5 Will Get You 10

It has been a while!  There are a few reasons for this.  I didn’t want to report back on the 38-55 Trapdoor project until I had some firm results.  I also just plain got busy.

For a long while I couldn’t buy any of the correct brass for this relined barrel.  The 38-55 comes in 2 lengths.  The longer 2.125” is the original standard.  A slightly shorter version came about several decades ago because nobody was making brass and a short brass could be made out of another, similar case.   Anyway, in the great “Obama’s going to steal my brass” hording scare of 2013, I found I was out of luck.  I did manage to find a work around for testing.  It was still possible to get “38 Basic” brass, which is way too long and ungodly expensive.  I picked up 20 cases and cut them down for testing.  Finally, about a month ago, Starline came through with standard cases.

Load testing was interesting.  I still have a long ways to go, but I at least know what not to do.  Like the 45-70, it doesn’t like light bullets.   I’m currently at 320 grains and looking to try bigger.  The higher loads are bad as well.  I’m currently at 44 grains and will be trying less.  I tried 1 batch of FFFG.  Typically, I don’t experience much difference with grain size changes.  On this rifle it made the pattern triple in size.

So today, now that I had some brass and a load, it was time to take the old soldier to a match.  It was a bit breezy, but I can’t really blame that much.  I’m incredibly pleased with how light the recoil is.  As it stands, the gun is shooting as well as my rolling block.  I’m convinced it has a ways to go.

You’re probably wondering by now “Why 5 Will Get You 10?”  Was there some Double-or-Nothing bet we don’t know about?  Take a look at this target.

I shot this today in the match.  5 in the black, and the other 5 floating about 1/4 inch away.  A 5% reduction in group size should do the trick.  Of course, if I'd just adjusted my sights up 1", that would have worked too.  Hopefully, I'll be updating this blog a bit more frequently now that I'm shooting the old girl again.

38-55 Trapdoor

The main reason I abandoned the trapdoor and got the Pedersoli rolling block was the barrel.   I’m not convinced that the rolling block action is any better than the trapdoor, and in some ways it is worse, but there was no getting around the worn and slightly pitted barrel.  The long term solution was a new barrel.

I pondered four options.  The first was to get an original barrel with crisp rifling.  I found that hard to find, and believed it to be too expensive, though it wasn’t bad compared to my final solution.  The second was to get a new barrel made to the original external shape.  This would allow me to move away from the original three groove, twenty two inch twist if I wanted.  This option is easier to find, but again money held me back.  The third option was to reline the barrel to 45-70.  This could either be the original three groove configuration or something different.  The last option, and the one I chose, was to reline to a different caliber.

The reasoning for the change in caliber was twofold.  The first was strength.  The relining process bores a hole all the way down the barrel and fills it with a thin barrel.  How strong this system is depends greatly on how well the inner liner transmits load to the outer remains of the original barrel.  When I looked at the wall thickness of the liner for the 45-70, I decided I just liked the 38-55 wall thickness better.  Both liners had the same outside diameter.  The second reason was accuracy.  The 38-55 has a fine reputation at medium ranges, and since I normally shoot at 200 yards, it seemed to be the cat’s meow.  A third, more subtle, benefit is reduced recoil.  I’m not much affected by recoil, but it could be a driving factor for some lighter framed shooters.

The  Process:

I’ve never done a reline of a barrel before, but I’ve spun a lathe a bit.  I knew that the #1 problem in most repair jobs is how to accurately and rigidly hold the work piece.  With the outside of the barrel tapered along the full length I knew that no chuck or collet I owned would do the trick.  I opted to pick up 2 “soft” collets.  These are steel, though they also can come in brass or plastic, that is machinable.  I set my lathe to cut the same taper as the barrel in the bore of the collets.   One grips the barrel a few inches from the breech, with the breech sticking out.  This is where 90% of the work is done.  The other grips a few inches from the muzzle for cleaning up the crown.  I will issue a warning that the collet near the breech left a few light scratches that seemed to have been put in just as I was seating the collet.  In my case I was unconcerned because I had bought a crusty rust pile barrel to do this to.  It was going to get a full refinish.  Also, the front collet struggles to get over the front sight.  The removable blade sight needs to be pulled, and a notch cut in the collet.

Before machining can begin, a bit of tool fabrication is required.  The main task is to make a long drill bit.  I purchased a bit with a bore riding pilot from Pacific Tool and Gauge.  It is a well made unit ground to the OD of the liner.  The trouble is that the shank is short.  I took a length of precision ground rod and bored a hole in the end that is a slight press fit for the shank, then pushed it in with Loctite.  Some people claim to weld the extensions on, but I can’t see how there isn’t heat warping involved.  The drill loads seemed very light anyway.

 

The shot above is the drill being held with the pilot in the chuck for alignment, being pushed onto the end of the steel rod that has been bored in the lathe collet.  The rest of the rod is about 3 feet long and rests inside the lathe spindle.

There are a few accuracy concerns in this job.  The first is that the drilled out bore needs to align with the original barrel for a neat, concentric crown.  The piloted drill pretty much assures this.  The second is that the chamber need to be concentric to the new bore, aligned to the new bore, and of the right dimensions.  Some of this is assured by using a piloted reamer.  The front of the reamer is thus forced to be true to the bore.  The rear of the reamer remains true to the bore solely by dint of all the cutting steps being taken in the same setup.  No removal and realigning of the barrel is required.  It is also a good idea to check alignment of the lathe tailstock in preparation for this job.  If the tailstock is offset, the reamer will be pushed to the side and will cause an excess taper with too large an ID at the breech.  You may also see an uneven amount of cutting on each of the reamer flutes in this situation. 

This shows a tap handle driving the reamer and a dial indicator to show the depth of cut, for when the final headspace is being cut.  Some companies make a floating reamer driver that can be aligned perfectly to the bore.  This is probably a good idea if you were super serious about accuracy.

The last accuracy concern is headspace, the control of the depth of cut.  In a rimmed cartridge, this becomes simply controlling the seating face for the cartridge rim.  You can choose to set per SAMMI specs, which will allow all cartridges to load.  Most target shooters set for minimum clearance on whatever brass they choose to shoot.   I used Starline and found they tended to have thin rims.  This allows me someday to do a cleanup cut on the chamber and use brass with a thicker rim.  It also means some other brass might not allow the action to close right now.

If the old action had good headspace, a simple depth measurement from the end of a seated cartridge to a fixed feature like the thread shoulder is all you need.  If you want a different headspace, some corrections can be made from there. 

The drilling went easily, with the trapdoor barrel being fairly soft and making “crumbly” chips.  The liner was glued in with green “shaft lock” type Loctite.  A little facing was done on the breech, then the chamber was cut.  This was done unpowered using the lathe for alignment.  The final cuts took a few iterations of fitting the breech block to check headspace.  When the barrel is removed and flipped the crown could be cleaned up.  I’m a little displeased with the crown.  When the cutter skims over the lands and grooves, it leaves little uneven burrs that I couldn’t quite control with any of the normal cutter tricks.  I’m also unable to prove the crown is truly concentric with the bore, since the setup had to be dismantled and flipped.  People seem to rave about an 11 degree crown.  It seems to me a true zero degree crown could be machined more reliably, and that might overcome a poorly made 11 degree crown.  Either way, I have ordered an 11 degree piloted hand crowning tool and will give that a try.

One final challenge.  The original extractor is too thin to reach the smaller cartridge rim.  I fabricated a new one and cut the notch for it in the relined breech.

 

This standard T-slot cutter fit the bill nicely.  I have never had nice "clinky" ejection, even with a 45-70.  I have seen it done and it is pure magic when the indians are raiding.  For target work, I am fine with the more restrained control of spent brass that my trapdoor ejector gives me.

 

Here's a shot of the 38-55 nestled in the big-bore-breech.  Cute!


Cost totals  (Some are guesses):

Old barrel, receiver, door. $75-100
Liner  $5.39/inch   Track of the Wolf.com
Drill  $75
Shank  $20
Reamer $95
T slot Cutter  $15
Crown tool  $85
Brass  $62
Dies  $50
Headspace gauges - cheap, but a total waste.  In bottleneck cases they measure something difficult to measure and important for safety.  In rimmed cartridges, they are glorified washers, and you should learn basic measurement techniques instead.

How does it shoot?  Well, I can’t let all my secrets out in one blog.   Stay tuned.

Trapdoor Trigger Pull.

When I got my Pedersoli rolling block, I was astounded at how firm the trigger was.  Taking it apart, the action proved to be very simple, not allowing for a lot of trickery.  Other than bucking up for a complete new double-set trigger setup, there are only 3 things you can do to improve trigger pull.  First, you can thin the mainspring.  This works, but it increases lock time and could lead to intermittent firing of the primer, so I left it alone.  Second, you can change the sear angle.  This also works, but there is a risk of making the sear unsafe if the nock tapers away from the sear.  The gun can just go off by itself because only friction is holding it cocked.  I left this alone as well, except that I do a little polishing to slicken up the feel.  Lastly, you can lighten the trigger return spring.  This spring pushes the sear up into the notch and the worst drawback if you go too far is that the hammer might not "lock back" and you'll set the hammer back slowly on the firing pin.  Once the hammer latches, the trigger return spring is no longer what actively secures the sear, the nock angle is.  So,  I made a new spring out of "safety wire."  This is .032" stainless wire and is significantly softer than the stock spring.

Here you can see the wire wrapped around the mounting screw and resting on the sear.  The original spring was a flat strip that filled the whole width of the trough.

The result was a trigger pull of 36 ounces.  This sounds light, but in the offhand position it feels terrible.

But this is a blog about Trapdoors, right?  Here's a shot of the same concept applied to the Trapdoor lock:

The wire loops around the mounting post and an extra loop slides into the slot that holds the stock spring.

Here you can see that the spring as it pushes on the sear.  It may look like the wire would easily fall out, but the wrap around the post holds it well and when installed, the wood of the stock traps the spring.

How does it work?  Trigger pull is down to 21 ounces and feels very nice.  This is the same setup I used to win the offhand competition a few months ago.  By comparison, my Izhmash Ural 5-1 target .22 is set at a pull of 6 ounces and feels like it isn't there at all.

An old soldier is recalled to action.

A little bit ago I attended a match with the American Single Shot Rifle Association (ASSRA).  While they are not specifically dedicated to black powder cartridge, they have a few matches that fit both my rolling block and trapdoor fairly well.  The one for the trapdoor is for military rifles with military sights at 200 yards shot offhand.  The ASSRA is what I consider a "somewhat vintage" organization that controls the vintageyness of rifles not with a specific age, but rather by outlawing bolt actions.  You'll see some brand new falling blocks, but all falling blocks look vintage, so what the hey?  In the case of military rifles, it means a trapdoor is about all there is, as the next generation was the bolt action Krag.  I didn't specifically discuss British or other falling blocks and trapdoors, but I assume they're legal.  Whatever the reason, 3 trapdoors stood shoulder to shoulder in mortal combat.  The target, just slightly smaller than a barn, shimmered in the distance.  I'd only once before shot a match with stock sights, and was at a bit of a disadvantage without the Buffington setup.  No matter, with keen eyesight, a rock stead hold, perfect form, and of course an excess of humility, I just managed to squeeze out a win, my first match win with the trapdoor.

A few weeks later I attended a mid range "gong match."  Gongs are hung at 200, 300, 400, 500, and 600 yards.  Each person shoots in turn and spotters try to tell you where you hit.  This was my second match at these kind of ranges.  My first was a silhoutte match where I did rather poorly.  I managed to hit 42 of the 50 rounds, which was near the bottom of the group attending, but not shameful.

The next day was the "Old Soldiers" match dedicated solely to trapdoors. There were about 7 in attendance, mostly rod bayonette style. One had been built up from parts just a month or so before. The same routine was shot. My score dropped to 24. Still this wasn't the worst out there. The best, however, was astonishing at 45.

Shooting was done in typical format, prone on cross sticks.

Below you can see the Buffington sight (not mine), poised to compete.

I'm glad I've found a couple of events where I can still bring the old soldier out to the field and march him though his paces.

Traitorous Action!

Up until now I have been happily struggling along trying to make this trapdoor shoot better.  Slowly I gathered experience and knowledge, even if it was just knowledge of what doesn't work.  Gradually my scores got better as my groups got smaller.  I learned the value of good sights.  I learned the importance or the right bullet weight.  I fine tuned powder, case prep, and cleaning ritual.  In the end, I have come to the realization that I am stuck.  I have also fostered the belief that the quality of my barrel is the issue.  While it is nice to be shooting my great grandfather's old Trapdoor Springfield, I have to admit it is both worn and pitted.  So, what to do?

My first step is to try a nice modern black powder cartridge rifle just to be sure the problem isn't me.  It is always possible that I am wobbly and blind, so nothing will make a lick of difference.  Another horrible truth is that I've become as connected to BPCR shooting as I have to trapdoors, so I want a rifle I can just go use.  After a little asking around, a reasonably priced Pedersoli rolling block presented itself.  Rolling Block!  A traitor to the trapdoor cause!

Well, there it is.  The rear sight I had on the trapdoor was a direct bolt on.  I added a cheek pad just like on the trapdoor since it worked so well.  How did it do?  First time out I shot my best score ever.  I also got my first perfect 10.

So what of the future?  Does this blog turn into "Developing the reproduction rolling block?"  I don't think so.  The old trapdoor still has some life in it.  I just need to find a barrel solution, and that will take time.  The best solution is to keep my eyes out for a sharp original barrel.  I can also find a truly crusty barrel and reline it, but I'm not sure that's much different than buying a new rifle.  Either option will take some time.  In the interim, I'll just keep plugging along with my "traitorous action."

The hand of luck giveth, the hand of luck taketh away.

As I was whiling away the hours googling "Trapdoor Springfield" and "BPCR" along with other related nonsense, I came across a product that actually looked useful.  On the Lee Shaver site he has front sight aperture inserts that are shaped like little animals.  Take a look:

The shapes are a bit blobby, but they match the general outlines of the silhouette shapes.  When testing at the range, the image just looked "icky" as each lumpy bumpy portion came in and out of alignment, then all of a sudden, everything came into alignment and it just fit "right".  I am convinced it is a much better system for me, but there is a risk that if things are going poorly, such as low light, mirage, rain, etc. I might not ever form that aligned picture, in which case I'll be lost.  I was ready for match day with my secret weapon!

I show up at the counter, pay my money, and look down at the targets.  A BUFFALO!?  A GROUNDHOG?!  A CROW?!  For a year and a half I've been shooting the same pig, goose, chicken and ram.  Today you decide to change to a buffalo, crow, groundhog, and ram.  Dejected, I put my round aperture back in.  If it wasn't for bad luck, I wouldn't have no luck at all.

But, luck is a fickle mistress.  After a frustrating sight in period where my rifle seems to throw the occasional flier, I lock in and am ready for competition.  First up is freehand (standing) at the crow, which otta be a chicken I tell ya.   Freehand is tough, with 1-2 hits out of 10 not being sneered at, 5 being well respected and 6 being the best score recalled at our club.  My first shot is just inside the back of the crow, a hit.  Immediately I relax.  Even if I miss all the rest, no-one will give me any grief.  Second shot, right inside the back.  That's a two, with eight shots to go.  I'm on air.  Sure enough, I get a flier way to the left.  I choose to ignore it and keep aiming centered.  By the time I'm done I have 4 solid hits in the body and one cheesy toe hit, but they all count.  This is my best offhand by 2 shots and a tie for best offhand target of the day.  OOOh, and I got a pin with a chicken and a 5 on it!  Worth every penny.

The sad thing, of course, is that I didn't change a thing in my equipment, training, or shooting style.  It was all just chance that a good group would eventually happen.  The hand of luck taketh away.  But that's OK if the hand of luck then giveth.

The Tortured Chamber

As I've fiddled on this old rifle, I've found that most of the forward steps I've made have revolved around the transition between the case and the barrel.  Having the bullet all the way out touching the rifling, having a heavy enough bullet to deform under load, having a soft enough bullet, all focus on the short distance where the bullet is leaving the brass and entering steel.  This got me to thinking, and measuring, and I quickly determined that my chamber is a fair amount longer than my cases.  This isn't a huge concern for a military type gun, since the case is held by the rim, but it seems a good avenue to play around with.

I picked up a product called Cerrosafe, which is basically a low melting point solder.  It is used to make castings of gun chambers so you can take a look at the shape.  This is especially useful for the trapdoor where the breech is all shouded and you can't get measuring tools in there.  You just plug the barrel with a wad, heat the Cerrosafe with a small torch or hair dryer and pour it in the chamber.  Be sure the ejector cutout doesn't fill in, or it will stick in there.  Also, be sure the wad isn't too deep or the plug will be too long to get out the breech opening.  Once it cools, it taps out with a cleaning rod.

Here's a photo of the plug:

In the center is the chamber casting.  As you can see, it was a bit cold and has folds, but it gives me the info I need, so I never remade it.  The brass on the right is one of my 45/70 cases.  The brass on the left is a 45/90 I got for this project.  What's a little hard to see in the photo is that the chamber runs straight past the end of the shell, then starts to radius in, then hits a firm chamfered taper to the rifling.  The goal is to trim back the 45-90 case until it fills the straight part of the chamber, reducing the distance the soft lead bullet travels unsupported.

WARNING - If done incorrectly, and especially with jacketed bullets, this can blow your gun up.  The mechanism is this:  If the case is too long, it rides into the radiused part of the chamber and acts like a crimping die, crushing the case onto the bullet.  Normally, this is no big deal, there are overcrimped shells shot all the time.  The trouble is that the chamber is still holding the crimp down when you fire, giving the case nowhere to expand to.  Pressures go to the moon, as do gun parts.  The solution is that the cases have to fit right, not too tight.

After measuring and trimming, I had 20 rounds where the cases were long enough to cover all the lube grooves.  At the same overall length, my regular cases leave a lube groove hanging out.  So, how did it work?  Measurably worse.  My horizontal variation went from a standard deviation of 2.2 to 2.9.  Vertical was better at 2.0 going to 2.1.  Oh well.  Even knowing what NOT to do is still knowledge.  A perverse part of me wants to try shorter cases.  It seems to be the logical direction based on the data, even if it looks odd.

One good thing I got out of my day at the range was a well managed comparison of my prone shooting to my standing.  While obviously my standing (offhand) groups are much larger, they also center in a different location.  I've just never measured it before now, because it takes a fair effort tabulating hole locations, and I'm lazy.  The data is in, and I shoot about 1/4" to the right and 2" low when I shoot offhand.  Now I can think back to all those shots just under the chicken's feet and pretend to myself that they would be hits.  That makes today a happy day, free from my tortured chamber.