257 roberts reloading data

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.257 Roberts Improved Data reloading data with 40 loads. Using bullets from Hornady, Sierra HP, Rem. Power Lokt, Sierra, Hornady Spire Point, Hornady Round Nose, Barnes.Wt. .257 Roberts (Using Nosler Bullets) reloading data with 150 loads. Using bullets from Nosler BT, or CT Ballistic Silvertip, Nosler BT, Partition Spitzer or E-Tip, Nosler Accubond, Nosler Solid Base Ballistic Tip (blue), Nosler, Nosler Partition Spitzer. Powders include Alliant, Accurate, IMR, Hodgdon, Vihtavuori, Ramshot, Winchester.Load Data for .257 Roberts . Bullet: 115 gr PART (NOS) Diameter: 0.257" Powder: Hybrid 100V (Hodgdon) Starting Powder: 42.0 gr. Max Powder: 46.0 gr .Home / Article/LoadDevelopment. Load the .257 Roberts. Author: Stan Trzoniec / Wolfe Publishing Co. Date: May 13 2019. Examples of .25-caliber cartridges include (left to …3071. Remarks: COAL: 2.942 inches; average of three shots (100-yard group): .98 inches. .257 Roberts Ackley Improved (Handloader issue 300) reloading data with 3 loads. Using bullets from Hornady V-Max, Swift Scirocco II, Nosler Partition. Powders include IMR, Hodgdon, Alliant.Wt. .257 Roberts (Using Nosler Bullets) reloading data with 150 loads. Using bullets from Nosler BT, or CT Ballistic Silvertip, Nosler BT, Partition Spitzer or E-Tip, Nosler Accubond, Nosler Solid Base Ballistic Tip (blue), Nosler, Nosler Partition Spitzer. Powders include Alliant, Accurate, IMR, Hodgdon, Vihtavuori, Ramshot, Winchester. Width: 0.473". Average FPS: 2790. Average Energy: 2039. Average Gr: 118. Recoil: 1.47. Power Rank: 3.29 of 20. The .257 Roberts was designed in the 1920s when wildcatter Ned Roberts started to do experiments on the .257 caliber cartridges. After some work he decided to go with a 7x57 Mauser as the parent case and Remington Arms picked up the ...

The .257 Roberts has a maximum average pressure of 54,000 psi and can be loaded with bullet weights ranging from 75 to 120 grains. It is commonly used for hunting deer, antelope, and other similar-sized game, as well as varmints. The popularity of the .257 Roberts has declined in recent years, with many hunters opting for newer cartridges that ... Width: 0.473". Average FPS: 2790. Average Energy: 2039. Average Gr: 118. Recoil: 1.47. Power Rank: 3.29 of 20. The .257 Roberts was designed in the 1920s when wildcatter Ned Roberts started to do experiments on the .257 caliber cartridges. After some work he decided to go with a 7x57 Mauser as the parent case and Remington Arms picked up the ...Feb 16, 2024 ... In this video we show you how convert 30-06 cases to 257 Roberts. ... Reloading, How to Reform Brass ~ Use What You Have! ... Kentucky Ballistics• ...Be Alert: Publisher cannot be responsible for errors in published load data. Wt. .257 Roberts in a Rem 700 Classic reloading data with 31 loads. Using bullets from Speer spitzer, Hornady hollow-point, Sierra boat-tail hollow-point, Speer spitzer boat-tail, Hornady round-nose, Nosler partition spitzer. Powders include Winchester, IMR, Hodgdon ...Apr 30, 2012. #7. Quite surprised at the velocity you are getting. You are making a 257 Roberts into a 25-06. I own two, 257 roberts rifles. One is a 50's Mauser with 22" raised-solid barrel and super fancy. It shoots 100 grain Speer bullets @ 3030 fps with 41.5 gr. 4064. Used it for decades and it has worked well./r/Reloading is a place for civilized discussions on the topic of Metallic and Shotshell reloading ... Best loads for 257 roberts with 117gr hornady sst h380 powder nosler +p brass and cci LR 200 primers . 10 years ago I made some loads that shot 1moa out of my M77 I lost the load data and am trying to make some loads like that again i have the ...Remarks: COAL (inches): 3.020; 3-shot 100-yard group (inches): .77. .257 Roberts Ackley Improved (Load Development) reloading data with 45 loads. Using bullets from Nosler Ballistic Tip Varmint, Hornady GMX, Hornady ELD-X, Nosler Ballistic Tip Hunting, Berger VLD Hunting. Powders include Hodgdon, Alliant, Ramshot, IMR, Accurate, Vihtavuori ... .257 Roberts (Hodgdon Data - Winchester Powder) reloading data with 14 loads. Using bullets from Hornady SP, Hornady HP, Barnes TTSX BT, Sierra HPBT, Speer SPBT, Nosler Part.

257 Roberts Load Data Using Hornady reloading data with the 257 Roberts bullets creates a great round that is popular with hunters who like its low recoil rates. The .257 Roberts dates way back to around the 1920's but many still use it to this day. Be Alert: Publisher cannot be responsible for errors in published load data.257 Roberts +P and H4350. Am going to try H4350 in my 257 Roberts as the powder should work better in the conditions I hunt (Alberta, Canada, where the temp during hunting season can be 10 above or 30 below). I have been using 115 gr Nosler BT with IMR 4350 and am getting great groups (44 grains, which is over max. does not …Jul 9, 2021 ... ... data, 2 or 3 online ballistic calculators for ballistic data. ... 257 Roberts: The Second Chance Cartridge. Ron ... 270 Weatherby: The Forgotten ....257" 25 Spitzer SP Hot-Cor® 25 HP 25 Spitzer BTSP Weight (grains) 100 Ballistic Coefficient 0.334 0.263 0.393 Sectional Density 0.1260.216 COAL Tested 2.770"2.760" Speer Part No. 1405 1407 1408 Propellant Case Primer Weight (grains) Muzzle Velocity (feet/sec) Weight (grains) Winchester 760 Winchester CCI 250 41.0 2804 45.0

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.257 Roberts Reloading Data (Using Hornady Bullets) reloading data with 307 loads. Using bullets from Hornady FP, Hornady V-Max or HP, Hornady SP, Hornady GMX, Hornady IB, Hornady SST, BTSP or RN, Hornady HP. Powders include Accurate, Hodgdon, Alliant, IMR, Vihtavuori, Winchester.The 257 Improved is a fi ne performer, adding up to 100 fps velocity over its factory cousin. One of its advantages, Ackley noted, is the fact that 257 Roberts factory ammunition can be used in an improved rifl e if necessary. Other 25 caliber wildcats are not this fl exible. The 257 Improved is all that the 257 Roberts is—and a bit more.Sep 24, 2022 ... These recoil figures can be adjusted with heavier or lighter bullets, of course, but when using the most common factory loads, the .257 Roberts ....257 Roberts Handloads Standard Pressure reloading data with 40 loads. Using bullets from Hornady Spire Point, Berger HP, Barnes TSX FB, Hornady SST, Sierra softpoint, Speer softpoint. Powders include IMR, Winchester, Hodgdon, Vihtavuori, Alliant, Accurate, Ramshot, NormaFeb 16, 2024 ... In this video we show you how convert 30-06 cases to 257 Roberts. ... Reloading, How to Reform Brass ~ Use What You Have! ... Kentucky Ballistics• ...

Never will understand folks fishing for reloading data on the Internet. There are so many documented loads out there, if you search even a little bit. ... Accuracy has come at the top of the loading charts for my 30.06 with 168g bullets and .257 Roberts with 75g bullets with 760. The sensitivity issue concerns me now that I read about it. I'll ...Jan 12, 2020 ... The 950 JDJ FAT MAC (The World's Most Powerful Rifle!!!) · 1.4M views ; 35 Whelen loads for a tc compass · 3.5K views ; Well I found some reloade....257 Roberts (Hodgdon CFE 223 Data) reloading data with 6 loads. Using bullets from Hornady SP, Hornady HP, Barnes TTSX BT. Powders include HodgdonMar 10, 2011 ... Looking for loads for a 257 Roberts, the rifle is used for elk, deer, and antelope. Thinking a 110gr Nosler ACCU-bond or 100gr Partition will be ... 257 Roberts Load Data. Using Hornady reloading data with the 257 Roberts bullets creates a great round that is popular with hunters who like its low recoil rates. The .257 Roberts dates way back to around the 1920's but many still use it to this day. Be Alert: Publisher cannot be responsible for errors in published load data. Wt. Bullet. 257 Roberts +P 117 gr SST® Superformance®. Increase your rifle's performance up to 200 fps without extra chamber pressure, recoil, muzzle blast, temperature sensitivity, fouling, or loss of accuracy. Superformance ® uses progressive propellants that take your favorite V-MAX, ® NTX, ® SST, ® CX,™ and InterLock, ® bullets to levels of ...Feb 16, 2024 ... In this video we show you how convert 30-06 cases to 257 Roberts. ... Reloading, How to Reform Brass ~ Use What You Have! ... Kentucky Ballistics• ...Mar 8, 2004 · Well, I'm about three weeks into reloading for the .257 Roberts +P. So far I have three good loads worked up and have loaded but not test-fired another batch. The results so far: Common components. Win brass, CCI 250 primer. 75g Hornady VMAX. COL 2.8025". 42.0g Varget. 3187fps, 7.0fps STD, 16fps E.S.

.257" 25 Spitzer BTSP Weight (grains) 120 Ballistic Coefficient 0.480 Sectional Density 0.260 COAL Tested 2.770" Speer Part No. 1410 Propellant Case Primer Weight (grains) …

Refer to the current SPEER® Reloading Manual for handloading instructions. Be thoroughly familiar with those instructions before using these loads. As Vista Outdoor Operations LLC has no control over individual handloading practices or the condition of firearms in which ... 257 Roberts +P 3290 3386 3381 3367 3295 3226 3187 3184 3170 3163 3153 ...Width: 0.473". Average FPS: 2790. Average Energy: 2039. Average Gr: 118. Recoil: 1.47. Power Rank: 3.29 of 20. The .257 Roberts was designed in the 1920s when wildcatter Ned Roberts started to do experiments on the .257 caliber cartridges. After some work he decided to go with a 7x57 Mauser as the parent case and Remington Arms picked up the ... Reloder 16. Select A Caliber or Gauge Below To View Recipes. 243 Win. 25-06 Rem. 257 Roberts. 260 Rem. 270 Win. 270 Win. Short Magnum. The .257 Roberts is a low recoiling, mild powered cartridge. In a short action, it has the potential for a suitable youth rifle but without care towards optimizing hand loads, can lack the power with many 117 to 120 grain loads to be of any great advantage over the more common .243.Date: Feb 11 2014. N.H. "Ned" Roberts developed the .257 Roberts cartridge during the 1920s by necking the 7mm Mauser case to accept .257-inch bullets, and by changing the shoulder angle from 20 to 15 degrees. Roberts was a well-known experimenter and gun writer, and his cartridge became a popular wildcat among custom rifle builders and hunters.Printed from Shooter's Reference on 05/03/2024: https://www.shootersreference.com/reloadingdata/257-roberts/Load Data for .257 Roberts . Bullet: 80 gr TTSX BT (Barnes) Diameter: 0.257" Powder: IMR 4451 (Improved Military Rifle) Starting Powder: 43.2 gr. Max Powder: 48.6 gr .

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Wt. .257 Roberts reloading data with 8 loads. Using bullets from Sierra jacketed hollowpoint, Hornady jacketed hollowpoint, Speer jacketed hollowpoint, Nosler Solid Base, Nosler Partition, Sierra spitzer boat-tail, Hornady hollowpoint. Powders include IMR, Norma, Hodgdon, Winchester.I am planning on trying the 110 gr AB in my 257 Roberts this spring. I am shooting a M700 Classic and have had excellent results with IMR 4350. I will start my load development with this powder. With the 100 gr BT or PT, I have been using 45.0 grs of IMR 4350. The 115 gr BT and PT use 43.0 grs of the same powder. 257 Roberts +P 2793 2858 2852 2836 2826 2770 2767 2758 2709 2705 2635 2545 2541 2527 2482 2003 START CHARGE 2817 WARNING: Improper handloading practices can result in serious personal injury and/or property damage. Refer to the current SPEER® Reloading Manual for handloading instructions. Be thoroughly familiar with those instructions before ... Warning! Notes: .257 Roberts, Ruger M-77 long action 24-inch barrel; Remington cases, 186 grains; CCI No. 200 primers; Oehler M-31 Chronotach, Oehler M-50 photoelectric screens; velocity at 15 feet converted to MV; temperature 70 degrees; this rifle had a rather loose chamber and would handle more powder than most rifles with every bullet ....257 Roberts - Published Manufacturer Loading Data Shellholders: Hornady #1 .257 Roberts (Hodgdon Data) reloading data with 122 loads. Using bullets from Hornady SP, Hornady HP, Barnes TTSX BT, Hornady GMX, Sierra HPBT, Speer SPBT, Nosler Part. .257 Roberts Handloads reloading data with 18 loads. Using bullets from Hornady FP, Speer FP, Hornady V-Max, Nosler Ballistic Tip, Partition, Hornady, Hornady boat-tail. Powders include IMR, Winchester, Accurate, Hodgdon, Ramshot, Alliant ... .257 Roberts Handloads: Warning! Notes: All groups are an average of three shots at 100 yards ...Oct 15, 2022 ... ... data, 2 or 3 online ballistic calculators for ballistic data. Do not modify any cartridge or firearm beyond what the manufacturer recommends ...Today we're choosing a load and we're going to select our bullet, powder, brass, and primer. And we're not just choosing a load for accuracy but a lot that w....257 Roberts Improved (RCBS Version) reloading data with 49 loads. Using bullets from Sierra HP, Sierra spitzer, Hornady SP, Nosler SB, Nosler Partition, Speer HP, Speer SBT, Sierra FB, Hornady HP. ... Notes: Test rifle: Enfield sporter with 24-inch Buhmiller barrel (rechambered from .257 Roberts to .257 Improved, with 28-degree RCBS chamber ...Warning! Barrel Length: 24 inches; Primer: Federal 210; Source: Handloader Magazine issue #306 February-March 2017. Be Alert: Publisher cannot be responsible for errors in published load data. Wt. .257 Roberts (using Alliant's RL-16) reloading data with 2 loads. Using bullets from Nosler Ballistic Tip, Hornady SST.The content on this website (including videos, articles, ammunition reloading data, technical articles, gunsmithing and other information) is for demonstration purposes only. ... November 14, 2021 Tyler Hale Hunting, Reloading Blog 25 Creedmoor, 25-06, 257 Roberts, Athlon, Ballistics Gel, Berger Bullets, ... ….

The current SAAMI spec for the .257 Roberts Maximum Average Pressure (MAP) is 54,000 psi. Winchester introduced a +P version with a MAP of 58,000 psi in the mid-1980s. That’s still less than the typical 60,000 to 65,000 psi of comparable modern rifle cartridges. The .257 Roberts was pretty popular for a few years before and after World ….257 ROBERTS ACKLEY IMPROVED - Published Manufacturer Loading Data Recipe Type: Rifle . Bullet Weight: ... 0.257" Powder: 2700 (Accurate) Primer: FED 210.257 Roberts Handloads Standard Pressure reloading data with 40 loads. Using bullets from Hornady Spire Point, Berger HP, Barnes TSX FB, Hornady SST, Sierra softpoint, Speer softpoint. Powders include IMR, Winchester, Hodgdon, Vihtavuori, Alliant, Accurate, Ramshot, Norma Load Data for .257 Roberts . Bullet: 120 gr HPBT (Sierra) Diameter: 0.257" Powder: IMR 4350 (Improved Military Rifle) Starting Powder: Max Powder: 41.5 gr . Primer ... Notes: Loads fired from a 24-inch barreled Montana Rifle Company Woodland .257 Ackley Improved with a Leupold 3.5-10x, set on 10x. All loads shot with Winchester Large Rifle primers. All cases were fireformed from .257 Roberts brass, and all groups were fired at 100 yards, except where noted. (Handloader Issue #266 - June, 2010) .257 Roberts reloading data with 91 loads. Using bullets from Hornady HP, Barnes TTSX BT, Hornady GMX, Sierra HPBT, Speer SPBT, Nosler Part. Powders include IMR 257 Roberts Load Data. Using Hornady reloading data with the 257 Roberts bullets creates a great round that is popular with hunters who like its low recoil rates. The .257 Roberts dates way back to around the 1920's but many still use it to this day. Be Alert: Publisher cannot be responsible for errors in published load data. Wt. Bullet. .257 Roberts in a 24-inch Barrel reloading data with 10 loads. Using bullets from . Powders include Winchester, IMR ... .257 Roberts in a 24-inch Barrel: Warning! Notes: Handloader Issue 130: Be Alert: Publisher cannot be responsible for errors in published load data. Wt. Bullet: Powder Manufacturer: Powder: Charge: Velocity (FPS) 90 ... 257 roberts reloading data, The .257 Roberts has a maximum average pressure of 54,000 psi and can be loaded with bullet weights ranging from 75 to 120 grains. It is commonly used for hunting deer, antelope, and other similar-sized game, as well as varmints. The popularity of the .257 Roberts has declined in recent years, with many hunters opting for newer cartridges that ..., Phone Orders & Customer Service. 1-800-272-3000 | Mon - Fri | 8am to 5pm CST. Pickup Room Hours. Mon - Fri | 8am to 5:30pm CST. Click here for holiday closures. Midsouth Shooters Supply's selection of reloading supplies includes 257 Roberts brass. Build your next load using our 257 Roberts rifle reloading brass., 257 Roberts Load Data Using Hornady reloading data with the 257 Roberts bullets creates a great round that is popular with hunters who like its low recoil rates. The .257 Roberts dates way back to around the 1920's but many still use it to this day. Be Alert: Publisher cannot be responsible for errors in published load data., The .257 Roberts, also known as .257 Bob, [2] is a medium-powered .25 caliber rifle cartridge. It has been described as the best compromise between the low recoil and flat trajectory of smaller calibers such as the 5 mm (.22 in) and 6 mm (.24 in), and has more energy, but is harder recoiling, similar to larger hunting calibers, such as the 7 mm ..., 257 Roberts +P 117 gr SST® Superformance®. Increase your rifle's performance up to 200 fps without extra chamber pressure, recoil, muzzle blast, temperature sensitivity, fouling, or loss of accuracy. Superformance ® uses progressive propellants that take your favorite V-MAX, ® NTX, ® SST, ® CX,™ and InterLock, ® bullets to levels of ... , Warning! Notes: case: Remington; bbl: 24"; pr: Remington 9 1/2; NEVER exceed loads listed. Be Alert: Publisher cannot be responsible for errors in published load data. Wt. .257 Roberts (IMR Data) reloading data with 11 loads. Using bullets from Sierra SP, Sierra Hollow Point Boat Tail. Powders include IMR., .257 Roberts Handloads reloading data with 18 loads. Using bullets from Hornady FP, Speer FP, Hornady V-Max, Nosler Ballistic Tip, Partition, Hornady, Hornady boat-tail., Characteristics of .257 | 110gr | Hornady ELD-X bullet and comprehensive load data for this projectile. .257 | 110gr | Hornady ELD-X | Reloading Data To be able to use the full range of Shopware 6, we recommend activating Javascript in your browser., Mar 23, 2012 ... Here is the loading data from Hodgdon's website for my selected powder and bullet for .257Roberts. Notice that it is a conservative load meant ..., Stan's .257 Roberts is a Winchester Model 70 Featherweight. The .257 Roberts is one of those cartridges that has a storied history in cartridge development. Noted gun and cartridge experimenter – Dr. Franklin Mann – was indeed a very important part of the .25-caliber concept. Ned Roberts of New Hampshire was the other part, and in fact was ..., 257 Rob +P - 120 grain Version 9.0 24" Lilja BARREL Twist 1-10" GRS. POWDER CHG. 0.391 69% 64% 69% 75% 6% ** = Compressed load “ Because Nosler, Inc. has no control over the actual components selected, the manner in which they are assembled or the condition of the firearm used, no responsibility, either expressed or implied is assumed for the ..., Rifle Data. Rifle Data. Here you will find load data for some of the most recent cartridges on the market, with more being added each week. We are currently populating the cartridge drop-down menu with updated cartridge renderings, new propellants and bullets, and links to complimentary product pages. Cartridge., .257 Roberts +P Handload Data (50,000 CUP) reloading data with 19 loads. Using bullets from Hornady V-Max, Speer flat softpoint, Hornady Spire Point, Nosler Ballistic Tip, Nosler Partition, Speer spitzer boat-tail. Powders include Hodgdon, Accurate, Alliant, Vihtavuori, Safety Data Sheets; Shipping & Delivery; Warranty; Login 0. 0. My Cart. 0. 0. Search suggestions. Site Search. Cartridge Selector (Tap to open) ... .257 ROBERTS IMPROVED 40° RELOADING ESSENTIALS .257 ROBERTS RELOADING ESSENTIALS .257 WEATHERBY MAGNUM RELOADING ESSENTIALS .25 AUTO (25 ACP) …, Oct 13, 2022 ... ... data, 2 or 3 online ballistic calculators for ballistic data. ... 257 Roberts ~ The Greatest All-Round American Rifle! ... Reloading 257 Weatherby ..., .257 Roberts Handloads reloading data with 18 loads. Using bullets from Hornady FP, Speer FP, Hornady V-Max, Nosler Ballistic Tip, Partition, Hornady, Hornady boat-tail., Load Data for .257 Roberts . Bullet: 115 gr PART (NOS) Diameter: 0.257" Powder: Hybrid 100V (Hodgdon) Starting Powder: 42.0 gr. Max Powder: 46.0 gr ., Dec 7, 2007. 465. 330. I have a Remington 722 in .257 Roberts that is grouping (3) 100 gr Nosler Ballistic Tips w/IMR-4350 under .5" @ 100 yards. I tried the same powder with Hornady 117 SST and groups open up to almost 2.0". Is anyone willing to share their load data for .257 Roberts w/115-120gr?, Dec 7, 2007. 465. 330. I have a Remington 722 in .257 Roberts that is grouping (3) 100 gr Nosler Ballistic Tips w/IMR-4350 under .5" @ 100 yards. I tried the same powder with Hornady 117 SST and groups open up to almost 2.0". Is anyone willing to share their load data for .257 Roberts w/115-120gr?, May 31, 2021 ... The Late .257 Roberts ... Hopeful Ballistics•1.5K views · 10:53 · Go to ... 257 Roberts varmint load Satterlee ladder test - Ruger M77 tang safety., .257 Roberts (Reduced Loads) reloading data with 4 loads. Using bullets from Hornady Flatnose, Sierra ProHunter, Nosler Partition. Powders include IMR, Hodgdon ... .257 Roberts (Reduced Loads) Warning! Gun: Remington 722; Barrel Length: 24 inches; Twist: 1-10; Primer: CCI 200; Case: Remington; Source: Handloader February/March 2017 …, The market for personal data is quietly infiltrating and affecting every aspect of our lives. When Judge Robert Bork was nominated for the Supreme Court in 1987, a reporter for the..., Loading Data . Warning; ... Reloading Costs Calculator; Case Crimp Calculator; Energy, Momentum, Power Factor, and Taylor Knock-out Calculators ... .257 Roberts ..., 3071. Remarks: COAL: 2.942 inches; average of three shots (100-yard group): .98 inches. .257 Roberts Ackley Improved (Handloader issue 300) reloading data with 3 loads. Using bullets from Hornady V-Max, Swift Scirocco II, Nosler Partition. Powders include IMR, Hodgdon, Alliant., The .257 Roberts was the premier combination varmint/deer cartridge until the .243 Winchester and .244 Remington were introduced in 1955. These cartridges were highly touted by Warren Page, the Shooting Editor at Field & Stream magazine, and appeared to be ballistically superior to the .257 Roberts., The current SAAMI spec for the .257 Roberts Maximum Average Pressure (MAP) is 54,000 psi. Winchester introduced a +P version with a MAP of 58,000 psi in the mid-1980s. That’s still less than the typical 60,000 to 65,000 psi of comparable modern rifle cartridges. The .257 Roberts was pretty popular for a few years before and after World …, Load Data for .257 Roberts . Bullet: 80 gr TTSX BT (Barnes) Diameter: 0.257" Powder: IMR 4451 (Improved Military Rifle) Starting Powder: 43.2 gr. Max Powder: 48.6 gr ., 60. Location. Fernandina Beach. That is interesting, and probably has something to do with the 257 Roberts being the only rifle cartridge that later had a +P designator. I currently don’t own a Roberts, but have loaded for 5 of them. All preferred H4350 and a good 100 gr bullet, such as the TSX or Nosler BT., Loading Data . Warning; ... Reloading Costs Calculator; Case Crimp Calculator; Energy, Momentum, Power Factor, and Taylor Knock-out Calculators ... .257 Roberts ..., 257 Rob +P - 100 grain Version 9.0 4" Lilja BARREL Twist 1-10" Expansion Tip® 0 .4 0 9 D u e to in te rn al co n stru ctio n d i˜ e re n ce s, alw ays b e g in w ith startin g lo ad s w h e n u sin g Exp an sio n Tip ® products. 81% 96% 72% 92% 81% 7% This data was developed to the 257 Roberts +P pressure level of 58,000 psi, and should only , IMR-7828. Subscribe. 2,608. Remarks: .257 Roberts Carbine reloading data with 33 loads. Using bullets from Sierra jacketed hollowpoint, Hornady Spire Point, Sierra hollowpoint boat-tail, Nosler Ballistic Tip, Nosler Partition, Sierra spitzer boat-tail, Speer spitzer boat-tail. Powders include Hodgdon, IMR, Alliant, Accurate., .257 Roberts +P (Speer Reloading Manual #14) reloading data with 116 loads. Using bullets from Speer FNSP, Speer Spitz SP or TNT HP, Speer Spitz SP, HP or Spitz …, Width: 0.473". Average FPS: 2790. Average Energy: 2039. Average Gr: 118. Recoil: 1.47. Power Rank: 3.29 of 20. The .257 Roberts was designed in the 1920s when wildcatter Ned Roberts started to do experiments on the .257 caliber cartridges. After some work he decided to go with a 7x57 Mauser as the parent case and Remington Arms picked up the ...