My new 300 WSM

[rpierce]

Well I finished load development on my new 300 WSM I built myself. I wanted to do a compact setup so I went with a 22" Benchmark carbon barrel since Im running a suppressor. The reamer is set up for 205 gr Bergers but will work for others in that weight class including the 215s. Contrary to popular belief it was easy to get my Defiance XM to feed in a mdt detachable magazine. I moved the hole forward .275 that has the spring go through it. This put more pressure on the front of the follower and would keep the round inline when getting chambered. Feeds flawless and won't go below the feed ramp like people have experienced w this combo. Very first load I tried out of this barrel to break it in shot in the .3s at 100.

After the barrel settled down for velocity I decided to do a powder charge test. Reloader 23 is pushing a 205 berger at 2860 fps with an es of 12 for 10 shots. I didn't hit pressure til 2935 fps. There was another node at 2900 but I didn't wanna be that close to pressure since it was less than a gr from hitting it. Picked the milder 2860 fps node. 4 seating depths later it shot a 3 shot group that measured .195" @ 100 yds. I decided to load 3 more rounds to verify at 580 yds. Heres the group it shot at 580 in a 10 mph wind. 1.5" tall by 3.0" wide. More than happy with it in those conditions.

While breaking the barrel in with a super mild load at 2650 fps I decided to shoot two 3 shot groups in a row at 580 yds. One measured .6" and the other measured 1.2". This cartridge has been about the easiest magnum Ive seen to load for that Ive seen. While breaking the barrel in I tried 3 different neck tensions and seating depths from .015-.060 off. It shot everything 1/2" or better with most being in the .3 moa range.

Im expecting 2000+ round barrel life with awesome accuracy since this will be only shot cold bore. Plugging in the ballistics of a 205 at 2860 youll see its pretty much identical in the wind compared to the 6.5 prc,saum/shermans etc with a 156. However it has 20% more energy at 1000 and way more barrel life. Very easy to keep in tune and minimal throat erosion.

Rifle has the following:

Defiance ANTIX XM length w nitride
Manners LRH
Benchmark 22" 30 cal 10 tw sendero light
Hawkins Bottom metal
Modified MDT magazines
Triggertech Diamond
Thunderbeast Dominus SR Suppressor
Nightforce ATACR 4-20x50 bedded into a set of NF Rings

Rifle weighs 11.0 lbs with optics and suppressor.

 

[DartonJager]

My experience with the 300wsm mirrors yours. Mine is a Tikka T3 Lite.
Second or third reload was shooting .5ishmoa for a five shot 100 yard group and was sub MOA out to 300 as far as I could shoot it. Didn't need to mess with seating depths or much of anything. Just did a ladder test and set bullet length to max for the DBM and was pretty much done by load number 3. Getting 2950 FPS/MV with IMR4831 and 180 NAB.
Fastest I reached was 3150 with RL17 but IMR 4831 gave more consistent SD & ES so I stuck with IMR4831.
That is one seriously Bad ***ed rifle you have there sir.
You have my envy.

 

[LongBomber]

Thats a sweet setup. Lots seem to overlook the 300wsm, easy to load for and you can push a 200-212gr bullet around 2900fps which is plenty of speed for that class of bullet.

 

[tim_w]

The 300wsm is one of the most forgiving cartridges when it comes to load development.

 

[howco]

Is that correct about using 210m primer? Did you use the 210 across the board for development?

 

[Mark37082]

Thats a sweet setup. Lots seem to overlook the 300wsm, easy to load for and you can push a 200-212gr bullet around 2900fps which is plenty of speed for that class of bullet.

Completely agree. The NM's, PRC's, and Noslers seem to be the craze right now. If I was building or buying a 30 magnum, the WSM would probably get the nod.

 

[LongBomber]

Completely agree. The NM's, PRC's, and Noslers seem to be the craze right now. If I was building or buying a 30 magnum, the WSM would probably get the nod.

The wsm is a easy to load for cartridge for sure. Nice wide tuning nodes.
I built this one last year. Hs precision action, ibi carbon barrel, manners prs1t and a rzr amg. I am limited to a 2.95" aics mag but it shoots a berger 200.20x or 208eld really well. Long range plinking I run a single shot adaptor and have loads tuned at around a 3.1" oal.

 

[Muddyboots]

This rifle just "looks" it has to be accurate!

I "fought" with my 300WSM UNTIL I switched to FM210's from recommendation by a LRH whom I cannot recall but it was spot on for me. It settled down big time. Not anywhere as impressive as @rpierce but very nice. It was my first build, made some mistakes, but the switch to FM210 was key to consistency.

 

[rpierce]

Is that correct about using 210m primer? Did you use the 210 across the board for development?

Yep. 210M primer is the only primer Ive tried so far in it. Didn't have any ignition issues in the mid 20's for temps Ive shot it in so far.

 

[Timnterra]

Fantastic build! I just put together a 22" 300 wsm and have yet to load a round for it yet but your experience has me excited! I guess I missed it, What brass are you using?

P.S. Do you store those calipers in the dirt at the base of that 580yd target? good grief those have lived a hard life

 

[rpierce]

Fantastic build! I just put together a 22" 300 wsm and have yet to load a round for it yet but your experience has me excited! I guess I missed it, What brass are you using?

P.S. Do you store those calipers in the dirt at the base of that 580yd target? good grief those have lived a hard life

ADG brass. I leave it in a plastic tote but sometimes I have forgotten to close the lid and itll rain on em. LOL

 

[highdrum]

Badass, 2860 node is where most br guys run 215s with H4350.

 

[rpierce]

Badass, 2860 node is where most br guys run 215s with H4350.

Ya like this setup. I've thought about spinning up a 26" barrel and trying the 215s in it. But for the distances I plan on using this,800 on in, it doesn't make a noticeable difference. Definitely wouldn't be the cause for a miss between the two bullets ballistics. I kinda dig the more compact setup since it has a can on it. I might try the 215s with reloader 26 or h4350 just to see what I can get out of it though. Simply so customers have some info to go off of.

 

[highdrum]

Ya like this setup. I've thought about spinning up a 26" barrel and trying the 215s in it. But for the distances I plan on using this,800 on in, it doesn't make a noticeable difference. Definitely wouldn't be the cause for a miss between the two bullets ballistics. I kinda dig the more compact setup since it has a can on it. I might try the 215s with reloader 26 or h4340 just to see what I can get out of it though. Simply so customers have some info to go off of.

My 22in 9tw would run 215s up to 2930 with rl26 but ot it was hard on the norma brass. Liked 2840 fps. I ran 200.20x for the most part at 2860 with rl23.