.338 conversion
Quote from customguns on 06/20/2023, 11:02Converting a .45 Paramount into a .338 smokeless muzzleloader using a #17 heavy contour Brux barrel. Ken at Brux tells me his heavy contour barrels are rated between 78Kpsi and 88Kpsi. Using Hankins ignition and want to keep pressure below 55Kpsi. Any recommended loads for a .338 using 250 grain Sierra Gameking bullets?
Converting a .45 Paramount into a .338 smokeless muzzleloader using a #17 heavy contour Brux barrel. Ken at Brux tells me his heavy contour barrels are rated between 78Kpsi and 88Kpsi. Using Hankins ignition and want to keep pressure below 55Kpsi. Any recommended loads for a .338 using 250 grain Sierra Gameking bullets?
Quote from Sideshow on 06/22/2023, 06:18I have ZERO EXPERIANCE IN THIS BUT….I DO HAVE A COUPLE THOUGHTS MAYBE WORTH HEARING….
The 45 Seems to be the smallest of the easy to tune bores with powder and bullets and stay out of pressure trouble and still achieve a clean burn .
The 40 seems to begin the Problems with Powders , pressures , and obturation .
This is evident especially above a 275gr bullet as for obturation becomeing MUCH MORE DIFFICULT TO GET COMPLETELY !!!! I think this also contributes to burn rate variabilities and dirty burns from pressure loss just as the far slower powders begin to get with the program accelorating the bullet . The bullets are becomeing awfully darn LONG for caliber . Not good . This messes up the internal ballistics within the barrel .
From what i can tell this continues to degrade as the bores get SMALLER . The 375 is the next step down and is worse yet . Ive HEARD the 235s are the easiest to get to shoot but nobody really wants them . They all want OVER 700BC G1 BULLETS WHICH ARE LONG AND HEAVY . AGAIN the same issues as the 40 ONLY WORSE .
The smaller the bore the more trouble they are . ESPECIALLY CHASEING BC = LONG HEAVY FOR CALIBER BULLETS . Lets also face it most every one is a tough core and tough jacket too . These by and large are BIG GAME bullets . Tougher than anvils for OBTURATION NEEDED IN A MUZZY . Way too long for caliber and not nearly fragile enough .
Youre gonna need short for caliber , and pretty flimsy construction WITH i BELIEVE D.I. IGNITION .
Good luck !!!
I have ZERO EXPERIANCE IN THIS BUT….I DO HAVE A COUPLE THOUGHTS MAYBE WORTH HEARING….
The 45 Seems to be the smallest of the easy to tune bores with powder and bullets and stay out of pressure trouble and still achieve a clean burn .
The 40 seems to begin the Problems with Powders , pressures , and obturation .
This is evident especially above a 275gr bullet as for obturation becomeing MUCH MORE DIFFICULT TO GET COMPLETELY !!!! I think this also contributes to burn rate variabilities and dirty burns from pressure loss just as the far slower powders begin to get with the program accelorating the bullet . The bullets are becomeing awfully darn LONG for caliber . Not good . This messes up the internal ballistics within the barrel .
From what i can tell this continues to degrade as the bores get SMALLER . The 375 is the next step down and is worse yet . Ive HEARD the 235s are the easiest to get to shoot but nobody really wants them . They all want OVER 700BC G1 BULLETS WHICH ARE LONG AND HEAVY . AGAIN the same issues as the 40 ONLY WORSE .
The smaller the bore the more trouble they are . ESPECIALLY CHASEING BC = LONG HEAVY FOR CALIBER BULLETS . Lets also face it most every one is a tough core and tough jacket too . These by and large are BIG GAME bullets . Tougher than anvils for OBTURATION NEEDED IN A MUZZY . Way too long for caliber and not nearly fragile enough .
Youre gonna need short for caliber , and pretty flimsy construction WITH i BELIEVE D.I. IGNITION .
Good luck !!!
Quote from customguns on 06/22/2023, 08:28Have my full length sizer. Waiting on powder I’ve ordered to try some loads. I’ve heard of several guys making .308s, but I haven’t heard the results.
Have my full length sizer. Waiting on powder I’ve ordered to try some loads. I’ve heard of several guys making .308s, but I haven’t heard the results.
Quote from customguns on 06/24/2023, 15:25Tried using my full length sizing die on the .338 bullets. I would have broke the handle on my press before getting the bullet to size. Was using a Lyman 7/8” press and did lube the bullet. Ordered a bushing to accept the 7/8” die in my 1.5” 50 BMG press. If that doesn’t do it I’ll need to find a different bullet.
Tried using my full length sizing die on the .338 bullets. I would have broke the handle on my press before getting the bullet to size. Was using a Lyman 7/8” press and did lube the bullet. Ordered a bushing to accept the 7/8” die in my 1.5” 50 BMG press. If that doesn’t do it I’ll need to find a different bullet.
Quote from Sideshow on 06/25/2023, 02:28Yep thats 1 of the problems enoutered . If i were you id contact Northern Precision bullets and Hawk custom bullets to see what they could do for you . Go lighter as in shorter for calber and softer construction . OR see what some of the custom copper bullets offer or orderable . Be prepared to anneal them . Heat with a propane torch till they glow then dump them into chilled vinegar with ice cubes in it . That gets the monos dead soft . Thats you best bets . Hammer or cutting edge MAY make them for you lighter and shorter but just like in a 40 this will need to be done if you want accuracy and obturation even full sized with a mono . Truthfully to hunt with this is the way to go . Short for caliber and soft is the answer . Tubb dust isnt a bad idea on the annealed , full sized bullets either so you dont copper up the last 8 inches or so of that barrel . Its on David Tubbs website for sale , Tubb Dust .
Yep thats 1 of the problems enoutered . If i were you id contact Northern Precision bullets and Hawk custom bullets to see what they could do for you . Go lighter as in shorter for calber and softer construction . OR see what some of the custom copper bullets offer or orderable . Be prepared to anneal them . Heat with a propane torch till they glow then dump them into chilled vinegar with ice cubes in it . That gets the monos dead soft . Thats you best bets . Hammer or cutting edge MAY make them for you lighter and shorter but just like in a 40 this will need to be done if you want accuracy and obturation even full sized with a mono . Truthfully to hunt with this is the way to go . Short for caliber and soft is the answer . Tubb dust isnt a bad idea on the annealed , full sized bullets either so you dont copper up the last 8 inches or so of that barrel . Its on David Tubbs website for sale , Tubb Dust .
Quote from customguns on 06/25/2023, 07:32Good information. Thanks
Good information. Thanks
Quote from customguns on 08/26/2023, 17:35Got the .338 Smokeless up and running. Used 250 grain, .330 diameter bullets run through a full length sizing die. 95 grains of H1000 gave a velocity of 2850 fps. Very good accuracy. 6 shot group was .75”.
Got the .338 Smokeless up and running. Used 250 grain, .330 diameter bullets run through a full length sizing die. 95 grains of H1000 gave a velocity of 2850 fps. Very good accuracy. 6 shot group was .75”.
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Quote from customguns on 08/26/2023, 17:59That picture started as a full target. Had to keep cropping it until it would upload.
That picture started as a full target. Had to keep cropping it until it would upload.
Quote from Ninering62 on 08/27/2023, 02:09Quote from customguns on 08/26/2023, 17:35Got the .338 Smokeless up and running. Used 250 grain, .330 diameter bullets run through a full length sizing die. 95 grains of H1000 gave a velocity of 2850 fps. Very good accuracy. 6 shot group was .75”.
Nice shooting Tim. Thats really cool as hell a .338 smokeless Paramount. Thanks for sharing the details about if & the load data.
Quote from customguns on 08/26/2023, 17:35Got the .338 Smokeless up and running. Used 250 grain, .330 diameter bullets run through a full length sizing die. 95 grains of H1000 gave a velocity of 2850 fps. Very good accuracy. 6 shot group was .75”.
Nice shooting Tim. Thats really cool as hell a .338 smokeless Paramount. Thanks for sharing the details about if & the load data.
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