Author Topic: Plain Base or Gas Check ?? (Read 951 times)

pistolfan · « **on:** February 12, 2005, 11:58:13 AM »

Hey Guys. I was wondering if I can use plain base bullets for my shooting needs. I shoot 41 mag, 44 mag, 357max, 38-55 and 7-30 waters all in a pistol except the 38-55. I buy gas check moulds right now but every once and awhile a nice plain base comes up but I don't get it because I'm afraid of the leading problem. I use mostly 50-50 ww/lino as of now or straight ww. I guess I need to know how fast I can push plain base bullets before leading enters the picture. I usually load in the mid range area for the above calibers. I don't have a chrono. so I'm guessing I'm usually around 1400fps - 1600fps most of the time. Thanks for any input. Peter aka pistolfan

Haywire Haywood · « **Reply #1 on:** February 12, 2005, 01:51:12 PM »

14-1600 is probably a little too fast for plain based bullets. The rule of thumb I've gone by is anything over 1200 probably needs a check.

Ian

Flash · « **Reply #2 on:** February 13, 2005, 03:35:53 AM »

Haywood is right. I shoot plain base from 700 to around 1,200 fps without checks and learned the hard way.

Leftoverdj · « **Reply #3 on:** February 13, 2005, 05:57:38 PM »

1200 fps is pretty much the limit in pistols and microgroove barrels. You can add a bit for rifle barrels with conventional rifling. 1400 in my experience. Some say 1600.

Yodar · « **Reply #4 on:** February 24, 2005, 07:50:52 AM »

There is a wide range of opinion on this subject. I got out my copy of the Lyman Cast Bullet Handbook (circa 1973), turned to page 239 and found the following:

"Plain Base Design: Bullets of this design are usually restricted to approximately 1600 F.P.S."

"Gas Check Design: The gas check fits snugly to the bullet base and allows for a higher velocity of approximately 2200 F.P.S. to be reached."

Take it for what it is worth. I am sure there are a lot of variables like condition of the bore, alloy used, lube used, temperature, etc. that are hard to quantify that may or may not cause leading.

Kingfish · « **Reply #5 on:** February 24, 2005, 09:34:51 AM »

I cast a plain base Lyman #429421 Keith type 245grn bullet that I shoot out of my Marlin 1894 at 1800fps without any leading but I'm using a 17 1/2 BHN melt and the Marlin has ballard rifling with a 1 in 38 twist. Also, rifle had to be well broken in with much shooting to keep from leading up with hard cast bullets.

Bill

buck1 · « **Reply #6 on:** February 24, 2005, 05:33:35 PM »

a harder tighter bullet can be pushed at higher pressures than a softer looser one ,with or with out a gas check. Of course a gas check will allow more push than with out one. Pressure is the factor to be watched more than speed, but Gas Checks are a plus in several ways......buck

pistolfan · « **Reply #7 on:** February 25, 2005, 04:20:09 AM »

Thanks for all the inputs, seems the more you shoot cast bullets the more you forget. I forgot to look in the Lyman Cast Bullet Handbook, I've got the book by Col. Harris also on cast bullets the one that is a compilation of articles from American Rifleman I think. I guess it comes down to trying it in the different calibers and seeing how much steam I can work up to. Can never have to many moulds can one. Again thanks guys you where a help. Peter aka pistolfan

w30wcf · « **Reply #8 on:** February 26, 2005, 09:08:12 AM »

In my experience, it depends on the powder one uses and the bullet hardness. I like wheelweights and can easily get to 1,600 f.p.s. with slower burning powders with good accuracy and no leading.

On average, faster powders like Unique will typically get you to 1,200 f.p.s. or so with no leading but you are pushing it beyond that.

w30wcf