I am shooting a 38 special 148 grain DEWC with 3.1 grains HP-38 out of a Taurus model 66. At 20 yard everything seems fine but at fifty yard several of the slugs hit the target board on their sides , indicating they are rolling or tumbling . What could be possible reasons for this . I dont have a chrono but the manuals suggest I should be getting about 800 ft/sec. out of this load . Any ideas?

I'd say you bullets are undersize. Push them through the cylinder throats, and make sure they are a tight fit there. It should take a bit of pressure to get them through, ideally a thousandth oversize. Check your barrel, as you probably have leading after that experience.

You didn't say how long your bbl. was but i doubt you are getting much over 700fps w/ a WC & 3.1gr HP38. If the groups are good @ 25yds I am thinking the vel. is just too low for 50yd shooting w/ your Taurus. Kick the load up to 4gr & see if your bullets settle down.

I'm with Waksupi,
Check you bullet diameter and slug your barrel to see if your bullets are undersized. I shoot 3.1 grains of HP38 or WW231 out of my model 52 Smith for Bullseye competition and it is deadly X-ring accurate at 50 yards with the bullets properly sized. They remain accurate at 75 yards, but haven't tested them at 100 yet. I use a H&G wadcutter that I lube with LBT Blue. If you are buying the bullets and not casting them yourself, you might want to try a hollowbase wadcutter instead of the double ender, I've found that swaged hollowbase bullets shoot much better than the swaged plain based bullets. It's a toss up between properly cast, lubed and sized plain or bevel based wadcutters and swaged hollow based wadcutters for accuracy. Please note, I did say properly cast and prepared cast bullets!!
Enjoy your shooting!

regards,
Graycg

[ 06-19-2003, 15:45: Message edited by: graycg ]

Keyholing can have several causes.

If the bullet is traveling too slow or too fast for the twist rate of the barrel, it will not stablize in flight. This doesn't sound like your problem.

If there are internal imperfections in the bullet causing uneven weight distribution.

Failure to engage the lands because the bullet is undersized.

Failure to engage the lands properly because the bullet is not seated properly.

Check the bullet diameter against the lands. It should be a snug fit. If not, get some properly sized bullets.

Check your seating die. Make very sure that the bullet is seated properly in the case. You are looking for concentricity (sp?) If you are crimping, reset the die. It may be "pinching" on part the case a bit.

If all the above fails, try a different brand of bullets. You may simply have a bad lot.

Once, while working up loads, for my 6mm I started to experience keyholing. Turned out to be a bad lot of bullets, which the maker acknowledged and refunded my money for.

Pete