I know this is a general question but here goes. My S&W M1500-DX in 222 Rem that I purchases some 20 years ago seems to have fallen off accuracy wise lately. I used to get .5" to .75" groups with boring regularity from pet loads but now the best I can seem to do is MOA. And, this with a new M8-12X versus the old 3X9 Vari-XII. Everything else remained the same. With no more than 1500 to 2000 rounds (and closer to 1500) through it, would that be enough to erode the throat sufficiently to produce such off results. I'm not complaining about MOA but the old groups sure were better.

Any ideas would certainly be appreciated.
Thanks

No, No, No!

Get some JB and some Sweets 7.62 solvent. Clean using the following steps:

wet patch through the bore
discard
wet patch through the bore 15 times back and forth
discard
JB patch through the bore 15 times back and forth
discard
wet patch through the bore
wet patch through the bore 15 times back and forth

If the patch is coming out dark blue, then repeat.
If it is faint blue, you're done.
I suspect you'll have to repeat three or more times, but accuracy will be restored.

Thanks Ralph,

I'll get some JB and Sweets and give it a try. Appreciate your help.