AR15 Velocity Low - W748 or Barrel?

[Abq-Defense]

Gun Setup:
I have a 16" AR that has a Odin barrel, 1:8 Twist. It has the Wylde chambering, and I run it with a TBAC suppressor. The barrel is new (200 rounds so far), and I use a Syrac adjustable gas block. This keeps the pressures at a good level when the suppressor is on.

Ammo Info:
AE XM193 .556:
My Reloads: 26.6gr W748, Hornady 55gr FMLBT, Coal 2.220, Rem 7 1/2 primers (also tried CCI 400 with the same velocity results).

Observations:
Using my Chrono that has always been on the money with my bolt gun use, I get 3010 fps with the XM193.
With my reloads, I get 2733 fps
The accuracy with both Ammo is very good. My reloads were just under 1 MOA, and I wasn't even using a rear bag/rest.

Questions:
I know accuracy is more important than velocity, but I am surprised at the 2733 fps chromo reading.
1) Could the low velocity be because the barrel is new?
2) Is the low velocity a Wylde chamber thing?
3) I thought 26.6 of W748 was on the high side. Should I try increasing this until I see my groups open up?

Any help would be greatly appreciated. I would like to get the best load possible before cranking a bazzilion out on the Dillon. ;-)

 

[JoshcBoucher]

1-no, 2-no, 3-

Check the reloading depot thread. Lots of info for that powder, there.

Gun Setup:
I have a 16" AR that has a Odin barrel, 1:8 Twist. It has the Wylde chambering, and I run it with a TBAC suppressor. The barrel is new (200 rounds so far), and I use a Syrac adjustable gas block. This keeps the pressures at a good level when the suppressor is on.

Ammo Info:
AE XM193 .556:
My Reloads: 26.6gr W748, Hornady 55gr FMLBT, Coal 2.220, Rem 7 1/2 primers (also tried CCI 400 with the same velocity results).

Observations:
Using my Chrono that has always been on the money with my bolt gun use, I get 3010 fps with the XM193.
With my reloads, I get 2733 fps
The accuracy with both Ammo is very good. My reloads were just under 1 MOA, and I wasn't even using a rear bag/rest.

Questions:
I know accuracy is more important than velocity, but I am surprised at the 2733 fps chromo reading.
1) Could the low velocity be because the barrel is new?
2) Is the low velocity a Wylde chamber thing?
3) I thought 26.6 of W748 was on the high side. Should I try increasing this until I see my groups open up?

Any help would be greatly appreciated. I would like to get the best load possible before cranking a bazzilion out on the Dillon. ;-)

 

[Steel head]

Seems a bit low but reasonable.
Most data listed is for a 20" barrel.
Lyman has data into the upper 27s and I got near XM193 with W748 near the top but accuracy left after 27 and it beat the crap out of my brass at the top.

 

[Road_Clam]

You FPS data when reloading to 26.6 of W748 seems low, although I can't verify my Alpha Master chrono is dead balls calibrated.

Here's some of my data shot out my Bushmaster AR 24" barrel:

52 SMK , 25.7 gr., W748, 3212 fps

52 SMK , 25.9 gr., W748, 3299 fps

62 fmjbt , 25.7 gr., W748, 3031 fps

69 SMK , 25.7 gr., W748, 2996 fps

These were all excellent loads for my barrel producing approx .380" to 1.3" groups @ 200 meters , depending on the weather conditions I was faced with.

 

[Abq-Defense]

Seems a bit low but reasonable.
Most data listed is for a 20" barrel.
Lyman has data into the upper 27s and I got near XM193 with W748 near the top but accuracy left after 27 and it beat the crap out of my brass at the top.

This is great info. A few other folks on the net have said the same thing, so I guess around 27gr, my groups will probably start to open up. I will watch for it...

 

[Abq-Defense]

You FPS data when reloading to 26.6 of W748 seems low, although I can't verify my Alpha Master chrono is dead balls calibrated.

Here's some of my data shot out my Bushmaster AR 24" barrel:

52 SMK , 25.7 gr., W748, 3212 fps

52 SMK , 25.9 gr., W748, 3299 fps

62 fmjbt , 25.7 gr., W748, 3031 fps

69 SMK , 25.7 gr., W748, 2996 fps

These were all excellent loads for my barrel producing approx .380" to 1.3" groups @ 200 meters , depending on the weather conditions I was faced with.

Thanks for the info. My 16" barrel should see 300fps less that your 24" barrel. It sounds like my velocity is a little low, but I can't increase my load much with this powder. I may just increase the load a little until the groups open up, then stop. I do like the accuracy of the load I have.

Thanks for the feedback.

 

[samnev]

I use W748 with 52 grain SMK's in all my 223/556 AR's and Remington 223 PSS. My load is 26.2 grains of W748. I worked loads of 748 from 25 to 28 grains in 0.2 grain increments and the most accurate load was 26.2 grains of W748.