12.7x44R Swede Rolling Block

[lar45]

I found some .047" spring wire.
I bent a new spring copying the original profile..
The trigger pull is at 5# now..
I also polished the hammer spring.

[marlinman93]

I found some .047" spring wire.
I bent a new spring copying the original profile..
The trigger pull is at 5# now..
I also polished the hammer spring.

Sounds great!

[Dutchman]

As long as we're on the subject of 12,7x44R rolling blocks....

12,7x44R Swedish rolling block
30" barrel sporter

Chronographed with 1867 Remington sporter
using Doudna 450 grain FN bullets .510".
All are excellent loads.
Blackpowder loads uses vegetable wad card
on top of powder (Buffalo Arms).
Cases - reformed .348 Winchester
Standard primer for Unique & XMP5744
Magnum primer for blackpowder

12.5 grs. Unique = 1074 FPS average
very accurate load

24 grs. XMP5744 = 1089 FPS average
26 grs. XMP5744 = 1151 FPS average
27 grs. XMP5744 = 1211 FPS average Do not exceed
70 grs. FFg = 1214 FPS average


350gr FN (Doudna) .510"
29 grs XMP5744 = 1337 fps average Do not exceed
44.44 extreme spread
18.02 std deviation
This is a very accurate load in my 1867 sporter

Using Accurate 5744 the cases showed no signs of excess pressure and the primers were rounded. Since I found black powder equivalent loads I went no further.

My rifle land diameter is .477" and groove diameter is .500" measured at the muzzle.

I have no idea what mold these are from. They were purchased decades ago! 350 gr & 450 gr.

[Dutchman]

A lesson in case length caution in the 12,7x44R rolling block.

Breechblock required just a touch of pressure to close. That SHOULD have been noticed. Two and two were not added until this happened. The case mouth had NO ROOM TO RELEASE the bullet. No matter what anybody else says about what length is ~correct~ for these rifles you must figure this out for YOUR rifle. They are not all the same. They were built in a time when quality control inspection hadn't been perfected. Your breechblock MUST FREELY CLOSE without resistance. This case shown was a black powder load.







This is why I disassembled this rifle down to the bare receiver. To inspect everything with a magnifying glass.

[lar45]

I can't get mine to chamber a round with .512 bullets. So I sized the top of the case in a 500S&W sizer and tried some .501" bullets to have something to shoot. My bore is .477x.505" . I have some 50-360 hb Minnie's loaded to try, but life got in the way yesterday. Hopefully it won't rain all day today.
I guess I could Beagle a .500 mold and try those.
It was shooting very high, so I put a new front sight on. I'll have to get it tweaked in today and see if I guessed close enough on the height.

[lar45]

I got a little shooting in today.
I tried some powder coated .502 round balls with 9 gn of unique. The rb shot okay for 25yds, left target.
Next was a powder coated 50-360 hollow base Minnie. I tried 33gn on IMR4198 , from pet loads, it gave 1507fps. Middle target. Probably going too fast. I'll try less powder and shoot again.
Last was a .501-420. 28gn of 4198 gave 1315fps and stacked 5 shots fairly tight, right target.
I guessed too high on the front sight and had to place a target above these to aim at.
I guess I should have just ordered an assortment...

The 5# trigger was soooo much better to use.

[lar45]

The stock sights are not really the best on this rifle. My eyes are getting older and can't focus as clearly as they used to also...
What would you think about this set of sights?
I'm wondering if the rear would fit the dovetail slot in the rifle? - I checked and it's a 1/2" slot for the rear.
What I probably really need is a good vernier tang peep sight.

[lar45]

This looks a little better, except I'd have to drill and tap a hole for it.

[vagrantviking]

Hopefully you can find one like that with enough height. Some have extended stem pieces.
I'd look at MVA or something similar myself

[Dutchman]

On the m/1867 rifles the date of mfg is on the bottom of the barrel under the forearm.

[lar45]

Midway sure has quick shipping.
Now I need to get a new tang screw.
I'm guessing it's metric. Anybody know off hand the correct size, or a source?
I've got an Ace hardware up the road, I might have to build one.
It measures .246x27tpi

[Red River Rick]

....I'm guessing it's metric. Anybody know off hand the correct size, or a source?
I've got an Ace hardware up the road, I might have to build one.
It measures .246x27tpi

M6 x 1MM

[lar45]

Thanks Rick

I Beagled the Lee C501-440rf with 2 layers of aluminum tape, and cast a bunch with pure lead. Then pan lubed with the new BAC, no gas check. Loaded with 28gn IMR4198 for 1211 fps. Shot a couple of targets tweaking in the new peep sight.

75 yds.

[marlinman93]

I can't get mine to chamber a round with .512 bullets. So I sized the top of the case in a 500S&W sizer and tried some .501" bullets to have something to shoot. My bore is .477x.505" . I have some 50-360 hb Minnie's loaded to try, but life got in the way yesterday. Hopefully it won't rain all day today.
I guess I could Beagle a .500 mold and try those.
It was shooting very high, so I put a new front sight on. I'll have to get it tweaked in today and see if I guessed close enough on the height.

If I had a .505" groove I wouldn't even want to shoot a .512" bullet down the bore if it could chamber it. That's way too large. I'd buy a sizing die for .505" and size them to fit the groove.

[lar45]

I ordered a push through sizer from NOE. The biggest they had was .504", so I'll just lap it out.

[lar45]

I lapped the die out to .507", cast some 500gn bullets, pan lubed with new BAC and sized them. Just tried 5 rounds and they tumbled. So it looks like the 42" twist isn't happy with 500s.

[lar45]

Made a new tang screw to fit the Marbles peep sight.




I picked up a M6x1 cap screw at Home Depot, turned it down with a drill and file. Cut the slot with a hack saw. Then flame blued.

[RustyReel]

Made a new tang screw to fit the Marbles peep sight.




I picked up a M6x1 cap screw at Home Depot, turned it down with a drill and file. Cut the slot with a hack saw. Then flame blued.

Wow, that's some pretty nice work with a drill and a file.