18" inserts, rifled for 45 Colt, chamber is .410/.45lc, in 1800's Parker 12ga SxS

[Pontiacthrasher]

Hello All : )

Have been reading all over the internet for clues but cannot find where anyone has documented figuring out this situation that I have chosen to put myself into, seems that I am "off the trail."

Basic goal: Put this old Parker Shotgun, which I have owned for about 35 years, but never fired, into safe and limited use, using only one size long brass shell casing, separately, for Shot shells, and .45 Boolits.

Foundation:
It has Side by Side 12ga Damascus Barrels that I personally refuse to take safety risks with, though I love the look and patina. I may take the Damascus Barrels down to near the 18" length of the Barrel Inserts, maybe 20", but still looking into and considering that.

Also looking into the best way to affix the barrel inserts into place to:

A) Prevent someone from loading modern 12ga shells.

B) Aid with accuracy. The factory provides rubber o-rings for aligning the inserts within the 12ga barrels, and they are widely accused of throwing off consistent accuracy when shooting Boolits. Some people recommend specific spec epoxy that can be removed using heat later when necessary.

The inserts are Chaszel: Rifle dimensions are .451″/.445″ with 6 lands and .145″ wide 1:12 twist rate.

For several reasons, (minimizing the jump to the lands for accuracy with Cast Boolits being a major one,) I would like to figure out a safe way to load long brass into it, without loading it too "hot" for this antique gun, so low pressure rounds well within .45 Colt Range.

I have yet to measure the chamber lengths, but believe that they accept 3" .410 shells, so they maybe about 3.5”, and appear to be stepped slightly. If so considering adapting some .45-120 brass, as it seems close to the right length for the chamber, and can be annealed, fire formed, and trimmed to desired length. I believe that those cases can be adapted and used in both ways, as shot shells, and for Cast Boolits, which is what this forum does so well.

From what I have been reading, between using wads and fillers, and the right powder, this is an attainable goal, if both the Cast Boolits and the Shot Shells use the exact same length brass, it would help with maintaining the chambers as far as switching between the two go.

I have BP, Unique, 3031, Triple7, and Power Pistol on hand, some .451RB’s and Conicals for my bp pistols, and molds for .457RB and 454190, to the extent any of that might be useful. Alloys on hand: some 15-18 BHN, some pure lead, and some big chunks (70 lbs) of unknown scrap…

Thoughts or experience you share will be heartily appreciated,

Regards!

[GhostHawk]

Like you I have a couple of Chazel's long chamber adapters.

I have a few that I have not yet shot (need to do that soon)

Unlike you I have been sliding mine into H&R single shot shotguns, 12 and 20 ga.

I have a couple of short adapters for .410 but have not done much with them.



A Regarding Damascus barrels. Since the chamber inserts are modern steel, I would not be concerned about firing them in a Damascus barrel.
The brass and the insert is going to contain the pressure.

B You will want to watch your loads as case thrust towards the rear as it is fired could be an issue.

C I think the solution you are looking for is Locktight. I believe that they have one that releases with heat.

D I suspect the biggest issue is going to be regulating the 2 barrels so that you get something that is practical.

E Personally I have stayed away from .45colt/.410 as it is neither fish nor fowl nor good red meat.
Rifled barrels do not play nicely with shot, period. And the .410 chambering means that the .45 colt has a HUGE jump to the rifling.

I guess if it was me I would start with a box of Magtech brass .410 ammo and see what you can accomplish.

I would strongly advise you to do a chamber cast or pound cast of the insert so you know exactly what dimensions you have to deal with.

[Pontiacthrasher]

The decision to get the .45colt/.410 was a major compromise, to the point that it is practically a salvage effort to sort this out. Getting the .45's sorted well is the priority. I agree the .410 aspect is a lost cause, though if I can come up an effective snake load it would be a good thing, as they are already coming out this year around here. Thank you for all the advice, sounds like I better learn about regulating the barrels and nail down the chamber situation before I go much further.

[elk hunter]

Pontiacthrasher;

As a Parker fan/collector I own and shoot a number of Damascus shotguns. You may be surprised at the possible value of your shotgun if it is a real Parker. If you cut the barrels you will make it much less valuable to a Parker fan/collector. Selling it to a collector could possibly get you enough money to buy a modern shotgun. Damascus barrels are not necessarily as dangerous as some people in the USA believe. In Europe Damascus barreled shotguns are frequently proved for smokeless loads of appropriate pressure levels.

[Texas by God]

I agree with elk hunter- leave that Parker alone. Get a $75 single shot 12 ga at the pawn shop for the purpose you are pursuing. One set of sights to regulate. Possibilities galore with no worry of hurting a treasure.

[Pontiacthrasher]

Thank you guys for the advice and comments, I agree with not wanting to cut down the barrels. These are severely pitted, really bad, so using them as is for 12ga loads just will not work, but they look nice on the outside. Hammers do not match each other, this is not a show piece. Has that great antique gun look, and what I really like is the fit to my hands, most comfortable double gun I have ever held, by far. Maybe I can exchange these inserts for some others, maybe a pair of 20 gauge inserts for shot only, or maybe 20ga on one side and .45 only (no .410) on the other. They have the full length liners available too.

[lar45]

I like the idea of doing a 20x45.
You can regulate the liners with brass shims at the muzzle. Just make the shim thicker on one side and rotate it around until it shoots to the sights.

[Pontiacthrasher]

Thank you Lar45,

The brass shims make good sense.

I was able to text back and forth just now with someone at Chaszel, and they are going to let me exchange these. I opted for the 20x45, with the 45 being 45-70 Government, and the 20ga a smooth bore. Both at 18". 45-70 Government Rifled dimensions are .457″/.450″ with 6 lands, .141″ wide, with a 1:20 twist rate, @ 18″ Long

That solves one of my safety concerns being as I have several 58 Piettas with .45 Colt Conversion Cylinders often in them, and want to use a little more power (to the extent that it is possible) in the Parker without risk of the higher power loads ending up in the "Cowboy Loads Only" Piettas. Of course the Parker action has pressure limitations too, so will be a process.

Reading up on the 45-120 led me to reading up on the 45-70, and it is a flexible and affordable enough cartridge for reloading that this is looking like even more fun.

I need a known excellent accuracy load for 45-70 Government in a comparable barrel at the lighter end of the pressure spectrum to be able to begin the process of regulating that barrel, and some wisdom regarding which barrel (Left or Right) to put the 45 into vs the 20ga.

[lar45]

45-70x20ga sounds like an excellent choice. How were the old Cape Rifles setup? Maybe go that route.
Any pics of this beasty?

[Pontiacthrasher]

260787

30 Inch Barrels, missing bead sight (broken off), one hammer does not match, as well as one hammer screw. I purchased it from the original owners family (Berge) around 1985, they were a wealthy family in Fremont California, almost a century before Fremont California was formed out of some old Townships. Long good ole' boy story short, the original owner (w/family) is buried essentially under the alter of the California Spanish "Mission San Jose" "rebuilt" Adobe Church. Not easy plots to come by... no sir.

Since looking it over after having dragged it out to take these pictures, most everything is tight, except that the lock-up needs a slight adjustment, which I can easily do. Two small dings in the barrel, one at 18" and one at around 20". Upon shouldering it, it seemed immediately obvious that having the rifled barrel on the left is better for target acquisition, at least for me.

Now reading up on 45-70 : )

[Pontiacthrasher]

260788260789

[Pontiacthrasher]

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[Tracy]

Sounds like a neat project. I wouldn't do the shim thing though, because I doubt it will have much if any effect with the inserts and might cause the barrels to start separating. The standard way to regulate inserts is to mark the breech end and rotate it 1/8 turn at a time until it hits where you want it.

[Pontiacthrasher]

[QUOTE=Tracy;4884058]I wouldn't do the shim thing though, because I doubt it will have much if any effect with the inserts and might cause the barrels to start separating.


Thank you very much for the warning, that would not be a desirable outcome.

Do you think the shims are ok to regulate the barrels, and to hold the barrel inserts in place during an epoxy pour or something like that to solidly affix the inserts in place?

People have held forth that unless the inserts are solidly fixed in place, that they will "whip" inside the 12ga barrels when shooting Cast Boolits, and in doing so, throw off the accuracy, another less than desirable outcome.

[GregLaROCHE]

I agree with the others who say it is a shame to alter an antique gun. Shoot it with low power loads and keep it original for future generations. You can easily buy a new gun, that can do what you want, probably better and cheaper. But it’s your gun and this is just my opinion.

[Pontiacthrasher]

I agree with the others who say it is a shame to alter an antique gun. Shoot it with low power loads and keep it original for future generations. You can easily buy a new gun, that can do what you want, probably better and cheaper. But it’s your gun and this is just my opinion.

I love your sentiment on this issue, and thank you for the input. That is why after years of lurking on this forum, I am finally here, and asking questions, to be able to get other's perspectives and to learn from others.


Looking over the Parker tonight, I saw two things:

1) The barrel numbers match both the receiver and fore-stock, which is truly excellent, and obviously on the side of do not modify.

2) There must be a thousand pits in these barrels, and dozens are craters, unfortunately, that is another thing entirely.

"Firearm" vs "Looks like a Firearm, but in use it's a Grenade"

Please consider what difference it makes that it cannot be safely shot even with low power loads, and is just a hunk of beautifully formed metal with a chamber and firing system waiting for some unlearned one to toss a common 12ga shell into and....?


I agree with you about it being a shame to alter an antique firearm, and have left it alone for the last 35 years, but would really like to safely shoot it, and leave it in "safe to shoot condition" for future generations as well. If it were a top of the line Parker, or rare due to some oddball short run design aspect, I would not consider modifying it, and it would probably be worth the price of barrel restoration.


Since the barrels assembly is all that I am considering modifying, I suppose a set of barrels from another gun could be modified to put this Parker back into practical action. That way the matching numbers barrels could just be left alone and used for display purposes only.

I have never went hunting another set of barrels, but have seen Parker barrels once in a while for sale, though I have yet to see a set for this model, I suppose the lucky find would be "lesser valued" set that already has been modified somehow by someone else.

[GregLaROCHE]

As I said before, it’s your gun.

[elk hunter]

Yes, it is your gun but, I'll throw out one more thing to consider. The 45-70 even in a black powder load generates much more pressure than your shotgun was proofed for. While I haven't done the calculations for the difference in thrust due to the difference in the size of the heads of the two cartridges I would consider the locking lug at the bottom rear of the barrels good enough for shotgun pressures but is less than what I would want for rifle use. Due to the short action bar length and the barrels acting like a lever on a fulcrum the barrels will flex downward away from the action face and the action and locking lug will be stressed. Even the dolls head extension of the top rib will not prevent the action springing to some degree.

[waksupi]

I had a friend who has now passed away who did quite a few old shotguns making .45-70 inserts for them. Never any problems I heard of.

[Pontiacthrasher]

Yes, it is your gun but, I'll throw out one more thing to consider. The 45-70 even in a black powder load generates much more pressure than your shotgun was proofed for. While I haven't done the calculations for the difference in thrust due to the difference in the size of the heads of the two cartridges I would consider the locking lug at the bottom rear of the barrels good enough for shotgun pressures but is less than what I would want for rifle use. Due to the short action bar length and the barrels acting like a lever on a fulcrum the barrels will flex downward away from the action face and the action and locking lug will be stressed. Even the dolls head extension of the top rib will not prevent the action springing to some degree.

Thank you Elk Hunter, I have been pondering (without your obvious knowledge and experience) along the same line. Since I already load cowboy loads for replica 58's with conversion cylinders, I could just take it easier on the old gun and instead do 45 Colt and 20 gauge.

The 45-70 load I am liking is: Lyman 457193 405 gr using IMR 3031 at 11,100 C.U.P.

Pressure is not high, close to that of 20 gauge, but as you pointed out, pressure is not the only consideration.

So have begun to read up on the likely pressure range that was originally safe for the Parker. Specific info on the (around 1878) Parker is not easy to find so far, and there is the condition of this gun to consider.

The Inserts contain the pressure other than the that behind the cartridge. The "Thrust" factor looks like the next hill I need to climb and see beyond, so will look into that, and seems to directly result among other things in: recoil.

The 20 gauge pressures are higher than the 12 gauge pressures, but if smaller payload... maybe less thrust...


Pondering and learning!

[Pontiacthrasher]

Thank you Waksupi,

Good to hear of some direct experience on this issue.

Still looking into this, but so far it seems like if careful it's not one of those "never do this" things, but still looking into it from the practical point of view. I believe I can shoot light round balls through all day long, but if that is all I could do, then I might as well just use 45 colt instead.

Then as a fallback I can use the 45-70 components in my 12 ga SxS Savage Fox B Series, it can easily take more than the Parker.

Either way, if not in the Parker, then in the Savage, because after researching the 45-70 round, "I'm in," and components are on the way.

[kenton]

If you are not married to the 45 caliber you might consider a 38 special insert. That way nobody could put a modern lever action or even worse a Ruger only load in the 45-70 barrel.

Awhile ago I did the math for bolt thrust on a 357 vs 410 for a project I was day dreaming about and found they nearly the same. But don't gamble your self on my memory or math.

You can download pdf s from saami's websight that show pressure, cartridge dimensions, and chamber dimension. Be sure to read it thoroughly, the technical data can be a bit dry.

https://saami.org/technical-information/cartridge-chamber-drawings/

[Pontiacthrasher]

[QUOTE=kenton;4885336]If you are not married to the 45 caliber you might consider a 38 special insert. That way nobody could put a modern lever action or even worse a Ruger only load in the 45-70 barrel.Awhile ago I did the math for bolt thrust on a 357 vs 410 for a project I was day dreaming about and found they nearly the same. But don't gamble your self on my memory or math.
You can download pdf s from saami's websight that show pressure, cartridge dimensions, and chamber dimension. Be sure to read it thoroughly, the technical data can be a bit dry.



Thank you very much Kenton, I have got the saami's link on my toolbar now, thanks to you, and plenty to read. Will be interesting to see where the data guides this project.

[bld451]

The problem as I see it is not the barrels. You are well aware of that problem, and have stated as much. As Elk Hunter observed, those actions were designed for shotshells that operate at 11k psi. There is a safety factor, of course but the proof level loads are not above 20k. Factory 45 colt loads (the ones everyone always complains about being low-powered) are limited generally to 14k to operate in older revolvers, so yes, stay well below the "balloon head" 45 colt loads. Should you go the metallic cartridge route, be very, very judicious with loading and ammunition management, and maybe not sell it unless you return it to its original configuration. Those actions release gas and brass 4 inches in front of your eyes when something lets go. It sounds like you are willing to accept the limitations, and its always good to see an old gun get to have some fun. Enjoy, and let us know how it turns out.

[lar45]

Bolt thrust is Area x Pressure
Area is calculated as pi*r^2 or roughly 3.14*radius*radius
This will give you an answer in square inches
Now multipy by the pressure which is Pounds per square inch.
the square inch on the top and bottom cancel each other out and you are left with pounds
I made up a quick and dirty Excell sheet for calculating Bolt Thrust
http://www.lsstuff.com/misc/bolt-thrust.xls

Feel free to put the 45-70 in with a base of .506" and a pressure of 28000
You can then see that the thrust of a standard 12ga is very similar to that of a Ruger level 45Colt, or standard 45-70.

[Pontiacthrasher]

Those actions release gas and brass 4 inches in front of your eyes when something lets go. It sounds like you are willing to accept the limitations, and its always good to see an old gun get to have some fun. Enjoy, and let us know how it turns out.

Thank you bld451 for the sober detailed advice, and the encouragement.

To everyone: I appreciate very much that you'all on this forum are helping me to figure out how get this old gun back into use, while avoiding pushing it beyond safety, or to the point where I am abusing it. General goal is to configure it to be safer to shoot than it's current state, and enjoy it occasionally, without insulting it by turning it into something too wimpy, after all, it was in its youth, a double barrel twelve gauge shotgun : )

[Pontiacthrasher]

Hello lar45

Wow...

To start with, great tool you are sharing, thank you VERY MUCH! And with such good news: "5627.67128" DANG : )
now if I can just make my gal 1/2 as happy on her Birthday this Saturday as I am right now!

You're the Man.

[lar45]

I put a 470NE together on a Belgian 12ga double. After about 400rds it's started to come off face, so I should have started with a heavy waterfowl action and probably would have been fine.
For regulation, I used thin brass shims at the muzzle to walk the barrel to the sights.
I did have to reinforce the butt stock to hold the recoil of the 470. It weighed about 8lb, so I put 2lb of lead in the butt also.

[elk hunter]

To anyone considering doing a conversion I have One last suggestion. Get a copy of Ellis Brown's book (Building double rifles on shotgun actions) ISBN: 0-9714802-0-6. Mr. Brown explains how he selects an action and all the steps needed to be successful in doing a conversion. Unfortunately Mr. Browns book was not in print years ago when I decided to convert a relatively new Ithaca 20 gauge double, built by SKB, to 30-40 Krag. When I started to regulate the barrels I discovered that the action was springing and would have gone off face, as the British say, very quickly. That project sits unfinished to this day as a reminder to do some research first.

Nothing I have posted here is meant as criticism but rather is cautionary. Please be careful.

[Pontiacthrasher]

I put a 470NE together on a Belgian 12ga double. After about 400rds it's started to come off face, so I should have started with a heavy waterfowl action and probably would have been fine.
For regulation, I used thin brass shims at the muzzle to walk the barrel to the sights.
I did have to reinforce the butt stock to hold the recoil of the 470. It weighed about 8lb, so I put 2lb of lead in the butt also.

Having never heard of it, I had to look up the 470NE, 2lbs of lead, great solution. Reminded me of everyone throwing some 90lb bags of cement against the tailgates of their El Camino or Ranchero to get some traction on Friday and Saturday nights.

[Pontiacthrasher]

To anyone considering doing a conversion I have One last suggestion. Get a copy of Ellis Brown's book (Building double rifles on shotgun actions) ISBN: 0-9714802-0-6. Mr. Brown explains how he selects an action and all the steps needed to be successful in doing a conversion. Unfortunately Mr. Browns book was not in print years ago when I decided to convert a relatively new Ithaca 20 gauge double, built by SKB, to 30-40 Krag. When I started to regulate the barrels I discovered that the action was springing and would have gone off face, as the British say, very quickly. That project sits unfinished to this day as a reminder to do some research first. Nothing I have posted here is meant as criticism but rather is cautionary. Please be careful.





Book is on the way, thank you.

[15meter]

Before you exchange the inserts you have, you may want to look at 444 Marlin brass.


It gets used as 410 brass shells, it should blow out from .429 to .452 dia quite easily. That will get you much closer to the rifling. Review case forming, I've blown 30/30 out to 38/55--virtually a straight walled case.

I haven't done any research on the feasibility of this, but off the top of my head it may work.

Regulating double rifle loads for light loads is done with pistol boolits. Start with experimenting with rotation of the inserts, once you've got that as good as you can get it. Start playing with boolit weight/speed.

For plinking/practice loads I've regulated 470 N.E., 450 N.E., 450/400, 400/350, 9.3X74R, 303 British and the 8X50R.

Light pistol boolits seemed to work the best, I got my start on the pistol boolit thing from a book on English doubles, apparently they were making light practice loads for the boomers for a long time.

Luckily none of those were inserts with that added variable.

May go make some reloading possibilities with a couple of boomers today now that you've got me thinking about it.

Good luck, sounds like a fun project for house arrest.

[rintinglen]

Given nearly equal pressures, the 12 gauge will have higher back thrust than the 45-70. The area under pressure from the 45-70 is half that of the 12 gauge (math done off the top of my head.) As long as you stay down at the BP pressure level, you should be OK.

[Pontiacthrasher]

Before you exchange the inserts you have, you may want to look at 444 Marlin brass.It gets used as 410 brass shells, it should blow out from .429 to .452 dia quite easily. That will get you much closer to the rifling. Review case forming, I've blown 30/30 out to 38/55--virtually a straight walled case.I haven't done any research on the feasibility of this, but off the top of my head it may work. Regulating double rifle loads for light loads is done with pistol boolits. Start with experimenting with rotation of the inserts, once you've got that as good as you can get it. Start playing with boolit weight/speed.For plinking/practice loads I've regulated 470 N.E., 450 N.E., 450/400, 400/350, 9.3X74R, 303 British and the 8X50R.Light pistol boolits seemed to work the best, I got my start on the pistol boolit thing from a book on English doubles, apparently they were making light practice loads for the boomers for a long time. Luckily none of those were inserts with that added variable.May go make some reloading possibilities with a couple of boomers today now that you've got me thinking about it.Good luck, sounds like a fun project for house arrest.


Hello 15 Meter, Laser sailor here, though not lately. Use to race it back in the Seventies, till I got my first Pontiac.

You're way ahead of me on this regulating stuff, thanks for the input.

I already exchanged (long distance slow motion process) the inserts, so two to work with on the way, waiting for Chaszel to do up a batch of the 18" 12ga to 20ga smooth bore, so will for now have one in 45 Colt, and one in 45-70 Government.

I knew brass/powder solutions were out there for the 410 chamber to get the 45 straightened out, what really did in the 410/45 Colt inserts for me was that the rifling would make the 410 shot shells far too problematic to be of much use or fun for me.

Looking forward to the process of regulating the barrels, my first time so something new to think about. I'd think that any barrel off-perpendicular to the Action Face would add leverage to challenge the strength of a firearms action.

Planning to start by slugging the bores, I believe I have Round Ball that will be accurate at low power for the 45 Colt, but will likely need another mold for the 45-70, unless the .457 RB mold I have will suffice for low power regulation needs.

I am brand new to this Double Rifle/Cape Gun thing, but it seems that the present practices for sighting and regulating barrels are seemingly still being ruled by a basic decision that was made well over a hundred and fifty years ago. They went with "cross eyed" barrels, with one shared sight between them... which is fine for shotguns, but rifles? Seems very limiting, though for fast shots in a short range Jungle and Woods situation, apparently just what was needed.

Thinking it worth a try to get away from that when using a good rifle round like the 45-70 Government alongside a shotgun barrel. I am going to install dedicated sights for each barrel. I would like the 45-70 to have the same accuracy capabilities as when in a comparable single barrel configured rifle.

Also wear glasses nowadays, so will be factoring that added complication in as I go, I can no longer effectively use Iron Sights, so going to explore that world too. Will be attempting some old Hybrid Sighting Technology, vintage magnification that uses a forward sight/external reference point. Have some antique odd looking brass thing on the way for that.

[Pontiacthrasher]

Given nearly equal pressures, the 12 gauge will have higher back thrust than the 45-70. The area under pressure from the 45-70 is half that of the 12 gauge (math done off the top of my head.) As long as you stay down at the BP pressure level, you should be OK.

That has been my general feeling from early on, and the math that people have assisted me here in the forum backs that up, thank you for adding to the opinions, it helps with confidence and such while trying to make decisions.

[15meter]

I may have misunderstood, didn't think you were going to use it as a shotgun.

I was thinking use the 444 Marlin case as a basis for in essence a 444 length 45 Colt. Your own fire formed wildcat as it were. Trailboss powder for low pressure, 45 Colt sizer die for neck tension.

I may have to do a little experimenting later, this has been just blue sky theorizing.

Need more of the "this is what happened when I did this" as apposed to armchair guessing.

[lar45]

The general theory on double regulation is the left barrel recoils up and left and the right barrel recoils up and right. Anyone feel free to correct me if I have this wrong.
When I did the regulation on my 470, I did it from a standing rest. I took some 2x4s and screwed them into a triangle to clamp to the upright post at the range. Then took a sand bag and put on the horizontal section and rest your forward forearm on the sand bag. Then get your sights aligned, raise up slightly and fire. Ideally you will have your left barrel hitting about 1" left of the bullseye and the right hitting about 1" right of the bullseye. That way they will shoot straight for whatever distance you want. If they cross(left hitting right of center and right hitting left of center) then you don't know how far off they will be if your shooting farther than the regulation distance. I set mine up to be about 1.5-2" apart at 50 yds. If you try shooting from the bench, then the gun won't recoil the same and your individual barrels will hit differently.

I mounted some NECG express sights right to the rib.
https://lsstuff.com/howdah/pics/470ne/sights02.jpg

FWIW

[15meter]

Dug out a 444 case, 45 acp expander, 170 45 acp boolit, 45 acp seater.

261335

Fits about 1/2 way into a standard .410 chamber, curious if it would fit into a 45 Colt/410 chamber.

Got a buddy who has one of the 45 Colt/410 Judge revolvers, when we come off house arrest I'll have to have him bring it to the club to see if it will chamber.

This may improve the accuracy of those hybrid chambered Judges and IIRC, Thompson Center also had a similar barrel available.