COrnFused

[carprivershooter]

I am getting ready to reload for my Rock River M-4 w/ 16 in. chrome molly r-4 profile barrel w/1:9 twist. My powder will be either Accurate 2200 or Hodgdon H335. Probably the H335 as I have some on hand, the cases will be fire formed 5.56 federal/lake city brass (fire formed to my rifle). The bullets will be winchester Gr full medal jacket. CCI small rifle primers. I will be loading on a Lee Turret press that I have used for many years loading handgun ammo. So the questions are Accurate reloading data give information on barrel length 24 ", and recommend reducing the load by -3% for barrels under 24" and barrels under 20" reduce -9%. then the give load data for Heavy Long bullets. The data for Hodgdon H335 gives no other data other just the gains for the bullet weight. So if I should decide to use the Accurate powder should I use the load data for the long heavy bullet or what. thank you for your assistance. Please don't flame me about my choices. It's too late to influence me on what to buy or use. OH! the ammo will be used for plinking and general use.

[mehavey]

I didn't see where you listed the bullet weight you intend to use, but by your other comments I assume it's a 55gr FMJ. Do not use load data for other bullet weights.

That said, I see all sorts of Accurate Load Data for that weight bullet with 2200:

Powder Bullet        Min(gr)  Vel   MAX(gr)  Vel  Press(psi)   OAL
2200  53 BAR TSX-FB   20.7   2,936   23.0   3,209   54,316    2.213
2200  55 BAR TSX-FB   20.0   2,798   22.2   3,058   53,713    2.190
2200  55 BRGR FBHP-V  21.0   2,898   23.3   3,167   54,243    2.260
2200  55 HDY SP       20.5   2,846   22.8   3,110   53,233    2.220
2200  55 NOS B-TIP    21.1   2,904   23.4   3,174   52,974    2.260
2200  55 SIE HPBT     20.6   2,890   22.9   3,159   54,159    2.175
2200  55 SIE SBT      20.9   2,934   23.2   3,207   54,317    2.230
2200  55 VNE HP       19.8   2,890   22.0   3,175   54,300    2.162
2200  55 VNE SP       20.3   2,939   22.5   3,212   54,950    2.203

For the moment I would ignore any powder reductions due to barrel length (I can't figure
any rationale other than unburned powder/muzzle flash. You can decide later on that.)

[carprivershooter]

accurate gives a lot of load data , and recommendations for different barrel lengths, they also give data for long heavy bullets of which the 55gram full metal jacket is listed. the data for the heavy long bullet does not say any thing about barrel length. I am wondering if the data from the long heavy bullet in safe to shoot out of a 16" barrel? Hodgdon does not give any data about barrel length which I found odd after looking at the Accurate data.

[mehavey]

they also give data for long heavy bullets of which the 55gram full metal jacket is listed

A 55gr FMJ is not a long heavy bullet by any stretch, and barrel length has no appreciable effect on chamber pressure.
I cannot see any safety issue here.

[ScottRiqui]

So the questions are Accurate reloading data give information on barrel length 24 ", and recommend reducing the load by -3% for barrels under 24" and barrels under 20" reduce -9%.

Re-read the Accurate data. They're not telling you to reduce the powder charge if you have a barrel that's shorter than 24" - they're telling you to reduce your expectations for velocity if you have a shorter barrel:

"For shorter barrels reduce velocity below as follows(ca): 20" -3.9%/-130Fps// 16" -9.0%/-300Fps"

[Wyoredman]

I just had a post a few days ago about velocities in my 16" ruger. I used the H335 and regular primers and at 25.3 grs under a 55 FMJ, I was getting 300fps less than listed in the manual.

It was suggested in that thread that I use a magnum primer with the H335 to regain some lost velocity. I haven't had the chance to try it yet, but I will update my other thread when i do.

http://thefiringline.com/forums/showthread.php?t=482289

[carprivershooter]

Thank you all for your input and clarification. the 55 grain bullet is listed first in the heavy and long bullet area of the Accurate load data for 1-7 1-9 twist and also list the bolt and semi auto NATO/Mil standards area of the load data.