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.

Tacticool Trapdoor

I've been forming the idea that trying to chase small variations in group size wasn't going to be very effective if my overall group is still out at 6 or 7 inches.  A 1/2 or 1 inch improvement is good, especially if coupled with one or two other improvements, but I can't find them very well in the shotgun pattern of my shooting.  The solution, my thinking goes, is to mount a scope for my testing sessions.  This should pull out all the variation due to any visual problems.  So, off to the all knowing interwebs for ideas.  There are a couple of examples out there, but they mostly involve attempts to mount historically accurate long tube brass scopes.  These need a funky swing away mount to make room for the trap door to open, or else need to be rigidly mounted along side the barrel.  I'm not sure I agree with this line of thinking, as the trapdoor was pretty much a high volume cheap soldiers gun, not a real marksman's piece of kit.  Anyway, I'm not looking for a permanent or classy solution, just something for testing.  Here's my solution:

 I know, it looks hideous.  The scope is an NC Star (super cheapo) pistol scope using a modified mount for a Thompson Center Contender.  I used the pistol scope because I had to mount the eye piece so far away to make room for the trap door.  The Thompson Center mount needed one hole opened up to take a stock rear sight screw and another hole made from scratch.  A small notch had to be machined to allow the stock loop to pass through.  All in all, another fine simple adaptation that in no way modifies the original rifle. 

Here's a close up:

As you can see, there's only one set of body clamps that will mount up, but the system seems to be pretty secure anyway.

Shooting it was pleasant.  The scope is only 7 power, but it gives a substantially more refined visual picture.  The adjustments seem pretty accurate and repeatable.  I did notice some parallax error.  It is set for zero parallax at 50 yards.  The texts seemed to say parallax gets less important at longer ranges, but I could notice a good couple of inches motion as I moved my head from right to left in the scope.  There are adjustable scopes that will take this out, but they cost money.

So, did it work?  Unfortunately, no.  There was nothing wrong with it, it just didn't shrink my groups an appreciable amount.  Tacti-uncool.  I intend to keep using it for ammo testing, but it certainly makes me feel better about my current aperture setup.

I haven't posted my spending lately:

Current cost per shot = $2.43

Shipping is 9.14% of all costs.