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Posted By: David Williamson Choke length - 12/21/16 06:37 PM
I didn't want to take anything away from claycrusher's post so I started this.

I often wonder if choke length makes a difference. The reason I say this is I bid on a set of Grade 1 L.C. Smith barrels that were 30". I asked the seller if he could give me the constriction of the barrels. He said he had no way of measuring them. I then emailed our records keeper and he confirmed these barrels left the factory at 32". I was the high bidder and no one bid higher so I was stuck with them. These were Fine Damascus and when I checked for constriction, the last 1/2" had .008 and .009. Most L.C. Smith chokes were 1" parallel and then 1 9/16" taper to bore.

These barrels circa 1899 were fit to a F grade hammer gun circa 1908 and are my go to barrels for sporting clays. I have never pattered them, but they reach out there and have no problem breaking targets with the 3/4 oz. loads I use.

So how much does length of choke matter.
Posted By: liverwort Re: Choke length - 12/21/16 07:32 PM
I bet it does. I have seen it explained here, I think, that if one just sort of gently roll crimped the end of a shotgun barrel that would cause the shot to disperse and throw a wide pattern. I also believe I read here that the Fox company used longer chokes and that allowed for a gentler constriction providing less pellet deformation and tighter more uniform patterns (theory?). That's what i remember reading. I may be remembering wrong or may be I am just wrong.
Posted By: David Williamson Re: Choke length - 12/21/16 07:58 PM
I can agree to what you said, but you have to remember that all shotgun shells at the turn of the last century had fibre and cardboard wads separating the powder and shot. Long tapered bores going to long chokes would help the now loose shot stay tighter when hitting these areas and for a short distance after it left the barrel. With todays plastic wads I think most of this tighter constriction is built in.

I found it curious with the above mentioned barrel on how the shot seemed to carry it's pattern longer than I would have expected.
Posted By: Paul Harm Re: Choke length - 12/21/16 09:44 PM
You'll find the 3/4oz loads seem to add about one choke construction - less shot being deformed because of the short shot column. Those loads are what myself and a couple of friends shoot all the time at SC's and reach out 35 to 40 yards with skeet chokes in our old SxS's. Different guns had different styles and lengths of choke. Some of my Remington 1894s have over 7" total choke. Most guns don't have more than 1" of parallel at the muzzle. I've been told that when opening chokes if you end up with more than 2" of parallel you'll just end up with a " hot center ". 8 or .009 would be between SK and IC and that should be plenty for most shots. I like SK and LM myself.
Posted By: 2-piper Re: Choke length - 12/21/16 09:46 PM
Not counting "Jug" chokes there were mainly two types of choke used. "Conventional" choke had a cone followed by a parallel section. "Taper" choke was strictly a cone with no following parallel. Full choke on some Lefevers which used the taper choke were as long as 4". This was longer than the entire length of many conventional chokes. With either type more open chokes were normally shorter than was Full choke.
I have NEVER sen the term "Extra Full " used in any old literature to describe the choke in any of these older guns. Poly-Choke made models which were marked for both Reverse & Extra Full though both were likely Wishful Thinking.
I do not at present have a Fox to check but to the best of my recollection they also used the Taper Choke.
Also I have never seen any gun on which the choke was a taper for the full length of the barrel as one so often hears spouted on some gun which will "Kill Farther & Deader" than any other gun ever made.
Posted By: moses Re: Choke length - 12/21/16 11:06 PM
Originally Posted By: 2-piper
some gun which will "Kill Farther & Deader" than any other gun ever made.

Hey ! I have one of those.
O.M
Posted By: J O'Neill Re: Choke length - 12/21/16 11:39 PM
Interesting discussion. It got me musing about taking things to an extreme... if a better, gentler-to-pellets pattern is given by a longer parallel after the taper, why not do the choking at the forcing cone, a long taper of course. In that case, nearly the entire barrel becomes one very long parallel. Again, not suggesting, just musing and wondering where the balance is struck.
Posted By: Drew Hause Re: Choke length - 12/21/16 11:50 PM
About 2008 I issued a request for 16g choke measurements and a number of respondents provided data for Parker, Fox, Baker, Ithaca, and Smith guns. Almost all had a choke length of 1 1/2 to 2 inches with a very short parallel section at the muzzle.

16g Parker guns made from 1891 to 1927 with chokes from .002 to .040 all demonstrated a choke length of 1 1/2" to 2".

Fox 16g doubles made in 28', 33', and 37' were found to have chokes about 3 1/2 inches long in the tighter choked barrels BUT a 36' 32-inch barrel A-grade had full chokes of only 2 1/2 inches.

I have no data for 20g

Dave Miles provided some excellent data from the PGCA showing that in full choke 12g. Parkers, the choke was bored with between .007-.010 constriction between 4 and 2 inches with the remainder of the constriction in the last 2 inches.
This is similar to what was found in a limited sample of 12g. Lefever, Remington, and Ithaca guns.

From Austin Hogan
Parker Chokes prior to sometime during Remington's ownership were cut with the adjustable nut borer and had the characteristic "OGEE" shape, with a parallel section 1/8 to 1/4 inch long. Late Remington barrels were reamed from the muzzle end, and have longer parallel sections.

P. 394 of L.C. Smith "The Legend Lives" shows the 12g choke specifications; a 1 9/16" taper segment with a 1" parallel segment as noted by Bro. David.


Dave Miles' information:

Parker DHE 16, 30" uncut titanic steel barrels, made in 1927
Bores are .665" both barrels choked .030" chokes 2" long

GH 16, 28" uncut Damascus barrels, made 1893
Bores are .665" choked .004" & .008" chokes 2-1/2"

DH 16, 30" uncut Damascus, made 1891
Bores are.675 (honed?) choked .020" & .030" chokes 1-1/2" long

DHE 20 Repro, 26" barrels made in 1980s
Bores .618" choked .010" & .020" chokes 2" long

PH 16, 28" uncut Twist barrels, made 1917
Bores are .670" choked .020" &.030" chokes 1-1/2"

Baker Black Beauty 16, 28" uncut barrels date unknown
Bores are .670" choked .030" & .040" chokes 1-1/2" long

GHE 12, 26" uncut Damascus barrels, made 1912
Bores are .735 choked .002" & .010" chokes 4" long

Posted By: Drew Hause Re: Choke length - 12/22/16 01:04 AM
Choke length; bore to choke constriction

1926 12g Smith Long Range courtesy of David Williamson
R: 3 3/8”; .730” to .688” with no parallel segment = .042
L: 2 1/4”; .7305” to .688” with a 3/4” parallel segment = .0415
Hunter Arms advertisements refer to the LRWF as being “…specially bored to a longer, tapering choke.”

1903 12g Smith 4E
R: 3”; .728” to .692” = .036
L: 2 3/4”; .728” to .693” = .035

1906 12g Smith 00
R: 2 1/4”; .728” to .720” = .008
L: 2 1/2”; .728” to .695” = .033

1902 16g Smith 0
R: 3 1/2”; .656” to .622” = .034
L: 2 1/2”; .650” to .620" = .030

1903 12g Smith 00E
R: 2 1/2”; .728” to .726” = .002
L: 2 3/4”; .728” to .712” = .016

1906 16g Smith 0E
R: 1 1/2”; .650” to .632” = .018
L: 1 1/2”; .653” to .630” = .023

1905 12g Remington 1894
R: 3”; .733” to .706” = .027
L: 3”; .732" to .697" = .035

1913 12g Fox Sterlingworth
R: 3”; .728” to .721” = .007
L: 3 1/2”; .727” to .710" = .017
Posted By: 2-piper Re: Choke length - 12/22/16 03:28 AM
Drew;
I will try to get you the choke length & constriction on my H grade Lefever, but not tonight. As I recall it has about 030"" in both barrels & definitely longer than 3" as I recall, no parallel all taper.
Posted By: Rocketman Re: Choke length - 12/22/16 06:02 AM
Originally Posted By: JDW
So how much does length of choke matter.


It doesn't. See "Sporting Shotgun Performance," by Dr. A. C. Jones, page 58, Figure 41. Neither does a parallel section.

Shot is at least a semi-fluid and subject (pretty much) to the laws governing fluid dynamics. Shot flooooows through the forcing cone and the choke. It does not smash into these constrictions. Rather, it flows through in an orderly fashion. Deformation occurs at ignition and early acceleration.

DDA
Posted By: David Williamson Re: Choke length - 12/22/16 11:59 AM
"Deformation occurs at ignition and early acceleration."
Rocketman, I have to disagree with you about that especially with todays plastic wads. Shot is still in the wad and deformation would not occur until after it left the barrel
Posted By: Drew Hause Re: Choke length - 12/22/16 12:19 PM
A.J. Aubrey had this all figer'd out in 1908 wink

"choke bored on the taper system"
1908 Sears, Roebuck & Co., Chicago, Ill. Catalogue No. 117:

I would very much appreciate if someone with an Aubrey would measure the bore and see if it tapers the full length.

"the choke is bored from breech to muzzle"



Daryl Hallquist has confirmed that an occasional Lefever 12 gauge has bores tapering from the breech to the muzzle (.756 to .708 left and .715 right on one gun). Most have a standard U.S. .729 - .732" parallel bore.

Starting in 1907, Hunter Arms catalogs included the following statement:
"All Smith Guns are bored full choke unless otherwise ordered. We bore all our guns according to our Multiplied Choke Bore System, which has made the Smith Gun famous the world over for long-distance, close-shooting and hard-hitting qualities."

LRWF marketing verbiage in 1923 "A distinctive L.C. Smith method of choking adds 15 to 20 yards to ordinary shotgun range...specially bored to a longer, tapering choke..."
LRWF have bores of .730" without tapering to the choke constriction of about 3 inches in length; slightly more than the standard constriction over about 1 1/2" with a 1" parallel at the muzzle. As noted, some have no parallel section but taper over the length of the constriction.
Posted By: L. Brown Re: Choke length - 12/22/16 12:32 PM
Originally Posted By: JDW
"Deformation occurs at ignition and early acceleration."
Rocketman, I have to disagree with you about that especially with todays plastic wads. Shot is still in the wad and deformation would not occur until after it left the barrel


Probably merits a topic all its own. I don't think all deformation on ignition is eliminated by plastic wads. Reduced for sure, but not totally eliminated.

And why would deformation occur after the shot leaves the barrel? Pellets running into each other?

Interesting subject.
Posted By: 2-piper Re: Choke length - 12/22/16 12:45 PM
Drew;
I have spoken with someone on these Lefever chokes, don't recall now if it was Daryl or perhaps Bob Noble. While it was true the bores were not totally cylinder all the way the majority of the restriction was still at the muzzle. The bores themselves did have some taper in them but not uniform. The dimensions which were given to me seemed as much as if it were just uncorrect reamer wear as any actual intentional thing. I have several Lefevers from an early side pivot up to an Ithaca assembled one & none show any significant taper to the bores, all have the taper choke at the muzzle. No parallel with full choke running up to around 4" in length.
I do not have a gun so bored to prove it, but am of the opinion that a barrel with a constant taper from chamber to muzzle would shoot pretty much cylinder as a cylinder, rather than as a choked gun.
Posted By: Stanton Hillis Re: Choke length - 12/22/16 12:49 PM
Originally Posted By: JDW
"Deformation occurs at ignition and early acceleration."
Rocketman, I have to disagree with you about that especially with todays plastic wads. Shot is still in the wad and deformation would not occur until after it left the barrel


David, your theory has been proven to be incorrect by science. Read this post I made last spring after speaking with Tom Roster over the phone concerning patterns. This is post #441238. The entire thread is very good, except for Wonko's rudeness.

"I spoke at length with Tom Roster this afternoon by telephone. I was really appreciative, and little surprised, that when he answered he took the time to talk, but he did. I asked him if anybody had ever done scientific testing on lead shot loads to determine if lead shot deformation, due to setback at ignition, was greater in any area of the shot load than any other area. I told him I thought I remembered reading about some such testing many years ago, and had searched the 'net for the last several days trying to find such, but had struck out. He said that someone had indeed done that, about 30 years ago, and that someone was him. What he did was basically this: Tom, who doing a research paper at an institute of technology somewhere, painted lead shot, from the same bag, three different colors. He then loaded it into a regular shotshell load in three layers ..... one color for the bottom third of the shot column, one third for the middle, and one third at the top ... each layer a different color. He then fired the loads (more than one) into a tank of water. (He paused to remind me that water will NOT deform a lead shot pellet when fired into it). Then, he recovered the pellets and segregated them by color. He said it was VERY obvious that the pellets that were on the bottom of the load were much more deformed than the one-third layer above it, and that the top third were the least deformed.

I had remembered reading about this test long ago, but could not put a finger on who did it and when, could not find evidence of it on the 'net, so did not mention it earlier in this thread. It just so happens that the one I called was the one who actually did the testing. Tom said the tests were not ON the net, because the net had not been invented when he did the tests, and he had never put the results on there.

He went on to tell me about two other tests he had done concerning lead shot pellet shape ballistics, but they do not pertain to this particular issue.

I refused to discuss this with the arrogant, and ill mannered individual who has replied several times here, but this may be interesting to some other cogent, and truly, sane board members here. What the other individual thinks of it really doesn't matter to me.

SRH"
Posted By: HomelessjOe Re: Choke length - 12/22/16 01:33 PM
I'm no scientist but the theory of deformation after the shot leaves the barrel sounds silly to me....

And as far as choke length most modern gun manufactures are making their chokes longer and longer for a reason.

I just bought a Browning 725 with the Invector DS chokes and they are really long.
Posted By: David Williamson Re: Choke length - 12/22/16 02:27 PM
I should have been more descriptive in saving that the shot in my opinion would be more deformed after it was leaving the wad, which would be by this time out of the barrel.

Stan, I can believe what Tom had written after his experiment, BUT if memory serves me, I recall reading about the shot in the bottom of the shell over-taking the shot in front of it. Actually almost like pushing it out of the way. I wish I had copied that article or remembered where I saw it. This was not too long ago and it might have been from either Batha or Gil Ash and I'm leading more to Ash.
Posted By: Drew Hause Re: Choke length - 12/22/16 02:39 PM
Pellets recovered from mallards at 45 yds. Ed Lowry, "Shot Penetration in Soft Targets", American Rifleman, Oct. 1988



Probably not worth the $25, but it appears "shot packing factor" is the issue
https://www.astm.org/DIGITAL_LIBRARY/JOURNALS/FORENSIC/PAGES/JFS11154J.htm

Bob Brister's illustration
http://www.classicshooting.com/blogs/com...easant-shooting

Posted By: David Williamson Re: Choke length - 12/22/16 03:55 PM
Brother Drew, Bob Brister's link is another great point on the amount of antimony. That slipped my mind and now makes it interesting on when some of these tests were taken and when antimony first started being used. This could explain a lot.
I have read from the different shot manufacturers on what their antimony content is and most seem to be in the 4-6% content but starting at #4 shot the antimony is very little. That would make sense as it would be harder to deform than #8's.

It would be interesting to note what happens to shot in a wad once the trigger is pulled. How long it is together before separation?
Posted By: Drew Hause Re: Choke length - 12/22/16 04:02 PM
We had this debate once regarding deformation and how much pellet surface area is in contact depending on pellet size, but my squishy brain can't remember when, or what Don (and science) decided frown
I'm thinking smaller pellets have more surface area abutting the neighbor pellets, but am a victim of K through post-graduate education in the great state of Missouri wink
Posted By: 2-piper Re: Choke length - 12/22/16 07:18 PM
Drew;
As promised, data on 16ga Lefever choke.
Gun = H grade SN 62,596 with 1907 patent date so one of the later ones though no indication of an Ithaca build. 28" barrels of "Best London Twist". Bores both measure 669" to within 4" of the muzzle. Choke taper begins here & ends @ 634" R (035" choke) & 632" L (037" choke).
Both chambers will take a .732" chamber gage to 2 3/4" (Current SAAMI Minimum chamber dimension for 16ga) I had thought I had previously determined the chambers actually measured to 3" which could be accounted for if they were just more than 001" undersize at forward end, though this may have been in error. They are at least a full 2 3/4" & not the usually expected 2 9/16" for 16ga.
Posted By: 2-piper Re: Choke length - 12/22/16 07:24 PM
I seriously doubt if shotgun pellets will be deformed after leaving the bore but I do recall this happening to a ML rifle which was tested years ago by the NRA. It was fired with pure lead round ball & both muzzle & down range velocity measured. With all powder charge increases the muzzle velocity increased but at some point ( with heavy charges) the down range velocity dropped. They accounted for this from deformation of the ball creating increased drag. Part of this deformation may have occurred in the barrel but they felt part of it was due to the force of air drag.as well. This was of course from a much higher velocity than obtained in a shotgun.
Posted By: Paul Harm Re: Choke length - 12/22/16 07:56 PM
Stan, thank you for your post. I also read of another individual testing 3/4oz loads in a 12ga. He said because the pellets in the bottom of the load were not deformed [ less set back ] the patterns were too tight at skeet ranges. He had to use fiber wads to open them up. I've opened up quite a few SxS's and the Remingtons seemed to have the longest total choke area - some were 7" with the last 1 1/2" parallel.
Years ago V.M. Starr wrote a small book about jug chokes. He use to shoot turkey shoots where the most BB's in a playing card would win. He used a muzzle loader shooting against cartridge guns and cleaned up - many competitors would not shoot against him. He opened up the bore 8" to 2" back from the muzzle leaving the last 2" parallel. This would allow him to still easily load the gun. I've done the same thing on guns when I wanted more choke. It works very well.
Posted By: 2-piper Re: Choke length - 12/22/16 09:11 PM
I am not thoroughly convinced that shot doesn't react as much as a Semi-Solid as a Semi-Liquid when traveling down a barrel. I distinctly recall having read that in the early days of choke boring many barrels which were rather thin toward the muzzles had a problem of "Lifted Chokes", IE a bulge at the choke. This was not confined to the use of very large shot either. This would seem to indicate a Checking, rather than a speeding up of the charge. This seems to have been Fixed, by a slight beefing up of the wall thickness in the choke area. I have measured a good number of fairly light weight barrels in which the smallest diameter of the barrel was Ahead of the choke with a larger diameter in the choke area itself.
Also Burrard reported on some tests run some years ago in England wherein loads were measured for pressure, recoil & velocity simultaneously. Velocity was of course at this point of course the "Observed" velocity over 20 yards. A specially prepared barrel was made with a screw on forward end carefully lapped in to same diameter as the bore except one extension was cylinder & the other full choke. Length & weight were made identical. A definite relationship was recorder that the full choke gave a slight increase in velocity over the 20 yards, but also produced a slight lowering of recoil. This would definitely seem to be contradictory as the higher velocity should produce the heavier recoil.
This was explained by the cyl bore actually producing the higher muzzle velocity, but the quicker spread of the shot exposed each pellet to individual drag much quicker than from the full choke. The shot from the full choke reacted much more as a single projectile just long enough for them to exceed the velocity of the shot from the cylinder bore.
Posted By: Drew Hause Re: Choke length - 12/22/16 10:47 PM
Thank you Miller.

One more; a SAC 0 grade 16g
R: 3 1/2"; .660" to .633" = .027
L: 3"; .660" to .630 = .030

I can not recall measuring any U.S. maker's choke constriction that did not have a short parallel section at the muzzle, but certainly have not measured them all.
Posted By: 2-piper Re: Choke length - 12/22/16 11:11 PM
Drew;
None of my Lefevers have a parallel, they are all strictly taper. If you find a Lefever with a parallel in the choke you can pretty well rest assured it has been opened.
Posted By: Drew Hause Re: Choke length - 12/22/16 11:13 PM
Thanks again Miller

Now could someone PULEEZZZ see if their Aubrey/Meriden bore is tapered from breech to muzzle, or just has a taper choke without parallel smile
Posted By: 2-piper Re: Choke length - 12/23/16 03:02 AM
Drew;I do not have an Aubrey/Meriden to check. Here is the way the Lefever choke is described in their 1889 catalog & seems to have remained essentially the same for the rest of their existence:
""Boring Guns
After many experiments and Long experience in choke-boring, we have adopted the taper system, having proved beyond a doubt it gives the most evenly distributed pattern and greatest penetration. Being a taper from breech to muzzle, all sizes of drop-shot pattern about equally well, and with our full choke guns an average of 75 percent of the entire charge can be made in a 30 inch circle at 40 yards with all sizes of shot from No 8 to FF.
Possessing this quality renders our guns invaluable for both trap & duck shooting.""

Only problem is I have to date not seen a Lefever so bored. Mine have a taper from Bore to Muzzle, but NOT from Breech to Muzzle. I am not even sire just how in 11889 they would have achieved a taper for the full length of the barrel.
I have serious doubts they could have successfully made & used a full length reamer. About t5he only way I can come up with is they would have had to step ream & then join the steps with short tapered reamers & blend them all in. I have serious doubts this was done & would doubly doubt it on a gun in the price range of the Aubrey. I have little doubt it has essentially the same "Taper Choke" as does the Lefever.
Note I am not saying that Lefever was necessarily deceiving their customers, the Ad writers may just not have known whereof they spoke.
Posted By: Ithaca5E Re: Choke length - 12/23/16 03:27 AM
Personal observations:

The Ithaca chokes I have measured have little to no parallel, and as a group have generated the better patterns. Period.

The shortest chokes I have measured (0.75-1.0" taper) were the work of a highly rated aftermarket supplier. As a group they have produced the poorest patterns.

Reclaimed shot. When I reload new shot, some of it always ends up on the bench, rolling every which way. Stray reclaimed shot hits the bench and stays put - doesn't go anywhere. The takeaway is that the deformation didn't happen when the shot hit the ground, or when it left the barrel, but rather in the barrel. It left the barrel deformed, every piece guaranteed to have at least one flat spot.
Posted By: Drew Hause Re: Choke length - 01/09/17 06:42 PM
Found another "Taper Choked Barrels"

Crescent "The Sportsman" - 1918 Lockwood-Luetkemeyer-Henry Co., Cleveland.



Somebody's GOTTA have a Crescent and can measure the choke taper, and we still need an A.J. Aubrey please
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