Gas Check vs Water Drop

[BJung]

Has anyone done a comparison of a cast bullet of the same alloy but one uses a gas check vs another being water dropped and PC'd?

[bangerjim]

Kinda like comparing apples to hand grenades. Same boolit - two different purposes.

But this group of fine people is old enough and large enough to probably have done messing around like that and I'm sure someone has some info for you.


I stick with 100% ES gun powered coating (not worrying about coating the bases) and GC + PC........BUT.........only on high velocity rifle boolits.

banger.

[Recycled bullet]

When I water drop my powder coated bullets they require a greater amount of force to shove through the sizer.

[popper]

Depends on the alloy. And you WD out of the PC oven. Describe your purpose to get better answer.

[Harter66]

Pistol bullets .
I've loaded some fairly excitable 357 in 18" carbines I found no advantage other than possibly expanding with a softer alloy with a gas check . I choose a bullet that eliminated that need .

In my experience, I learned paper patch to avoid gas checks , at the "over 1800 fps it'll lead like crazy" type 12-1500 fps levels it doesn't make a lot of difference. Held under 28kpsi it matters even less .
BUT, cause there's always one .....
Checks will make rifle loads much , much easier to have success with.

I caved to buying checks for 6.8SPC because it was for a gas gun . At that point I'd succeeded with 30-30,308,06' ,7.62×39,358 Win and a 7mm wildcat in getting sub 2" 100 yd groups of 10 at 21-2400 fps . That decision changed everything. It may have been better having a zero mileage new barrel of correct dimensions , not trying to fill up a throat .006 oversize into .004 oversize barrel with .300 jump like the SKS or the 06' that would take 3.995 OAL , I enjoyed the 2" 2150 fps almost instantly in a 16" carbine the 20" rifles , ARP 5R , went 1" and 2275 fps with shared loads .

So , if you're goal is cheap pop can killing and proficiency training it's fine to run PB up to 35kpsi and harder alloys . If it's more business, whether it's friendly/ serious competition or groceries , use the checks .

[Rapier]

I ran a controlled comparative tests on cast GC Vs GC moulds cut for but with no GC bullets, all water dropped, all hard cast, all With lube, not PC. Wrote a magazine article about shooting this test with the 7mm 145, 30 cal 165 and 357 162 grain. at 50 meters or 55 yards from a rest with 3 and 2 of five rounds in 5 shots groups with the two loading mixed in each group in two separate groups, the 2 and the 3 of 5 shot into the same group with no discernible difference in velocity over a chronograph nor a digfferance in group size between the two groups or the bullets. Once the bullets are loaded, the shooter does not know which is which of the bullets if you mix each group of five up, intentionally. In other words, the 7mm TCU shot 1/2" groups with the 2+3=5 group and the 3+2=5 group and both were 1900 fps out of an XP-100 with a 14" barrel and an 8x scope. Same day, same gun. The idea being to actually test GCs VS no GC in a same same load that should have required a GC.
However, I did check the same loads at 100 and the group opened past the nominal 1.5 to 2x group size at 50 that one would expect at 100, indicating to me the non GCs became slightly less accurate as the 145 GCs shot 1/2" at 100.. So I continued to use GCs on the GC cut bulllits, for shooting past 55 yards but then changed to a plain base and powder coating and went to .43 inch groups...with a RCBS 200 cast 358 bullet in a rifle at 2,500 fps. So I stopped using GC bullets for powder coating, period.

I hope this is close to answering the questions you were asking?

[Barry54]

I ran a controlled comparative tests on cast GC Vs GC moulds cut for but with no GC bullets, all water dropped, all hard cast, all With lube, not PC. Wrote a magazine article about shooting this test with the 7mm 145, 30 cal 165 and 357 162 grain. at 50 meters or 55 yards from a rest with 3 and 2 of five rounds in 5 shots groups with the two loading mixed in each group in two separate groups, the 2 and the 3 of 5 shot into the same group with no discernible difference in velocity over a chronograph nor a digfferance in group size between the two groups or the bullets. Once the bullets are loaded, the shooter does not know which is which of the bullets if you mix each group of five up, intentionally. In other words, the 7mm TCU shot 1/2" groups with the 2+3=5 group and the 3+2=5 group and both were 1900 fps out of an XP-100 with a 14" barrel and an 8x scope. Same day, same gun. The idea being to actually test GCs VS no GC in a same same load that should have required a GC.
However, I did check the same loads at 100 and the group opened past the nominal 1.5 to 2x group size at 50 that one would expect at 100, indicating to me the non GCs became slightly less accurate as the 145 GCs shot 1/2" at 100.. So I continued to use GCs on the GC cut bulllits, for shooting past 55 yards but then changed to a plain base and powder coating and went to .43 inch groups...with a RCBS 200 cast 358 bullet in a rifle at 2,500 fps. So I stopped using GC bullets for powder coating, period.

I hope this is close to answering the questions you were asking?

I would love to read that article! Is it online somewhere?

[405grain]

Rapier: I second Barry54's request. I shoot the 7-145-Sil bullet in a 7mm TCU carbine. Any information that improves accuracy would be well received.

[Bronco72]

I have a 50-110 that I cast bullets for, I found that water quenched bullets are about impossible to size the next day. After some reading I found that the water quenching bullets take about 24 hours to reach their hardness. If water quenching I would suggest to PC them and size them as soon as possible. I don't PC the 50-110 bullets but I cast them in the morning and size and lube them that night.
Just passing along my experience

[BJung]

I have cast various MP HP bullets and have tested them for expansion. At best, I expect to have a graph of various bullet calibers with different charges and expansion. I can graph the MV and KE to the bullet expansion. Having found certain bullets to expand nicely, the charge weight is high. My accuracy loads tend to be less than maximum. A gas check or water drop should resist bullet deformation and allow me load up to the KE level that expands the bullet. And so, I plan to carve a gas check groove on the base for gas checks. Another option would be to temper the base by heating a sized PC bullet, heating it, and quenching the base up to the base of the HP. I'd like to quench a cast bullet and measure the hardness and how far the tempered lead migrates up the bullet from the water line.