gas check question

[mnhntr]

I am a new reloader and have only loaded 400 rds of 38/357. All the rounds were the same bullets (sierra 140gr JHC) and two powders. I am looking at loading some lead non-jacketed rounds for USPSA matches and was wondering if I need gas checks or not? And is there anything i need to be aware of between jacketed and non-jacketed bullets besides the loading data? Is there any secrets i need to know? And what about the swagged cast bullets?

[snuffy]

gas check question
I am a new reloader and have only loaded 400 rds of 38/357. All the rounds were the same bullets (sierra 140gr JHC) and two powders. I am looking at loading some lead non-jacketed rounds for USPSA matches and was wondering if I need gas checks or not? And is there anything i need to be aware of between jacketed and non-jacketed bullets besides the loading data? Is there any secrets i need to know? And what about the swagged cast bullets?

Lead bullets are either swaged, or cast, they can't be both. Swaged bullets are lead slugs that are cold formed in dies under tremendous pressure to the final shape and weight. Cast boolits are made by pouring molten lead into a mold, then removing after it has cooled.

Gas checks are thin copper discs that are pressed onto the bases of cast lead boolits, that are made to receive the gas check. They cannot be put on any boolit with a plain flat base. They are normally only used for hot magnum calibers, at magnum velocities.

Swaged lead bullets are normally very soft. They also have very little lubricant on the,. They are only capable of low velocity loads. Any use at higher velocities will result in severe leading of the bore.

[Sevens]

Does anyone have a source for gas checked bullets from their favorite caster?

I but lots of cast lead in 9/10/.357/.44/.45, but I don't see folks selling gas checked bullets often. The few times I see them is in bags of 50 or 100 at a gun show.

[kraigwy]

I have found some guns like gas checks, some dont. Even using gas check bullets.

I tried Lyman 358156 (a gas check bullet) in my Model 27 Smith. It shoots the same bullet with out the gas check then it does with I put the gas check on it.

If you have a gas check bullet, try it in your gun with and without the gas check and see which it shoots best.

[Magnum Wheel Man]

see if this link helps 7's...

http://www.midwayusa.com/Search/#gas...__1-2-4__2_16_

there are 3 pages of cast gas check bullets listed if the link works

https://secure25.securewebsession.co....com/order.htm

doesn't look like there is a gas check easily available for each caliber...

but back to the O.P. cast bullets are much harder, & will not lead your barrel the same way soft lead swagged bullets will, unless they are shot out of very hot loads

[hornady]

As with any Gun bullet combination its trial and error. A load that works great in my gun may stink in yours. One recommendation I would give, I too cast all my hand gun bullets, but I use different loads for gas checked or none checked bullets. There was a study done by Hand loader magazine. Where they believe gas checks increase pressure significantly more than previously thought. I have not tested this as of yet. But plan on testing two groups of 357 rounds, one group checked one unchecked with the same load on the chrony. I will post the results when I get them.

[mnhntr]

thanks i will buy the cast and try them

[mnhntr]

I ordered some Oregon Trail laser cast bullets. I guess I used the wrong word I meant to say knurled bullets instead of swagged, in my question. If anyone has any loads they would like to share with these 158gr LSWC and either tightgroup or A-5 powders, feel free.

[Unclenick]

Hornady,

That's a good experiment. If you have enough bullets, try to get a mean velocity for about 30 rounds of each. Most people shoot tests with much smaller numbers not realizing their statistical insignificance can fool you. It is an old statistician's rule of thumb that it takes about 30 samples to give you reasonable confidence that the mean (average) is close to the center of the bell curve. Higher velocity will indicate higher start pressure in the checked bullets. The slower the powder, the more difference that is likely to make.


Mnhntr,

If you get into shooting lead bullets with revolvers you will find there are a few things to watch out for that can make a big difference to how well they work out.

For one thing, the chamber throats in each cylinder need to be larger than the bore of the gun by at least half a thousandth of an inch, and up to a couple of thousandths bigger. Revolver accuracy smiths usually ream the chambers of a cylinder to SAAMI maximum dimensions as the first step in a revolver accuracy job. This is both to get the needed clearance and to ensure they are all the same. It is pretty common for them to be different. (I don't know how the makers manage that? I can only assume the chambers are not all reamed at the same tool station.) Cylindersmith.com offers a reaming service for about $40. Slugging your cylinder throats and bore with pure lead slugs then measuring the slugs with an OD thimble micrometer with 1/10,000 scale will tell you if you need to do this?

Another matter is that many revolver barrels are tightened into their frame threads so hard that a constriction occurs in the bore at the throat. Like a narrow cylinder throat, that constriction will narrow a lead bullet, which then is loose in the rest of the bore. That allows gas blowby which causes poor accuracy and deposits lead in the bore. You can correct a constriction either by fire lapping or by hand lapping.

Finally, a very rough bore can often promote leading and is harder to clean either lead or copper out of than a smooth bore is. Firelapping fixes that, too.

If your gun has alignment problems it can affect lead bullet accuracy more than it does jacketed bullets. The latter are strong enough to line themselves up without distorting or tilting in the bore, but lead bullets need to be started out right. Check that you cylinder timing is good and that the cylinder tends to lock up with its chambers centered in the bore. If they are much off to one side or the other, you need to get a gunsmith to correct it, unless you are up to doing it yourself?

[hornady]

Unclenick, It should not be a problem, as I cast my bullets with a 4 cavity Lyman mold. Thanks for the idea of 30 rounds test group.. I want to get everything the same. Other than the checks. As I said I cast all my bullets but from batch to batch there will be a variance in weight. So I will weigh and select bullets of the same weight, and match all other variables ,Cases, primer. and weigh all charges. Individually.. It may take me a couple days to get all this done. but I will post all pertinent information once I have it.

[Ozzieman]

I don’t shoot 357's but I use Penn's 44 cal and reliably push them to 1000 fps with out any leading. He makes his bullets in several hardness levels and they are very good bullets.
Personally I would stay under 1000 fps and not worry about gas checks.


http://www.pennbullets.com/38/38-caliber.html