Gas check on powder coated boolits?
- Thread starter Azul69
- Start date
I assume from the word "pure" you mean Pb as in lead and not PB as in plain base, nor PB as in patched bullet, nor PB the IMR powder. Lots of PB initials in shooting. I even know shooters who take PB sandwiches with them for lunch on a long match day.
Lots of alloy cast bullets have gas check bases molded in. Some argue the harder alloys need them more than soft alloys or pure lead because a hard bullet is not so easily upset by pressure back up to groove diameter after passing through a bore constriction as soft lead is, thereby leaving gaps for gas cutting to occur. A number of example of soft bullets sealing the bore well exist. Indeed, Elmer Keith developed the 44 Magnum predecessor loads for his Mode 21 S&Ws with 20:1 and later 16:1 lead:tin alloy, both of which are soft by hard cast standards. About BHN 10-12.
As for the coated bullets, the coating fills grooves well and prevents gas bypass, so you wouldn't normally need a gas check with it. That would change with high enough pressure to strip the coating off. I don't know for sure what happens pushing coated bullets to rifle velocities, as I haven't done it. I also don't know how well powder coated rifle bullets shoot in general. You need good mass symmetry for accurate rifle bullets, and any unevenness in the powder coat would potentially throw it off.
Lots of alloy cast bullets have gas check bases molded in. Some argue the harder alloys need them more than soft alloys or pure lead because a hard bullet is not so easily upset by pressure back up to groove diameter after passing through a bore constriction as soft lead is, thereby leaving gaps for gas cutting to occur. A number of example of soft bullets sealing the bore well exist. Indeed, Elmer Keith developed the 44 Magnum predecessor loads for his Mode 21 S&Ws with 20:1 and later 16:1 lead:tin alloy, both of which are soft by hard cast standards. About BHN 10-12.
As for the coated bullets, the coating fills grooves well and prevents gas bypass, so you wouldn't normally need a gas check with it. That would change with high enough pressure to strip the coating off. I don't know for sure what happens pushing coated bullets to rifle velocities, as I haven't done it. I also don't know how well powder coated rifle bullets shoot in general. You need good mass symmetry for accurate rifle bullets, and any unevenness in the powder coat would potentially throw it off.
If you have a powder coated bullet and you have a desire to use a high temp burning powder, then you could apply a gas check to the bullet ( assuming it's got the correct profile to accept a gas check ) to prevent the smell of the high temp powder burning the powder coat polymer upon firing.
But most will tell you that putting a gas check on a powder coated round is generally " repetatively redundant " ;-) - you shouldn't want / need both.
General rules of thumb on gas-checks -
Pure lead castings - Rifle - yes - should have a gas check to prevent barrel leading.
Pistol - depends upon the barrel ( Glocks lead quicker than other barrels generally )
- depends upon the powder - H Titegroup burns hot and will give you more leading than H HP-38 which burns cooler and results in less leading
- depends upon the caliber - magnum calibers with more powder result in more leading - recommend gas checks on these. But .40 caliber or less typically don't need gas checks, indeed casting molds with gas check creases for them are hard to come by. Best bet on .40 and below is to alloy your lead with some tin or even some scrap solder will do it and harden the cast rounds by quenching them in water as they come out of the molds. I fire both powder coated and lubed .40 and haven't yet come across a bullet mold in .40 that has a gas check crease.
One warning note on powder coating - do NOT skip putting your powder coated bullets through a sizing die before loading as a cast round that chambers right by itself will be too large to chamber right once powder coated unless you size it again. In semi auto this gives you an extremely hard jam to clear.
But most will tell you that putting a gas check on a powder coated round is generally " repetatively redundant " ;-) - you shouldn't want / need both.
General rules of thumb on gas-checks -
Pure lead castings - Rifle - yes - should have a gas check to prevent barrel leading.
Pistol - depends upon the barrel ( Glocks lead quicker than other barrels generally )
- depends upon the powder - H Titegroup burns hot and will give you more leading than H HP-38 which burns cooler and results in less leading
- depends upon the caliber - magnum calibers with more powder result in more leading - recommend gas checks on these. But .40 caliber or less typically don't need gas checks, indeed casting molds with gas check creases for them are hard to come by. Best bet on .40 and below is to alloy your lead with some tin or even some scrap solder will do it and harden the cast rounds by quenching them in water as they come out of the molds. I fire both powder coated and lubed .40 and haven't yet come across a bullet mold in .40 that has a gas check crease.
One warning note on powder coating - do NOT skip putting your powder coated bullets through a sizing die before loading as a cast round that chambers right by itself will be too large to chamber right once powder coated unless you size it again. In semi auto this gives you an extremely hard jam to clear.
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not at all unlike an entire web site full of cast boolit information.
http://castboolits.gunloads.com/
I have pushed lots of no gas check HF red PC coated bullets pretty hard with good results.
The 200 gr Lee shoots good at full power in my 357 Maximums.
I am doing ok with the 30 cal Lee 170 at up to 1800 fps. This one has been a little bit of a challenge as the PC makes the nose too big. I had to come up with a nose sizing setup to get the nose back down to 0.300". I am still working on improving the sizing setup to get the boolits as true and uniform as possible.
I recently built a 16" 357AR rifle (357 Max rimless for the AR-15 platform). I have a 200 gr PC coated plain base that does under 2 MOA out to 200 yards with a muzzle velocity of over 1950 fps.
With PC, go ahead and try your loads without gas checks. Most of the time they should work fine. Some boolit + gun + load combinations may do better with checks, but you wont know for sure unless you try it both ways.
If you are after top accuracy, you may want to watch out for dings on the bottom of the gas check shank.
The 200 gr Lee shoots good at full power in my 357 Maximums.
I am doing ok with the 30 cal Lee 170 at up to 1800 fps. This one has been a little bit of a challenge as the PC makes the nose too big. I had to come up with a nose sizing setup to get the nose back down to 0.300". I am still working on improving the sizing setup to get the boolits as true and uniform as possible.
I recently built a 16" 357AR rifle (357 Max rimless for the AR-15 platform). I have a 200 gr PC coated plain base that does under 2 MOA out to 200 yards with a muzzle velocity of over 1950 fps.
With PC, go ahead and try your loads without gas checks. Most of the time they should work fine. Some boolit + gun + load combinations may do better with checks, but you wont know for sure unless you try it both ways.
If you are after top accuracy, you may want to watch out for dings on the bottom of the gas check shank.
As it is always said, fit is king. If you have a good tight bullet and you aren't blasting magnum pressures, you can get away with shooting it without a gas check. And yes, powder coating helps a little, because it makes the bullet a little bigger and provides a little more seal, but keep in mind..... powder coating is only a thousandth of a inch of melted polyester (plastic) coating the bullet. It isn't going to prevent it from stripping the rifling if you blast it too hard and it won't keep the gas behind it like a gas check if you put enough oomph back there to blow by it. It's great stuff, but it's very very thin and the actual purpose of it is to make the bullet really slippery so that you won't need lube, and so I would use gas checks if you have em. I do gas check my PC bullets that are a gas check design, some before coating and some after, depending on the shank size and when the check fits the best.
Powder coating will allow you to use softer bullets than you could normally use, but it's mostly because it helps provide a little more diameter and a little tighter fit in the barrel. It won't replace a gas check for controlling gas that really wants to be in front of the bullet.
Good luck and happy shooting!!
Powder coating will allow you to use softer bullets than you could normally use, but it's mostly because it helps provide a little more diameter and a little tighter fit in the barrel. It won't replace a gas check for controlling gas that really wants to be in front of the bullet.
Good luck and happy shooting!!
armoredman
New member
I do gas check my 7.62x39mm cast powder coated boolits. It might be unnecessary, but I do it anyway.
I’ve coated 10,000 plus bullets and never have used a gas check. This includes cast bullets in .30-06 at 1,500 to 1,700 FPS and .460 S&W at 1,300 to 1,500 FPS. Going up to higher velocities in these cartridges and I’d probably start looking at gas checks. Most of my shooting is with 45 ACP, 38 Special and 9mm. Gas checks would offer little to no benefit for me in these calibers and would just be an additional cost of money and time.
armoredman
New member
Unclenick, it's just a reference to the best cast bullet website, castboolits.gunloads.com, that's all.
Back years ago when I worked the 12 hr. night shift during our slack time we could use the company computers at our station to access the internet. Of course anything gun related that had certain words in it was blocked by the company software. However, Boolits instead of Bullets was not one of the them so I could enjoy browsing the Cast Boolits website when nights were really slow.