
The Mosin in question is a run of the mill Izzy 91/30.
I set out to fix a few 'issues' with the Mosin to make it an enjoyable shooter.
1) I wanted a pistol grip. Due to a wrist surgery, I have lost a great deal of range of motion. I can't grip a rifle normally.
2) I needed a longer length of pull. I have a two meter wingspan. (Hence my username...) You should see me shoot an SKS, it looks like a toothpick in my hands.
3) A way to get my cheek higher, so I could put the butt of the rifle lower into the right area, and get it off my damn collar bone.
Installation
Installation went easily. I've read that a few people have had issues with the trigger, and the rear bolt. I can happily say that I had neither. The trigger, when fully actuated, just barely touches the trigger guard.
The rear bolt went in fully. Twice, because I forgot loctite the first time.
Overall, the stock is a very tight fit on the rifle. I left the barrel adjustment out, and it's free floated.
Issues
I did, however, run into two magazine issues.
1) The magazine would not properly accept rounds, and the follower would get jammed.
> Solution was to disassemble the magazine. I put a little lube on the edges of the follower. After reassembly, no problem.
2) The magazine would not lock into place.
> After some investigation, I found it would lock into place if I tapped it very, very firmly in place. Only the true king of England is able to remove it afterward, though.
Upon further inspection, I found that there is a metal nub on the Mosin that was stopping the magazine from clicking into place.

I then noticed a wear mark at the top of the magazine. So I beveled the top, then slowly worked a groove into the magazine body with a file and fine sandpaper.
Additionally, I smoothed out the plastic seam on the magazine.

Now, it clicks right into place, and will very nearly drop freely when released.
Handling

The pistol grip is pretty good. It allows me to comfortable hold the firearm and manipulate the trigger.
The adjustable cheek pad is good on its own, and helped me get just the right height.
The adjustable butt pad gave me a good length of pull.
However... in concert, the additional length of pull means that my cheek rested halfway off the cheek pad. It could be improved greatly if it was an inch or two longer.
Adjustments are heavy, and very unlikely to go out of adjustment on their own.
With the cheek pad up, the bolt still opens fully. You have to wiggle it a bit to remove it. Additionally, you might need to lower the cheek pad to run a cleaning rod through the gun. (But all we do anyway is spray it with Windex and hang it out on the line overnight to dry anyway, right?)

One further thing I found a little troubling - There really isn't a good way to hold the firearm with your off hand.

The magwell is too sharp of an angle to effectively use as a handstop. The rest of the handguard is as ergonomic as a brick.
I'm contemplating some way to add a bit of rounded plastic. I really like firing the Mosin standing up, and this just won't do.
Wait, can we put forward pistol grips on bolt action guns here? I'm just kidding. Maybe.

Shooting

One inch squares, 50 yards.
This is after a lot of wasted ammo figuring out that the Mosin shoots high and to the right.
I wish I had the pictures from when I shot the Mosin with the original stock at 25 yards, it wasn't nearly as nice.
I attribute that to the fact that the Archangel fits me much, much better than the original stock.
The archangel stock didn't transmit any heat through the handguard to me, even after 60 rounds. I do think that my groups opened up a bit around the 50th round.
Possibly due to heat, possibly due to me being worn out.
And recoil? It's slightly lower, but now that I can hold the rifle correctly, it's much better. 30 rounds before beat my ***. Now 60 rounds, and I'm not even sore.
But back to the magazine...
These have a reputation for not feeding correctly. About 1 in 3 magazines would jam in this fashion:
The first round would chamber and fire.
When cycling the bolt, it would lock about 3/4 of the way forward hard.
After dropping the magazine, I discovered that the round was angled, and another round had tried to feed below it, pushing it up.
The first time, It was locked up hard. The subsequent times, the bastard second round would fall out after the magazine and free the bolt.
It seems to me that cycling the bolt slowly caused it to happen. Or maybe it just happened because.
It's still easier than loading the original fixed magazine.
Overall, I'm fairly satisfied with it, and it's made the Mosin a lot more fun to shoot. I'll just need to figure out a forward hand guard, and some way to extend the cheek rest.

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