I've been working up loads for a "new" Rem788 in .243. A few days ago I made it to the range and fired seven 5-shot groups with 46.5gr IMR 4350 pushing a 75gr Hornady V-max. All seven groups were under an inch and they averaged just under .75. The best group was in the mid-5's.

I recently picked up a box of 75gr Hornady HPBTs, flat base. I had some of those loaded with the same charge of 4350 and at the same bullet jumps that I'm using for the V-maxes. I fired two 5-shot groups and was disgusted. One group was around 1.3 and the other was 1.5.

I realize that even when working with bullets of the same weight, the standard advice is to work up the loading from scratch. Still, I was pretty shocked that my very accurate V-max load didn't work better with those flat-base 75s.

Has anyone else run into situations where two bullets of the same weight didn't like the same powder/charge? Where would you go from here? Try different charges of 4350 or try a completely different powder?

Thanks.

A lot of times its the bullet that is the problem, and changing powders will not help. I would try adjusting the OAL of the loaded round first. Load 20 rounds. 5-bullets with the base of the bullet seated to junction of neck, shoulder. Another 5-seated to max. length that the throat or magazine will allow. 5- more inbetween the longers oal and the shortest oal. last five same as before except different oal, fire and see what u get. 243winxb

I had a good day at the range yesterday with my 788 in .243.

The stock is glass bedded, and the barrel free floated back to 2" in front of the recoil lug. I have also worked the trigger.

I use a 10X fine crosshair Leupold scope on this rifle, with Leupold rings and bases. When shooting for group, I use a small black square on a white background as an aiming point.

I shoot the 85 grain Sierra BTHP exclusively with 43.5 grains of IMR 4350, and a CCI primer. OAL is set at 2.685".

Mine shoots honest to goodness 1/4" three and four shot groups with the above recipe. A couple of guys had some heavy barreled varmint rigs at the range yesterday and simply couldn't believe what my old 788 would do. I had to shoot a second three shot, 1/4 MOA group to prove to them that the first one wasn't a fluke. (I did clean the bore and shoot a fouler before attempting the second group--this isn't a BR rifle!)

Anyway, my whole reason for telling you this is that the 85 grain Sierra BTHP and IMR 4350 will do wonders in your rifle. Contrary to what many folks will tell you, rifles of the same make and model normally respond well to the same load. Adjustments to the OAL to accomodate throat differences and individual harmonic whip may be in order, but charge weight and other components need not change.

Good luck with your rifle, and to answer your initial question, the difference you're probably noticing is the difference in the bearing surface of the bullets. Some bullets, even though they may be of the same weight, will have more of thier surface touching the walls of the bore on the way down the barrel. This will result in higher pressures for the bullets with more bearing surface, and of course different velocities, which equal different groups.

Go to the Sierra 85 grain HPBT and don't look back. The above mentioned load is also a good performer on deer at 150 yards and under.

Dan Newberry
green 788

Thanks for the load tip, Green. I'm having a lot of fun with this 788. I bought it mostly to use as a compact carry gun for yotes. Since I'll seldom need to shoot as far as 100 yards (Kentucky), all the accuracy I really need is in the 1-1.5 MOA range. But since I've heard what great shooters these 788s are, it was impossible for me not to start fiddling and tweaking, trying to see just what it will do.

I've switched from 3-shot groups to 5-shot groups because I think the higher number is really a better assesssment of a particular load. So far, I've shot two groups in the mid-5's with the 75gr V-max and IMR4350. As mentioned above, the last time out I shot enough .75 5-shot groups to honestly call it a 3/4 inch rifle with this particular load.

It's interesting, Green, that you mentioned higher pressures and velocity with the flat-base bullet, because that's exactly what I saw, at least in terms of velocity. I don't have the targets in front of me right now, but I'm sure the flat-base 75s shot at least 100-150fps faster than the boat-tail 75 V-maxes. I'm wondering if I might get better accuracy by dropping the velocity on the flat-bases down to where it matches my accuracy load with the boat-tails. In the meantime, I'll locate some of those 85gr Sierras and get them loaded up.

Out of curiousity, does your 788 in .243 have the 18.5 inch barrel (which mine does)? I'm thinking a good deal of that 4350 charge is burning outside the barrel and I'm wondering if I might get better velocity with a faster powder. Of course velocity without accuracy isn't worth squat, but have you found any faster powders that your gun likes?

Take a look at the ballistic coeffient of the Sierra 85 gr bullet. I made the same mistake years ago by using their 75 gr hollow point for long range varmints.

The Ci is only .279! Thats no better than a 50gr .224" spitzer and it's going to be going a lot slower.

Of course if the purpose is only 150 yards on deer the velocity will be OK but there are much better bullets and cartridges for short range shooting.

For instance the 80 gr Sierra will out range the 85 "Gameking" for target or varmints.

There has to be better bullets for game than that 85 gr HP. As far as a all around bullet goes I think you have to go with what is less likely to fail and the .243 Win is borderline anyway.

I'm pretty sure my rifle has the 22 inch barrel. The carbine, which you have, is a more collectible and harder to find rifle. All else being equal, the shorter barrel should shoot even tighter groups than the long one, because of the smaller diameter of the whip cycle on the shorter barrel.

Many folks in these parts have had excellent results with the 85 grain Sierra HPBT on deer. I don't use a .243 for deer, but I wouldn't be afraid to shoot one at 100 to 150 yards with this bullet.

I have three sub MOA (again three shot groups) at 450 yards using the 85 grain Sierra bullet and the IMR 4350 charge listed above.

I think Varget will do you a good job in your rifle, though it seems that IMR 4350 is going to be hard to beat.

You may be able to slow the flat based bullet down and tighten the groups--it's worth a try.

Keep me posted on how things go. And take care of that 788!

green 788