Hi all, I just found this forum and the information here is really impressive. I'm from Australia and tactical matches are just starting to take off here, I shot my first one back in May and learnt a lot about what I would need to be a little competitive in these matches.
My first thought was a 260AI or a 6.5x47 but I came across a barrel already chambered in 6BR and threaded to suit a Howa with only 40 or so rounds through it so it was too good a deal to let go. I swapped the barrel for some milling work so it was pretty much cost free.
I've got a machine shop so I made a chassis for the Howa to fit the AICS skins, I made it as light as possible given I planned to use it in these sort of matches.
I had a 223 Howa that had done a fair bit of work and the barrel was getting a little second hand so it donated its action. I'd never had a barrel off a rifle before but I read a fair bit about it so I made up a barrel wrench that fitted around the front of the action and the recoil lug.
The barrel was ultra tight so I stuck it in the lathe and cut a relief just in front of the action to unload the threads, the barrel spun off no problems after that.
I cleaned and measured the action and it was lovely, everything was square and straight so it needed no work, the lugs were both bearing evenly so I didn't worry about lapping them. I did need to open up the bolt face to take the BR case. I stripped the bolt down, set it up in the little CNC mill and opened the bolt face to the right diameter and skimmed a couple of tenths of a thou off the face just to ensure it was square.
Then I measured up the barrel tenon and chamber position using a go-gauge and depth mic, everything seemed fairly close so I screwed the barrel into the action and gave it a test.
Seeing I only had a go-gauge, I made some shims from .0025" paper and used them with the go-gauge.
With no shim the bolt closed easily, with .0025" it was firm to close and with .005" there wasn't a hope of closing it. The headspace came out at .002", not too bad for a barrel that was chambered to suit another action, Howa must machine these things pretty well!
Once I knew the headspace was right, I modified the original 223 extractor claw to work with the 308 case head size. A little trial and error got it working fine so I cleaned and reassembled the bolt.
I set the barrel up in the lathe on a soft spigot and centre so I didn't damage the crown or chamber and gave it a polish, then engraved the caliber into it. I had a typo on the engraving but once it's cut, it's too late so I've got a 6 milimetre instead of a 6 millimetre. (Aussie spelling)
I gave it all a clean then put it back together again.
I'd heard a couple of horror stories about getting the 6BR to feed from a magazine and I tried a couple of different setups, finally I settled on the plastic AI mags from my 223, I opened them out to let the BR rounds feed up and shortened the feed lip to let them pop out a little earlier. About an hour with a die grinder and porting roll and a smooth file had them working beautifully, I can fit 7 rounds in the mags, 6 is probably more comfortable, that's fine as 5 would have been enough though I am going to make some single stack 10 round mags for it where the follower only pushes on the case but they're some time in the future.
Here's a video of it feeding (if it shows up)
http://www.youtube.com/watch?v=uAZ6-X5i-vo
So far I've put around 200 rounds through it and I haven't had it misfeed or jam up yet, it feels as smooth as the 223 was.
I did end up milling the bolt handle and making a bigger knob for it, it was a little tight extracting with the factory knob and with the wider stock and bigger scope, there wasn't a lot of room to operate it.
I topped the rifle off with a Warne 20 MOA rail, Leupold QWR rings and a Vortex Viper PST 4-16x50 FFP mil/mil scope. I'm very impressed by the scope, it's very good mechanically and I was using it today to spot for a mate at 500m so the optics are far better than the price would indicate!
I've done a bit of load development over the last week or so and have got it pretty much sorted using the 108gr Berger bt's and 30.2gr of 2208 powder with the bullet seated .010 into the lands. I'm getting 2960 FPS out of the 22.5" barrel and it's shooting .2-.3MOA out to 500m which is as long as the local range is. I've got a couple of matches next weekend out to 800m so it will be interesting to see how it goes!
Anyway, sorry for the extraordinarily long post and congratulations on a really good forum, I can see myself spending some hours poking around here!
Cheers,
Greg
My first thought was a 260AI or a 6.5x47 but I came across a barrel already chambered in 6BR and threaded to suit a Howa with only 40 or so rounds through it so it was too good a deal to let go. I swapped the barrel for some milling work so it was pretty much cost free.
I've got a machine shop so I made a chassis for the Howa to fit the AICS skins, I made it as light as possible given I planned to use it in these sort of matches.
I had a 223 Howa that had done a fair bit of work and the barrel was getting a little second hand so it donated its action. I'd never had a barrel off a rifle before but I read a fair bit about it so I made up a barrel wrench that fitted around the front of the action and the recoil lug.
The barrel was ultra tight so I stuck it in the lathe and cut a relief just in front of the action to unload the threads, the barrel spun off no problems after that.
I cleaned and measured the action and it was lovely, everything was square and straight so it needed no work, the lugs were both bearing evenly so I didn't worry about lapping them. I did need to open up the bolt face to take the BR case. I stripped the bolt down, set it up in the little CNC mill and opened the bolt face to the right diameter and skimmed a couple of tenths of a thou off the face just to ensure it was square.
Then I measured up the barrel tenon and chamber position using a go-gauge and depth mic, everything seemed fairly close so I screwed the barrel into the action and gave it a test.
Seeing I only had a go-gauge, I made some shims from .0025" paper and used them with the go-gauge.
With no shim the bolt closed easily, with .0025" it was firm to close and with .005" there wasn't a hope of closing it. The headspace came out at .002", not too bad for a barrel that was chambered to suit another action, Howa must machine these things pretty well!
Once I knew the headspace was right, I modified the original 223 extractor claw to work with the 308 case head size. A little trial and error got it working fine so I cleaned and reassembled the bolt.
I set the barrel up in the lathe on a soft spigot and centre so I didn't damage the crown or chamber and gave it a polish, then engraved the caliber into it. I had a typo on the engraving but once it's cut, it's too late so I've got a 6 milimetre instead of a 6 millimetre. (Aussie spelling)
I gave it all a clean then put it back together again.
I'd heard a couple of horror stories about getting the 6BR to feed from a magazine and I tried a couple of different setups, finally I settled on the plastic AI mags from my 223, I opened them out to let the BR rounds feed up and shortened the feed lip to let them pop out a little earlier. About an hour with a die grinder and porting roll and a smooth file had them working beautifully, I can fit 7 rounds in the mags, 6 is probably more comfortable, that's fine as 5 would have been enough though I am going to make some single stack 10 round mags for it where the follower only pushes on the case but they're some time in the future.
Here's a video of it feeding (if it shows up)
http://www.youtube.com/watch?v=uAZ6-X5i-vo
So far I've put around 200 rounds through it and I haven't had it misfeed or jam up yet, it feels as smooth as the 223 was.
I did end up milling the bolt handle and making a bigger knob for it, it was a little tight extracting with the factory knob and with the wider stock and bigger scope, there wasn't a lot of room to operate it.
I topped the rifle off with a Warne 20 MOA rail, Leupold QWR rings and a Vortex Viper PST 4-16x50 FFP mil/mil scope. I'm very impressed by the scope, it's very good mechanically and I was using it today to spot for a mate at 500m so the optics are far better than the price would indicate!
I've done a bit of load development over the last week or so and have got it pretty much sorted using the 108gr Berger bt's and 30.2gr of 2208 powder with the bullet seated .010 into the lands. I'm getting 2960 FPS out of the 22.5" barrel and it's shooting .2-.3MOA out to 500m which is as long as the local range is. I've got a couple of matches next weekend out to 800m so it will be interesting to see how it goes!
Anyway, sorry for the extraordinarily long post and congratulations on a really good forum, I can see myself spending some hours poking around here!
Cheers,
Greg
;D
