Load help for a sbr 223 Wylde chamber.

[chevytruck_83]

I recently picked up an 7.5” inch long 223 Wylde chamber 7 twist ar barrel. I’m looking to start hand loading for it just to see what it’s capable of. I’ve loaded heavy 80 grainers for long barreled bolt actions a lot of 69 grainers for several other rifles but n get for such a short barrel. Can anyone suggest a starting point or share their experience?

 

[Twitchy]

I recently picked up an 7.5” inch long 223 Wylde chamber 7 twist ar barrel. I’m looking to start hand loading for it just to see what it’s capable of. I’ve loaded heavy 80 grainers for long barreled bolt actions a lot of 69 grainers for several other rifles but n get for such a short barrel. Can anyone suggest a starting point or share their experience?

Just load to normal barrel lengths and then realize you're pushing them much slower due to the short barrel. I have more than a few SBRs, but the shortest is 223 is 10". I mainly load 77g SMKs for them since it's a trade off of speed/bullet mass. I get around 2500 with a stiff load of varget behind the 77g.

I've used Varget, 8208, PP2000MR, and believe it or not-AA1680. I wouldn't recommend 1680 as it was an experiment and not in the usual load list for AA anymore. With he typical powders I just used normal charge weights.

 

[chevytruck_83]

Just load to normal barrel lengths and then realize you're pushing them much slower due to the short barrel. I have more than a few SBRs, but the shortest is 223 is 10". I mainly load 77g SMKs for them since it's a trade off of speed/bullet mass. I get around 2500 with a stiff load of varget behind the 77g.

I've used Varget, 8208, PP2000MR, and believe it or not-AA1680. I wouldn't recommend 1680 as it was an experiment and not in the usual load list for AA anymore. With he typical powders I just used normal charge weights.

Not worth chasing a fast burn rate powder to get more speed? I know 223 brass takes a beating already.

 

[Nowhere Man]

I didn't buy an SBR expecting accuracy. It's a short range blaster that's a hoot to shoot.

 

[243winxb]

See if RPMs match bullet length.
http://www.jbmballistics.com/cgi-bin/jbmstab-5.1.cgi


See change in velocity as 1" is cut fron the barrel. Starting with 22" barrel , cutting to a final 10" length.

3336 fps to 2779 fps.

223 Remington.52 gr bullets. 3 different powders.

http://www.accuratereloading.com/223sb.html

 

[243winxb]

Hodgdon data list 2700 fps with a 24" barrel and 80 gr bullet.

Will an 80 gr bullet feed from an AR15 magazine?

Cut to 7.5" Anyone know the remaining velocity? Looks like around 1700/2000 fps?

When we started down into the SBR zone, we sometimes saw velocity losses of more than 100 fps just from a 1-inch change in length.

Read more: http://www.gunsandammo.com/gunsmithing/barrel-length-vs-velocity/#ixzz5E4AaaBb8

Interesting.

 

[Beau]

SBR and a Wylde chamber seems like a non sequitur.

 

[yotehater]

Look in the pistol section of most reloading manuals list faster powders for short barrels. Works good for 16" barrels too. Better idea of what to expect of data from 15" Contenders than 26" rifles.

 

[Dave in WI]

If you find hard extraction, try changing the weight on the buffer to an H2 or H3. I've found some short barrels tend to start extraction when pressure is still high. Cases sticking and/or rims getting torn. Heavier buffer changes timing slightly to let pressure drop before extracting.