Bullet Casting & Coating MegaThread

I’ll post some test results when I hit the range. I played musical scopes so this needs to be sighted in again. I will say these have been a pleasure to load and shoot and my BP’s will see more range time now. The sabots I would be fighting or swabbing after three shots and the time to reload was much longer. My goal is to get this up to par and take a deer with it this year. Getting a deer in my zone can be a PITA… I shot the only two deer I saw this season. Thankfully I didn’t miss.
 
mac1911 said:
More or less under 1500 fps you should be good with no gas check
1500+ need a gas check
I gas check all but the slow gallery type loads
Click to expand...
Thanks. I knew there was an upper limit but he pushed 1700 fps with no gas check.

I just kind of figured to make it easy that rifle would need a gas check but not so much for pistol.

Maybe that’s why it went all wobbly when he exceeded 1525. Not so much due to the powder changes affected actual accuracy
 
ddeck22 said:
Thanks. I knew there was an upper limit but he pushed 1700 fps with no gas check.

I just kind of figured to make it easy that rifle would need a gas check but not so much for pistol.

Maybe that’s why it went all wobbly when he exceeded 1525. Not so much due to the powder changes affected actual accuracy
Click to expand...
I personally would not push a gas check designed bullet much more than 1200 fps.
The sks or many 30 cal rifles are 1-10 twist the SKS is 1-9 ish
So your rpm threshold on cast can cause accuracy issues.

Leading mostly caused by bullets not correctly sized for the lead/bore

The lee .312 155 is a gas check design , that faster burn rate powders like 2400 can cause some over obturation and actually gas cut past the taper of the gas check seat.

The velocity/rpm rang cast bullets rpm in is some where in that 125.000-140,000 area. The fast the rpm the more any defects in the bullet will start to show.

so some where in that 1600-1800 fps range should be ok for the RPM RPM calculation is muzzle velocity X 720 / twist

Personally with the small case of the x39 I would try H4895 at around 18 grains and increase .5 until 100 percent function. 25 grains will get you to the top end of your rpm thresh hold.
I got my best accuracy with my ak/sks with H4895 gas checked .312 155 at 1750 ish fps
 
I found some time yesterday to load up some more 14 grains x39 and a few 38 spl with True Blue and True Blue looks like it will meter really good in the Dillon. I was ringing steel at the 100 till the plate fell off and that was good enough for my purposes for now. I’m going to give the gun a good cleaning to see what the barrel looks like and possibly slug it again and measure with a micrometer. I don’t know if I used dial calipers when I measured the first time and came up with .324. @pastera gave me a great lesson on slugging and measuring with micrometer at the casting class the other year so I’ll do it again.

@mac1911 thanks for the detailed explanation because it makes sense and I want to keep poking and playing to come up with the best combos. 2400 is what I have a few pounds of but I do have a limited supply IMR-4895 if that can be used as an alternative.

Another question I wanted to throw out there is how much variance in the weight of the bullet will have on the overall accuracy. I know its a big factor if I was going to bench rest precision rifle shooting over a large distance. Yesterday I was loading up the test rounds for the 38SPL with True Blue with bullets the kid casted and he landed a large percentage right at 158.8 mark with the Lee 158 FP mold where some of my .312 155 grain varied from 158 to 162gr and some of that was due to diff alloys and my technique. I didn’t know if there is a standard like if they are all within X percent of the total weight you shouldn’t see any major variance in performance. I know there are variables that come into play but this is one that could be controlled.
 
Jay77 said:
I found some time yesterday to load up some more 14 grains x39 and a few 38 spl with True Blue and True Blue looks like it will meter really good in the Dillon. I was ringing steel at the 100 till the plate fell off and that was good enough for my purposes for now. I’m going to give the gun a good cleaning to see what the barrel looks like and possibly slug it again and measure with a micrometer. I don’t know if I used dial calipers when I measured the first time and came up with .324. @pastera gave me a great lesson on slugging and measuring with micrometer at the casting class the other year so I’ll do it again.

@mac1911 thanks for the detailed explanation because it makes sense and I want to keep poking and playing to come up with the best combos. 2400 is what I have a few pounds of but I do have a limited supply IMR-4895 if that can be used as an alternative.

Another question I wanted to throw out there is how much variance in the weight of the bullet will have on the overall accuracy. I know its a big factor if I was going to bench rest precision rifle shooting over a large distance. Yesterday I was loading up the test rounds for the 38SPL with True Blue with bullets the kid casted and he landed a large percentage right at 158.8 mark with the Lee 158 FP mold where some of my .312 155 grain varied from 158 to 162gr and some of that was due to diff alloys and my technique. I didn’t know if there is a standard like if they are all within X percent of the total weight you shouldn’t see any major variance in performance. I know there are variables that come into play but this is one that could be controlled.
Click to expand...
Probably not enough to see any down range performance.
Your rifle/skills are a larger variable than a few grains on the bullet.
If it helps just sort your bullets.
I will sort sometimes.
Target weight plus minus .2 grains then under and over

Play around with a ballistics calculator.
 
The .312 has a 2.5% variation in weight (4/160)
For ringing steel at < 100yards you'll not likely notice is too much.
If you want to get some better accuracy, find a couple that look perfect - good bases, no mold flash - and weight those. They should all be within 0.3 or so. Then bin +/-0.25g around that. For the rest drop them into high and low bins and use for plinking.
Most of the inaccuracy is going to come from out of round bullets (mold not closed properly) and too a lessor extent poorly cut bases. Slight velocity differences from the actual weight aren't going to have large effects at shorter distances
 
mac1911 said:
Probably not enough to see any down range performance.
Your rifle/skills are a larger variable than a few grains on the bullet.
If it helps just sort your bullets.
I will sort sometimes.
Target weight plus minus .2 grains then under and over

Play around with a ballistics calculator.
Click to expand...
Gordons Reloading Tool
16" barrel; 7.62x39
18g 2400 (GRT puts this at pretty much a max load)

158g - 40140 psi; 1883 fps
162g - 40788 PSI; 1866 fps

You'll get much worse from factory ammo
 
Jay77 said:
I just downloaded the Gordon tool to play with later….
Click to expand...
I've found it is pretty accurate for powders with "green" calibration data

Problem is that Gordon passed last year and all of the databases are static until the probate stuff is over and the family can give control to other supporters/developers
 
@Jay77 has motivated me to try casting for my SKS again with 2400[mg]
I am running the same Lee C312-155-2R bullet as him but, in the past, had terrible luck with IMR-4198. Reading C.E. Harris-The Practical Dope on 7.62x39 and seeing how well Jay's results were, i have decided to try it again with 2400. Picked up 1lbs at Shooting Supply today and loaded up 20 rounds starting at 14gr to 15.5. Hoping to get to the range on Friday and see how it goes.
-Mixed brass, trimmed to 1.519
-Lee C312-155-2R, alloy is COWWs and a bit of added tin, 3 coats of HiTek, water quenched on 3rd coat, sized to .314 (SKS bore slugged at .312), average weight is 163gr with gas check
-Seated to crimp groove, 2.159 OAL
20230405_183144.jpg

Practical Dope on the 7.62X39

Practical Dope on the 7.62x39 By C.E. HarrisUpdated 3-27-94 I have reloaded thousands of rounds of 7.62X39 ammunition with both cast bullets and jacketed, in the AK and the SKS. I got frustrated with the AK as accuracy of these seems is generally poor, at best about 5-6" at 100 yards. The...
castboolits.gunloads.com
 
Last edited:
I got so excited because it does meter really good through the Dillon, far better then the Clays I’ve been using. I started at 5.0 grains with the 158.8 gr Lee and I had some unburnt yellow flakes that went away around 5.3 and they got a bit snappy as they approached 5.6. I’m going to load some more at 5.6 and see how it goes, but I think I have a winner here.
 
We ripped through a hundred on Friday and they were great. Running out of tips and recently snagging some great COWW from @Chaparral66 I decided to pour some more. Mmm think it was time to give the Lee pot a cleaning because pouring was a PITA. So I emptied out the lead and found a bit of that fine dust in the spout. So for my curiosity… if everything floats to the top how does that fine dust get to the bottom? I leave about an inch or two of lead in the bottom when I stop. And I use a generous amount of saw dust to flux.
 
Some reason I’ve always have had great success coating those Lee 158gr .358 bullets with Hi-tek. Over the weekend I tried to run some with just lube but it took longer then coating and running through the lee sizer. 14 mins at 198C did the trick and that was just two coats.
 

Similar threads

Cast bullets in 300BO for AR
2
Replies
38
Views
2K
240Geezer
2
Bullet Mold Porn ✊💦
2 3 4
Replies
104
Views
3K
magoo
magoo
Want to start Casting bullets
Replies
29
Views
1K
Artie
Artie
Back
Top Bottom