243 win with imr 4166 and 80 gr sierra btsp chrono results

[MildBill]

Worked up some loads for my tikka t3 lite stainless for coyote hunting with imr 4166 powder and the sierra 80 grain btsp blitz bullet. brass is winchester, fired 3 times prior to this, neck sized,

lit with cci 200 large rifle primers. cartridge overall length is 2.635.

all powder charges thrown light and trickled up to weight on rcbs 10-10 older one made in usa

group size with these loads is all in the 0.5 to 0.7" range with them being on the smaller end at the two higher charge weights without the magnetospeed on the barrel.

so here are the results from the magnetospeed

it was about 40 degrees at the time of shooting.

scratching my head at the results,

wondering if trying cci br2's might tighten speeds up a little

I know groups were at least half again as big when tried with winchester large rifle primers.

39.4 grains- ave 3237 sd 20
3234
3219
3259

39.7 grains- ave 3229 sd 16
3225
3215
3248

40.0 grains- ave 3272 sd 15
3255
3282
3280

40.3 grains ave 3273 sd 13
3280
3257
3282

 

[Zero333]

40gr of that powder with that bullet leaves some air in the case.

I would try a slower powder that leaves little to no space in the case after the bullet is seated.

IMR-4451 would work better. IMR-4350, H-4350, IMR-4831, Hybrid-100V, RL-19, Norma-UPR, Norma-204, Ramshot Hunter, Vihtavouri-150/550, Accurate-4350.

Those are some of the powders I can think of that will give you a better case fill.

You can even try slower powders than those I listed if you don't mind compressed loads.

 

[CanusLatransSnpr]

X2 on the H4350! You won't be disappointed!

 

[Zero333]

Look at your results and note how more powder in the case (less air space) brings down the SD.

 

[MildBill]

yup

I saw the variability decline with higher charge weights.

I also know that imr 4166 and imr 4064 kick the others powders suggeste above butts for group size with this bullet in this rifle. Don't know about velocity on them, so far only measured velocity on the best grouping combinations.

the purpose of this rifle is to ruin coyote's days while out calling.