.243 load - Input Requests

[Bocefus]

I have a Rem. 700 - 20" barrel. I finally was able to get quality chrono data on the loads I had made by purchasing a CED M2.

The load seems quite slow, .vs what I expected from the data on the Hodgden website. I realize that the barrel is less than standard length, but even accounting for that and atmospheric conditions, this seems like a low velocity compared to that provided at Hodgden.

Here are the results:

100 grain PPU SP Flat base projectile
32.8 grains IMR-4895 powder
Remington Large rifle # 9.5 primer
2.260 OAL

Velocity @ 15 feet
80F, 500 feet elevation, 100% humidity

Average 2500 FPS

Hodgden website data expects 2683 FPS for that loading, but I do not have rifle barrel length or other atmospheric data.

Possible reasons for low reading:
1) Chrono is not accurate
2) Atmospheric or barrel length are not identical to that used to provide Hodgden's data

I have loaded up more cartridges with increasing powder charges, up to the maximum. I will be sure to watch for signs of overpressure. I am not satisfied with such a slow velocity, as I intend to be shooting out to 500 yards in competition, and desire a flatter trajectory.

Thoughts?

Thanks!

 

[ChadTRG42]

Re: .243 load - Input Requests

Yes, I think you answered your own question. It's a 20" with a minimum (starting) load with a fast burning powder. Work backwards from max. If max is 35.7, work backwards from max and load up at that low end. Also, this powder is not the best suited for max velocity. The powder is too fast burning. You need a slower powder to get max velocity, if that's the goal. But, if you have a lot of it on hand, it will work.

 

[Breeze260]

Re: .243 load - Input Requests

20" will take some from you but not all

I'm shooting
95gr Sierra BTHP
36.3 gr Varget (overmax)
Win brass
Win primers
.010 off the lands
a little over 3100fps
savage model 12 w/24" barrel

 

[ggmanning]

Re: .243 load - Input Requests

Look at Varget and RL22 for velocity with your .243