Gas checks needed for magnum calibers? [Archive] - Glock Talk

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ustate
10-07-2010, 20:39
Just curious if gas checks are needed/recommended for .357 mag or .44 mag? I'm guessing that as long as you're aren't pushing them too hard just using a harder BHN like MB sells is good enough.

I've loaded lead for most of my calibers except the magnums and once my current supply for them is gone I may go with cast.

AA#5
10-07-2010, 20:41
I've loaded hard cast bullets in 357 & 44 without gas checks but only up to 950 fps. I've never had any leading in my 629 or Marlin 1894.

fredj338
10-07-2010, 23:22
Leading ais a product of bullet fit, matching alloy BHN to pressures, bullet lube, powder choice & smoothness of the bbl. I have run pretty soft LHP, 10BHN, @ 1200fps w/o a GC & no leading.
http://img.photobucket.com/albums/v703/fredj338/9mm-136-1200.jpg
Sometimes, a hard BHN bullet will lead @ low vel, as the base never upsets enough to seal off the bore & hot gas blows by to melt the sides. Same if the lube isn't upto scratch.
The biggest leading culprit in any bore is bullet fit. The bullet needs to be LARGER than groove dia. At least 0.001" larger. Pistols, not as big a deal, just slug the bbl & go 0.001" larger. In rev. the cyl throats need to match the groove dia as close as possible. Rugers are notorious for undersized throats. My one RBH had 0.450" throats & 0.451" grooves. The bullet gets swaged down as it passe the throats & then bumps up as it hits the bbl forcing cone. I always got leading in the first 1" or so. After opening the throats to 0.451", it now shoots even more acurately & no leading w/ plain base 10BHN LHP @ 1100fps.
Of course a rough bore will lead w/ any alloy/lube/size combo. Only way to know is shoot some lead bullets. Best to clean as much copper fouling out as possible before going to lead. It tends to want to stick to the copper in the bbl.

EOD3
10-08-2010, 04:40
As you can see in Freds picture, modest velocities are all you need with lead bullets. If you cast them too hard, planning to MAGNUM the load, you'll fragment the bullet and get LESS penetration than if you had used a lower powder charge and softer bullets. A .44 SWC or Keith bullet weighing 250 to 300 grains moving at 900-ish to 1200-ish fps will punch a hole clean through Bambi and keep on trucking. You MIGHT recover the bullet if you poke a large pig or a black bear. YMMV

Bob2223
10-08-2010, 06:29
Whats a gas check?
:whistling:

As Fred sez harder bullets aint always better, bullet fit is one of the most important factors.


example, pure lead and tin, and no lead'in with mid range loads .
http://i23.photobucket.com/albums/b376/BobMKIII/100_3005.jpg

Bob

dudel
10-08-2010, 16:43
Just curious if gas checks are needed/recommended for .357 mag or .44 mag? I'm guessing that as long as you're aren't pushing them too hard just using a harder BHN like MB sells is good enough.

I've loaded lead for most of my calibers except the magnums and once my current supply for them is gone I may go with cast.

Gas checks are a function of projectile design and speed they are shot. Boolits designed for gas checks will have a space for the check to be crimped on. Boolits shot at less than maximum speed won't need gas checks.

Of course this also depends on the hardness of the boolit, the roughness of the barrel bore, the size of the boolit to the bore, lube selected and the flame front temp of the powder selected.

WiskyT
10-08-2010, 18:44
With the correct powder, you don't need gas checks, assuming you are using a non-gas check design bullet. For full house magnum loads, use 2400, H110, or other similar powders and you'll be fine.

EOD3
10-09-2010, 01:21
Just to clear up any remaining questions... Gas checks are not required for bullets designed to use gas checks PROVIDED the bullet has substantial rotating band to lube groove surface. The rear rotating band must be thick enough to hold up under pressure and seal the bore.

If this leaves you more confused than before you read it, I'll give it another shot.

sig2009
10-09-2010, 21:21
Gas checks are a function of projectile design and speed they are shot. Boolits designed for gas checks will have a space for the check to be crimped on. Boolits shot at less than maximum speed won't need gas checks.

Of course this also depends on the hardness of the boolit, the roughness of the barrel bore, the size of the boolit to the bore, lube selected and the flame front temp of the powder selected.

Well I sure didn't buy a 357 Magnum to shoot fart loads.

dudel
10-10-2010, 05:12
Well I sure didn't buy a 357 Magnum to shoot fart loads.

In that case, you'll likely need a gas check, or you can deal with leading. Or just shoot jacketed rounds.

357 Mag has a whole range of speed other than fart loads and +P+ loads. The wise shooter finds the one his gun likes; not the one his ego likes.

WiskyT
10-10-2010, 05:57
Well I sure didn't buy a 357 Magnum to shoot fart loads.

1500fps with a LSWC and no gas check and some Lil'Gun, is that what you mean?

dbarry
10-10-2010, 08:25
Well I sure didn't buy a 357 Magnum to shoot fart loads.

Me likey big flash and BOOM with my 357 loads too. :O)

fredj338
10-10-2010, 10:52
In that case, you'll likely need a gas check, or you can deal with leading. Or just shoot jacketed rounds.

357 Mag has a whole range of speed other than fart loads and +P+ loads. The wise shooter finds the one his gun likes; not the one his ego likes.

It depends a lot on the gun, but match the cly throats to the groove dia & size the bullet accordingly, cast from water dropped ww, lube w/ something like CarnubaRed, you can run those to 1400fps w/o leading & no gc.