Reloading and short chambers

[richard lambert]

This is a subject I posted in another forum but thought it would be a good one to pose here.

I am not trying to put anyone down but looking for an open discussion on the subject of shooting longer shells in short chambers of older shotguns. For years I have read of this practice being done.

1. Is this practice reasonable with low pressure loads?
2. Would a steady diet of longer shells in shorter chambers, rather low pressure or not, cause an older shotgun's action to loosen.
3. If one reloads for an older (shooter not collectible) shotgun, would it be acceptable to lengthen the forcing cone and shoot low pressure 2 3/4 shells.

An article in "Gun Reports" by Russell Corbitt addresses some of this. Article (http://www.gunreports.com/special_reports/long_guns/Older-Shotgun-Chamber-Maintenance155-1.html?type=pf)

Dick

[Mark Landskov]

In all of the articles I have read on the subject, the answer was always 'Yes, pressure increases slightly'. Would the pressure increase to the point of peeling open a composite or fluid steel barrel? That was always the part where the author/researcher bowed out. I suppose it is a liability issue like some one asking on the forum if their gun is safe to shoot. We all agree that the person should have them looked at by a qualified individual. I suppose the guys writing short chamber articles don't want to be held liable. I would think that if pressure increases, the rearward thrust on the breechface would increase, along with forward thrust on the hook. I dunno. I will watch this thread, too. Cheers!

[Dean Romig]

"Common knowledge" says that shooting 2 3/4" shells in chambers designed for 2 1/2" shells will cause an average increase in pressure of maybe as much as 150 psi.

[richard lambert]

"Common knowledge" says that shooting 2 3/4" shells in chambers designed for 2 1/2" shells will cause an average increase in pressure of maybe as much as 150 psi.

Pretty small pressure increase when dealing with low pressure shells I would think. :corn:

[Mark Ouellette]

It is not the pressure one has to worry about. It is the increased recoil! I do not know exactly why but it is true...

[richard lambert]

From 12006 "16 Ga. Gun Talk" Topic

ITHACA CHAMBERS -- The last Flues period catalogue (1925) states -- "Unless otherwise ordered Ithaca 28 Gauge and 20 Gauge guns are chambered for the standard 2 1/2 inch shell, 16 Gauge and 12 Gauge for the standard 2 3/4 inch shell and 10 Gauge for the standard 2 7/8 inch shell. Longer chambers are furnished if ordered on new guns without extra charge, but it should be remembered that shells of standard length do not give quite as good results in chambers which are longer than the shells and it should be remembered that extra long shells are more expensive and it is much harder to find a dealer who carries extra long shells in stock."

In the published book "The Parker Story, the Remington vintage specification sheets on pages 164 to 169 call for a chamber 1/8-inch shorter than the shell for which it is intended. I have a 1930-vintage VH-grade 0-frame 20-gauge and its chambers are 2 3/8 inches intended for the old 2 1/2 inch shells, eight years after the 20-gauge Super-X shell was introduced in a 2 3/4 inch case!!"

American Rifleman: "And here's the reason why better patterns resulted from slightly overlength shells in short chambers (or chambers marked 2 3/4" that weren't really that long): Remember that we're talking the pre-WWII days, paper cases and felt or cork wads, no plastic shotcups. One reason for pellet deformation back in those days is that the unprotected pellets would slam into the walls of the forcing cone when the gun was fired. However, if the paper case mouth opened into the forcing cone, the mouth of the shell itself afforded some protection to the shot charge, on its initial contact with the bore. Tests established that slightly shorter chambers resulted in tighter patterns. Some trap shooters even when so far as to shoot 3" shells in 2 3/4" guns. Today, of course, with plastic hulls and wads, there's no longer any pattern benefit to shooting longer shells in short chambers, because the wad itself does a much better job of protecting the shot."
__________________

[Mark Landskov]

Richard, that American Rifleman article is interesting. That is the first time I heard of that theory!

[Paul Harm]

Ah, it sounds like a very good theory. I have a Parker 10ga with 2 5/8 chambers. It has about a .020 "step", so for that reason I cut shells. If it had the regular forcing cone I'd just shoot the longer shells. As to shooting shorter shells in longer chambers you'd get some blow-by and pressure loss. I've read that chambers of old were shorter so the cushion wad would still have some in the shell as the front was at the end of the forcing cone; thus giving a good seal. Paul

[Mark Landskov]

Paul, my 10 gauge 1879 Lifter is configured like yours. I have a 'cheesy' inside divider and managed a crude measurement of .809" about 2" forward of the chamber. There is an imperceptible jump from the chamber to the bore. The chokes measure .790"-ish (I don't have the figures at my desk). I questioned the bore size, but have been informed that Parker bores, at that time, were not always consistent with any set standard. I will re-check my measurements this evening. I am preparing to chase the Ruffies this morning with my RBL. Cheers!

[Paul Harm]

Mark, I have a 12ga Parker with .742 bores. Some of the more knowledgeable on this board have stated that Parkers before certain serial numbers had larger than standard bores. I have a 11ga Claybrough with .765 bores. The chambers almost took 10ga shells so I opened them up enough to take 10 to 12ga Gaugemates. Paul

[Mark Landskov]

Paul, my 10 gauge bores measure .810"-.812" just forward of the chamber. Both chokes measure .795". The left choke has obviously been augered out. There are some rough tool marks. The chamber mouths are .855", which would have been the 10A shell. I believe that system was still in place in 1879.

[Paul Harm]

I've been busy - going to Bachelders with Mark [ where I got a 10ga from Mark before he let Brad see it ] and getting ready for our leagues dinner out at the club. Haven't measured the barrels in the "new" 10 yet- but did have to get the right barrel to cock. The trigger was staying up just a hair. The gun had been restocked so I'm thinking the difference between the top tang and the trigger plate was a bit closer togeather causing the problem. Waitng for a top lever spring from Brad- when that comes I'll put it in and class-bed the reciever and stock [ a small gap there ] - remove a dent in the barrel,and it'll be ready to shoot. I'll measure the bore, chamber and chokes to see what they are. Paul

[Mark Landskov]

Paul, my 10 gauge has also been restocked. It looks pretty good, but it wasn't mated flush/flat to the rear of the receiver. I will have to do a bit of bedding to fix that. I may also have a top to trigger plate issue like yours.

[Paul Harm]

It would cock both triggers when the stock was removed. It looks like the top tang to trigger plate screw was replaced [ the front one]. All I had to do was tighten it a bit and it wouldn't cock the right barrel because the trigger was pushing the sear up. Paul

[Dave Purnell]

Paul and Mark,

I also have a 10ga lifter with 2 5/8" chambers. Made in 1875, it has the step from chamber to bore rather than a forcing cone. I purchased Rocky Mountain Brass at 2 5/8" for loading black powder and they work very well. I wanted to try some smokeless loads, so I loaded Sherman Bell's lowest pressure target load at about 4800 psi in a 2 7/8" shell, and they worked very well. Then I tried Sherman Bell's lowest hunting load at around 5800 psi if I'm remembering correctly. This load in a 2 7/8" shell resulted in tremendous recoil that made it hard to hold onto the gun. I haven't tried that load again because it was unsafe for this gun.
I'm wondering if anyone else has had any problems with longer shells in shorter chambers, or if my problem was a matter of pressure for the configuration of this gun?

Dave

[Mark Landskov]

Dave, I have been told more than once that the 2-7/8" RST ammo would be safe in my 2-5/8" chambers because of the negligible step from chamber to bore. When I get around to loading my own, I plan on trimming the Federal hull to 2-5/8" and using Mr. Bell's loading info. My original idea was the RMC brass cases, but with smokeless. I don't know if anyone here has tried smokeless in the brass cases or if it is even feasible.

[Mark Ouellette]

Paul,

Go back one page and read my post in this thread of 10-13-10.

Think about it. Buring powder produces expanding gas that pushes against wad and shot. If a shooter restricts the path of that wad and shot by shooting a long shell in a short chamber the velocity of the expansion will be slowed but the powder will still be buring and gas will still be expanding. If the wad and shot cannot move forward the gun will move backward producing more felt recoil.

There are a lot of variables such as the thickness of the shell housing and angle of forcing cone but the theory if solid. If one restricts the rate of expanding gas a reaction will be created. All else being equal a 10 gauge produces less pressure than a 12 and a 12 more than a 20 and so on.

If you don't believe me load up some 2 and 3/4" and also 3" shells of the same shot weight and pressure. Then, shoot them is a 12 gauge with 2 & 3/4" chambers. If the gun has sharp forcing cones you will feel a big difference. It the gun has long forcing cones (1.5" or more) then you may not feel much difference in recoil. Chances are any old Parker will have sharp forcing cones.

You could also do the same for your 10 bore using correct length and longer cases.

Have fun!
Mark

[Mark Landskov]

Dave and Mark,
I should have added that the advice I was given about the RSTs in my short chambers was taken with a grain of salt. I have never used improper ammunition in any of my guns. It just isn't worth it. I have a nice Lee Loader for the 2-7/8" 10 gauge and plan on taking it from there. I made a 2-3/4" Lee work for 2-1/2" 16 gauge shells, so I think I can make this one work for the 2-5/8".

[Dave Purnell]

I have other tens with 2 7/8" chambers. I had purchased RMC brass in
2 5/8" to use in all of my tens. With the Federal hulls, I didn't make the same connection, cut them to 2 7/8", and forgot about the one short ten in the collection. I've read many threads over the years about a tighter gas seal being achieved by a shell slightly longer than the chamber. This is true in later guns with a tapered forcing cone. But, it is not necessarily true in an older lifter that has a sharp step from chamber to bore. This sharp step from chamber to bore was made for hand loaded brass casings of that time. It isn't designed for a longer Federal hull. At the lowest pressures it may work without appreciable increase in pressure and recoil, but in a higher pressure hunting load the recoil may increase drastically. Sorry to steal Sherman Bell's phrase, but this is my version of "Finding out for myself".

Dave

[calvin humburg]

My 10 has chambers for brass I cut my hulls to 2 7/8 then wondered if I should of went a 1/16 shorter to make sure they didn't open and hit the edge of the chamber. Or do you all think it is anything to worry about. If you don't understand my qustion tell me i'll try again. Thanks ch Mark I haven't tried it but I've heard that smokeless in brass don't work to good it seems you need a good crimb because smokless needs to build pressure?

[Paul Harm]

I couldn't get smokeless to work in brass, but not saying it won't. Read my thread on "crimps". The depth of crimp is very important for pressure [ .030 to .070 verys pressure from 9000 to 13000psi ]. Because we're shooting smoothbores the only resistance the shell sees is the crimp. I don't know where the "glue crimp" would be on the resistance scale for producing pressure. Paul

[shane johnson]

Hello all, interesting thread.
I was pointed in your direction from a UK site after I started asking around for some data to reload some shells for my 10 bore hammer gun, its a Thomas Bland, 2 5/8" chambers, damascus barrels but nitro proofed.
When I got the gun, I was also given some old Eley paper cased loads, both 2 5/8" and 2 7/8" which to be honest, shot the same with no discernible increase in recoil.
I have never shot anything else through it and now with the lead shot ban have been trying unsuccessfully to get some reloading data so I can try to put some ITX shot through it.
I have noted the comments about a small step in the chambers but have not really noticed that so will be having a closer inspection later.
Have any of you home loaders used Bismuth or Tungsten Matrix through your older guns and if so, do they measure up to lead.

[Mark Ouellette]

Shane,

If you can buy bulk (loose shot) Tungston Matrix please do so and load up!!! You will of course owe me your source since I've never seen bulk TI for sale.

ITX is okay at best. Some like Bismuth which provides good performance but not that of TI or lead.

Nice Shot is my favorite of the AVAILABLE non-toxic loads. It provides performance close to lead. My load of an ounce and a eight of #2 in a 12 bore at 1200 FPS laid out Canada Geese over my pond at 60 yards. I also used 1 and 3/8 oz in 10 bores with equal success! During the early goose season I had an incident of multiple severely wombed geese with two shoots from a rather well used EH Parker. I wish I had a witness and photo of that! Oh, it was one of those days when I was glad it was the early season allows a bag limit of 5 geese! Yup, filled my limit with 2 shots to drop them and 2 perhaps unnecessary clean up shots.

Be advised that the hardness of Nice Shot raises pressures by apporimately 1500 PSI (per their website). I started with a 7000 PSI load and with the additional 1500 PSI well in the safe working range of my GOOD CONDITION LC Smiths and Parker #2 and 3 Frame Damascus barreled guns. If you shoot Damascus You will of course have to determine if your gun meets the condition and design for a given pressures. Please refer to page 515 of the Parker story for Service Working Limits for pressure for each of Parker's gauges and frame sizes.

Shoot well and shoot safely,
Mark

[shane johnson]

Mark, I can indeed buy all the non toxic shot I need together with the components but what I am struggling to get together is a kit to do the reloading plus get some data for suitable loads. I was also looking at getting some brass cases made rather than having to buy the big plastics and cut them down.
I see from your profile you are in S E Michigan which means that the import costs would be prohibitive from the local supplier I have found.

http://www.claygame.co.uk/Cat22Page13Shot.pdf

[richard lambert]

ballistic products
ITX Shot (bag/7 lbs) $129.00

TEAL TAKER LOAD
Load# 80611-368
HULL: FIOCCHI 12-gauge 2.75” (#064121600)(#64121602)(#0641208)
PRIMER: FIO616
PROPELLANT: HODGDON UNIVERSAL CLAYS 25.0 Grains
WAD: BP TPS35MM Pre-slit(#3227735) Mica dust wad please.
SHOT: 7/8 ounce ITX #4 shot (382 grains).
BUFFER: None
FOLD CRIMP: 6-point (Recommended for new hulls). Over shot, #OS12 card used.
Results: 9600 PSI 1365 FPS

EARLY GOOSE GETTER
Load# 80611-371
HULL: FIOCCHI 12-gauge 3.50”
PRIMER: FIO616
PROPELLANT: HODGDON UNIVERSAL CLAYS 31.0 Grains
WAD: X12X(#322X12X) + TPS1275(#3227701) Mica dust wad please.
SHOT: 1 1/4 ounce ITX BB shot (546 grains).
BUFFER: None.
FOLD CRIMP: 6-point (Recommended for new hulls). Over shot, #OS12 used.
Results: 12500 PSI 1380 FPS

[Mark Ouellette]

Shane,

Send me a PM with your email and I'll send Sherman Bell's 10 Ga loading data. Mr Bell did the "Finding Out For Myself" research in DGJ that a lot of us rely on.

The ITM available from your supplier would be perfect for your Thomas Bland. If you use a load recipe for lead add 2000 PSI to it for the harder non-toxic and you should be fine in that nitro proofed gun. There are many 6000-7000 PSI lead loads that with any extra pressure from ITM a nitro proofed gun would be fine with. But, if you notice any flatness of the primer the pressure is getting up there...

Mark

[John Dallas]

I'm missing something. All other things being equal, why would harder non-tox shot generate higher pressures?

[Mark Ouellette]

John,

During firing the bottom rows of lead shot are crushed/deformed providing a cushion which reduces peak pressure. This concept is similar to how a piston of a plastic shot cup reduces deformed shot and also lessens pressure.

Mark

[Dave Suponski]

"Flatness of the Primer" Mark could you explain this to me?

[Mark Ouellette]

All other factors remaining constant such as the chamber/gun, type of hull, and primer, when pressures continue to raise a primer will eventually be pushed against the flat wall of the breach.

I have often seen primers from my trapshooting friends' reloads that have been pushed flat against the breach face. Their loads often exceed 1300 PFS for 1 and 1/8 oz. Now, the pressure of those rounds may have been within the 11,500 SAAMI 12 gauge working maximum but they are far above what I desire to shoot in a Damascus gun!

If you load the same hulls and primers at 6000 psi and also 10,000 psi take a look at the edge of the primer cups where it curves from the flat portion that the firing pin/hammer strikes. The primers from higher pressure loads will start to loose their curve. When pressure is higher (not necessarily too high) that portion of the primer will fill in.

I have noticed a slight flattening of primers with my hunting loads. This is not referenced to any measurement of pressure but it does indicate that something is happening!

Here is a photo of a flattened primer from a rifle.
http://i131.photobucket.com/albums/p307/Chesador/FlattenedPrimer.jpg

There is a lot of debate about this subject on the reloading and rifle and pistol shooting forums. My experiance from loading for both rifle and pistol is that when I pushed to the top of the loading data the primers flattened out upon firing. Also, when the bolt was hard to open the primer was very, very flat!

PS: If I opened my Parker and noticed primers as flat as in the photo I would drop me my knees and thank God for sparing me from my stupidity!

[Dave Suponski]

Thank you for the explanation Mark.

[John Dallas]

I dunno. Has this been tested, or is it conjecture? Seems to me that the compression section of the wad would obviate most of that phenomenon.

[Mark Ouellette]

John,

Test it yourself and let us know the results!

Follow the simple directions from my previous post. Load identical hulls and primers in loads at low psi and high psi. Shoot in the same barrel and examine the primers.

If however you use very hard primers such as Remingtons the flattening may be less or not evident. The Cheddites which I use easily flatten.

Mark

[John Dallas]

Mark - I agree with that "Test", however, that doesn't answer my question whether or not hard shot causes high pressures. Can you say that hard shot has caused flat primers?

BTW, a friend of mine - a major league engineer for the big three, and a national caliber hot rodder, works up his high velocity rifle loads until he needs to use a mallet to open the bolt. Needless to say, I don't shoot on the bench next to him!

[Mark Ouellette]

John,

Hard shot contributes to higher pressure. Before I noticed the 1500 PSI increase notice on the Nice Shot website I spied that my 7000 psi Nice Shot loads were slightly flattening the primers. That made me think... It wasn't long afterward that a fellow web-poster referred me to the Nice Shot warning.

I also recall recently reading something to this effect in an old shotgun book. I do remember that Askins wrote in The American Shotgun that 30% of the pellets are deformed upon firing. That book was published in 1921.

Mark

[John Dallas]

I'm not doubting your experience, but I'm calling BS on the good Colonel. Howinell could he ever back up that statement?
I am a proponent of slow-burning powders as a means of reducing peak pressure, and the resulting "Poke" it generates. I do believe that more gentle "Push" results in fewer deformed pellets

[charlie cleveland]

does any body have smokless loads for the brass 10 ga shell..i noticed somebody posted it didnot work for them in brass shells....just wandering.... charlie

[Paul Harm]

It didn't work for me in 12ga- believe it was because the thin brass allowed more volume. I went up about half again [ 20 to 30grs] and still got bloppers. Seeing how I've already blown up one gun I quit trying. Paul

[charlie cleveland]

thanks paul... ive tried smokeless also in the brass shell with a lot of bloopers...i will keep trying.. i was using blue dot and herco powders...may try a faster burning powder....or maybe i need to go to a hotter primer ive always used whinchester primers...any suggestions from anybody..... charlie

[calvin humburg]

Somebody told me you need a good crimp to make smokeless work. Compressed shell with crimp to hold it tight??????????? ch

[Paul Harm]

why doesn't someone try their normal load and another without crimping - just stick a overshot wad in it and fire them both. Let us know the difference in the two. Paul

[charlie cleveland]

paul i have tried what you recommended...you will have more recoil with crimped loads espesially star crimped....the ones with only wadding and no crimp will have away less recoil but will have more bloopers.... charlie

[Paul Harm]

That's what I thought. I have a box of Remington Ducks Unlimited brass 12ga shells made in 1987 that have a slight crimp to hold the overshot wad in place. Wonder how they'd shoot. Paul

[charlie cleveland]

would hate for you to have to shoot one of those ducks unlimited shells but ibet it would still go bang.... charlie