OK spent some time at the range today with the .222 now as this was just soem practice and trigger time I picked up a box of 55 gr Hornady FMJ's for £15;40. Now I had some IMR 4198, old stock as it is in the Red flat tin and not the modern plastic tubs. Now up until now I had been shooting the 55 Grn Nosler Balistic Tips and some Hornady 55 grn SP's loaded over 19.0 grains of IMR 4198 with fair results.
Anyway as I am using a different bullet even if it's the same weight so i got the books out and the dies etc and took a look at what they say. Hmmmm confusion as Speer #13, Hodgdons #26 and Ken Waters pet loads all give different charge weights.
I looked at the lee powder scoop chart and noticed that the 1.6cc one was near where I wanted to be then noticed that this is the size lee supply with the dies . So I poured some powder into the ceramic dish i use and filled a scoop levelled it off with a card and weighted it. 20.0 grains spot on....Hmmmm 20.0 grains is a 100% load. The FMJ bullet was tested for COL and once found that was reduced 0.015" so none would be jammed into the lead. The COL turned out to be 2.174" so the cartridges were loaded to that. I can play with the seating depth slightly at a later date.
Now the cases were brand new Lapua mouths deburred and primed with CC! 400 on the Lee hand primer. After weighing the first four charges and finding no difference bewteen them i went to weighing every 5th one and they were very consistant
At the range they shot reasonably a bit of playing with the seating depth should tighten it up a bit and the cases extracted very slickly aand primers still have rounded edges. Now comes the rub:-
Another ememebr had the clubs chronograph out so once he had finished i fired a few through it to find out what they are givign velocity wise. The new load of 20.0 grns IMR 4198 gave and average of 3200 fps which is about 200 fps MORE than the books claim
The Nosler BT's have an average of 3002 fps and the Hornady 55 grn SP's 2931. Now the Extreme spread fo each were 61 fps, 59 fps and 53 fps so now the cases are fire formed I'll do a retest and see if they improve the ES figures. AS THE VELOCITY OF THE FMJ's IS A BIT UP ON WHAT IT SHOULD BE on the way home I called into Forest Lodge guns and picked up a box of 50 grain Sierras to try with the 20.0 grain load. The dro in weight should help the pressures a bit Although there are no signs of excessive pressures but the velocity tells me that it's bit high soooooooooooooooo .