with the tune I shot these groups. After the top 2 groups I changed my zero. This 100yds, slug 9 at 870fps average.

I feel like these groups were solid shooting with no shots pulled. There was a stiff breeze at times.

 

[caliusoptimus]

Spent some time shooting a few of these slugs last weekend and... it was a bad day. None of the slugs were shooting well. 3moa day. I've narrowed it down to the two most likely reasons...

1. I was shooting poorly.
2. Lapping my barrel made it worse.

After my last post above I gave the barrel a good lapping with 600 grit. This time I got it looking really good and purdy on the bore scope.... 95% cleanup on lands and grooves. I had lapped it previously and got maybe 30% cleanup. Yesterday it occured to me that I may have warped it with heat. Checked it straightness today, worst spot (middle) was .010" TIR.

I don't know if this is why I had bad grouping... I think it was more likely my fault. Still, not ruling it out.

Anyway... having a bit of a crisis now lol. Not sure if the previous bad groups were me or the slug. Now I've gotta double check my results.

Also... I made another mold. #14 up next for testing. (Left.) 170 grain. 20mm length. I call this:

"It looks like a boolit, I sure hope it flies like one."

Also a .25 39gr that I made at the same time. (Right.)

 

[JimBentley]

Spent some time shooting a few of these slugs last weekend and... it was a bad day. None of the slugs were shooting well. 3moa day. I've narrowed it down to the two most likely reasons...

1. I was shooting poorly.
2. Lapping my barrel made it worse.

After my last post above I gave the barrel a good lapping with 600 grit. This time I got it looking really good and purdy on the bore scope.... 95% cleanup on lands and grooves. I had lapped it previously and got maybe 30% cleanup. Yesterday it occured to me that I may have warped it with heat. Checked it straightness today, worst spot (middle) was .010" TIR.

I don't know if this is why I had bad grouping... I think it was more likely my fault. Still, not ruling it out.

Anyway... having a bit of a crisis now lol. Not sure if the previous bad groups were me or the slug. Now I've gotta double check my results.

Also... I made another mold. #14 up next for testing. (Left.) 170 grain. 20mm length. I call this:

"It looks like a boolit, I sure hope it flies like one."

View attachment 477065

Also a .25 39gr that I made at the same time. (Right.)

This is only my observation, not meant to be taken as degrading you.
From my experience in casting thousands of center fire bullets, it appears that your casting technique needs some polishing. Wrinkles and non filled bullets will make you chase your tail.

 

[caliusoptimus]

This is only my observation, not meant to be taken as degrading you.
From my experience in casting thousands of center fire bullets, it appears that your casting technique needs some polishing. Wrinkles and non filled bullets will make you chase your tail.

No offense taken. Which ones do you see an issue, and what do you recommend to fix it? Ignore the tip on the last two, that's actually chatter in the molds I made, not a casting defect.

The one thing I struggle to get is 100% shiny boolits. No matter what the best I get is half shiny with the other half looking a bit drossy. I also get inclusions sometimes, and cull them when I see em. I don't understand how this happens with a well fluxed and stirred bottom pour pot.

 

[JimBentley]

In my experience frost and shiny appearance is temperature related. Careful measurements should show a slight difference in diameter. I always cast at 750 degrees. There are several different methods of fluxing the mix, bees wax being among the oldest. I flux multiple times when using my 20 lbs RCBS pot. Even with a hot plate to pre heat my molds, I find that the first few drops go back in the pot. That gets the mold up to an even temperature