Throat don't like some bullets?

[JohnH]

Is that accurate? Have you experienced this? I pulled my hair out trying to get my 357 Maximum to shoot an LBT 180 grain knock off. Boolit has a wide meplat, a kind of ojival wad cutter. Dang thing refused to shoot them well. The same with the Lee 358-158-RF, their .357 Cowboy bullet. Rifle wouldn't shoot the design consistantly. Switched to the RCBS 35-200 and the rifel shoots like a house afire.

My 375 JDJ refuses to shoot my Lee 379-250-RF with anything. 3" is good. Same bullet from my NEF 38-55 will shoot 10 shot ragged holes at 50 yards. However, the JDJ will put one on the other of the Lyman 379449 with Pyrodex, AA#9, and a duplex load of 4895 and WC860 (tried duplexing with 4198 to no good end, swithched to 2 grains 4895 and it shoots really decent)

So what gives? The full length groove diameter, ojival wad cutters are wupposed to be the best thing since sliced bread in cast boolits, but I've got two rifles won't shoot them for beans. Any ideas as to what gives?

[44man]

Have you checked the twist difference between rifles?

[Bass Ackward]

John,

There is a good chance that you have worn a nice, smooth surfaced taper in the 38-55 as opposed to the 375. Since a cast bullet is weaker than other bullets, you want to get it moving fairly easily without tipping. A one diameter probably encounters resistance before another design would and will increase pressure accordingly. So you might just be comparing apples to oranges here even though you are in the same bore diameter.

New throats wear fairly quickly until the tool marks are gone and this is why it is tough to fit a mold. Take my 35 Whelen. From the base of my neck my first weight was 210 grains as I was in a hurry to get started. Two months later I owned a 220 which is a paper weight now too. Then she really shifted and I jumped to a 250. Now it has stabilized and the 250 works even better than it did. Or to look at it another way, you may do better with slower powders until things clean up. I seem to remember reading just a couple of weeks ago how this gun had .... some issues down the pipe. It may not have cleaned up just yet. If something else is working in the mean time shoot it!

[JohnH]

44Man, the 38-55 is 1:18, the JDJ is 1:12

BA, I've decided to shoot and quit thinking for a while. Your post confirms that is appropriate. I shot ten rounds toady using a duples of 2 grains 4895 and 53 grains WC860. On returning to the house I was looking at the muzzle, a faint gray wash. Took my machinist magnifiers and took a close look and found a radial tool mark about every 5/16" to 3/8" on the lands. I can feel it on one land with the tip of a screwdriver for eyeglasses, I can see it on six of eight. Gun at present has about 200 rounds through it. The groups have tightened up noticably from new unfired three weeks back. So I'm just gonna shoot it for a while and watch what happens to these tool marks. I've two exposed lube grooves and have considered filing one with 600 grit lapping compound for about 10 rounds, but don't want to over do it. Comments?

[slughammer]

Is that accurate? Have you experienced this? I pulled my hair out trying to get my 357 Maximum to shoot an LBT 180 grain knock off. Boolit has a wide meplat, a kind of ojival wad cutter. Dang thing refused to shoot them well. The same with the Lee 358-158-RF, their .357 Cowboy bullet. Rifle wouldn't shoot the design consistantly. Switched to the RCBS 35-200 and the rifel shoots like a house afire.


Those are (3) different weight boolits. Your gun likes the 200's.

[Bass Ackward]

The groups have tightened up noticably from new unfired three weeks back. So I'm just gonna shoot it for a while and watch what happens to these tool marks. I've two exposed lube grooves and have considered filing one with 600 grit lapping compound for about 10 rounds, but don't want to over do it. Comments?


John,

You have gone this long with it. I would simply shoot some jacketed (cheap bulk stuff) through it to knock off the rough edges. How many? Until the grey wash goes away when you go back to cast.



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