300 Weatherby Help

[norcal7.3]

Hello Everyone,

I sort of hijacked a thread on here about reloading the 300 Weatherby a couple weeks ago and for that I apologize. So heres the deal, Weatherby Accumark in 300 Weatherby, I have tried a few different load combos and am having some issues getting something I find acceptable. I am very new to reloading, but have had great success reloading for a couple of my other rifles (non-weatherby). I started with norma brass, IMR 7828 ssc, Federal 215 match primers, and Nosler 180gr accubonds. First test loads were mostly unsuccessful COL of 3.700 inches, 81 grains of 7828, 82 grains of 7828, 83, and 84 grains of 7828. Best group was with the 84 grains of powder. I had 2 almost touching and one real flyer. Next test load I shortened up the COL to 3.560 as per recommendations on here, similar results ensued with this test group. Now I just got home from the range after shooting 4 more groups of 4 shots with 84 grains of 7828, 84.3, 84.7, and 85 grains. This with a COL of 3.560. I shoot one fouling/warm up shot before group testing. With the 84 grain group I had the first 2 shots touching, one flyer about an inch and a half away and the other about 3 inches away from the first two. The 84.3 and 84.7 shot pretty bad with about a 3 inch total group. The 85 grain group was what I considered the best, it went like this. One shot, second shot about one half inch away, third shot touching the second, and the 4th about 3 inches away from the center of the first 3. Not sure if I flinched it or not, but it felt solid. I was hoping you guys could give me some direction on where to go from here? I have a couple of ideas, but I am very open to all suggestions.

Thanks,

Justin

 

[Mulemania]

Drop down to .1 grain differences above and below the 85g then when you find your most consistent move the seating depth in and out 10tho if it gets better in one direction go another 5 or 10 to see if it gets even better

 

[Gunnersdad49]

Assuming all bench shooting methods are solid and consistent, and the forearm of the rifle, not the barrel is touching the front rest;

Consider a different bullet. Some barrels are picky.

Make sure your brass is trimmed to equal lengths.

Grab a chronograph and look for low SD and ES in your loads. If those are off, meaning inconsistencies in velocities, accuracy will surely suffer.

 

[Alaskanopolis]

I've developed loads for 4 different Weatherby rifles and they we all very picky with bullet selection and powder type and charge. But I was always able to eventually find a load that shot great.

 

[Ganderlander2]

My brother has had good luck using etip 180’s in his 300 wby. How long are you waiting in between shots, I know my 300wm xbolt pro gets hot quick and will start sending flyers. Where in NorCal are you located? Maybe we could get together at the range and get it worked out

 

[Archer86]

X2 about letting the rifle cool I know on a my remington 700 rifles with sporter barrels it will have flyers if I dont let it cool enough between groups or if I try and shoot to many in one group it tends to open up the group some.

Also is this a factory rifle? Factory stock no bedding and factory trigger?

 

[madtom]

My brother has had good luck using etip 180’s in his 300 wby. How long are you waiting in between shots, I know my 300wm xbolt pro gets hot quick and will start sending flyers. Where in NorCal are you located? Maybe we could get together at the range and get it worked out

How long do you usually wait between shots? I try to wait two minutes, but not sure what others recommend.

 

[Archer86]

I shoot 3 how ever long it takes me to get comfortable for every shot then let the barrel cool and I can feel no heat coming off it usually 15 to 20 min between groups when doing load development

 

[Ganderlander2]

2 minutes seems about right, I’ll usually check the barrel between shots with my hand, I’ll wait longer if needed.

 

[Alaskanopolis]

How long do you usually wait between shots? I try to wait two minutes, but not sure what others recommend.

I take a laser thermometer and shoot the barrel in the same spot between shots and choose a temperature to consistently shoot at - usually around 75F. I also have a chamber cooler fan I toss in it to help it get to that temperature quicker. I don't think the specific temperature matters as much as consistency, so long as you don't choose a really high temp. When I go to sight in I try to let my barrel cool down to ambient air temperature for each shot. But my big powder burners, like the 338-378 seem to have a decent POI shift from totally cool barrel to warmed up barrel. I zero for hunting, so I try to get it dialed for that first cold bore shot. For a target rifle I would zero it for a warm barrel. Although, I'm definitely not an expert and some more experienced guys may take issue with my process, but it makes sense to me.

 

[norcal7.3]

I have been letting the barrel cool down adequately in between shots. I just ordered a laser thermometer to make sure I am consistent with temperatures between shots. I will give a different bullet selection a try, I just feel I can make this gun shoot better than what I am getting so hopefully it will come together soon.

My brother has had good luck using etip 180’s in his 300 wby. How long are you waiting in between shots, I know my 300wm xbolt pro gets hot quick and will start sending flyers. Where in NorCal are you located? Maybe we could get together at the range and get it worked out

E-tips are my next choice so I will give those a go.

 

[Ganderlander2]

I have been letting the barrel cool down adequately in between shots. I just ordered a laser thermometer to make sure I am consistent with temperatures between shots. I will give a different bullet selection a try, I just feel I can make this gun shoot better than what I am getting so hopefully it will come together soon.


E-tips are my next choice so I will give those a go. Im in Live Oak currently, about an hours drive north of Sacramento.

We should meet up some time at oroville, I’m in yuba city. Pm me if you want to meet up sometime