Powder coat and chamber pressure

[Coopaloop86]

I'm not so much suggesting, just telling you what works for me. I almost exclusively use jacketed data of a similar weight and profile for PCed boolits and find that I get slightly better velocities with slightly lower pressures. With the proper fit it also leaves my barrels squeaky clean.

[charlie b]

How do you know you get lower pressures? And how much difference in velocity?

I used to think that copper plated bullets would work like jacketed, but, mfg loading data says otherwise. I wish someone with the proper gear would measure pressures for PC bullets. There is a lot of speculation on this topic but I have not seen anything measured.

I do find that PC bullets are very slightly less accurate than lubed. They do seem to be less 'tolerant' of load, ie, takes a bit more tweaking to get a good load than it does with lubed bullets.

Sent from my SM-P580 using Tapatalk

[Driver man]

Im wondering if anyone has anything to add to this thread

[Larry Gibson]

I ran an extensive pressure and velocity test using the Lee 452-230-TC naked and lubed with BAC vs 4 different PCs. The test included identical loads except for the PC in the 45 ACP and 45 Colt in 5 handguns and two rifles.

The PC'd bullets neither raised pressures not increased velocities above the naked/lubed bullets. All variations of pressure and velocity were well within normal test to test variation.

Here is the data;

45 ACP/452-230-TC/5 gr Bullseye/WLP/R-P Case
Sherman Williams
Metallic Silver 1 Coat
Firearm…………… Grp @ 25 yd……..Velocity……SD……..ES……psiM43)…..SD……ES……..
TC Contender………3.9”..(8 in 2.8”)……1019 fps….11 fps…35 fps…..20,200…….900…...3,300……
S&W M1917/25…….4”…(8 in 3”)……….890 fps….15 fps…54 fps…....
Colt Gvm’t M1911….5.5”…………………919 fps…..12 fps…42 fps……
M98 Rifle..(50 yd).....3.2”..(7 in 1.1”)…….1046 fps….17 fps….58 fps…..

Sherman Williams
Metallic Silver 2 Coats
Firearm…………… Grp @ 25 yd…..Velocity…….SD…….ES………psiM43)…..SD……ES……..
TC Contender………4.6”……………..1006 fps……19 fps…58 fps……19,400…...1,200….3,400…
S&W M1917/25……5.4”..(9 in 4”)…….903 fps……14 fps…41 fps
Colt Gvm’t M1911…6.5”………………919 fps…….19 fps…54 fps
M98 Rifle…(50 yd)…5.25”……………1044 fps……10 fps…33 fps

Cardinal Pearlescent
Steel Gray 1 Coat
Firearm…………… Grp @ 25 yd…..Velocity….…SD…….ES………psiM43)…..SD……ES……..
TC Contender………4.4”……………..1002 fps……14 fps…53 fps……19,900……1,500…4,000
S&W M1917/25…….4.9”………………895 fps...…17 fps…54 fps
Colt Gvm’t M1911….5”………………...917 fps…...10 fps…35 fps
M98 Rifle..(50 yd)…5.2”………………1038 fps…...13 fps…48 fps

Cardinal Gloss
Black 1 Coat
Firearm…………… Grp @ 25 yd……Velocity……SD…….ES………psiM43)…..SD……ES……..
TC Contender………2.2”………………996 fps……16 fps…..61 fps……18,700……1,200….4,100
S&W M1917/25……2.2”………………886 fps……16 fps…..43 fps
Colt Gvm’t M1911…3”…………………917 fps……9 fps…...31 fps
M98 Rifle…(50 yd)..3.6”…(8 in 1.4”)…1035 fps…...14 fps….43 fps

Naked Cast
BAC Lube
Firearm…………… Grp @ 25 yd….Velocity…..…SD…….ES………psiM43)…..SD……ES……..
TC Contender………2.1”……………..1004 fps……12 fps….40 fps…..18,900…….900……2,900
S&W M1917/25……2.25”…………… 917 fps……..9 fps…..30 fps
Colt Gvm’t M1911…2.75”…………….922 fps…….12 fps….37 fps
M98 Rifle…(50 yd)…2.2”……………1060 fps…….15 fps….45 fps

45 Colt/452-230-TC/7 gr Bullseye/WLP/W-W case
Sherman Williams
Metallic Silver 1 Coat
Firearm………………. Grp @ 25 yd….Velocity………SD…….ES……psiM43)…..SD……ES
TC Contender………….2.8”……………..1080 fps……10 fps….34 fps…..14,800……800……2,900
Uberti Evil Roy SAA…..3.6”……………..896 fps……..12 fps….34 fps..
Uberti M73 Carbine..(50 yd)..3.6”………...1153 fps……12 fps…41 fps

Sherman Williams
Metallic Silver 2 Coats
Firearm………………. Grp @ 25 yd….Velocity……..SD…….ES………psiM43)…..SD……ES
TC Contender…………..3.1”……………1070 fps…….12 fps….39 fps…..15,700……500……1,700
Uberti Evil Roy SAA…..3.6”…………….900 fps……...8 fps…...24 fps
Uberti M73 Carbine..(50 yd)….2.8”..……1142 fps…….8 fps……27 fps

Cardinal Pearlescent
Steel Gray 1 Coat
Firearm………………. Grp @ 25 yd….Velocity………SD…….ES………psiM43)…..SD……ES
TC Contender………….3.9”…………….1070 fps……..7 fps….20 fps……16,000……600……1,700
Uberti Evil Roy SAA…..5”……………….899 fps……..18 fps…59 fps
Uberti M73 Carbine.;(50 yd)..4.2………...1135 fps………5 fps…17 fps

Cardinal Gloss
Black 1 Coat
Firearm………………. Grp @ 25 yd…..Velocity…..…SD…….ES………psiM43)…..SD……ES
TC Contender…………..1.8”……………1066 fps…….11 fps….31 fps……15,900…..500……1,700
Uberti Evil Roy SAA…...2”………………896 fps……..10 fps….31 fps
Uberti M73 Carbine..(50 yd)..2.5”………..1134 fps……13 fps…..49 fps

Naked Cast
BAC Lube
Firearm………………. Grp @ 25 yd…..Velocity……SD…….ES……..…psiM43)…..SD……ES
TC Contender…………..1.8”…………….1078 fps….9 fps…….35 fps……16,700……900……2,900
Uberti Evil Roy SAA…..2”………………..902 fps….12 fps……44 fps
Uberti M73 Carbine..(50 yd)..1.7”………..1135 fps…..5 fps…….15 fps

[Driver man]

I thought Id read all your posts but I must have missed this one . Thanks for reposting . I will add this to my files.

[cupajoe]

Years ago I did a small test of plain lube and sized boolits versus pc'd and sized boolits in my S&W 67-1 revolter with a 4 inch barrel clamped in a ransom rest at 33 yards. The plain boolits were sized and lubed in my LAM 2 filled with BAC, sized .358. The pc'd boolits were coated with yellow/green from Smoke and sized to .358. All were loaded in WW Super 38 special brass, Winchester sp primers and charged with Titegroup powder. The chrono was 10 or 12 feet from the muzzle, I don't remember, been too many years. After I settled the pistol in the rest I shot a group with Magtech 38 special+p 158 gr sp factory ammo for grins, six shots grouped into 2.17" at 808 fps. I fired all the lubed/sized loads first, then fired 6 more of the factory loads to burn the lube out of the barrel, the group was 1.68". Then fired the pc'd loads.

3.2 gr. TG, lubed-2.37", 696 fps...pc'd-1.26", 729 fps
3.4 gr. TG, lubed-1.80", 734 fps...pc'd-1.67", 769 fps
3.6 gr. TG, lubed-2.89", 760 fps...pc'd-2.18", 788 fps
3.8 gr. TG, lubed-2.74", 801 fps...pc'd-1.68", 826 fps

Does this prove anything? Heck no, just a little more data. These all were only 6 shot groups also. The BAC lubed group using 3.6 gr. of TG is suspect because one shot opened the group from 1.14" to 2.89"!! Lube purge maybe?