[Deadeye]

Could someone please explain why one style/type of bullet gets a GC and another of the same weight/dia. does not? I've heard/read several differing explainations. Just wondering if someone with more smarts than me could "splane it real simple like"? I've also read that the GC can come off as the bullet exits the muzzle causing eratic accuracy. If so can you just leave them off?

Thanks Deadeye

 

[Wizard]

I'm glad you asked that question, Deadeye. I too, would like to hear the answer.....

 

[Wuchak]

The gascheck's sole purpose in life is to prevent the barrel leading that occurs when you push a bullet cast with a soft alloy or pure lead to magnum velocities. If you use a harder alloy you don't need the gascheck and you can switch to a design that doesn't require it. If you leave the gas check off a design that requires it accuracy will probably suffer and you might get leading even with a harder alloy since the base of the bullet will not fill the case diameter and will provide an extension of lead that can be completely surrounded by flame. I have not heard of the GC coming off and affecting accuracy. Some of the gas check designs are intended for long rang silhouette shooting where accuracy is critical.


If want to avoid the gascheck you just match your alloy with your velocity. The Missouri Bullet Company is one of the few that actually tell you the Brinell hardness of their cast bullets so you can match the hardness to the intended velocity. They offer the same .358 diameter SWC at a Brinell of 12 for lower velocity target shooting and 18 for magnum velocity use. The higher hardness rating is a little more expensive due to the more expensive alloy. They could have offered the Brinell 12 in a gas checked design for magnum use.

They have a good explanation of matching hardness to velocity. http://www.missouribullet.com/technical.html

 

[Deadeye]

Wow! Thank you Wuchak, thats great info. I've swithed to Jacketed Bullets for my hot loads any way, but its allways good to stay "Edgeamakated" on these things. Now for my next question (drum roll please!). I've heard that if you fire a copper plated/jacketed bullet after your lead rds. the copper will push the leading right out of the barrel. I know that leading will affect accuracy, but at least that sounds like a good way to clear it out before clean-up.

Thanks again Deadeye

 

[Iowegan]

Wuchak, You're on the right track ... just a bit more clarification. Yes, the sole purpose of a gas check is to prevent lead fouling which goes hand in hand with accuracy. Lead fouling is not a product of velocity but rather of chamber pressure. If you use a fast burning powder such as Bullseye, you can actually achieve very high chamber pressure yet not very high velocities. On the opposite end when using a slow burning powder such as W-296/H-110, you can generate very high velocities yet keep chamber pressures fairly low.

I'm not sure where missouribullet got their information but I did get a chuckle. The process of lead expanding under pressure is called "obturation", not obduration (they must spell different in Missouri). The industry standard formula is BHN=PSI/1440. BHN = CUPS/(1422*.90) was used when pressure was stated in CUP instead of PSI.

OK, back to gas checks. If you do as Wuchak suggested and match the lead hardness to the chamber pressure, you may be able to get by without using a gas check. Either a harder or softer alloy will cause lead fouling if it doesn't match chamber pressure. If you don't know the lead hardness (measured with a lead hardness tester calibrated on the Brinell scale) and the actual chamber pressure, your best bet is to use a gas check. Also, any time you shoot lead bullets in a rifle, a gas check is highly recommended.

A gas check is a "coin" shaped piece copper or guilding metal that is typically a few thousandths shy of bore diameter and is pressed into the base of the bullet. When a round is fired, the copper wafer will not melt and will keep hot expanding gasses from escaping around the circumference of the bullet (called blow-by). If blow-by is allowed to happen (no gas check), hot gasses will actually vaporize the circumference of the bullet and leave lead residue behind as the bullet travels down the bore. The next bullet fired must fight the previous fouling and will add even more. After a few rounds, lead build-up has fouled the bore to a point where accuracy will be poor and cleaning will be quite a chore.

Deadeye, With mild fouling, jacketed bullets will indeed clean out the bore, however in a badly fouled bore, you're dealing with a different situation. The lead won't compress so as a jacketed bullet passes, the barrel can develop a bulge. It's not worth the risk or ruining a barrel ... just clean the old fashioned way with solvent and a bore brush.

 

[Deadeye]

Thanks Iowegan! "presheate it" I generally just clean my bore with a too small brush with a piece of copper "Chore Boy" wraped around it. It takes the lead out toot sweet. By the way I keep seeing references to your "IBOK" or something like. At the risk of sounding "Iggernant". What the hells an IBOK anywho!

Thanks Deadeye

P.S. Don't be too hard on them boys from Missouri, any state that spawned the likes of "a good ole Rebel" like Jesse James can't be all bad!!!

 

[454PB]

Gas checks are a wonderful way to avoid leading when firing cast bullets. However, they have risen in cost to about 3 cents a piece for .44/.45 caliber. In addition, they aren't needed until certain pressure/velocity parameters have been exceeded.

Guys like me that shoot cast bullets in a revolver at 55K and 1700 fps. HAVE to use them. There is no combination of alloy hardness that will reliably protect the base of a cast bullet pressed to those extremes.

If your requirements are less, you would be wasting money and time adding a gas check to your cast bullet.

 

[OldCowHand]

Don't be too hard on them boys from Missouri, any state that spawned the likes of "a good ole Rebel" like Jesse James can't be all bad!!!

[BEGIN THREAD DRIFT]
Gawd help us -- he was a relative of ours, and not one of the nearest and dearest. He managed to buy his way into some food and shelter from time to time by divvying the proceeds of his, um, endeavors with some of the other cousins near and far, but my great-grandmother wasn't having any of that robbing-the-rich-to-give-to-the-poor nonsense. She viewed him as just a thief and a waste of, well, everything. Not that she was opinionated!

Several of my generation were real interested in genealogy for a while, until we discovered our several-times-removed cousin Jesse. We kinda quit shakin' the family tree at that point, for fear of what else might shake out ...
[WE NOW RETURN YOU TO YOUR REGULARLY-SCHEDULED THREAD]

 

[Iowegan]

Deadeye, I wrote two "how to" books on Rugers. One primarily for GP-100s and other Ruger DA revolvers with a similar design, the other is for all models of the Ruger 22 semi-auto pistol called the MK Series. Iowegan's Book of Knowledge = IBOK. Up 'till recently, I was emailing them out on request but a couple of bozos ruined it by publishing my email address on several other forums. I now get 300-500 emails every day from spammers. Besides, I got several very rude and demanding emails from some of our members because their email accounts wouldn't handle large files or they had their spam filters set to block .... like it was my fault. I decided a few days ago .... enough was enough and quit responding to IBOK requests.

454PB, I don't cast bullets any more but when I did, it was always a challenge to get the hardness right for the intended loads. In fact I cast several different hardness bullets with the same moulds to try to find the optimum hardness. Later I bought a good Brinell tester (not the cheap Lee kit) and learned a lot more about alloys. Although I really hated casting, I did get excellent results from my lead bullets.

Mean time, I had several thousand bullets in several weights and calibers already cast that I didn't want to melt down again so I pressed gas checks in them. It didn't seem to make much difference if the lead was a little too soft or too hard ... with the gas check, they shot very accurate and didn't foul. I never loaded any lead bullets at your pressures but I'm sure you're right about even the hardest lead alloys fouling without a gas check.

If you don't cast, it's very difficult to find bullets in the hardness range you need. Most companies cast bullets are way too hard for midrange or light load use. The more popular cast bullets tend to run in the 20-25 BHN range when what you really want is in the 10-12 BHN range. The only solutions are to goose up your loads, install gas checks, or get bad fouling and accuracy .... so my use of lead bullets has changed considerably since I quit casting. I use Hornady swaged bullets for 38 HBWCs and 45 Colt factory equivalent loads (very soft, BHN 10). Other than those, I usually just load jacketed bullets. By the time you buy gas checked lead bullets, you might as well spend the same money for a decent jacketed bullet.

 

[Deadeye]

Wow again!!! and thanks again Great info guys!!! I plan to cast several bullets as I have 2 5gal buckets full of wheel weights. Does anybody know the average BHN of WW? I have some tin solder I can add to the mix if needed.

P.S. I'm going to Ignore what OldCowHand said and not start any of that political crap again.

 

[Wuchak]

Thanks to Iowegan and others who chimed in after me for the clarifications. Good to learn something new.

I think the best way to remove leading is with a Lewis Lead removal kit.

http://www.missouribullet.com/shop/details.php?prodId=71&category=7

 

[Iowegan]

Deadeye, There's a ton of information about bullet casting on the Internet. Just Google a topic such as "bullet hardness" or "lead bullet alloy" and you'll get a lot of web sites to choose from.

Wuchak, Looks like you found the magic tool. I've not seen any other system that removes lead faster or easier than the Lewis Lead Remover. A "must have" investment if you are going to shoot lead bullets.

 

[Deadeye]

10-4 Iowegan & Thanks again!!!

 

[454PB]

If you want to learn more about bullet casting and other home made projectiles (swaged, jacketed swaged, paper patched, etc.) come on over here and look around:
http://www.castboolits.gunloads.com/

These are some of the most knowledgable and helpful guys you'll ever find.

As a side note, I did an experiment a while back with cast bullets and it failed. The bore of my Ruger RH .44 magnum was completely coated with lead, so I fired a couple of mildly loaded gas checked bullets through it. All visible leading was removed by the gas checks.

This has to be done carefully and with mildly loaded rounds. Heavy leading is technically a bore obstruction.