Need help with feeding problem

[ndnchf]

I know this has been discussed numerous times and I've read most of those threads, but I'm still having problems getting my Model 1871 Springfiield Spencer Infantry rifle to feed.  I put an S&S block in it, and only had to do minimal work to get it to fit.  I've been trying both Lyman 515139 and Rapine 350 bullets in starline brass.  I've made up dummy rounds with each bullet in varying lengths from 1.515" to 1.625".  On a couple of occasions I got the 515139s to feed with an O/A of 1.575".  But the next time I loaded them they would jam again.  The cartridge guide spring seems to be good, putting pressure on the bullet's nose.




I've rounded the front edge of the upper block, but I'm wondering if I did it enough.  Could some of you who have done this post a photo of your block to show how much rounding was done?  Here's what mine looks like now.  I sure would appreciate your input on what I need to do.

[Herbert]

You have rounded of the block more than enough,putting a curve on the edge of the block is to stop it digging into soft lead bullets and you do not need much,if it is left sharpt it will somtimes leave a cut mark on the bullet.Fist thing is were is it jameing and is it leaving a mark on the bullet or is it jameing in the magizine ,or not cycling into the chamber properly.A couple of things to try befor going to far is use a hard bullet and make sure there is a crimp on the case so it can slide into the chamber with out catching,1.6 is a good OAL for original Spencers

[ndnchf]

It is jamming coming out of the magazine.  I the first pic is a  515139 bullet loaded ot an OAL of 1.575" .  if I shine a light down into the back of the breech where the cartrdges emerge from the magazine, it looks like the rim of the first cartridge is still inside the tube and the rim is catching.  But it is really hard to see inside there. So it seems shorter cartridge length is needed.  But I've made them shorter and it still hangs ug.  Maybe I'm making them too short and need to find that happy medium?. 

[Herbert]

You can not tell if the rim is in the right placeby looking from the top,the opening in the magizine is much further back at the botom of the magizine opening,so what should happen when the action is opened is a cartridge will slide foward over the upper block an be stoped by the combined action of the cartridge stop on the lower block and downward pressure of the cartridge guide on the cartridge ,when the action is closed the cartridge moves foward enough to expose the rim of the cartridge at the botom of the magizine opening to the leading edge ot the top of the upper block,here it is important that the shape of the bullet is right so the block can push the following cartridge back into the magizine and at the same time push the cartridge to be chamberd foward.This is a long winded way of saying the bullet may have the wrong nose shape to cycle properly,so if posible try a more pointed bullet, one that starts to curve just foward of the case,you coulld also try seating the bullet shown to the cover the geese groove and crimp this may work,also check to make sure that the bullet is catching the cartridge stop(this can be checked by very slitly closing the action then opening it again slowly ,if every thing is in sink the cartridge will move back into the magizine slitly)

[ndnchf]

Great explanation Herbert, thank you.  I tried loading just one cartridge in the mag and it cycled and ejected just fine.  I did this a couple times and it worked good each time.  So That tells me the cartridge is not too long and does not have a problem exiting the magazine fully.  But with 2 rounds it locks up.  I tried the check you mentioned at the end of your last post to see if the bullet nose is up against the cartridge stop.  I started to cycle the round up to the chamber and then went backwards a little.  The cartridge moved back as it should, so I think the bullet nose is being properly captured between the cartridge stop and guide.  This is with the Lyman 515139 bullet.

So at this point I'm thinking I need to lengthen the cartridge in small increments to find the sweet spot where the cartridge fully exits the mag and the UBB just catches the bullet nose of the next round and pushes it back.  I'll reload my dummy rounds this afternoon.  The bullets are pretty beat up now and I want to start with clean bullets to see the marks on them.

[ndnchf]

I worked on this today and have made some good progress. 

The rounds I made earlier were much too short.  To determine optimum length using the Lyman 515139 bullet, I started out by determining what the maximum length cartridge the action would handle with this bullet.  I started out with an OAL of 1.700".  I loaded one round and tried to cycle it.  That was too long; it would not completely exit the magazine.  So I started shortening the OAL until one round would clear the magazine and cycle.  That ended up being 1.680" OAL.  So then I loaded a second round to the same length and loaded them both.  The first one cycled in, but the second one's nose got caught and cocked the bullet in the case a little.  The problem was that the Starline brass is not long enough to support the bullet at this OAL.  I had previously ordered 50 Starline .50-70 cases, in case I needed them for the Spencer.  I wanted the case to cover the lube grooves, driving bands and fully support the bullet.  So measurement of the 1.680" OAL cartridge indicated that I needed a case length of 1.356".  So I cut down and trimmed one .50-70 case to this length, reduced the rim diameter to .645" and beveled the rear edge of the rim.  Ran it through the .56-50 sizer, then tried it in the chamber - it fit nicely, but the rim was too thick and the block would not close completely - Grrrr. 

I measured the Starline rim thickness.  It varied from .057" to .059", the .50-70 rim was .065".  So I thinned the rim (from the front edge) to .058" and tried it again in the rifle.  It chambered fine and the block closed snugly.  So at this point I made up a dummy, and loaded it and the Starline cased cartridge of same length, the longer cased cartridge being second in line.  I tried to cycle them and they both worked well, although the second bullet's nose had a little divot from the UBB.  I was pleased at this point.  So I made another cut down .50-70 case and tried two dummy rounds , both cycled well, but still getting a little divot on the second round's nose.  I went on to make 3 more cut down .50-70 cases and dummy rounds.  I loaded up all five and 1,2,3 and 5 cycled well, but it got hung up on #4 -  Hmmm.  Then I remember reading on the forum that adding a little grease to the bullet noses helps a lot.  So I tried it and SHAZAAM! – all 5 rounds cycled, chambered and ejected nicely.



I think I've got a workable cartridge now.  I'll make up 5 more cut down .50-70 cases this week, then load up all 10 and go to the range and give them a try.  My bullet alloy is wheel weights with some tin solder added, somewhere around 25:1.  I think a harder alloy will help the nose hold up better to the UBB's bite.  I'm not sure if I should do any more work on the UBB's leading edge or leave it as is.  Overall it's been a productive day.  I still have some work to do with it, but I'm pretty close.

After this, I'll start all over again using the Rapine 350T bullet....

[Herbert]

If you can use the longer case lenth(not many Spencers will acept this ) you may want to try the 32ga brass shot shells,they have the advantage of holding 5gr more powder,a friend of mine has a Sprinfield converted carbine to rifle that he uses the longer cases with the Lyman 515139 bullet and 45gr of Swiss FF with very good results.The Rapine 350T bullet takes up a lot of case room that is needed for powder (you need good velocity in the Sprinfield barrel to get the best acuracy because of the slower 1 in 42 twist rate)but with the longer cases it would be worth a try,it has the advantage of carying plenty of lube,somthing that is very impotant when shooting BP

[ndnchf]

It was a nice surprise to find the longer shell fit the chamber.  I didn't realize that Springfield cut longer chambers in these.   But your friend's converted rifle sounds the same.  It will be interesting to see the powder capacity of this longer case.  I plan to load it wiith 1.5 Swiss and the 515139 bullet with SPG.  I hope the lube will last the full length of this long barrel. The difference between the Rapine 350 and the 515139 inside the case looks minimal.  The 350 may take up a tad more space, but I don't think it will be a big difference and the extra lube will be a worthwhile trade off.  More of a concern is getting the OAL correct with the 350 bullet so it will feed well coming out of the magazine.  I think harder bullets will be a benefit, next time I'll add more tin.  BTW, groove size of this rifle is .5145".  I'm sizing my bullets .515".

[Herbert]

Seem like every thing is starting to come together,the Swiss 1 1/2 will be fine,the Rapine bullet will defintly hold enough lube,weather you can get enough powder in the case with the cut-down 50-70 cases withh the Rapine bullet is hard to say,if not try the 32ga shot shells,in any case you will need a compression die,once you choose the bullet you want to use you can modifiy your expender die to do booth jobs at once

[ndnchf]

I haven't tried the 32 gauge shells yet, so far the Starline .50-70 brass works well.  I did discover after my initial check, that the Starline .50-70 rim thickness is .0625" - .063" and this chambers fine in my rifle after the rim diameter is reduced to .645".  The Starline .56-50 brass has a rim thickness of .058".  So it seems that Starline .56-50 brass would cause excessive headspace in my rifle.  Since Springfield armory installed model 1868 trapdoor barrels when they made these infantry rifles, I'm starting to think perhaps those barrels were already chambered for .50-70 and they cut a ittle off the breech, threaded them to the receiver and using a Springfield made .56-50 reamer, re-chambered them.  That might explain the longer than normal chamber and the rim thickness matching the then standard .50-70.  Its all speculation, but it makes me wonder....

[Herbert]

With the Starline cases being a bit thiner is not a problem as they are solid head cases,with original copper rim-fire cases head space would have been bad,even with the 32ga semi baloon head cases there is enough suport for BP presuers even though the rim on these cases is even thiner.Reguarding the chamber in the Sprinfield Spencers it would be interesting to do a chamber cast to verify your thinking,I to belive this is could be the case

[ndnchf]

I tried a full length .50-70 case in the chamber.  It goes in most of the way, but about 5/16 -3/8" still protrudes from the  end of the chamber.   

The long cases of mine (1.356")hold a lot of powder.  I could easily put 45 gr by volume (49.3 gr by weight) of 1.5F Swiss.  I poured this through a 24" drop tube (not really necessary), then to take up some space, added a .030" card wad and a newspaper wad.  Then compressed it .100", then seated the Lyman 515139 bullet to an OAL 1.680".  I hope to get to the range Friday after work and try it out.

[Herbert]

Load sound good,will look with interest for results,are you trying the Rapine 350T bullet as well

[ndnchf]

Yes, I will try the 350T next.  Initially I was trying them both with dummy rounds, but I then narrowed my experiments to the 515139 to get that worked out.  I'll work on the 350T next.  I would really prefer to use the 350T bullet because of the largerr lube capacity needed for this 32" barrel.  The nose shape of both bullets is very similar, so I'm hoping the same OAL will work for both. 

[Trailrider]

I have long been of the opinion, based on a study of the cartridge dimensions of the .56-50 and the .50-70 Gov't rounds, that the latter was a centerfire development of the former.

[ndnchf]

Trailrider - i agree, the similarities are too many for it to be othewise.  I'm doing some research on this and will post an upadate soon.  I'm off to the range this afternoon for my first test firing of this rifle 

[Arizona Trooper]

I would agree also. If you ever encounter one of the early bar anvil primed 50-70s you will be convinced. Frankford had the machinery to make 56-50. It seems like it would have been a simple matter to modify the dies to make those early inside primed 50-70s.

Let us know how the range session goes.

[ndnchf]

I went to the range yesterday for my first test firing of the Springfield Spencer rifle. The rifle cycled and ejected great.  I found that a very small smear of grease on the bullet noses made feeding much smoother. I'll make the next batch of bullets out of harder alloy and hopefully can do away with the grease.

This thread was about the feeding problems I was having. I'm now over the feeding hurdle. I like to keep things organized and I plan to document my shooting and load development.  So to avoid one run-on thread that meanders over different topics, I'll start a new thread on shooting the Springfield Spencer.  Thanks for all the help getting the old rifle working smoothly.  Now on to the next phase.