bullet weight difference and accuracy

[XD40SC]

How much will accuracy at 100 yds be affected by a grain difference of + or - 2 grains in a 250 grain bullet?

[necchi]

At 100 very darn little.
 What caliber?

[XD40SC]

38/55

[Lloyd Smale]

could be very little and could be alot. The actuall differnce in velocity will only change point of impact a inch or two but where things get dicy is that the same gun might shoot one of those loads into an inch at that range and going up or down a grain can open groups up to 3 to 4 inches. Now add the one or two inch differnce because of velocity and you sure could miss the vitals of a game animal. I guess what im saying is the only way your going to really find out is to shoot it.

[shot1]

The way I understand your question is will + or - 1 to 2 grs IN BULLET WEIGHT of a cast 250 gr bullet effect accuracy much at 100 yards? It could. But it depends on a few things. If the weight difference is caused by the bullet not having all the lube grooves filled sharp or the base of the bullet edges not being filled sharp or there could be an air pocket some place in the bullet then yes accuracy will suffer. If the weight is from different melt mixes where you did not get the contents exactly the same but you have a fully filled out bullet it wont make much of a difference. If you are casting bullets yourself and using the same mix and you start to get bullets the weigh more or less during your casting you need to flux your mix again and stir it some because your other metals are separating from your lead.