7wsm chambering

[muffo]

So im about to order a barrel chambered in 7wsm for a savage build. I will be running 180 grain projectiles and possibly some smaller weights for shorter distance. My main use for it will be shooting small critters at 1000 yards plus, and every now and then to shoot f class (not that il be trying to be competitive) Is there anything i need to order as far as accuracy goes except the standard 7wsm chamber

 

[Steve Blair]

9" or faster twist and .200-.220" freebore.

 

[muffo]

Cheers I planned on a 9 twist. Ill probably have to buy a reamer for the job. What size neck would you recommend

 

[Steve Blair]

Both my .284 Win and Shehane chambers have Ø.313" necks but that obviously requires turning. I don't know what folks are using for 7mm WSM no-turn necks. I recommend .004-.005" diametral clearance. My loaded .284 rounds are Ø.309".

 

[muffo]

Yeah I don't mind turning necks. .il be forming brass anyhow. I think I read somewhere that people were using 313 necks so this might be the go

 

[Jeffvn]

I run 0.313 on the chamber, but run a 0.013 neck for a loaded dimension of 0.310 on my 7WSM; my brother uses the same dimensions of his .284 Shehane.

Jeffvn

 

[Dirtball]

My reamer has a 0.311 neck, (Winchester brass) my loaded rounds 0.3085 to 0.309, with a 0.190 freebore (recommended by Dave Kiff).
I have chambered an F-Open rifle (32" barrel) and a Speciality Pistol (21" barrel) with this reamer and both guns will put 180gr and 175gr bullets through one raged hole at a 100 and both will hold well under 1 moa out to 1,000.

Dave

 

[Kyle Schultz]

I'm taking a slightly different tack with my 7-300WSM.

Necked Norma 300WSM brass down to 7mm. Case necks after forming are close to 0.0170" thick. Just finished my second round of turning. Necks are uniform but still a little thick at about 0.0149". I plan to turn down to 0.0145 on the final turn. Loaded round will be 0.313".

Have spec'd 0.316' reamer. If gun acts up, I can turn a little more off to open up the clearance. Based on a dummy round (Berger 180 Hyb) I sent PT&G, they spec'd a 0.220" freebore.

Hate the idea of thinning the necks way beyond the point they reach uniform thickness. I plan to anneal after every shooting so I think my neck tension will be as uniform as practically possible.

Even if I screw up, as fast as these barrels burn up, I won't have to live with the mistake for long. Compared to the price of barrels, bullets, and brass, reamers are cheap.

Good luck!

 

[muffo]

Thanks for the info I did think about the 7 300 but don't want to much extra work I might try and hire a reamer as il be getting very close to budget by the Tim I pay 900 for the barrel

 

[Gunny81]

I paid Krieger $400 for my 8.5 twist. It was a blank. I had Dave Kiff @ ptg make a .313 .211 fb reamer for my smith. I think the reamer was about $150. Just let him know your plans. I've found you can get about five cuts from his reamers and that's good considering your not looking at many rounds before you have to rebarrel this chambering. My other short mags have been pretty dead set on throat erosion. I'd say 1200-1500 rds before it's suffering.

 

[muffo]

yeh unfortunately I cant get prices like that as im in Aus. I didnt think about it that way I will probably buy the reemer so I dont have to hire it again in the future

 

[muffo]

On the bright side I dont have to buy the reamer as I found a gunsmith that will make me a barrel and he already has the right reamer