7mm-08 barrel is on...

I bought a Model 11 in .308 several months ago and went to the range. I had fun with a 100 yard zero trying to guess hold over at a 700 yard silhoutte with a couple different loads. I was close several times, but was really there to get my .223 Howa dialed in so I switched the rifles and went to town at 200 and 300 yards. I have been considering several options for a long range varmint load/caliber for dual use as a deer (and bear if I decide to try that) round. I traded an unused scope for a 7mm-08 Shaw varmint contour barrel and believe it is between 9 and 10 twist from my measurements. Being on a tight budget, I am extremely thankful to THOMAE and WHIT for allowing me to borrow the tools etc. to swap my barrels and the advice I was given when we met. It took about 45 minutes to get everything done to my satisfaction. I put it in a HS Precision stock I purchased from another member and it looks like it is ready to draw blood. I now just need my pre-ordered scope to come in (promised to ship in the spring so it could still be a while).

Down to the gritty...I purchased some Prvi Partisan 7mm-08 ammo this morning and took a couple rou ds in a mag to the bas of a hill by my house. With muzzle pointed at the base of the hill, I cycled the action to check the headspace and make sure all was feeding properly. The bolt was stiff, but closed on the rounds. I checked the bullet and there are no marks. I also don't see marks on the shoulder or anywhere else on the case. Every round extracted perfectly. I bumped the barrel on the gauge and tightened the nut, added a piece of scotch tape to the gauge and it was hard to start camming the lugs. I felt the tape start to squish (very technical term) and stopped because I was using more force than I feel comfortable using to chamber a round. The feeling of the cases this morning chambering required about half that amount of downforce I used before stopping on the pseudo No-Go gauge. Should I back the barrel out a tad so it closes on one piece of tape but not 2? I had an experienced handloader cast a .308 chamber for me and do some custom loads years ago. From my recollection, they were also difficult to chamber, but slightly less than that Prvi. Should I do a remote test fire as is or...? If this is normal, I'm thrilled. If it isn't, I'm glad to learn before things go boom.

Some times a Go-gauge can be a tad bit on the short side. That's why it's a good idea to have an actual No-go gauge too. I set one of my barrel's up head spaced on a go gauge and the bolt would not close on no go gauge, I thought I was done. No. I tried chambering a new winchester case and it was too tight. I ended up loosening the barrel nut and turned the barrel out a little and tried again, this time the bolt close with just a faint bit of resistance at the end. I tried the no go gauge again and the bolt still would not close, not even half way, hope this helps.

I dont snug my barrel down tight on the go gage. All i use is a barrel nut wrench and barrel vise......... I snug down the action till it wont turn onto the barrel threads anymore with light pressure and back it off maybe the width of one of the flat grooves of the barrel nut. That way in case i need to use factory ammo for some reason i wont have problems. The bolt will not close on two pieces of blue painters tape. so its not at min headspace its a hair past it.

I figure if the factory does it that way ,cuz i cant see them setting a barrel to min headspace, it should be good enough for my needs.

Brian

Thanks. I read all 7 pages of the HEADSPACE sticky and minimum headspace was said to be best if you handload, which I plan on doing soon. I just wanted to make sure it would be safe. I guess I could back it off a little and still be ok, it's not diffucult to do. Also, some once fired .243 and .22-250 brass chambered without problem as it is. I believe the 22-250 has a sloghtly shorter headspace, but the .243 is the same, right?

No. They use diff headspace gages. I thought the same too but did some reasearch. The 22-250 is based on a diff parent case than the 243. Similar yes......exactly the same .....no.

Brian

OOPS, 7mm-08, .308, and .243 are the same?, 22-250 is slightly shorter. Looking back, I see I could have worded that better. I am pretty sure it would be safe to shoot the PRVI, but was double checking.

Quote:

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Originally Posted by Hersh5317

OOPS, 7mm-08, .308, and .243 are the same?, 22-250 is slightly shorter. Looking back, I see I could have worded that better. I am pretty sure it would be safe to shoot the PRVI, but was double checking.

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The same go/no-go gauges are used for the .243 Win, .260 Rem, 7mm-08,.308 Win and I believe the .358 Win and .338 Federal. These are all based on the .308 as their parent case.

The .22-250 is based on the 250-3000 Savage and .300 Savage case and they are not the same as the .308.