Home Forums Reloading Varmint Rifles 243 reloading/ powder choice????

Hi all thanks for reading
I have a query about reloading/possibly powder choice issues with my 243
Basically my reloads are slow and they show pressure signs before they reach the velocities that similar bullet weights in factory ammo give
I get cratered Primers and extractor marks at about 100-150fps less with my reloads
Tried various powders but mostly vhit n160 and h380 mostly with rem 9 1/2 primers and nosler custom cases with bullets seated 5-10 thou off lands in 22" barrel 85-87 gn bullets
Would a faster powder help do you think? Or slower?
Or perhaps hotter primers? Ive read rem primers are not that hot
Or maybe seat further from lands???
Any help appreciated

I've found Varget to be a good powder for the 243 Winchester. In general, the more overbore a cartridge is and the heavier bullets you're shooting, the more a slower powder will benefit you.



IMR 4831 works pretty well also. I have never shot factory loads in my 243 Winchester rifles and have never chronographed them because honestly, the only thing I care about is how accurate they are.

You don't say what bullet you're using so I can't say how far you should be seating from the lands. If what you're using is a monometal copper bullet like Barnes, then moving away from the lands may help. For the usual copper jacketed lead bullets, closer to the lands is best in most cases.

As for primers, I think the Remington primers you're using are fine. Changing primers will not give you more velocity.



The coyote had no idea how fast the bullets were going.

You do not say what bullets and powder charges you are using. We need that info.

If you can get some 4451 I have found it does help on the velocity end. Varget is my gold standard in 308 cases for accuracy. If Varget won't shoot accurately I start looking close at the rifle

100 FPS or so is nothing to worry about in most cases. Work up to accuracy and if velocity is even remotely reasonable go hunting and kill stuff.

Thanks for the reply Grumulkin

Its not really that im a desperate for every ounce of velocity but im just trying to get a handle on why it is that the barrel can obviously produce expected velocities with factory but with home loads pressure signs show at lower velocities
Id like to find a load that is accurate and fast enough without buying factory!
Ive mostly been using 87vmax and 85 tsx and am getting around 3000fps but in previous 243's got 3150 to 3200 fps
Puzzled and wanting to get to the bottom of it!!
Thanks again
Bob

With the 80 TTSX and 87 Vmax I use imr4350 and with the 105 Hornady BTHP Match I use H1000.

I shoot 44.5g of R#19 with a win primer with the 85g triple shock in my rem 700, very accurate and fast.

Are you using a chronograph, so you can see if your loads are slower than the factory? If not, they may not be. I noticed you are using Nosler brass. Nosler is very good brass, but holds less volume than others, so you will get pressure signs a lot sooner than you will with other brass. I believe the brass is the culprit in your case and I would bet that the velocities with the slower loads are up with the factory velocities.

You sure on those primers?

What weight bullets are you using?




Travis

Thanks all for the ideas
Just some more information from memory
Factory remmington 80gn sp chrono at 3220-3260fps with no pressure signs at all
My 85-87 home loads show best accuracy at pressures showing cratered primers and occasionally extractor marks but only chrono at 2975-3020fps
Thanks again

I see now you are using 85ish. Go slower.




Travis

Sorry you're right remmy 9 1/2 primers!!

Yes, go slower. W760, RL-17, RL-19, 4350 or even H4831.

17 man. 17.

Thanks for all your ideas
Ive loaded some test rounds up with some lapua and federal cases i found kicking around
Ive got no reloader17 but have loaded some up with n160, re22, h380, and lovex so70 all at a shorter seating depth and with pmc primers just in case

Hopefully i will get to try some later today and post an update
Atb

1. Remington probably uses some proprietary powder that isn't available to reloaders.

2. There was a test done one time on 10 supposedly identical rifles shooting identical loads. Velocity differences between the various identical rifles varied by up to 200 fps.

I only get out the chronograph after I've worked up what I think is a good load. The only reason I even do it then is to get a better idea of what the projectile trajectory will be and I NEVER use velocities as an indicator of pressures. If pressures are safe and accuracy is acceptable, stop there and be happy.

<THIS> but I'm using 45.0 grs of RL19 with to 80gr TTSX. lights out on anything it hits so far

In a heavy 243 I no longer own:

760/414 worked very well for me under light bullets (I shot a lot of 70-grainers).

H-1000 worked best for me under the 100 grain (and up) boat tails.

Well I finally got some time to try out some loads and thought I'd post my findings so far

87 Vmax, Nosler case, rem 9 1/2 primer, 43 grains h4350,0.040" off lands
3093 fps primer slightly cratered

87 Vmax, Lapua case, CCI br primer, 43 grains h4350 ,0.040" off lands
3078 fps no pressure signs not good accuracy

87 Vmax, Lapua case, cci br primer, 43.5 grains h4350 ,0.040" off lands
3100 fps very slight cratering on 1 case out of 5 accuracy good

---------------------------------------------

87 Vmax, Nosler case, rem 9 1/2 primer, 43 grains Vhit n160,0.040" off lands
2948 fps primer slightly cratered slight extractor plunger mark

87 Vmax, Lapua case, PMC primer, 43.5 grains Vhit n160 ,0.040" off lands
2966 fps no pressure signs

--------------------------------------------------------
87 Vmax, Federal case, PMC primer, 41.5 grains Lovex so70 ,0.040" off lands
2826 fps no pressure signs

----------------------------------------

87 Vmax, federal case, PMC primer, 47.5 grains Re22,0.040" off lands
3095 fps primer flat but not cratered

------------------------------------------

87 Vmax, Lapua case, Rem 9 1/2 primer, 41.5 grains h380 ,0.040" off lands
3148 fps 2 rounds 1 cratered primer, 1 extractor mark

87 Vmax, Lapua case, PMC primer, 41.5 grains h380 ,0.040" off lands
3128 fps primers quite flat

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So from this lot I am thinking that I see more pressure signs with the Nosler cases probably down to the decreased case volume thats been mentioned
Also I think I see more pressure signs with the rem 9 1/2 primers, and definately more cratering

Im currently trying to find some reloader 17 to try out with some new Lapua cases I've got and the CCI br primers and see what I get but powder supply over here is abbismal at the moment.
To me accuracy is the most important thing and I'm not wanting a super fast load but I'm thinking that because I'm getting the best accuracy at the top edge of safe pressure I might as well try and work up a load that gives me the best speed.
Maybe I'm overthinking this but if I'm running top end pressure and getting 2950ish fps I just feel its a good experiment trying some different components and get 3150ish with similar pressures

Thanks again for reading and contributing and I will be back to update if and when I try something different!
ATB

H-4895 up to 80 grs. H- 4831 85 and up.

IMR 4064 in my world....right up thru a 100 grains...