7/300 WSM- Need help making this shoot

[Texas]

I have a new 7/300 WSM that I am working with. I based the reamer off the 270/300 case so I could use Norma brass. Gun is built on Rem 700 action trued with PTG bolt. Brux barrel in 9 twist, hunting weight about .670 muzzle in a Hart varmint stock that is pillar/glas bedded. Leupold 8.5-25 scope with ken farrel base and TPS rings.
Norma brass, match prepped. Federal 210 primers. I've been using RL25 because I am getting velocity with minimal pressure.
I've tried Berger 168, Berger 180 Hunting and hybrid, ELD 162 and 175. I did pressure testing at 100 yards and then all my development has been at 300 yards as I feel that gives the bullets time to stabilize and give me a better idea of what the gun will do at longer ranges which is it's entire purpose. Here is the issue: I have yet to shoot an acceptable group with any bullet and have shot about 150 rounds in testing. The best group so far is 1.75" which I'm not satisfied with. I shoot 4 shots for group and have shot several times where 3 shots are in a tight triangle about 1 inch and then 1 shot flies way out to around 3 inches. This has happened with every bullet. I've checked bedding, sorted bullets, prepped brass as best I can and always use the same shooting technique. I shot bench rest for years and my other rifles all shoot half MOA or better. This one is driving me crazy though. Depending on bullet, my velocities have been anywhere from 2,980 to 3,250.
Should I give up on RL25? I have Retumbo, H1000, RL17 and H4831 but was hoping to stick with the RL25. I should also note that my seating depth has been approximately .010 off to start. I figured if I could get something with potential I would tweak seating depth from that point. The 175's have shot 3 shots an inch or less several times but always throw one out.
Any ideas? Switch powders, jam the bullet, get a new barel? Any ideas would be helpful.

 

[dkhunt14]

For accuracy I would try a faster powder. Maybe the H4831. I know most BR guys use H4350 in the 7mm with a 180 Berger. I would also move the bullet to .005 in the lands. Matt

 

[Kyle Schultz]

I've been shooting this cartridge for several years. I have had great luck with H1000. Both with the Berger 180 hybrid and the Sierra 183 MK.

I have a fairly long free bore so my bullets sit pretty far out. My COAL runs about 3.30". My current load with the Sierra 183s is 62.5 gr H1000 and I clock around 2890 fps from a 32" barrel.

I believe Larry Bartholome, whose spent brass I'm not even worthy enough to pick up, still shoots a 7/270WSM, which is essentially the same cartridge. Last I conversed with him, he was loading with H4831SC. Based on his advice, I tested H4831SC in my gun. But to me, the gun felt like it had a more violent recoil. H1000 seemed to shoot softer.

I'm convinced, based on some limited testing, that there are higher nodes than the one I'm exploiting at 2890 fps. But the gun performs well for me where I'm at and I haven't pushed the envelope any further.

I think the real unrealized potential for this cartridge is with the Berger 195. I'm convinced that even the .284 improved cartridges lack the boiler capacity to launch this bullet at optimum speeds. But, up until now, I just haven't wanted to invest any barrel life to test them.

If you've already invested in the brass, dies, and barrel, I would encourage you to continue to test. Based on your user name, I'm assuming you are in Texas. I live in Fort Worth and shoot pretty regularly (during the cool season) at Bayou Rifles and less often at Carthage and Midland. Send me a PM if I can help any more. Good luck!

 

[Mark deluia]

I'm also in DFW area with a 7/300 wsm. I'm using retumbo 66.2 or 7828sc
64 1/2 Both 5 thou in ,, less than 5 inch groups at 960 yards 5 shots
195 Berger all loads


Mark

 

[FURMAN]

What is the longest distance you have access to?

 

[Texas]

What is the longest distance you have access to?

I have access to 300, 600 and 1,000. I should mention that it's very hot in Texas, so maybe the heat is making the RL 25 act up.

 

[whatwind?]

Yes, try 61 gr H4831sc with more jump and the 180 Bergers like 2900-2950 and then 3000 fps, also anneal every loading and it seems most bbl settle in around 200 rounds now adays and I don't think this cartridge loves hot weather a lot either

 

[Elwood]

The first thing I would try is a primer test. I would be testing BR2's and CCI magnums and Wolf primers. Sometimes it will have no effect, other times the difference can be huge.
If that doesn't work I would be looking at H4831sc H1000 or N165.

 

[FURMAN]

I would do a ladder with H4831SC at 1000 and take the best load and tweak seating depth.

 

[Texas]

Thanks. I will try a few of these suggestions.

 

[Yellow11]

Thanks. I will try a few of these suggestions.

I have been shooting the 7-300WSM for around six years and as many barrels.

Originally, I used 66g RL25... That is until 2015, when the newer powder imported into the UK had no date of manufacture... It also spiked the Mv in excess of 100fps. Readjusting loads failed to give me the same accuracy as the older powder and I turned to N165. Using 65.3g, Federal 215's and 180 Hybrid Berger's gave me exceptional accuracy and Mv of around 3045, depending on the temperature.

Hope that is of some help

 

[mike.e]

Do you Anneal all your brass, I was having issues with "random" fliers and annealing all my brass after each firing solved the issue

 

[conor m]

texas , the 7-270/300 wsm is a great round ,it has its draw backs ( 1) recoil (2)torque . you said that you are using fed 210 primers ,there is the first problem , not a magnum primer .you said you had h 1000 ,great powder for that cartridge ,put that together with a fed 215 or cci 250 . i have shot this cartridge for about 7 years in compition ,way back when al warner shot it in the f-class nationals . L bart is a great source of info as you a based in texas and he is in el paso .
tell him conor sent you.

 

[Lbart]

Connor,

I am sure since Sam lives only a Texas ‘hoot and a holler’ down the road from me (about 750 miles) he will stop by tomorrow.

I agree with you that recoil & torque may present a problem. Unless I missed it Sam did not say how long the barrel is or what the rifle weighs. The shape of the forend and butt will also affect the torque factor as will weight. My FC rifles have squared off forends to reduce torque. As for powders, I shoot only Hodgdon H-4831sc. I tried H-1000 and H-4350 and keep coming back to SC. I load only Hodgdon Extreme powders in all my various calibers. Why take a chance on temperature problems?


I shoot Berger 180 Hybrids in 1-9” twist Bartlein’s. I had been using 31.5” barrels but have cut them back to 28” to try and meet the Ottawa, Canada range rule velocity limits for the 2017 FCWC. I also reduced my powder charge by 0.7 grain. My vel used to be 3000 FPs or a bit more but now I am at 2950 fps to insure I am below the range limits. My current charge is 61.0 of H-4831sc. The only primers I have used are Wolf large Rifle.


Another thing not brought I believe is your hold on the rifle. I have a pretty good hold on the pistol grip and my shoulder is up against the butt plate. My cheek is also down on the cheekpiece with a bit of pressure. When I trip the trigger I want to ride the recoil, not have it come back and hit me. When you do have body pressure on a rifle though, it has to be exactly the same each and every time. Or shots are going to fly off for parts unknown.

Connor say hello to the boys in Ireland for me. I miss shooting with them.

P.S. Kyle, You are more than worthy enough to pick up my brass but at what it costs I’d rather pick it up myself.

 

[Texas]

The barrel is a 27 inch Brux and rifle is about 11 pounds. I will try switching to CCI 250 primers. I've been annealing. My neck tension is .001. I was thinkng I might increase this? I will give the H4831 and the H1000 a try.
Thanks for all the feedback.

 

[whatwind?]

@Lbart, what case trim length do you use, 2.090 or shorter?

 

[17VLD]

I would try H4831 with the Berger 168 and Retumbo with the 180 hybrid
I assume you have a 9 twist so you should be good to go with the 180
Matt

 

[Lbart]

Texas,
My rifles weight a lot more than yours so recoil would be big factor but the first thing I would do is to get someone else to shoot a few groups for you and eliminate that possible factor. Also change scopes, put a known good one on. Check the bedding, scope bases, rings and everything else. While my rifles may have larger groups than I would like to see wild shots like you are getting do not happen. While changing primers, powders and neck tension might help I tend to think something very basic is wrong. When all else fails go back to basics.

Best of luck.

 

[Lbart]

Whatwind,
I use a Sinclair Chamber Length Gage Insert to measure my barrel chambers. Mine measure 2.111”. My reamer print says 2.100”. I don’t worry about the length until they get close to my measurement. Even with 5 loadings I am still well under my measurement.

 

[RGRobinett]

If the other powders fail to deliver, try some 160 Sierra GameKings,or, 150 Gr. MatchKings - both of the Berger bullets you mention are on the long side for 1:9" twist. While they may shoot fine via some 9" twist barrels, not so much in others - I have seen several 7mms act as if the shorter bullets, "turned on the lights". RG