.300 WSM help

[Dexter Grayson]

Heres the skinny, I am somewhat new to reloading but have a pretty good grasp of it. In august I am going to Kyrgystan in search of a mid-asian Ibex. My Shots will range anywhere from 200-500 yards so i would like to get proficient to atleast 500 yards. My elevation will be anywhere from 12k-15k feet and temps ranging from 20-80 degrees fahrenheit, with those being extremes.

My problem, I have a Tikka .300 WSM and I did quite a bit of load development over the winter and found a load that performed way above any of my expectations. Problem is this was one of the only loads that performed at all.

Load
.300 WSM
Nosler Brass
CCI 250 primers
180 gr Nosler AB
66.0 gr of RL-17
COAL 2.895

This load worked great until the temps started to increase above 70 degrees, with temps above 70 my pressures start to spike. (stiff bolt lift and loose primer pockets). And my POI changes significantly.

Ive done some research on RL-17 and the temp sensitivity seems to be quite common. Ultimately I'd like to stray away from this powder if possible.

Powders I've tried so far:
RL-17
RL-19
IMR 4350
H4831SC

Projectiles I've tried so far:
165 AB
180 AB
168 TTSX
175 Berger hunting VLD (performed well when seated out past mag length)

I will say that the factory Nosler ammo performs quite well out of my gun (MOA'ish) and that is my back up plan if all else fails.

My question is there something im missing here or could do differently to find a load that will perform well out of my gun?

Any other powders, projectiles, or loads that you guys recommend?

I was thinking of trying 7828, 7828scc, Retumbo

Any help or input will be greatly appreciated and dually noted

Thank you, Dexter Grayson

 

[Timber338]

It's hard to tell what exactly you've tried with all of your various load combos, but your current load sounds like it's at max pressure. when pressure increases for any reason, you are now over pressure.

I personally think that if 250 yards is your max, do your best to find a 1 moa sweet spot at lower velocity/pressure than you are currently getting with your 180 AB RL17 load. maybe just drop a couple of grains. you should be able to find another sweet spot, and even if it's 100 fps slower it will still have plenty of power for your upcoming hunt.

If you've tried all those other powder and bullet combos and none of them work at any velocity, I would think that there might be something going on with the rifle.

 

[Dexter Grayson]

I actually went to the range yesterday with loads using 1 gr and 2 gr less than previous and the pressure went down but the groups were terrible.

Should I back it off a grain or two and do a seating depth ladder.

It would take forever for me to list the load combos I've tried so far.

 

[Barrelnut]

Few thoughts:
H4350 would be a good try. H4350 is not temp sensitive in the range of temps you will be shooting and is very consistent.

Try different primers. Maybe Fed 210m and 215M if you can find them. Some use regular primers with the 300 WSM, but with low side of your temp expectations, I would stay away from them.

Berger 185 and 210 VLDS work well in the 300 WSM try working up a load seating them until they are just touching the lands. They almost always shoot good that way. Hopefully they will still fit in the mag that way, if not, you could single load for long range shots.

Also cutback on the RL-17 load. 66 gr is probably over max for the powder. I just use at most 64 gr of RL-17 with my 300 WSM load with 180 NBT. Try to find a lower node with less powder. Then, if you use a ballistics program, allocate 2 FPS per degree temperature change and see if your ballistics start to line up with the temperature changes. RL-17 is very temp sensitive. I proved that to myself just a few weeks ago.

Below are a couple easy 600 yard loads in in my 300 WSM

H4350 63 gr.
180 AB
fed210M
Norma brass
Seated .005 from lands

H4350 57 gr.
210 berger VLD
Fed 215M
Norma brass
seated to touch the lands

 

[Timber338]

I actually went to the range yesterday with loads using 1 gr and 2 gr less than previous and the pressure went down but the groups were terrible.

Should I back it off a grain or two and do a seating depth ladder.

It would take forever for me to list the load combos I've tried so far.

If you found a load that shoots good with RL17 and the 180 AB, I do not think you need to repeat all of your other loads. Generally speaking a barrel should have a sweet spot (node) at least every 100 fps. when you are not in a sweet spot, it will throw them all over the place. When you are in the sweet spot, life is good. It looks like dropping 1 to 2 grains is not in a sweet spot.

So your current 66.0 grains shoots great, but is right on the edge of max pressure. you know that 64 and 65 grains do not work. I would probably try 3-shot groups with the following:

61.0
61.5
62.0
62.5
63.0
63.5

Typically a sweet spot will shoot to the same point of impact over about a 1 grain variation (all rifles will vary). Hypothetically, you might find that 62.0, 62.5 and 63.0 all shoot to the same point of impact with very good accuracy... If that were the case I would load all of my hunting loads at 62.5 to be in the middle of that sweet spot. Then if you encounter some temp sensitivity above 70 degrees, you will still be within your sweet spot and same point of impact.

 

[Dexter Grayson]

I shot some 175 VLD's and they shot really well when seated just off the lands, but at that depth they are too long for the magazine.

 

[Timber338]

I shot some 175 VLD's and they shot really well when seated just off the lands, but at that depth they are too long for the magazine.

I think there are some Tikka users here that have modified their magazine box to fit longer bullets. not sure on this though... but maybe you could use the search function in the upper right and find some threads on that.

I still think you can get your 180 AB's to shoot good.

 

[Barrelnut]

I shot some 175 VLD's and they shot really well when seated just off the lands, but at that depth they are too long for the magazine.

You might be able to get the 210 VLD seated to the lands and still fit in the mag. The 300 WSM has a very short throat. Also the 210 would buck the wind better at long range.

 

[Shortmagman]

I have seen very few guns that would not shoot Barnes TTSX bullets well with the proper seating depth.

If I had your gun I would try Barnes 168 TTSX bullets and H4350 at 60.0 grains and work up. The bullets should be seated 50 thousands off the lands. I would shoot 3 shot groups and take the best group. If this group was not good enough I would seat three more with the same powder and move the bullets 70 thousand off the lands.

If I found my gun did not like the 168 TTSX bullets I would move up to the 180 grain TTSX bullets and use IMR-7828 at 64 grains and work up. Seat the bullets 50 thousand off the lands to start. Follow Barnes instructions on the seating depth if the 50 thousand does not work.

I think that you can find a load that will shoot well in your gun and be sable as the temps climbs.

 

[TBuckus]

The issue of COAL can be solved by changing your bolt stop and modifying your magazine. Easy fix if that is what you feel is your problem stopping your groups.

I didn't have any problems with R19 and 180 gr ttsx's so I can't help you. My only thought is either to try H4350 or back off on your grains.

 

[Dexter Grayson]

Buckus, you have any more info on the bolt stop and mag modification?

Also, what are the differences in IMR 4350 and H4350?

 

[Timber338]

Also, what are the differences in IMR 4350 and H4350?

IMR and H 4350 have very similar burn rates, but are totally different powders made by different companies. If you do a google search you will get tons of info on the differences. H4350 has worked great for me and is all I shoot out of my WSM's. The problem is that so many other people use the powder it is nearly impossible to find.

 

[BountyHunter]

H4350 and F210s are standard for the 300.

My WSM and F210s, 168 TTSX are a proven combo also

 

[Dexter Grayson]

Ok, I think I've solved my problem, hopefully for good. Looks like in gonna have to jump ship on the accubonds and join the Berger band wagon. The wind finally died down today and I was able to shoot a little before work and ended up with this. 3 shot group @ 218 yards. Gonna load and shoot 5 more to validate.