Pb .357s and gas checks

[Airweight38]

Conventional knowledge has left me with the impression that .357s and .44 Mags normally require gas checks, as they are over 1000fps and will at the very least leave a lot of lead fouling if they aren't checked.

Last night, I read in my Lee mold instructions that if rounds are kept under 1400fps, they typically do not require gas checks, and because of this, most handgun rounds do not require them.

I recently purchased a mold for .358 caliber 158gr FRN slugs. I was originally thinking about not using these in my .357 because they do not have a recess for gas checks, but in light of this info, I am reconsidering. Any thoughts? Would I have a lot of leading or other problems if I run light-moderate .357 loads without a gas check? My Lee reloading data is showing light loads around 1050 or 1100fps. (IIRC).

[Cherokee]

I do not have gas check bullets for 45, 44, 41 and have loads that exceed 1000 fps all the time, no leading. Have 358156 GC that I quit using in my 357 Mag because the GC was not necessary IMO. Bullet fit and alloy make a big difference in leading. Most commercial "hard" cast are far harder than needed. Soft alloys work best for light to medium loads, and just fine in some of my hot loads.

[Larry Gibson]

With hard cast bullets no GC is needed up through 1400 fps as mentioned. However, if you want to use a much softer alloy for expansion (many of us do), especially with HP'd bullets then the GC is necessary to prevent leading. I drive quite soft 358156 HPs cast of very, very soft alloy (recovered .22LR alloy) to 1400+ fps out of a 6" Ruger Security Six without leading and they expand very well. I do the same with a 429244 out of my .44 Magnum.

If you ever get a rifle in .357 and want it to shoot accurately at higher than 1400 +/- fps then the GC bullet is also needed.

Larry Gibson

[Down South]

I've used a Lee 358 158 many times in my .38 and 357 Magnum without any leading problems. Actually I don't have any GC moulds for the .38/357. And I was pushing those boolits close to max with the powders that I was using.

[Blammer]

I shoot a plain base 358 boolit at about 1900 fps, no leading.

I also shoot a 250gr boolit in my 44 mag at 1350, plain base, no leading.

[BoolitSmith]

I use the Lee 158gr RFN, ACWW over 6 grs of Bullseye in my 4'' Security Six and my Marlin 1894c.Not sure what the velocity is,but for sure over 1000 fps.These are plain base boolits and I have never had any leading in either gun.

[Hurricane]

Any bullet, even hard ones, will lead if they are undersize. Size your bullets at least .001 over barrel size and the bullet will fill the barrel completely. Lead is very soft compared to steel and the bullet will have no trouble sizing a little in the barrel. When you have a good bullet fit, most or all of your leading problems will be over. Elmer Keith never used gas checks in his magnum revolvers and did not have leading problems.

[Larry Gibson]

...... Elmer Keith never used gas checks in his magnum revolvers and did not have leading problems.

Not quite correct. Reading his writings you will find he had lots of leading unless he cast them hard.

Larry Gibson

[GrizzLeeBear]

I shoot lots of PB boolits in the 357 as well. I use the 105 gr. Lee SWC for target loads around 900 fps and the Lee 158 gr. RF at 1050 - 1100 fps for a general purpose load. For real magnum loads I use the gas checked 358156 (Lyman 155 gr. SWC) at 1200+ fps. In my experience the 358156 likes to go fast and I don't shoot anywhere near as many full power loads as I do the lighter loads, which keeps down the number of GC's I need to buy. If I was forced to choose just one load for the .357 I could live happily with the Lee 158 RF at 1100 fps (but where's the fun in that).

[medicstimpy]

My friend and I shoot non-GC lead out of .357 all the time and we load them really HOT. They are the Lee TL 158gr SWC's and I also use a RCBS 180gr Shilouette. He uses Lee Mule SNot and I use Lars's Red Carnuba. Again, no leading from water quenched pure WW's.

For 44, I run them at both mild target loads with Titegroup and HOT with H110. RCBS 245gr SWC with Red Carnuba. Again, no lead, even with the max H110 load.

[runfiverun]

i only have one g/c mold for my pistol cartridges.
the main reason i got it is i needed more lube groove area then the mold i was using
in a 24" bbl rifle.
and the n.i.b. [cheap] mold i found. used a g/c.
i do use this same boolit in my super-mag and feel that the g/c is needed for the pressures/velocity i run it at.
especially with the softer alloys.

[Bret4207]

Not quite correct. Reading his writings you will find he had lots of leading unless he cast them hard.

Larry Gibson

Lets be clear on that. Keith used lead/tin alloys. Pure lead, pure tin. Not WW alloy with antimony and arsenic and the other trace elements. IMO WW alloy can do most of what we need with HT and WQ. Hard in Keiths terms are different than what we speak of.

[Dave B]

I shoot Lee 125 gr made with wheel weights at about 1500fps in a Marlin rifle with no GCs. I shoot them sized to .358. I tumble lube them before I size them and again after with thinned lube. No problems.

[Larry Gibson]

Bret4207

Yes, let us indeed be clear on that; "cast them hard" are Keiths words not mine. He also used many other cast bullets than with just lead/tin alloys. As I said; "read his writings" as my answer was about "leading". Keith got it quite a bit with different bullets he tested. he always recommended the lead/tin alloy though. He also was very unhappy with the leading the Remington factory loads produced in .41 and .44 and often mentioned the horrible leading with "Lubaloy" in the .357.

Perhaps I didn't explain fully so you could understand. Hurricane stated; "Elmer Keith never used gas checks in his magnum revolvers and did not have leading problems." I should have said something like "Keith had leading problems with cast and commercial bullets unless he cast them himself (or had others cast them) of lead/tin alloy. If you read his writings you will find that."

Larry Gibson

[mainiac]

Only one thing that i can add, I have 7 different molds for the .357, and when i want the most accuracy, it is with the 358156 pushed along at max speed. None of the other molds that i have can match it for accuracy.BTW it is the only .357 mold that i use that takes a gas check.

[Bret4207]

Bret4207

Yes, let us indeed be clear on that; "cast them hard" are Keiths words not mine. He also used many other cast bullets than with just lead/tin alloys. As I said; "read his writings" as my answer was about "leading". Keith got it quite a bit with different bullets he tested. he always recommended the lead/tin alloy though. He also was very unhappy with the leading the Remington factory loads produced in .41 and .44 and often mentioned the horrible leading with "Lubaloy" in the .357.

Perhaps I didn't explain fully so you could understand. Hurricane stated; "Elmer Keith never used gas checks in his magnum revolvers and did not have leading problems." I should have said something like "Keith had leading problems with cast and commercial bullets unless he cast them himself (or had others cast them) of lead/tin alloy. If you read his writings you will find that."

Larry Gibson

I'm not arguing with the point you made Larry. I have every book Keith wrote except "Safari" and the "Gun Notes" books too. I know about when he had to go to 1-10 lead/tin. And I agree he didn't have much use for the factory stuff. All I'm pointing out is Keith stuck almost exclusively to lead/tin and WW alloy is different. That's all.

Also, if I recall correctly Keith did try GC boolits, just never found them to be necessary in his loads. "A mistake" is what he called them.

[missionary5155]

Good morning
I will add Lyman 358429. Drops around 173 SWC with a soft mix. Has a nice THICK base that withstands pressure. I use this boolit in my 3.5" S&W model 19 with 7 grains Unique.. It is accurate and penetrates. It smacks with athority. I tumble lube with LLA and then give it a smear of 50/50 Beeswax and axle grease. No leading. NO GC. To me a far superior boolit.
Cast with WW it can get pushed faster with 2400 (13 grains) . My 6" Dan Wesson shoots tiny little 100 groups of 1.5" off a bench. My 10 inch barrel does even better. Again NO GC. This load leaves a "Dust" of lead particles. I shoot 50-100 and run a brush through the barrel.
So there is another option... Give me a heavier boolit any day.
God Bless You !

[Larry Gibson]

Bret4207

I wasn't arguing either and I think we are agreeing, just in different ways. Keith did stick to lead/tin alloy for his own bullets but he did a lot of testing, not only with his own bullets but with others. It was mostly the others where he had problems with leading. I was simply pointing out that Keith did have problems with leading. However you are correct also in that he didn't have much problems with his own. We just approached this from two different angles and neither of us got our point across correctly, eh?

Larry Gibson

[Black Jaque Janaviac]

I'm another shooter who has chronied velocities well past 1400 fps and got acceptable accuracy w/o gas checks. In fact I've never used them, I figure, if I gotta rely on someone else to make a copper check for me I might as well have him make the entire bullet.

Not that GC won't solve the problems that they are intended to. I just believe that many of those problems can be solved in other ways. GC's can help maintain base erosion caused by gas blowby. However, this can also be prevented by eliminating the blowby to begin with for which there are lots of different possibilities.

Ironically, sometimes leading caused by blowby can be eliminated by actually increasing the powder charge and velocity. For example, I've used bullets from that same Lee 158 gr RF mold you've got. When I cast with WW alloy and load them with .38 spl loads I get leading. However, with the same bullet loaded over a moderate .357 charge the leading is eliminated. I suspect this is because the bullet obturates more.

[Bret4207]

Bret4207

I wasn't arguing either and I think we are agreeing, just in different ways. Keith did stick to lead/tin alloy for his own bullets but he did a lot of testing, not only with his own bullets but with others. It was mostly the others where he had problems with leading. I was simply pointing out that Keith did have problems with leading. However you are correct also in that he didn't have much problems with his own. We just approached this from two different angles and neither of us got our point across correctly, eh?

Larry Gibson

Okie dokie! We're on the same page.:cbpour:

[azrednek]

OK I'll kick off another argument!! Lets keep it friendly though. Gas checked bullets are more accurate. Yes, no, why?? My Lyman 45266 (I think, if I'm wrong on the number I'll edit it correctly) Drops a tapered bottom. Don't know if it were meant for a gas check but a gas check fits. Same load, same guns the gas checked boolits simply prints smaller clusters.

http://i2.photobucket.com/albums/y17/dnisbet/AAAAA-45bullet.jpg

This is the only picture in my files. I have since got a mold in better condition. You are correct if you assume the old rusted mold would drop inaccurate slugs. I got a decent mold with no pits, did the same comparison and the gas checked boolit shot more accurately. I use the boolit both with and without shoes in 45ACP, AR and LC. The guns it is used in, not all mine includes sons and friends. AMT Hardballer, 2 Roltintonfields (A GI 45 assembled with Colt, Remington, Rock Island & Springfield surplus parts) Star Firestar, 2 Brazilian surplus S&W 1917, S&W 25-2 and Rossi lever rifle. I recently got a Ruger 45 Convertible for Christmas but haven't had a chance to compare.

All guns, same load which is usually 4.0 Bullseye the gas checked boolit always prints a tighter group even though the load is mild. I currently don't have a working crony so I can't attest to any difference in velocity.

Now to argue against myself!! A Lee 44 cal 240 gas checked boolit. Shooting mild plinking loads, using he same powder bushing dropping a 4.0 charge of Bullseye. With unsized tumble lubed boolits and TL'd gas checked going though a .431 sizer that rarely if ever touches lead. I see no difference between the two except in a Rossi 44 lever rifle, the gas checked boolit shoots much tighter groups. In a S&W 29-2 and Ruger Super Blackhawk I can't see any difference on paper.

Most my shooting and casting is with double end or button nosed full wad cutters. I cast, tumble lube and shoot them. If I'm going to take the time and expense to get a hard, good flowing alloy, size and hard lube. I figure I might as well use a gas check to get the best possible results.

[Bret4207]

Well, I have yet to see a boolit designed for a GC shoot MORE accurately without one. That tapered base sure looks like it was meant for a GC. As to whether a GC boolit will be more accurate than a PB- it depends. It depends on the gun, load, boolit design and the hundred variables that can crop up.

I can give you my opinion, which in my opinion is about worthless- In handguns I think a PB can be as accurate as a GC given the same care in casting, loading, etc up to a certain speed which is dependent on a mess of variables. In rifles I think above 1200fps or so (depends on the guns again) the GC really comes into play and makes a more accurate cartridge. I think there is a pressure point or threshold that handguns only rarely come up against that rifles generally do. Where that point lays is completely different between different guns, boolits and loads. Little pipsqueaks like the 32 S+W you would never think would benefit from a GC, but I have, or rather had, a 32 S+W rifle that did much better with a GC boolit than a PB. Why? Who knows! Maybe if I had owned a PB design that fit better it never would have made a difference, but using the GC was sure easier, and there's the rub. IMO the GC makes it EASIER to get good grouping around and above that threshold area or where the boolit fit isn't quite right. It won't fix everything, but it can make things easier.

[Black Jaque Janaviac]

My guess would be that the gas check preserves the integrity of the bullet base. The tapered base looks like it makes for a rather thin rear driving band. If you think of that rear band as a "dam" holding back the pressurized gases it doesn't take much to understand that a thin dam will "break" easier. Or if not break it can warp or deform.

If the pressures at exist are high enough, when one part of a deformed base exits the muzzle before the rest, the gas escapes to one side. So just at the point where the bullet leaves the muzzle it gets hit with some lateral force.

The harder copper check keeps the bullet base square to the bore axis. When the bullet leaves the gases break evenly around the bullet.

Just my hypothesis as to what causes the gc to be more accurate in your situation.

[Bret4207]

My guess would be that the gas check preserves the integrity of the bullet base. The tapered base looks like it makes for a rather thin rear driving band. If you think of that rear band as a "dam" holding back the pressurized gases it doesn't take much to understand that a thin dam will "break" easier. Or if not break it can warp or deform.

If the pressures at exist are high enough, when one part of a deformed base exits the muzzle before the rest, the gas escapes to one side. So just at the point where the bullet leaves the muzzle it gets hit with some lateral force.

The harder copper check keeps the bullet base square to the bore axis. When the bullet leaves the gases break evenly around the bullet.

Just my hypothesis as to what causes the gc to be more accurate in your situation.

I think you're right. The part I made bold applies to PB and GC. Without a near perfect base you'll have problems. That's why GC designs shot without the GC seem to give you problems. The harder you push them, or a bevel base design, the more chances for inaccuracy. Some guns handle some designs w/o the GC pretty well. To me that's a sign of good boolit fit and a balanced load, not that the GC is unneeded. Pop those suckers outta the muzzle a little faster and soon you'll have patterns rather than groups.

[MakeMineA10mm]

I started a thread about Gas Checks that got a lot of good posts. I think it might be in the Moulds Maintenance and Design forum?

I've also kept my eyes open to the topic, and going through some old magazines, I found an American Handgunner from 1990 that had a reloading column on Gas Checks!

The author talked about GC bullets being unquestionably more accurate, because Silohuette shooters used them almost exclusively. He said they did so because of the better accuracy. I hadn't heard this before, because I was always under the impression that their purpose was to reduce leading... He also said he had spoken with four ballisticians from three different powder/mould companies about the effect of GCs and moulds with them and without them. Naturally, he got nearly 4 different answers to each of his questions, and they all had some sort of "proof" backing up their individual angles.

His assertions left me scratching my head pretty good, because I'd recently read all the posts on my GC thread which said that Plain Base boolits shoot more accurately, as long as velocities (and hence pressures) are kept reasonable for the hardness of the alloy you are using...

Also, in my experience, I've found no significant accuracy difference between PB and GC boolits. (Of course, I'm not a great long range shot with a handgun either. - At least I'm not in the league of Silohuette shooters.) I've also found nearly ZERO leading with all of my cast boolit shooting (both plain base and GC). I basically use straight WW to WW+2% tin, and 95% of my loadings are around 1200fps or less.

[Bret4207]

MM10- You know what they say about opinions! Talk to the Schutzen boys about how inaccurate those PB designs are. There are some records made with plain base boolits that would be hard to beat today even with GC's. I stand by my opinion that GC's make things easier to a point and then become needed due to pressure/velocity. Accuracy depends on fit until pressure makes the GC needed, and then the GC has to be square to the base and of proper size to work right- fit you see.

[Echo]

Did I miss it somewhere? The boolits in the original post were bevel-based, which makes them much easier to insert and seat in the reloading process, but is NOT there for GC seating. The fact that the GC's seated, and provided better accuracy, clues me that the alloy in use was fairly soft, appropriate for the .45's mentioned. By and large, BB boolits are less accurate than flat base, or GC. As has been mentioned, the base of the boolit is the rudder by which the boolit is steered - a previous thread mentioned boolit exit from the barrel and uniform gas escape.

Not to hijack the thread - I never fired on the old Ada Zilker range in Texas, but I understand there were some jokers who shot there. Woe be to the shooter who came with only exactly enough ammo for the match! If they had to fire an alibi string, they would have to borrow some ammo to complete the match, and the ammo they received might have boolits whose base was cut at an angle and was charged w/BP! The round would go down range, but exactly where was always open for speculation, since a dense cloud hung over and in front of the firing point and there were no holes on the target...

[Bret4207]

Ed, if that's a bevel base it's a HUGE bevel. I seem to recall seeing a mould with a GC "shank" that looked similar to that in Handloaders Digest some years back. Of course, my rememberer isn't the best anymore, but look how long that bevel is! If it is a BB it's a horrid design.

[vanilla_gorilla]

I've gone to 1400 fps with purchased .358 bullets and 1300 fps with home-cast WW .429 boolits. Never fired a GC bullet in my life, and the only leading I've experienced has been from under pressure loads.