[frozentorso]

Hey, guys. Long time no see, so to speak. Been chasing girlies and its kinda cut into my shooting time. I had some time this morning so I took a couple of my favorite rifles to the range for a little bonding. One was my M70 .243 SS. I have a couple of boxes of 55 grainers, but with deer season on us I decided to stop by Cabelas for a box of 100 gr. This rifle has shot 55 and 100 gr. wonderfully, but all Cabellas had was the 95 gr. At the range I couldnt get 4" groups from it. It was all over the target. It was cleaned last time it was shot, and the weather was great(75 degrees with a whisper of a breeze). I know guns like certain bullets better than others, but could the 95 and 100gr have that much affect? I think I might have read somewhere way back where somebody had this same problem with the 95 gr. Anybody have a clue?

[Lng Rng]

I guess I have never had that much variation from switching 5 grains. Are your scope mounts tight? Did you try shooting any other bullets with different results?

[at4rxj]

If you always shoot the 55 gr well, the 100 gr is a big jump. The twist rate on your barrel may be set up for the lighter bullets (a higher numerically = slower) twist rate. The havier stuff needs a faster twist rate (lower number).

Check and see if you can find what twist rate you have. If it's a slow rate, it's not stabilizing those heavy bullets properly, and you won't get good accuracy.


EDIT... just re-read and saw that you have shot the 100 gr before... there goes all my typing for nothing.

If your gun likes the 100 gr, shoot that. Sorry, don't know what to say now.

[samuel]

Quote:       Originally Posted by at4rxj

If you always shoot the 55 gr well, the 100 gr is a big jump. The twist rate on your barrel may be set up for the lighter bullets (a higher numerically = slower) twist rate. The havier stuff needs a faster twist rate (lower number). Check and see if you can find what twist rate you have. If it's a slow rate, it's not stabilizing those heavy bullets properly, and you won't get good accuracy. EDIT... just re-read and saw that you have shot the 100 gr before... there goes all my typing for nothing. If your gun likes the 100 gr, shoot that. Sorry, don't know what to say now.

Iwill use your writing to fill in mine.If you have a 1in10.twist and those 95gr bullets have a long body and short ojive you could have problems stabilising them.If the 100gr bullets have a shorter body and longer ojive they should stabilise fine.Some rifles in .243 are 1in9 1/4" and the longer body should stabilise.You should be able to tell by looking at them.If they look pug nosed or shorter from the start of the taper to the point they would be long body,short ojive.No doubt they are boattail causing the body to be even longer.Answer:use the 100,s with shorter body and longer ojive. They also make a 1in8"twist for .243,s of both casings that will stabilise 107gr bullets. sam.

[frozentorso]

I bought the 95's out of necessity, but will stick to what works. Strange, though. I'd be perfectly happy using the gun for varmints, but I killed 7 pigs(some the size of footballs) with it at over 150 yards using the 100's.