HELP.. Imr 4350 Swift Aframe 300 Grain .375 h&h Load Data

CharlieB, attached is a QuickLoad simulation of the caliber, powder type and bullet you mentioned.
It is below max pressure and very close to the "optimal barrel time" This program has been reasonably accurate in the past, but I have ZERO personal experience with this powder. Use at your own risk. As stated previously you should start with a little less powder and work up.
354 H&H IMR 4350 300 Gr SWA.PNG
 
Don't get wrapped around the axle, shoot what you have. Chances are one of those loads will work fine. You are not looking for 1/4 MOA groups. You are solid with 1MOA or better. Factory ammo shoots in most rifles, the ammo you are making will be better than Factory, find the one you have that works the best. Then load up a bunch of ammo. Otherwise you are going to burn up all your components and not have any time to replace them.

Hitting a 6" target at 200 yards off the sticks. Anything close 1MOA is going to do that all day, if the shooter can.
 
CharlieB, attached is a QuickLoad simulation of the caliber, powder type and bullet you mentioned.
It is below max pressure and very close to the "optimal barrel time" This program has been reasonably accurate in the past, but I have ZERO personal experience with this powder. Use at your own risk. As stated previously you should start with a little less powder and work up.View attachment 557200
Wow that's insane! Okay thank you!
 
CharlieB, attached is a QuickLoad simulation of the caliber, powder type and bullet you mentioned.
It is below max pressure and very close to the "optimal barrel time" This program has been reasonably accurate in the past, but I have ZERO personal experience with this powder. Use at your own risk. As stated previously you should start with a little less powder and work up.View attachment 557200
71.9 is way lower then I would of expected!
 
Do you have a cronograph? If not, get one. It's the only way for the average guy to know what kind of performance your loads are giving. If your velocity readings are close to what the book is showing with a particular load, you know you're at least in the ballpark in regards to pressure.
 
Probably no help but Sierra 300 gr in that cartridge lists max of 78.4 of IMR4350. I switched barrels a week before my last hunt but I was at the range every day and had a good supply of previously proven bullets. Having said that, I'm with others, buy some factory rounds and go with them.
 
This is what I have loaded so far out of the swift manual.
Holy smokepole Batman, are you looking at the wrong page in the Swift manual?

Only one of your loads is below book maximum. Please go back to the manual and take another look.
 
Holy smokepole Batman, are you looking at the wrong page in the Swift manual?

Only one of your loads is below book maximum. Please go back to the manual and take another look.
Will do!
 
Many variables with each gun - rough barrel vs a smooth barrel, barrel length, primers, cases, etc… as others have mentioned each rifle is different and there’s no way to tell other than load some, shoot, check for pressure signs with the primer, case, bolt lift etc. chronographs are good to tell you where you are sitting but I usually focus on group size. Get to an acceptable group size and stop - 2,200 fps is plenty - faster can be better depending on what you’re doing, length of shot and animals on the list etc.
some of my buddys start at max load - I’ve seen good rifles (2 to be exact) ruined that way…. That’s why pretty much everyone here says start on the lower end and move up
 
Many variables with each gun - rough barrel vs a smooth barrel, barrel length, primers, cases, etc… as others have mentioned each rifle is different and there’s no way to tell other than load some, shoot, check for pressure signs with the primer, case, bolt lift etc. chronographs are good to tell you where you are sitting but I usually focus on group size. Get to an acceptable group size and stop - 2,200 fps is plenty - faster can be better depending on what you’re doing, length of shot and animals on the list etc.
some of my buddys start at max load - I’ve seen good rifles (2 to be exact) ruined that way…. That’s why pretty much everyone here says start on the lower end and move up
Wow I must say thank you all!!! I have found out more today from everyone's dms and messages then I have in years!..think you guys just made a life long member!
 
1694644002863.png


This is what the hodgdon website lists for the IMR4350 and 300 grains bullets.
 
I've seen some IMR 4350 loads with 300 grains bullets going up to 80 or 81 grains but they are in older manual. Like said earlier, a chronograph is really your best friend when developing handloads. A 125$ Chrony will do the job just fine.
 
Thank up
I've seen some IMR 4350 loads with 300 grains bullets going up to 80 or 81 grains but they are in older manual. Like said earlier, a chronograph is really your best friend when developing handloads. A 125$ Chrony will do the job just fine.
Thank you qc! ...I take it you are from quebec? Going there next week for moose!
 
Use current load data. Try Hodgdon online. Also, Lyman data seems to be consistent and reliable. Be cautious using predictive models like Quick Load. Yes, a cheap Chrony, set up and used right, works fine. Try H4350 instead of IMR4350. Load toward a velocity goal watching for high pressure signs when working up. 2450-2500 fps is a realistic goal with 300 gr bullet in the 375HH.
 

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