Burn rate chart...

[Jody Simcox]

I've got a great little model 7 compact in 243 Win that I really love to shoot. It's got an 18" barrel, with 9 1/8 twist (maybe 9 1/4). My question is where on the burn rate chart do I need to be looking for an appropriate powder for a 90 gr accubond... all of the load data in my manuals reference a longer barrel... thanks.

 

[LHSmith]

From 4895 powders to the 4350 series should work well. When I first acquired a model 7 in .243 when the rifle was first introduced, I used IMR 4831, but eventually settled on IMR 4350 based on accuracy testing. FWIW, I started with 95 gr. Nosler Partitions and ended up with 100 gr. Nosler Solid Base. I limit all my testing on Model 7's to 3 shot groups.

 

[WayneShaw]

You might want to lean to the faster burning side with the 18-1/2 barrel, but it really comes down to what your gun likes. 4350 is a proven powder, that would be my slowest powder to start with.

 

[Whitehunter]

From 4895 powders to the 4350 series should work well. When I first acquired a model 7 in .243 when the rifle was first introduced, I used IMR 4831, but eventually settled on IMR 4350 based on accuracy testing. FWIW, I started with 95 gr. Nosler Partitions and ended up with 100 gr. Nosler Solid Base. I limit all my testing on Model 7's to 3 shot groups.

From Shooting Times February 1988 by Rick Jamison W760= 41.3 grains Winchester case and primers works for me. He also used 90 grain Speer IMR 4350 = 43 Grains RP case Rem 9 1/2 primers FPS 3181. Wayne Fears Nosler 85 gr. H 380 = 40 gr. rem case and primers, Sierra 90 gr. IMR 4350 = 43 GR. Win primers and case. These loads are from FEB 1988 Shooting Times title The Amazing .243 hope this helps

 

[chop house]

These loads are from FEB 1988 Shooting Times

i have not cross correlated any of these loads, but i still have a 2nd edition hornady manual circa 1980 as well as modern 9th edition. The data from back in the day is not nearly as conservative as published now. the debate continues which changed more - the powders (they do, even from lot to lot) or the publishers risk tolerance (it has), or even producation chamber dimensions (i think headspace and throats on production rifles have tightened marginally). The data gets published along with rifle type, barrel length, cartridge length, but no insight into the chamber. (Freebore mitigates pressure)

I, like others, have strayed off the beaten path and experimented with newer powders but always seem to find my way back to 4350 for all my .243's.

 

[Jody Simcox]

Thank y'all!

 

[Mulligan]

I use 38.4 gr h4895 in my 243 compact.
I looked at the TC pistol data in the Sierra manual
Velocity good, accuracy is outstanding with 85 gr Nosler BT's
CW

 

[Zero333]

Quickload shows best powders for best velocity for a 30" barrel are the same powders that generate best velocity in a 18" barrel with few exceptions.

Muzle blast might be a different story.

 

[XTR]

Don't go down the road with H4350, it's the most popular powder with the Open/magnum/6mm shooters and can be ridiculously scarce.

IMR4350, H4351sc, IMR7828ssc, Re16, Re26 would all be choices that are more available to the average reloader.

 

[KMart]

Another good choice for that bullet weight would be IMR 4064. Somewhere around 37 grains

 

[Mulligan]

Quickload shows best powders for best velocity for a 30" barrel are the same powders that generate best velocity in a 18" barrel with few exceptions.

Muzle blast might be a different story.

I could not get any velocity using H4350 in my compact rifle, although after measuring it, it sports a 16 1/2" barrel.
CW

 

[Shawnba67]

Isnt IMR 4451 supposed to be their answer to h4350.
Guy at my gun shop said in HIS creedmoor same charge was within 6fps
It is much more available
Also a good starting place for 243.