Do i need to tweek powder charge ?

[zap]

I have a target rifle configuration with a savage target action rb lp, shilen heavy barrel in 6.5x47 lapua. I have been working on load development for a few outings. I got my powder charge where i wanted it and the next step was to do different seatings in .005 increments closer to the lands.
Now, after i had the powder charge settled, i changed two things. I put a new PT&g bolthead on, and put on a Ken Farrel rail.

I sighted back in, ( nightforce nxs) and i was not impressed from what i saw at the range today. Groups were pretty consistent in the threes and fours. All three shot groups. All 7 groups today were worse than the last time i shot the same powder charge. I am quite certain everything is tight on the rifle.

I am sure i will get many different responses on this, but my question is.....

Can changing the bolt head and putting that rail on cause me to have to go back and try different powder charges again ?
Also it was twenty degrees warmer today, than the last time this powder charge of r15 was used.

[390fe]

I would lean more towards the possibility that the warmer temperature has increased the velocity of your round and pushed it beyond the rifle's sweet spot.

[earl39]

Changing the bolt head can change headspace and that can change your groups. The rail change, unless the old one was loose or the new one is loose, should have no affect on groups.

[natesatt]

I'd also check your headspace first.

[sharpshooter]

I'd put the original bolt head back in and see what happens.

[zap]

I did re headspace , as it did need it. I am thinking that i will try a few more powder charges with this particular powder.
Thanks for the replies.