Bergara Reloading reloading for a 300 Win Mag

[SmokinAces69]

Hello all...!! New to site so go easy on me...
Currently have a Bergara Premier Mountain 2.0 Rifle 300 Win Mag
Starting to put together some practice rounds to get it dialed in for hunting ELK. Max 600 maybe 700 yard is what I'm looking for.
Scope is a Swarovski Z6 3-18x50 BT Plex Riflescope Black 59610 with turret
All I currently have is IMR-4350 about 7 lbs. worth. Impossible to find any powder these days unless you want to pay $100 for a pound.
Below I have 12 rounds of below loaded and hitting the range Sat. morning
Any input would be helpful...
Thanks in advance

BULLET	GRAIN	TYPE BULLET	POWDER	GRAINS	Primer
Nosler	180	Accubond	IMR-4350	67	Fed 215
Swift	180	Scirocco	IMR-4350	67	Fed 215
Barnes	180	TTSX BT	IMR-4350	67	Fed 215
Hornaday	180	GMX	IMR-4350	68	Fed 215

 

[46and2]

Is your barrel brand new?
Factory barrels may take a proper barrel break-in procedure or up to 150 rounds to settle down and really show its bullet and load preference.

That said, I'll never shoot different brands of bullets down the bore without cleaning the barrel free of copper first. It seems that different copper jacket fouling do not play well together, thus giving the impression that the barrel doesn't like a particular bullet.

Try to work up in .5gr increments until you see pressure signs like ejector marks on the case head or firm bolt lift.

With imr4350 let your barrel cool WAY down before the next shot, it is temperature sensitive. I do not do load development for a hunting rifle over 70°. The barrel and load may shoot completely different in cold weather.
I prefer to use a powder that gets me as close to 100% + case capacity in my 300win mag barrels.
I'm pretty sure your imr4350 has left a lot of air in the case. Keep an eye out for imr4831, 7828, h1000 or reloder 23.

Be careful, pay attention to pressure signs and keep your ammo out of the blazing sun...its a hunting rifle.

 

[SmokinAces69]

Is your barrel brand new?
Factory barrels may take a proper barrel break-in procedure or up to 150 rounds to settle down and really show its bullet and load preference.

That said, I'll never shoot different brands of bullets down the bore without cleaning the barrel free of copper first. It seems that different copper jacket fouling do not play well together, thus giving the impression that the barrel doesn't like a particular bullet.

Try to work up in .5gr increments until you see pressure signs like ejector marks on the case head or firm bolt lift.

With imr4350 let your barrel cool WAY down before the next shot, it is temperature sensitive. I do not do load development for a hunting rifle over 70°. The barrel and load may shoot completely different in cold weather.
I prefer to use a powder that gets me as close to 100% + case capacity in my 300win mag barrels.
I'm pretty sure your imr4350 has left a lot of air in the case. Keep an eye out for imr4831, 7828, h1000 or reloder 23.

Be careful, pay attention to pressure signs and keep your ammo out of the blazing sun...its a hunting rifle.

Thanks for your input..!!!
Greatly appreciated