6x45 freebore?

[dakor]

I am going to build a 6x45 (6mm-223) and I want be able to shoot 55gr to 95gr VLD bullets out of it. Right now I have the reamer spes with .065 freebore does this seem like a enough freebore for the heavier bullets but still allow to shoot the lighter bullets?

 

[swd]

.065" will work well for the 95 but will be a little long for the 55's. It will perform surprisingly well with 95's out to 600+.

 

[MrMajestic]

Kiff spec'ed .077" for the 87 gr. V-Max in my 6X45AI. Just an FYI.

 

[expiper]

OP,,,as you are learning one size does not fit all,,,the neck on a 6x45 is very short compared to a BR and needs more FB to keep the base of the bullet away from the "donut" area,,,,just for instance you mentioned a 95 VLD ,,it has a very short bearing surface compared to other 95 gr bullets,,,so it can work well with a FB as short as ~.040",,,,but if you use 80/88 gr FB (boutique) bullets they seat "wayyyy" in and prolly need a FB ~.080",,,, and the 55-60 gr bullets can work with FB as short as "0",,,,,,soo as you can see somewhere ~.060" should be a good compromise,,,,Roger

 

[dakor]

Thank you. I thought about it and I will more than likely shoot 80gr bullets up to the 95gr. The rifle is going to be a 600 yard practice rifle and also double as a calling rifle for predators. Should I still stay with the .065 freebore or bump it up some more? The bullets I am thinking about using are the 80gr Berger flat base varmint for calling. For long range practice 87gr berger vld, 87gr Hornady v max, 95gr Berger VLD and the 95gr Sierra Matchking.

 

[swd]

.065 is perfect for the 95SMK. The 87 VMax has more bearing surface than the 95 SMK or the Berger 95 VLD and will get seated down a little deeper. Shoot 75-87's for critters and 95's for LR practice and it will do everything you want it to. I also use 95 Partitions on deer and it puts them in freezer no problem. It's a great little cartridge.

 

[dakor]

Thank you!

 

[GrocMax]

Are you restricted to AR15 mag length? If so go shorter yet.

 

[dakor]

It will be on a Remington 700 223 short action that I plan on modifying the mag box so I can go longer with the OAL.

 

[Coleridge]

It will be on a Remington 700 223 short action that I plan on modifying the mag box so I can go longer with the OAL.

Yes, you will need to modify mag. I have a 6x45 on a Stiller Tac30 using rem bottom metal. Loading 70gr Nosler BT nearly kissing into a .040 free bore has me good bit longer than the factory box coal. The 90+ will be LONG...

Also, from experience... I wouldn't use the 80 Berger on coyote at 6x45 velocities. That is a pretty hard bullet. Even at 6BR velocities I got more runners than with any other varmint style bullet I've used (which is nearly all).

 

[dakor]

Thanks for the heads up on the bullet and mag box. Do you have a suggestion for a fur friendly bullet with the 6x45?

 

[1lnbrdg]

So question.

Can i chamber a barrel with a .223 reamer and then open up the neck with a 6MM neck/throat reamer?

The .223 reamer accepts the 6MM pilots. What else could go wrong?

 

[swd]

So question.

Can i chamber a barrel with a .223 reamer and then open up the neck with a 6MM neck/throat reamer?

The .223 reamer accepts the 6MM pilots. What else could go wrong?

Yes you sure can.

 

[fredo]

Thanks for the heads up on the bullet and mag box. Do you have a suggestion for a fur friendly bullet with the 6x45?

I've shot fox as close as 15yds with a 60gr Sierra HP from a 6x45, and they just zipped right thru.
Tough little bullet, never had one "blow up" or make a mess of a coyote, either. And they'll still work (touch lands) in a longer freebore chamber due to the (low b.c.) 'round-ish' shape, LOL.

FWIW, my 6x45AI has .050" FB.
Going off the top of my head:
87 Vmax jammed in the lands @ 2.320"
70 Blitzking..........................@ 2.385"
95 SMK................................@ 2.485"

For reference...

.050-.065" FB is where you want to be with a bolt gun. And a 1:8 will let ya throw them 95s without worry, if that is of any interest to you?

Good luck & have fun!

 

[Coleridge]

As fredo stated, the 60gr Sierra is a really tough bullet. It blows apart at high 243 velocities but is surprisingly friendly at the 6x45 velocities. I found the same with the 75 sierra & is likely the best all around bullet I've used. It acts more like a controlled expansion hunting bullet than a varmint bullet. Expect small hole in & about dime sized out. Even if you hit bone (I try to hit shoulders), VERY seldom do you ever get a bad exit. I know some guys don't consider any bullet that exits "fur friendly". But personally a small exit every time is better than the sometimes cantelope exit size...

I had an AR in 6x45 with a 10 twist. Really liked the cartridge but hated the 2.26" magazine restriction. Built the boltgun in 12 twist .040 freebore to shoot the 70-85gr bullets and it really shines. For sane ranges it sure makes a lot of sense.

 

[dakor]

Thank you I will give the 60 Sierra and 75 try I don't mind if the bullet exits with a smaller hole. The barrel I have is an 8 twist so I should be able to shoot most bullets out of it.

 

[GrocMax]

For comparison/further data a 6TCU with .045" FB 2.5 deg leade angle and 58 vmax is touching at 2.335" OAL. 2.5 deg ramps perfect on the lightweight varmint slugs, might be best left at 1.5 for the longer ogive heavies.

 

[dakor]

After talking to a couple people and doing some measuring I went with .080 freebore and a .270 neck. Thanks again for all the information I really appreciate it!

 

[expiper]

purrrrrfect ,,,,that way you wont have to turn the necks,,,and can make hundreds of rounds by just running them thru the die,,,you will be happy,,Roger

 

[swd]

That'll work and it will give the 87 V Max a little more room. Let us know how it turns out!