I'll just give a quick introduction before, I'm Alex and I'm a new bullet caster. I picked up my 77/44 because I wanted a rifle for hunting Sitka Blacktail on the Queen Charlotte Islands, now known as Haida Gwaii. It had to be stainless because of the weather, short range, have a clip(road hunting). It also had to waist less meat then my .308. I also wanted something which I could experiment to get me into reloading and casting.
So here goes my results, out of the box the rifle was nice but had a couple of quirks which came up. First was that I could not group factory ammo <4" at 50 yards which was VERY disappointing. So which the help of some snap caps toss into the magazine I traced part of it to the trigger. Lighter spring and a quick touch up on the sear and I closed up to about 2-2.5" @ 50 yards. I then put together that the shots were stringing vertically so an investigation of the stock found that it was pre-loading the barrel. I have free floated my barrel and am now in the <1.5" groups with some of my loads.
Some quick gun stats:
18.5" Barrel with 1:20 Twist slugges at .4293"
Bushnell Banner 1.5-4.5 Scope with Ruger Rings
Being new I have two powders I have been experimenting with Hercules 2400 and H110. With LP and LPM primers.
Now I find the gun loves 240 JHP(.430) with 24gn H110, forgive me but I didn't start in the casting right away. It's doing 1760fps+/-10
I have also shot some 200 JHP with 26.5gn H110 which is a bit bigger group but <2"
When I shoot some of lee's 310 FP's with 15.7gn H110 it's going about 1310fps and shooting about 7" low, the same with 15.7gn of 2400, going 1420fps(The group with H110 was ~2" and the 2400 was ~3". They were sized to .429". The rate of twist seems to be able to stabilize them.
Now my real question is why the drastic drop with the big lead at 50 yards? I also tried some Speer 300 FP(18, 18.5, & 19gn H110) just to compare and had the same result; shooting being quite low. I've heard a couple of theories the main one being barrel time except they are going much slower which should translate into higher?
Please forgive me if this post is in the wrong section. It kind of became two problems in one. Also I'm looking for a second mold for .44 and thinking 240 Keith/Thompson with the gas check from Saeco or 240/280 from LBT.