.243 SST load and OAL Suggestions

[the great orator]

   Does anybody have any good loads for the .243 95gr SST bullet using either IMR 4350, 4064, or 4831?  They're the powders I have on hand and would like to use these up before buying any more powder.  Also looking for the COL with this round, as my last hornady book was apparently published prior to the SST being made.  I'm looking to load for a magazine fed bolt action and was considering seating the bullet to the cannelure, but i'm open to suggestions.

I'm trying to find a good load for whitetail deer.  I was using Federal Fusion factory stuff, but when I was chronographing it last month, I had several shot variations that went from 2700 to 2280 fps.     I think I got a bad lot of ammo, but I don't want to test the waters with a nice deer with that much deviation in ammo.

[Kurt L]

To start with is this a pump,auto,bolt?

I have had great results with87, and 105 bullets with H4350 in mine .700 bolt action.
with your choices I think I would try the 4831 or 4350 you have.If you have a bolt action.
The C.O.L. does not mean NOTHING but a starting point to use and cyle the ammo.
every gun is a diferant animal.with out the tools needed you can run and empty in your sizer just a very little bit and size the tiip of the case mouth and start a bullet in it 95sst and put it in the gun and force the bolt closed this way you get the C.O.L. for that bullet and your gun and set it up to seat your bullets about.10 to .15 deeper than your test one you made.I am sure you will be back  but this will get you started.

[jasonprox700]

To start with is this a pump,auto,bolt?

Bolt action.  Says so in the post!

One thing you could do is take a fired round, slightly dent the edge, and insert the bullet just enough to hold it.  Color the bullet with magic marker, and chamber it a few times.  Measure the OAL of each chambering, and average that.  Then back the bullet of the lands .005 - .020", whatever you want.  Then when you load the rounds, you can see if they will feed reliably.  If not, seat the bullet deeper.  The loading handbooks may be able to give you better directions than I can.   

[Kurt L]

WELL color me stupid I looked right at the bolt part and missed it
I will stand up and take my Here's your sign award

[wncchester]

"I was using Federal Fusion factory stuff, but when I was chronographing it last month, I had several shot variations that went from 2700 to 2280 fps."

That much variation makes me suspect your chronograph read wrong.  Most times, when the velocity reads far lower than it should, the first (start) screen is triggering on the shock wave from the muzzle blast.  I find it best to set my first screen at 12 ft. or more from the muzzle to prevent this.

I can tell you what works best in my .243 but duplicating it will only mean you are loading for my rifle.  IMR-4350 is likely to be the best of the three you mention, likely to be best of any.  Load up a few to near max and try it.

[yooper77]

The maximum C.O.L. is 2.710" for 243 Winchester, and I would use no longer than that for hunting ammo.

Please don't force your bolt closed, this will or might cause the case to be pulled off the bullet during extraction and leave the bullet stuck in the rifling. In order to find the bullet maximum C.O.L., little by little seat the bullet and try it in the gun use the seating die, not the bolt.

Your powder selections are perfect for heavy bullets in the 243 Winchester.

My first choice would be IMR-4350 and start at the minimum and work up slowly to find the best accuracy.

You made a great choice of bullet weight and cartridge for taking any deer on the planet.

yooper77

[OR-E-Gun Bill]

The C.O.L. suggested in the Hornady 6th Edition is 2.630" for the 95 gr. SST.

The load data shown for it is the same as listed for the 95-100 gr. Hornady SP, BTSP and RN

Zat help?

Bill

[the great orator]

Thanks for the helpful information.  Regarding the Chrony, It was not mine, but another co-workers chrony.  It was set up approx. 10 feet from the muzzle.  We were originally getting Chrony readings for our work guns with the temps in the 80's, for our books.  Every shot was very consistant with the .308 Fed. GM, between 2650 and 2670fps for a 10 shot average our of my .308. 

When I switched to my Rossi .243 (not mine, a friend's daughter's gun) and the Fusion, that's when I got the wacky readings. (barrel is 4" shorter than my .308).  I thought that maybe the chrono was off, so we shot the .308's again and got consistant readings.  Back to the .243, back to erratic deviations.  I'm saving the rest of the two boxes that I have to shoot up for brass.  I won't be hunting with rounds from that lot again.  Every company has a bad day once in a while so I'm not badmouthing them, because I've killed two deer with the fusion prior to this. 

Oh, and it's not the Rossi either; that shot fed 100 blue box very consistantly. 

Anyhoo, I'm liking the SST's, so I'd like to load some up for Deer Season.

[Don Fischer]

I love Hornady bullets but have never loaded an SST. Don't see any problem tho, load as normal. To get the over all length, I slip a bullet into the chamber with the bolt out. Hold the bullet to the lands with a dowel, pencil, ect. and run a cleaning rod down the barrel to just touch the bullet. Then I mark the cleaning rod right at the muzzle. Now take out the bullet and re-insert the bolt. again run the cleaning dor down the barrel to the bolt face and again mark the cleaning rod at the muzzle. the distence between the marks is what I use as a starting point to find the best OLL of a cartridge.

My favorite powder for the 243 is IMR 4350

[wncchester]

"When I switched to my Rossi .243 (not mine, a friend's daughter's gun) and the Fusion, that's when I got the wacky readings. (barrel is 4" shorter than my .308)."

Okay, that makes me suspect that muzzle blast is the cause of your funny low readings even more.  

It isn't the speed of the bullet, super sonic or not, but the high pressure explosive speed of the gas blast when it's released that allows it to fool the start screen.  The released gas, light and under high pressure, will ALWAYS out run the bullet for a short distance, that's why we can't set up the first screen at the muzzle.  

All loads have slightly varying time:pressure curves.  Your short barreled .243 releases that Fusion blast at significantly higher pressure than a longer barrel would.  They probably used a slower burn powder in it.  Bet you also got a serious ear slamming BANG when it fired!

The fact that your weird results are inconsistant suggests you are ALMOST far enough away now.  Try your "bad" ammo again but add a couple more feet.

[the great orator]

Ok, I'm up for trying anything, I'm no expert in this.  Thanks for the pressure info.  Wouldn't this happen with the 100 gr. bullets as well?  the factory rated velocities are within a hundred fps of each other, so I'd think that they would probably be using similar powders.  What would make this change in velocities from one bullet but not another?

[yooper77]

Yes, it does make a difference in velocity and powder charges.

Take a look at this website for your powders used in with 243 Winchester.

http://data.hodgdon.com/cartridge_load.asp

yooper77

[the great orator]

Yes, it does make a difference in velocity and powder charges.

Take a look at this website for your powders used in with 243 Winchester.

http://data.hodgdon.com/cartridge_load.asp

yooper77

I know that different powders will give different pressures, velocities, etc.;  I just didn't think that Federal would be switching between powders for the same caliber with a slightly different bullet/weight. 

As soon as i get a chance, however, I'm going to go out and set that chrony back up approx. 15" from the muzzle and try again with that lot of ammo.  I need the brass anyway.

[yooper77]

It's tough at times to match factory velocities, because ammunition manufactures have the luxury to customise powders in order to gain the best velocity.

I have always used the common sense simple things approach, as everyone veteran reloader knows.  I start at minimum and slowly work my way up in order to locate the best accuracy and never load over maximum.

yooper77

[huntswithdogs]

I've loaded a bunch of 243s using H4831 and 100gr bullets. If I remember correctly, most of the manuals don't make much difference between 100 and 95 grain bullets.