Feeding problems eased... (56-50)

[Jbar4Ranch]

I expect this has already been covered somewhere, BUT...

With a little close observation, it's very easy to see why my 56-50 needs to be operated rather vigorously in order to reduce feeding problems. The top edge of the breech block is very sharp and digs into the nose of the next bullet in the magazine when closing the lever. If the lever is closed slowly, the sharp edge digs in and continues to dig in. If the lever is forced closed, a wedge of lead is shaved from the ogive of the next bullet in the magazine. If it is smartly closed, the breech block bounces the bullet away from the sharp edge for a microsecond, allowing it to clear the bullet with no further interference. I took a 1/4" square stone to the sharp forward edge of the top of the breech block and slightly rounded it, just breaking the knife edge really, and it made a very noticeable improvement in feeding. When operating the lever slowly, the breech block still skids along the last eighth inch or so of the next bullet, but it doesn't dig in like the sharp edge did. This is very hard steel, and a file won't touch it. It could be done with a Dremel, but please use nothing coarser than a polishing stone if you take this route.

[Two Flints]

Jbar4Ranch,

Earlier you started a thread showing three different bullets:



Lee on the left @ about 322 grains, RCBS in the middle @ about 357 grains, and the Ten-X on the right @ about 340 grains - I lubed the Ten-X for uniformity in the pic - they are NOT lubed as they come loaded from Ten-X

Have you tried each one in your Spencer?  Does one feed better than the other two after filing/modifying the breech block as you did?

You should try combining your posts into one thread since they all deal with the same topic, pretty much. Just a suggestion.  Your posts are very much appreciated

Two Flints

[Jbar4Ranch]

I have tried all three; the Ten-X factory ammo & RCBS definitely feed better than the modified Lee bullet, and dulling the sharp edge of the bolt/breech block definitely helped. I believe a short nosed, truncated cone design would feed best of all. Perhaps "short nosed" isn't quite the proper description - the nose from the crimp groove forward would be the same length, but the truncated cone wouldn't start til it reached a point where the angle would be sharp enough to slide back off the breech block as it closed. The sharper angled surface would be easier to push back into the magazine as the breech block came up to push the first cartridge into the chamber, rather than carving a piece of lead off or jamming against the top.
Something like this maybe.



Could someone post decent pics of the Rapine 515320 and 515365 bullets?

[Herbert]

onother thing that helps is to put a tiny radious on the edge of the chamberwere it joins the rim this is onother reason originals feed smoother

[Jbar4Ranch]

To put it mildly, I am amazed by this little carbine. Ten-X smokeless factory rounds, the modified Lee, and the RCBS bullet (with black powder and APP) will all shoot one hole groups at 25 yards, and most of the time they will all be touching even at 50 yards. I stretched it out to a hundred yards today with the Lee bullet and 37 grains (volume) of 2F KIK (no wad, no pre-compression), and was pleasantly surprised to be able to consistently put five rounds under 4 1/2", with my best five round group being just a hair over 3 7/8", center to center. The worst problem is the first round out of the magazine often takes a bit of jiggling the lever to get it to load, and then the rest are fine as long as the lever is operated "vigorously". I might keep it above the door this hunting season in case an elk wanders through the yard.

[French Jack]

It has been my experience that the Jim bullet from Buffalo Arms feeds more smoothly than any of the ones mentioned.  It has a rounder ogive and a broad flat nose that might appear unsuitable.  Such is not the case.  It feeds smoothly whether eased into battery or operated rapidly.  Examination of dummy rounds made up for testing with this bullet shape show no indication of being gouged or pinched by the block.

[El Tigre]

I expect this has already been covered somewhere, BUT...

With a little close observation, it's very easy to see why my 56-50 needs to be operated rather vigorously in order to reduce feeding problems. The top edge of the breech block is very sharp and digs into the nose of the next bullet in the magazine when closing the lever. If the lever is closed slowly, the sharp edge digs in and continues to dig in. If the lever is forced closed, a wedge of lead is shaved from the ogive of the next bullet in the magazine. If it is smartly closed, the breech block bounces the bullet away from the sharp edge for a microsecond, allowing it to clear the bullet with no further interference. I took a 1/4" square stone to the sharp forward edge of the top of the breech block and slightly rounded it, just breaking the knife edge really, and it made a very noticeable improvement in feeding. When operating the lever slowly, the breech block still skids along the last eighth inch or so of the next bullet, but it doesn't dig in like the sharp edge did. This is very hard steel, and a file won't touch it. It could be done with a Dremel, but please use nothing coarser than a polishing stone if you take this route.

I had the same issue. OAL must be 1,6 inch. Do not move the action slolely, move it quick. The it works

[Jbar4Ranch]

It has been my experience that the Jim bullet from Buffalo Arms feeds more smoothly than any of the ones mentioned.  It has a rounder ogive and a broad flat nose that might appear unsuitable.  Such is not the case.  It feeds smoothly whether eased into battery or operated rapidly.  Examination of dummy rounds made up for testing with this bullet shape show no indication of being gouged or pinched by the block.

I assume this would be the JIM513350? The shorter, rounder nose would definitely help, just as the TC design I posted above. Having a sharper angle or more curved surface is the answer, I think.

[French Jack]

I have found that the O.A.L. AND the shape of the ogive are the key to feeding properly.  The shape of the ogive is the most critical, simply because the cartridge guide at the top of the action uses the ogive shape to register on the round as it is coming up into battery.  The ogive also dictates how the following round is prevented from jamming the block at its lowest position. 

That said, the Jim 513-350 or the 512-350 (they are identical in length and shape, feed more smoothly than any others I have used, in a direct comparison with the Lyman 515139, the Rapine 350-T, the RCBS 50-350 CB, and the NEI version of the Rapine, a LBT LFN 360 gr., and the shortened Lee bullet.

[Jbar4Ranch]

I had the same issue. OAL must be 1,6 inch.

Crimped just over the forward driving band, the modified Lee is 1.575", and the crimp groove on the RCBS makes it 1.51". Crimped at the top of the top lube groove, the Lee is too long to fit between the extractor and the face of the breech block.

I have found that the O.A.L. AND the shape of the ogive are the key to feeding properly.  The shape of the ogive is the most critical, simply because the cartridge guide at the top of the action uses the ogive shape to register on the round as it is coming up into battery.  The ogive also dictates how the following round is prevented from jamming the block at its lowest position.  

That said, the Jim 513-350 or the 512-350 (they are identical in length and shape, feed more smoothly than any others I have used, in a direct comparison with the Lyman 515139, the Rapine 350-T, the RCBS 50-350 CB, and the NEI version of the Rapine, a LBT LFN 360 gr., and the shortened Lee bullet.

I just scaled up the drawing of the JIM513350 on Buffalo Arms' Web site to compare it to my pics of the Ten-X, Lee, and RCBS bullets, and the JIM bullet is even shorter from the crimp groove to the nose of the bullet than the RCBS orTen-X.

If someone has a Lee R.E.A.L.320 grain 50 cal mould, do some experimenting with it and see if my theory about a truncated cone bullet holds water. It may not shoot worth crap, but it would be interesting to see how well it feeds with its severely coned nose.

[French Jack]

Yes, it is a hair shorter, BUT the ogive shape is much fatter where it engages the cartridge guide.  This is what makes the difference.  The other shapes allow the guide to ride lower, which has the same effect as a much shorter OAL.

If you PM me, I'll send you a few so you can make up a dummy round and then you will see what I am trying to explain.  Iirc, Tuolumne reached the same conclusion that I did with this bullet. I measured the OAL and it is 1.513.  The Lyman is 1.515, and the LBT is 1.545 --- just to compare OAL.  

BTW, if you go to NEI Handtools, (website), you can look up the Lakota Spencer Bullet, and the nose shape is virtually the same as what you are sketching with your proposal.

[Jbar4Ranch]

I chucked up a dozen of the RCBS bullets in the ol' JET lathe and turned the radius down to a truncated cone shape with no better results. And I was absolutely sure the TC shape was the key too. Different OAL's didn't ease the problem any either.

I had reason to take the lever & block assembly out and noticed the magazine well is way off center at the receiver end - there must be some logical reason for this, but I don't see what it is. The receiver is milled a good 3/16" - 1/4" off to one side where the mag tube enters it. How come?

Mag tube spring tension also seems to have a good deal to do with feeding properly. The first round always hangs up and needs a bit of jiggling the lever around to get it to feed, and the second one almost always does, then the next five go in just fine.

[French Jack]

The magazine tube is offset due to the space taken up by the lock.  You might need to check the follower as well as the spring, and make sure it is not too long.  The extra tension can make a difference in feeding.  I have heard of some of the Armi Sports having a plug in the magazine tube to limit the round count.  Mine did not have one, but others have indicated theirs did.

[Jbar4Ranch]

The "plug" is a short rod screwed into the base of the follower and limits capacity to five rounds. Mine had it installed when I bought it. Two Flints, I think, thought it might have something to do with import laws.

[.56/50 Iron]

Hello!
     I had an awful time getting my Spencer to feed from the tube. I knew that the next round was jamming up the works, but you can't see into this action well enough to know where the source of the problem is. I took care of my problem by adjusting the length of the cartridge(the one being fed up on the block) LONGER until it worked. The base of the cartridge going up on the top of the breechblock has to  momentarily (millesecond) have its base form a "wall" that the next cartridge's bullet nose rubs against as the first round is jacked into the chamber. If the cartridge going up on the breechblock is too long, the base of that cartridge will still be hanging a little into the tube and will jam as the back of the block comes up. If the cartridge going up on the block is too SHORT, it will allow the nose of the next round to enter and also try to get onto the breech block as it is closing on the first round. You are correct. There is a lead disruption on the front edge of the bullet where the back of the block tries to slice the nose off the next round. I did not think about dulling the top edge of the back of the breech block but now will also take care of that problem! Thank you for the idea! Getting the cartridge the correct overall length for the bullet I am using was what finally got my Spencer to feed. Most generally, it will now feed when I operate the lever as I would any other lever action gun. No extra force or speed needed. You might also notice that in general, the Spencer feeds smoother if the muzzle is elevated a little as the lever is operated. As the Spencer has no mechanical EJECTOR, it also throws out the empty casing better if the muzzle is again elevated as the lever works to eject. Thus, elevate the muzzle as the ejection starts and keep it elevated a little as the next round is being chambered. It appears that the new Spencer carbines can be quite a project to get operating as more than a single shot! They are beautiful little guns and when the tube feeds that ammo as it is supposed to, it is quite an experience shooting one.
     Thanks again for this note discussing what you did to the block. All of this helps.
.56/50 Iron