Stoeger choke markings. These stainless steel 12 Gauge flush mount choke tubes are designed to fit Stoeger Semi-Auto and Pump shotguns, including M3500, M2000 and P350 models. Choke tubes are …

WinChoke Fully steel shot compatible. Fits all Winchester Winchoke shotguns. Will not fit Winchester Super X2 or other Winchester shotguns that require Browning Invector Plus Choke Tubes. Code. Description. 6130103. 12 Gauge Extra Full. 6130113. 12 Gauge Full.

Stoeger choke markings. Brands. Boito, Stoeger. Number of employees. ~300 (2010) E.R. Amantino (also known as Boito) is a Brazilian firearms manufacturer founded in 1955 at the city of Veranópolis, in the state of Rio Grande do Sul, Brazil. The company is well known for its double barrelled shotguns marketed and distributed in the United States under the Stoeger brand.

Mar 23, 2023 · The Best Chokes and Shells for Hunting with the Stoeger M3000. This video takes you through a pattern test for the Stoeger M3000. This is a great way to dete...

Oshawa, Ontario Canada L1J 7E2. It also has the ability to screw in choke tubes and it has 26-28 inch barrels. Cylinder choke tubes come with the freest flight patterns and offer a viable firing range that is the most precise. Markings on Stoeger choke tubes come in a wide range of variations, but their meaning across the spectrum is largely ...What are the various choke markings for Stoeger shotguns? The fixed choke markings are denoted by * marks on the bottom of the barrel under the forearm assembly. 3 on the left barrel and 4 on the right. *** Modified choke **** Improved Cylinder. What are some brands of double barrel shotguns?

Use the included shim kit to adjust the fit of the gun for drop and cast. Stoeger Model 3020 semi-auto shotgun comes drilled and tapped to accommodate Weaver®-style scope bases, and includes 3 choke tubes (IC, M, XFT) and a choke tube wrench. Outperforms every other 20-ga. shotgun in its class. Stoeger's famous Inertia Driven operating system.Sold Item. $300.00 - Used STOEGER SIDE-BY-SIDE RARE 28 GAUGE UPLANDER BOXLOCK, IGA OF BRAZIL 26 INCH " BARREL. Sold Location: Hinsdale, NH 03451. Sold Date: 1 month ago. $396.00 - Used GAUCHA IGA UPLANDER FIELD SXS 12 GAUGE STOEGER 28" VENT RIB 12-GA. Sold Location: FL 32216 us. Sold Date: 1 month ago.Standard chokes for all but the .410 bore guns were Full and Modified in 28 and 30 inch barrels and Modified/Improved Cylinder in 26 and 24 inch barrels. .410 bore guns were choked Full/Full. Other standard choke combinations were furnished by special order at no extra charge, at least in the early years.WinChoke Fully steel shot compatible. Fits all Winchester Winchoke shotguns. Will not fit Winchester Super X2 or other Winchester shotguns that require Browning Invector Plus Choke Tubes. Code. Description. 6130103. 12 Gauge Extra Full. 6130113. 12 Gauge Full.Choke tubes are designed to change the pattern of the shot that is released when the shotgun is fired. By changing the little tube in the front of the barrel, a shooter can increase firing distance or accuracy. By changing the choke tube, a hunter can specialize their firearm for specific hunts. Choosing the right choke tube can make a huge ...Similar to the Stoeger Double Defense model, the Charles Daly 204XT is an over/under tactical break-action shotgun with 20-inch barrels, rails for optics and accessories, extended choke tubes and a single selective trigger with a tang mounted safety control switch. Blued steel and a black synthetic stock add to the overall modern and tactical feel.WARNING: Never check the choke designation, install choke tubes or remove choke tubes unless the gun is unloaded and the action is open. REMOVING MAGAZINE PLUG 1. The capacity of the shotgun is (4+1), but your shotgun is delivered to you as (2+1). You can change the capacity of the shotgun by removing the restrictor plug from theOur Top 5 Best Choke for Sporting Clays 2022. Carlson’s Beretta/Benelli Mobil chokes: Best All Around Choke for Sporting Clays. Carlson’s Browning Invector: Best 12 Gauge Choke for Sporting Clays. Carlson’s Long Beard XR 12 GA: Best Choke for Beginner Sporting Clays. Browning Midas Grade 12 Gauge Choke: Best Choke Brand …

WTB Krieghoff K80 12 ga choked barrel. A forum community dedicated to Shotgun owners and enthusiasts including the Remington, Beretta, and Mossberg shotguns brands. Come join the discussion about optics, hunting, gunsmithing, styles, reviews, accessories, classifieds, and more!WTB Krieghoff K80 12 ga choked barrel. A forum community dedicated to Shotgun owners and enthusiasts including the Remington, Beretta, and Mossberg shotguns brands. Come join the discussion about optics, hunting, gunsmithing, styles, reviews, accessories, classifieds, and more!People use full, improved modified, modified choke types in their shotguns, as well as imp cylinder and cylinder choke types. Five notches on the end of the choke will indicate that the cylinder is a cylinder. What does the number of shotgun chokes mean? The effective range of the shotgun is determined by a choke tube to some extent.A: It depends on the shotgun. . A gun of modern manufacture with 70mm chambers and preferably no more than half choke should be perfectly safe to use with standard steel cartridges, provided that . it is in proof and in sound order. Because steel is less dense than lead or bismuth, you should choose a shot size that is at least two sizes larger ...

Most popular choke systems are shown which include, Browning Invector, Invector Plus, Remington, Winchester Invector, Benelli, and Beretta. Hello everyone, I have a 15.3/15.7 and a 15.1/15.7 marking on my Stoeger Zephyr calunnia 20g. The colic elk may cause damage or injury. Flush Mount Choke Tube for semi-auto & Shotguns pump, 12ga.

Shop Carlson's Choke Tubes Stoeger M3000/3500 Magazine Extension | Up to 15% Off Highly Rated on 4 Reviews for Carlson's Choke Tubes Stoeger M3000/3500 Magazine Extension + Free Shipping over $49. Toll-Free: +1-800-504-5897 Help Center Check Order Status. About Us Policies Reviews How To.

Hello i need to know what chokes a stoeger m3500 takes because i want to buy a carlson choke tube for ducks in a modified or improved modified. Help . Reply. Save. 1 - 4 of 4 Posts. D.The Patternmaster Code Black and Carlson’s Cremator are two of the best choke tubes for the Stoeger M3500. They can deliver results of over 80% pellets inside a 30-inch circle at over 40 yards with the right ammo. Their ported design helps reduce recoil and muzzle jump, making follow up shots quicker and more accurate.Buy Discount shotgun Chokes online for all shotguns. Choke-Tube.Com an LG Enterprises, LLC Company ... Maverick Accu-choke models, Winchester 1300, Browning Invector models, H&R Excel, Ithaca, New England Firearms Pardner, Stoeger Uplander/Condor models. Pro-Factor 2 fits: Berett Mobilchoke models, Benelli and Franchi Standard …Manuals. Download the appropriate manual for your Benelli shotgun or rifle. Title. 828 U Product Manual (14.83 MB) For: 828 U Shotguns, 828 U Upland Performance Shop Shotguns, 828 U Sport Shotguns. 828U 04-2020.pdf (16.67 MB) For: 828 U Shotguns, 828 U Limited Edition. ETHOS Shotgun Product Manual (11 MB) For: ETHOS Sport Shotguns, ETHOS ...

For choke sizes of other gauges and brands, see this chart. Benelli Choke Tube Markings. Markings on Benelli choke tubes come in a wide range of variations, but their meaning across the spectrum is largely the same. Manufacturers can use notching/serration systems, color coding, alpha naming schemes, and color banding to indicate the diameter ...Choke markings , lets see , Chokemarkings , and Prints of Markings :D What are the various choke markings for Stoeger shotguns? The fixed choke markings are denoted by * marks on the bottom of the barrel under the forearm assembly. 3 on the left barrel and 4 on the right..410 bore shotguns are the smallest shotgun gauge used for hunting and measure in at 2 ½ to 3 inches. The payload is also the smallest, with most loads weighing in at ½ ounce. Due to these factors, it's important to keep the pattern together longer, and that means a tighter choke tube.. The modified choke tube, at 0.402", is the best choke tube for the .410.Stoeger. 12 Gauge. 20 Gauge. Premium Stoeger Briley Replacement Chokes for Factory Threaded Barrels which are manufactured to be the best in market with the highest quality shotgun, firearm, and rifle standards. Shop now for Stoeger at Briley, A Legacy of Shooting Innovation.Choke is simply a minute constriction built into the last few inches of the inside of a shotgun's barrel just before the muzzle. The constriction is so small that it's measured in thousandths of an inch. Older shotguns have what is known as "fixed" chokes, meaning the choke cannot be changed. Newer shotguns, however, frequently come ...Fixed or Removable Choke. Associated Costs. Review of the Best Side By Side Shotguns. Best Side by Side Shotgun under $500: Stoeger Coach Side-by-Side Shotgun. 2. CZ-USA Hammer Classic 30" 12 Gauge. 3. Browning Side-By-Side (BSS) Best 20 Gauge Side by Side Shotgun: Dickinson Arms ST Estate 28"" 20/28 Gauge.Stoeger's line of double-barrel shotguns is made by IGA of Brazil. The Condor I is a no-frills over/under shotgun. The $559 20 gauge version of this model is equipped with extractors, instead of ejectors, and a single non-selective trigger. Its barrels, which are available in lengths of 26 or 28 inches, have 3-inch chambers and screw-in choke ...The IGA guns were made in Brazil by Armentino for Stoeger. The most certainly are NOT made by Benelli. In fact, no gun that carries the Stoeger name, is made by Benelli. The 2000 and 3500 are based on the Benelli design, but the quality control and the materials themselves are somewhat less. To the original poster.Several styles of grip pieces and markings have been noted. Mod. IV This was the original Llama pistol, dating from 1931-32, in 9 mm. Largo (Bergmann) caliber. It is a full-size reproduction of the Colt-Browning recoil-operated pistol Mod.1911. ... Unfortunately, it is not possible to determine the age of a Stoeger Arms Llama 380 by just ...Start by obtaining choke tubes indicated for the type of shooting you do, and pattern them with your favorite load. To do this, shoot off a rest at a center mark in a 30-inch circle at 40 yards ...The Stoeger Condor Field is a perfect choice for those who need a versatile shotgun for hunting and competition. This model features a durable synthetic stock and a sleek black finish. ... Choke: IC M; Type of Sights: Front bead sight; Stock: Synthetic; Caliber or Gauge: 12ga; Handedness Right Hand; Drop at Heel: 2-1/2" Drop at Comb: 1-1/2 ...When paired with the factory modified choke, the M3020 delivered 69 percent of the steel shot in a 30″ circle at 40 yds., and it did so with relatively consistent distribution around the point of aim, too. From the gun's 28″ barrel, the lightweight, yet pellet-packed, Fasteel load achieved a scorching 1572 f.p.s.Ships in 17 to 19 business days. These extended chokes fit Stoeger's Condor, Uplander, Coach Gun or Single Barrel model shotguns. Individual chokes sold separately according to pattern constriction. Stoeger Extended Choke Tube - Improved Modified 12 Gauge. Stoeger 39195.For advice on choosing a choke tube appropriate for your shotgun, READ MORE HERE. The Standard Invector interchangeable choke tube system offers consistent, dense shot patterns with the right constriction needed for the shooting situation. Standard Invector is standard on 10, 16 and 28 gauge, and .410 bore Citori 725, Citori, Cynergy and Gold ...In this short video I show you how to identify chokes for the tactical line of shotguns by Benelli and a few from Beretta without having to remove them. Simp...HIGH PERFORMANCE: Carlson's Choke Tubes Cremator Non-Ported Waterfowl Compatible for Beretta Benelli Mobil 12 Gauge come in 2 Pack and measured at Mid Range & Long Range constrictions. LIFETIME WARRANTY: We back all of our choke tubes with our lifetime warranty so you can focus on busting clays and filling bag limits.To do this, shoot off a rest at a center mark in a 30-inch circle at 40 yards. Full choke should put 70 percent of the shot in the circle, modified 60 percent, improved cylinder 45 percent. Cylinder, or no choke at all, should shoot from 25 to 35 percent. With interchangeable choke tubes, a hunter can use the.Stoeger Mobile Choke 12ga Extended - Black $ 33.99; Stoeger Flush Choke 12ga $ 33.99; Stoeger Choke Extended X-Full/Turkey 12ga - Black $ 33.99 OUT OF STOCK; IGA Choke Extended 20ga - Black $ 29.99; IGA Choke Extended 12ga - Black $ 29.99; IGA Choke Flush 28ga - Black $ 26.99; IGA Choke Flush 20ga - BlackStoeger semi-automatic shotgun is chambered in 12 gauge. It has been designed to fire 2 3/4" (3 dram 1 oz) to 3 " magnum (76mm) length with lead or steel shot. CAUTION: Use of Full or Improved Modified choke tubes is not recommended with steel shot. CAUTION: Use ONLY factory loaded ammunition. Use of re-loaded ammunition voids the 1-Year

Briley is the BIGGEST and BEST shotgun choke tube manufacturer IN THE WORLD! Account My Account; My Orders; My Wishlist; Login - 0 Items Toggle navigation. Shop All Categories. Briley 22 Raptor; Briley 3 Gun; Gift Cards; Sporting Clays; Chokes and Choke Accessories; Tube Sets, Accessories and Cases ...The Patternmaster Code Black and Carlson’s Cremator are two of the best choke tubes for the Stoeger M3500. They can deliver results of over 80% pellets inside a 30-inch circle at over 40 yards with the right ammo. Their ported design helps reduce recoil and muzzle jump, making follow up shots quicker and more accurate.The Stoeger M3000 is a well-balanced, 12-gauge, 3-inch, Inertia Driven®, semi-automatic shotgun that offers solid control and handling. It takes 100 to 200-rounds to break in. It's great for hunting turkey, pheasants, and waterfowl. You can go for good 3-inch slugs for deer hunting with the right optic sights.The Stevens 315 is a hammerless side-by-side shotgun in a boxlock design. There were two production versions of this shotgun: the original from 1910 to 1939, and then a second higher production model from 1935 to 1959. It was made in .410, 28 -, 20-, 16-, and 12-bore. The original price on this shotgun was around $17.Choke Tubes Extended IC, M, F (2 each) and wrench. Stock AA-Grade gloss walnut. Right-handed palm swell on grip and stock with fully adjustable comb. ... Please be aware of online merchants impersonating as direct Stoeger retailers. LEARN MORE. Shotguns. Shotguns. By Series. By Type. By Model. P3000 Series. P3000 Series. View Complete Series ...A well-establish tradition of craftsmanship. Shoulder a Franchi shotgun or rifle for reliable performance afield and at the range. It's got the weight, fit and feel you want.Fausti USA Inc. ::: 3509 Shannon Park Dr. - Fredericksburg, VA 22408 Phone 540.371.3287 - Fax 540.371.1170 ::: [email protected] Privacy Policy - Cookie Policy ...

Viper G2 Wood - 28 Gauge. Barrel Length: 26 inches. Weight: 5.2 pounds. Chokes: 3 Beretta®/Benelli® mobile-style choke tubes (IC, M, F) Located in Kansas City, Missouri, TriStar Arms is a primary importer of quality Turkish shotguns and handguns. The company is driven by the same mission that it set out on since its inception - to provide ...Select the correct choke tubes for your Stoeger shotgun: Stoeger Coach 12 gauge, Condor 12 gauge, Uplander 12 gauge, STF 3000 12 gauge and Stoeger single barrel 12 gauge shotgun barrels all interchange with Muller's Invector/WinChoke threads. The Stoeger 2000 Semi-Auto 12 gauge, P-350 12 gauge pump and the 3500 12 gauge barrels all interchange ...Most double shotguns represented here. Double gun shotguns - Side by Side shotguns, and over under shotguns - Including drillings, double barreled rifles, SxS double rifles, combination guns. Makers - Darne, Merkel, Arrieta, Beretta, Browning, Holland, Purdey, Richards, Bernardelli, Parker, Fox, LC Smith, and most other double barreled shotgun, gun and double rifle makers.Before making an expensive purchase of multi-barrel sets, or if you have any questions at all about the choke tube system your shotgun is fitted to accept, call our Customer Service department for clarification. Browning Customer Service. One Browning Place. Morgan, UT 84050. TOLL-FREE: 1-800-333-3288.You have a Browning Invector, Winchester 500 choke system. (Note NOT INVECTOR PLUS). Several companies make them. I also have a condor, 20 ga, that is very picky. With factory chokes it patterns almost everything really, really bad.Choke Tube Optimachoke HP "DLC Model" Extended 20mm 12 ga. Tri-Active EVO Jacket. Roundneck Logo T-Shirt. Beretta By TSK Stock for DT11 and DT10 - Trap. Shooting Towel. Tech Cap. Corporate Sweater. Best results. hunting/outdoor collection 2023-24.410 bore shotguns are the smallest shotgun gauge used for hunting and measure in at 2 ½ to 3 inches. The payload is also the smallest, with most loads weighing in at ½ ounce. Due to these factors, it's important to keep the pattern together longer, and that means a tighter choke tube.. The modified choke tube, at 0.402", is the best choke tube for the .410.0.25. Standard. $479. Right Handed. up to 1000 fps with alloy pellet / up to 830 fps with lead pellet. Yes. Suppressed. Two-stage, adjustable. The P3500 pump-action shotgun packs all the great features its stable mate the P3000 offers; a chrome-lined barrel, dual-action bars and a rotating bolt head, to name a few, and is chambered to handle up ...III / Modified. IIII / Improved Cylinder. IIIII / Skeet. IIIIII / Cylinder. I-I / SC I. II-II / SC II. Choke tubes can be identified by the number and placement of small notches found on their muzzle ends. Be sure to clear and make safe any shotgun before looking at any installed chokes. Notches / Chok. With a blend of modern features and contemporary styling, the Rock Island Armory Side-By-Side in 12 ga. is a current Turkish take on the old double-barrel shotgun design.Extended Choke Tubes C, IC, M, IM and F. Downloads ... Please be aware of online merchants impersonating as direct Stoeger retailers. LEARN MORE. Shotguns. Shotguns ... Antonio Zoli with S/N prefix below 238: .725 bore- interchanges with Trulock’s Antonio Zoli style. Antonio Zoli with S/N prefix of 238 and higher:.732 bore- No known interchange. BSA 12: interchanges with Trulock’s Beretta/Benelli style. Baikal 12 and 20 gauge: interchanges with standard Tru-Choke.Best Overall: Indian Creek Black Diamond Strike Turkey Choke. Best Budget: Primos Jellyhead Maximum Turkey Choke. Best Long Range: Carlson's Long Beard XR Turkey Choke. Best 20-Gauge: Rob ...I recently tried to remove the Improved Cylinder choke from my Stoeger 2000, and it was a bear to remove. Even when I had the tube unscrewed past the threads on the tube, it still would not come out. I had to keep unscrewing the tube. Eventually, I got it out of the barrel. I could see faint thread marks impressed into the tube below the actual ...Vintage Shotgun Choke Markings. Unlike most manufacturers, Savage chose not to mark their shotgun barrels with standard choke markings of Full, Modified, Improved Cylinder and Cylinder. Instead they chose to use a series of asterisk (*) marks as code to specify the choke constriction of a given barrel. This code can be found stamped on the ...Browning B-SS, Sporter, Side-By-Side Shotgun, 20 guage 26" barrels Mod-Full fixed chokes 14.75" LOP Single tigger, non-selective Blueing is excellent Wood a a few light handling ...Click for more info. Seller ... The shotgun does have some small handling marks on the stocks and barrel. 95% plus conditon overall. ...Click for more info.Stoeger Condor Choke Tube Question. I have a Condor that I won in a Texas Ducks Unlimited raffle in 2004. The choke tubes don't have any kind of designation such as a "m" or "ic" on them. What they do have is a stamp, if you will, on the ends of the tubes. The top barrel has one that has 3 individual marks on it and the one in the bottom barrel ...WinChoke Fully steel shot compatible. Fits all Winchester Winchoke shotguns. Will not fit Winchester Super X2 or other Winchester shotguns that require Browning Invector Plus Choke Tubes. Code. Description. 6130103. 12 Gauge Extra Full. 6130113. 12 Gauge Full.

Standard chokes for all but the .410 bore guns were Full and Modified in 28 and 30 inch barrels and Modified/Improved Cylinder in 26 and 24 inch barrels. .410 bore guns were choked Full/Full. Other standard choke combinations were furnished by special order at no extra charge, at least in the early years.

Most choke tubes contain markings on the outer wall of the cylinder that indicate the brand of choke, choke system it fits, and diameter of the choke. This data can then be compared to the specs of the shotgun to …

Performance Shop Extended Choke Tube. $55.00. Not Yet Rated View Available Options. "OLD STYLE" Crio 12ga. Extended Choke Tube, Matte Black. $105.00. Not Yet Rated View Available Options. "OLD STYLE" Crio 12ga. Extended Choke Tube, Nickel.Choke markings , lets see , Chokemarkings , and Prints of Markings :D What are the various choke markings for Stoeger shotguns? The fixed choke markings are denoted by * marks on the bottom of the barrel under the forearm assembly. 3 on the left barrel and 4 on the right.In fact, many folks are faster with this double barrel than with a semi-auto. Because of its shortened barrel and intuitive controls, the Stoeger promises fast reloads and even faster pointing and swing. After asking around, the biggest complaint I heard about the Coach was its out-of-box issues handling cold weather.Weeds can be a nuisance in any garden or lawn. They can quickly take over and choke out other plants, making it difficult to keep your garden looking its best. Fortunately, there are several methods of weed control available, including the ...These Stoeger double-barreled shotguns feature some of the industry's sturdiest and reliable components. ... 12, 20, 28 gauges and even a 12/20 gauge combo. To make the Condor as versatile as possible, they provide IC and M chokes with all of their 12, 20, and 28 gauge Fields, with flush and extended C, IC, M, IM, and F chokes as aftermarket ...The Stoeger P3000 is all about simplicity. The pump shotgun comes in only one configuration, black synthetic 12-gauge, 2-3/4" and 3.". The ventilated-rib barrel is 28" with a red fiber-optic ...There can be several styles of chokes used by a number of shotgun manufacturers. Please check our detailed interchange guide to be sure this is the right product for your shotgun. Click here for that information.410 CHOKE TUBES Beretta-Benelli Mobil 410ga; Long Invector (1.9" Flush) Short Invector (1.5" Flush) ...Brownells Gun Tech Steve Ostrem fills us in on some of the very basics of Shotgun Choke tubes. He covers the applications of different chokes as well as maki...

1link fbisd loginveteran rewards ffxivhighly offensive memesbrickseek scraper github Stoeger choke markings butler county ovi checkpoint [email protected] & Mobile Support 1-888-750-4433 Domestic Sales 1-800-221-5440 International Sales 1-800-241-9064 Packages 1-800-800-6696 Representatives 1-800-323-7794 Assistance 1-404-209-8490. Manuals. Download the appropriate manual for your Benelli shotgun or rifle. Title. 828 U Product Manual (14.83 MB) For: 828 U Shotguns, 828 U Upland Performance Shop Shotguns, 828 U Sport Shotguns. 828U 04-2020.pdf (16.67 MB) For: 828 U Shotguns, 828 U Limited Edition. ETHOS Shotgun Product Manual (11 MB) For: ETHOS Sport Shotguns, ETHOS .... nfl mock draft 2023 sim IM. 30-50. 25-40. Full. 40+. 30-45. Cylinder choke tubes come with the freest flight patterns and offer a viable firing range that is the most precise. Open choke tubes are highly recommended to use for buckshot choke and birdshot at a short distance or range. Moreover, They deliver a broad pattern that kills targets at short ranges.8. Don't think that makes TriStar the new kid on the block, though. The company's management team has more than 75 years of combined experience in the business. They know what they're doing. 7. TriStar largely—especially on this website, at least—is recognized for its shotguns. And rightly so. huntington bank withdrawal limit321081669 routing Jun 4, 2021 · Skeet 1: Specialty choke for skeet shooting, a form of moving (clay) targets for shotguns. Constriction is 0.13mm/0.005in. barrel to muzzle, and patterns 45% at 40 yards, 75% at 25 yards. Usually identified as "SK1" instead of notches. 2010 honda accord serpentine belt diagramomega jungkook New Customers Can Take an Extra 30% off. There are a wide variety of options. The Stoeger P3000 shotgun is chambered 12 gauge. It has been designed to fire 2 3/4” (70mm) to 3” (76mm) length with lead and steel shot. Use of Full and Improved Modified choke tubes is not recommended with steel shot. WARNING: Never use cartridges with a case longer than the chamber, as this could cause serious injury or even death. In this short video I show you how to identify chokes for the tactical line of shotguns by Benelli and a few from Beretta without having to remove them. Simp...Sep 21, 2009 · Choke markings; 15.7 is the metric bore size. The 15.3 and 15.1 are the muzzle measurements. 15.7 divided by 254=.618 which is very close to normal bore size for a 20. 15.3 divided by 254=602: difference of .015=mod. choke. 15.1 divided by 254=.594: difference to bore; .024=full choke. http://www.colonialarms.com/chokespecs.html