Going with less powder?

L

Lurky BoDean

New member
My brother in law and I bought a reloading kit about 3 years ago. I just recently started actually getting into it. I've been trying to work a load up for my .243.

Remington Model 700 ADL
24.25" barrel
As of now Winchester brass (have some new Hornady brass)
CCI 200 Large Rifle primer
Hornady 95gr SST
C.O.L. has been right around 2.690"

I tried IMR 4831 at 38 and 40 grains with best group at 2.75" at 100yds.
I then tried H4350 at 37.5, 38 and 39 grains. The best group I got was at 37.5 grains which was right at 1". The 39 grain produced an 1.2" group. The 38 grain was the 1.6".

The question is would it be ok to go below the Hornady load chart at 37.4 to an even 37 or less grain for the H4350? If so, what are the drawbacks of less powder outside of velocity?

Lurky
 
Surely you can cut a half grain out.

I suggest that you continue to experiment with 4350. You don't want to go too far down in the charge, and there is at least one solid reason for it.

These powders are formulated to burn properly under a flexible, but definite set of conditions.

They have to burn at a certain minumum pressure that may be around 50K psi. There has to be a certain weight of powder involved, it must ignite properly, it must fill a certain level of empty space, maybe 80%. There must be a certain amount of back pressure, so that the charge is allowed to completely burn as the bullet is pushed out of the barrel. There are a lot of other conditions that must be met to make the charge burn efficiently.

You can count on certain powders and cartridges to burn properly at a wide range of conditions, there are others that will be picky. When you get inconsistent burn, you have inconsistent velocities, which leads to innacuracy, among others.

this probably explains your terrible results with the 4831
 
did some reading.


this is a chart copied from hodgdon. starting charges only. max charges on next chart for a few.

Look at 483i. largest charge, highest pressure, best velocity. Normally a good situation. You have a narrow range, though, less than 3 grains from start to max, and you are shooting below minimum. your accuracy sucks. I don't like that load.

4350 has just about a 4 grain spread. It fills most available space. Your max charge is listed as being only70 grains slower than the 4831, which I don;t really like anyway, and pressures are 500 psi lower, using a tiny bit less powder. I can vouch for 4350 at 40 grains.

Moving to the others, for example, 4895, you will see significantly lower charges, lower velocities, and identical pressures at min charge. Go to max charge, look again. You have only a two grain spread. Your pressures wind up practically idenitical. That small charge generates pressure rapidly, spikes higher and faster, and probably isn't optimal.

I am an old school type that likes to use powders in the lower range. it worked for years. Newer powders are very different and work differently, and some of them are very good. Out of those, your best chance of a good load is to use 4350, IMO, it is a good fit for that cartridge data.



powder Grs. Vel. (ft/s) Pressure


H4831 42.0 2,930 47,000 CUP
4350 38.0 2,792 43,200 CUP *
H38 36.0 2,779 43,000 CUP *
Varget 33.0 2,870 45,000 CUP *
4064 33.0 2,745 43,500 CUP
H4895 33.0 2,865 45,000 CUP

4831 44.5C 3,052 50,700 CUP
4350 41.8 2,993 50,200 CUP
H4895 35.0 2,990 50,700
 
I have 2- 243's, a vanguard and a M77 Ruger, I shoot 70 gr match out of the vanguard and 85 hollow points out of the Ruger for deer and I have found Varget to be my goto powder for both.
 
varget would be better with smaller bullets as the lighter weight allows the quicker burning powder to work better. 4350 still works well with the lighter bullets as well. just takes some work to find what works. powders and charges either work well or not, and there are many gray areas as to what works best.
 
"...ok to go below the Hornady load chart..." Absolutely not. 37.0 of IMR4831 and H4350 is 1 to 3 grains below minimum(not enough to be unsafe.) for a 95 already. Too far below minimum a load can be as dangerous as too far above max. Causes weird pressures from the powder detonating instead of burning.
You need to work up the load from the Start load, not just picking a few loads and hoping.
Been using IMR4350 with 90 and 105 grain bullets for eons out of a 1 in 9.125" rifling barrel(same as your ADL).
2.710" is the max OAL for the .243. Using the max OAL given in your manual saves a lot of mucking around. There is no need to fiddle with the whole off-the-lands stuff until you have a load. Really no need to fiddle with it at all.
 
I don't know what data you are looking at, but mine shows 39gr as minimum and 42 as max. I've found max or very near it to usually produce best accuracy. I'd go back to 39 gr and start working up.

Another possibility is that your barrel is twisted so that bullets that heavy are unstable. That bullet weight needs about 1:8 or 1:9 twist. The 700 is 1:9 1/8. Making it very borderline. With that barrel and bullet combo you may not get great accuracy, but I still think acceptable big game hunting accuracy is possible. I like heavy for caliber bullets, but the barrel has to be able to handle them.

varget would be better with smaller bullets as the lighter weight allows the quicker burning powder to work better.
Click to expand...

A 95 gr bullet is a HEAVY bullet in 243.
 
I shoot a lot of .243Win, in competition and hunting and have been for a long time. 58g to 115g and 2600fps to 3600 fps. It is one of my favorites and if you hold it in the right windows, it is excellent.

H4831SC is a great powder for the heavier (95 to 115 grain) bullets, but it needs to be about mid range to max to get good accuracy and low SDs. H4350 is actually pretty close to 4831 and if you are looking for lighter loads, still not the best choice. As mentioned, Varget is decent for the lighter bullets, but still does not like the lower end of the charge range for the best accuracy in the .243Win.

4895 and 3031 are two of the better powders for lower charge weight/lower velocity loads in the .243Win if that is what you desire.
 
a 95 grain bullet is a heavy bullet in .243
Click to expand...

Of course it is. What's your point?

I said that varget would be good for lighter bullets and not so much for the 95 grain that he wants loads for.
 
You must log in or register to reply here.
Back
Top