223 reloads using 8208

[djkost]

Hi, my load is this: 556 LC Brass- 23 grains of IMR 8208-CCI rifle primers- 60 grain Nosler Ballistic tip- I'm shooting it out of a 16 inch Rock River varmint barrel 1 in 8 twist.

I ran a 5 shot string and got the following reading thur my Beta Master. 1-2679 fps 2-2644 fps 3-2613 fps 4-2630 fps 5-2622 fps.

I looked the ballistics up on the Hodgdon site and according to their data 21.5g is 2857 fps and 23.6 g is 3057 fps.

Does anyone know if by shooting a 16 inch barrel if velocity going to drop that much??

I used a dillon 550B to reload and checked every 5th round of powder to make sure it was dropping the right amount of powder and it seem to have.

The temp outside was 41 degrees and sunny. The rounds didn't sit outside long before firing.
Thanks.

 

[Bob L Swagger]

Re: 223 reloads using 8208

If hornady runs their tests and gathers data like sierra does, this is how they get their info. It may be a 16" test barrel, but it is bolt action - hence higher velocity than your AR-15. (look at 2:16 of the video)

http://www.youtube.com/watch?v=Hkr1NS7bEUU

 

[biner626]

Re: 223 reloads using 8208

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: djkost</div><div class="ubbcode-body">Hi, my load is this: 556 LC Brass- 23 grains of IMR 8208-CCI rifle primers- 50 grain Nosler Ballistic tip- I'm shooting it out of a 16 inch Rock River varmint barrel 1 in 8 twist.

I ran a 5 shot string and got the following reading thur my Beta Master. 1-2679 fps 2-2644 fps 3-2613 fps 4-2630 fps 5-2622 fps.

I looked the ballistics up on the Hodgdon site and according to their data 21.5g is 2857 fps and 23.6 g is 3057 fps.

Does anyone know if by shooting a 16 inch barrel if velocity going to drop that much??

I used a dillon 550B to reload and checked every 5th round of powder to make sure it was dropping the right amount of powder and it seem to have.

The temp outside was 41 degrees and sunny. The rounds didn't sit outside long before firing.
Thanks.

</div></div>
That sounds slow. I was getting 2774 out of an 18" 1:7 twist with a 77SMK at 24 grains of 8208 @70F. You may need more powder.

 

[djkost]

Re: 223 reloads using 8208

I think it slow also. I ran my 22 250 on the same chrono and had 3850fps so I thing the readings are right. I don't think it matters if the rifle is an ar or bolt if the load was shot in both rifles. I'm stumped. I was hoping for at least 2900fps.I know you lose some velosity but that much. My mistake I shooting 60 grain nosler ballistics in the round/

 

[hntbambi]

Re: 223 reloads using 8208

Hodgdon is using a 24" barrel to get 3057 fps with your load. I modeled some similar loads in QL and it shows a 300 fps drop due to barrel length and a little drop for temp. You are shooting ~2.5% below max to start with so the numbers are in family.

The old rule of 25 fps per inch is pretty much valid for that setup.

 

[19dsniper]

Re: 223 reloads using 8208

RRA 18" Middie Varmint Upper with Wylde chamber.
60 Grain Hornady VMAX
23.4 grains of 8208
CCI Match Primer
Win brass
Chrono said avg. of 2,639fps for 10 shot strings in 100 degree texas heat this summer. I thought it would be quite a bit faster. I am only 0.1 grain below max. I get an average of 0.4-0.5 MOA 5 shot groups at 100 yds. I still expected more velocity out of the 18" upper.???

 

[308sako]

Re: 223 reloads using 8208

My earlier lot of IMR 8208 XBR was a little faster than the current 16 lbs I am working with. For my 16" Armalite 1 in 9 CL bore 23.6 was really great precision and the chrono SD 10, Vel = 2854. Win 748 at 25.6 was the equal for accuracy and velocity