1322 ACP Carbine Saga Continues

I’ve finally gotten in the parts I was needing to continue working on my 1322 ACP (air conserving pumper). One of those parts was a flat top valve and piston set from Airgunsmith. I highly recommend this setup, as the parts are well machined and thought out. The primary reason I chose this setup was for the felt oiler. Multistroke pneumatic airguns need to maintain a film of oil for consistent powerful results.

I also added a Crosman steel breech. I had to rethread the bolt handle, but aside from that, they make a killer breech for the money. It adds a nice heft to the carbine and gives a rock solid scope mount as well. There was a good deal of bolt flip with each shot, so for now, I’ve added a disc magnet below the bolt handle to correct that. This helped to tighten the extreme spread.

1377 ACP Carbine

Once all the new pieces were installed, performance went up a good deal. With 11 pumps for the initial fill and 8 pumps between shots, it was averaging 505 fps with CPHPs. Accuracy is great when the LDC is properly adjusted and the right pellet for the barrel is selected:

Looks like I need to stock up on RWS Superpoints

H&N Sniper Lights and RWS Superpoints are nearly neck and neck in performance, easily capable of shooting dime sized groups at 20 yards. Since I am building this for hunting at sub 25 yard ranges, I just placed an order for 1750 of the Superpoints to keep the carbine well fed.

I wasn’t satisfied with the performance, as I’d like to be able to hunt squirrels with this rig. To improve performance, I turned my attention to tuning my free flight hammer. The spring guide and everything attached to it is accelerated with the hammer. The more massive this setup is, the more energy it robs from the hammer. I installed a nylock wingnut for the external stop, cut off the wings, and ground it as close to the nylon as I dared. All excess parts of the spring guide were ground down. Here’s the end result:

Lean, mean spring guide

Performance has gone up dramatically. It is now tuned for an initial fill of 15 pumps, with 9 recharge pumps between shots. Average muzzle velocity with H&N Sniper Lights is now 553 fps and muzzle energy is 9.5 FPE. This is good enough for my intended purposes. Combining a quick sip of high pressure air with the LDC makes this carbine super quiet.

An even lighter spring guide combined with a 18″ barrel will probably get me over the 600 fps mark. I’m hoping to achieve that with no more than 10 recharge pumps. I’ll continue to document my progress as time allows.

Quick Pest Control Hunt

During firearm deer season, I realized that chipmunks were really making a comeback on my land. I don’t mind having them in the woods, but they really become a problem when they start moving toward the house and vehicles. I’ve received a lot of the parts I was needing for my 1322 ACP project, and decided it was time to take it in the woods for a test drive.

A beautiful late fall day in my woods
A beautiful late fall day in my woods

I began my excursion initially after a squirrel. He stayed about 30 yards away, right on the west property line. With 8.2 FPE at the muzzle and my 1322 zeroed at 20 yards with a duplex reticle scope, there just wasn’t enough margin for error to warrant taking the shot. That’s when I saw a quick scurry 20 yards away toward the east. The chipmunk stopped on a large log, facing me.

As you can tell from the above picture, there’s a lot of saplings mixed with fairly mature trees. These saplings make living shooting sticks, and this time was no exception. Steadying my shot with a sapling, I slowly squeezed off the shot. I pulled a little to the left and missed the intended brain shot. Instead, it smacked through the right cheek, deflected, and exited the ribs on its left side.

The chipmunk was blown off the log by the impact, kicked a time or two, and lay still. The 1322 drew its first blood:

The 1322 scores its first kill
The 1322 scores its first kill

A little further away, I spotted something on a fallen log that spans my weather creek. Through my range finder I could see a chipmunk from the shoulders down, this time 18 yards away. Steadying my shot once more with a sapling, I aimed right between the shoulder blades. This time, I didn’t pull the shot. The smack of the impact is shockingly loud when you hunt with a LDC! Unfortunately, he tumbled down into some rocks and I was unable to retrieve him. At any rate, I’ve taken two chipmunks out of the woods, hopefully helping to keep them from crowding into my yard, vehicles, and home.

Daisy Powerline 880 Receiver Strengthening

If you never disassemble your Daisy 880, you’ll probably never need to do this modification. People like me who can’t make it a week without opening their rifle will quickly discover that the screws that hold the upper portion of the receiver halves together will strip out their holes leading to poor accuracy and problematic scope mounting.

Upper receiver halves to staying together
Upper receiver halves not staying together

More drastic measures may need to be taken later, but I’ve got a simple solution that so far has worked quite well. I carefully drilled out the existing holes with a 1/8″ drill bit, chasing the bottom hole a little deeper to give more thread engagement. The next thing I did was to thread them carefully using a 6-32 machine screw.

Location of holes that need to be drilled and threaded
Location of holes that need to be drilled and threaded marked by the long screws

Now that the holes are threaded, I cut a couple #6 screws and dressed the ends so they would fit my receiver perfectly. I reassembled my 880, tightening these top screws first, then working my way down. The heads protrude just slightly and could use some paint, but the important thing is that my scope can now hold zero because the halves no longer flex along the top.

The 880 receiver halves are locked in place now
The 880 receiver halves are locked in place now

Should this arrangement wear out, I’ll simply drill all the way through and hold the two halves together with a machine screw and nut. In the meantime, I’ve got my accuracy and spent next to nothing on the modification! A similar process can be used for the two small stock screws, as these tend to wear out as well.