too much freebore??

[HeathGT]

I just bought a brand new Christensen arms ridgeline rifle in 6.5x284. I am trying to come up with an overall length using a modified case and the hornady overall length tool. I am using 142 grain nosler accubond lr's and berger 140 grain hybrids. When the measurement is taken there is less than 100 thousandths of the bearing surface in the case neck. This does not seem correct to me. Am I crazy for thinking my chamber has too much free bore. If this is the case I am left little to no room to chase the lands and grooves as they erode. Any input would be helpful!

Thank you!

 

[Terry]

I would call Christian Arms.

 

[chuckshooter]

I'll bet you are going to find it was done that way on purpose. something about creating higher pressure when the bullet starts at the lands and the 6.5x 284 is already a fairly high pressure round. most factory 204's you would not be able to seat the bullet and touch the lands. just my 2cents

 

[HeathGT]

I called them and they acted like it wasn't a big deal. He said the rifle met their sub MOA guarantee or it wouldn't have been shipped out. But he did say that I could send it back for them to look at. It took over three months to get the rifle after I ordered it. Who knows how long it will take to get back.

 

[HeathGT]

I'll bet you are going to find it was done that way on purpose. something about creating higher when the bullet starts at the lands and the 6.5x 284 is already a fairly high pressure round. most factory 204's you would not be able to seat the bullet and touch the lands. just my 2cents

I see what you are saying, but the Christensen rep told me they use a SAAMI reamer in all their rifles. I have loaded for other factory built 6.5x284 rifles in the past and never ran into this issue.

 

[BP1]

Take it to a competent smith and have him make you a case for measuring sometimes the hornady case doesn’t work it all chambers.

 

[chromatica]

Take it to a competent smith and have him make you a case for measuring sometimes the hornady case doesn’t work it all chambers.

Take an empty case and place a bullet in the case mouth just deep enough for it to stay put. Gently place it in the chamber and gently close the bolt. Then remove the assembly and measure the base to ogive length and compare it to specs. That should tell you if there is something radically wrong with the chamber

 

[fguffey]

When the measurement is taken there is less than 100 thousandths of the bearing surface in the case neck. This does not seem correct to me.

I could see using one bullet but if one bullet is short and fat and the other is long and pointed ?

I tested one rifle, it was a 7MM wildcat; I used a 170 grain bullet, the bullet came out of the case and slid forward over .200" before it hit the rifling. The owner asked me how could that happen; I had to say. "I do not know but I have a feeling someone read R. Weatherbys philosophy about free bore and had no clue what R. Weatherby said".

Again, I am the fan of the running start, I want my bullets to have that jump.

F. Guffey

 

[4xforfun]

Dumb question...are you getting the case ALL THE WAY into the chamber. I had this happen one time,,it ended up being that SOMETHINE was keeping the specialised case from fully chambering. I took the tool apart and reinstalled the bolt and chambered up the round and it was obvious that something was resisting. I cycled the bolt a few times till it would fully chamber, took the bolt out and tried it again and POOF....was actually perfect.

Tod

 

[fguffey]

4xforfun. the builder of the rifle made the reamer, he build 4 magnificent rifles, three of the rifles were accurate and never came back. And then there was the last one, one of the smiths involved was a genius in my opinion. Before one of them called me he took the rifle to ever smith in this part of the country including one with a bore scope, none of them had a clue. And then? He called me to explained the problem, he wanted to know what was wrong, I said I do not know and then he asked me where would I start when determining the problem. I explained to him I had a pile of home made tools and gages; as is always the case he got onto the Internet and them came for a visit.

I used his fire formed cases, we loaded 120 rounds using different powders and bullets, the rifle was very accurate at one narrow window. The further we got from the narrow window the more the bullets scattered like a shot gun blast.

F. Guffey

 

[NorCalMikie]

What is your target telling you??
I know H.S. Precision has looong free bores on their .308 rifles and are DEADLY accurate with a LOT of jump to the lands.
You looking at a problem that isn't there??

 

[fguffey]

You looking at a problem that isn't there??

I seated a 170 grain bullet, I pushed the bullet out of the case, the bullet skidded down the barrel another .250"+ and then the bullet hit the rifling.

You looking at a problem that isn't there??

That is a cute saying, "You looking..", Again, the man that built the rifles is a very disciplined reloader.

F. Guffey

 

[timeout]

It may well shoot fine seated way off the lands, but I think most would not want their new rifle built with only .100" into the neck when just touching the lands. I know that I wouldn't.

 

[HeathGT]

Dumb question...are you getting the case ALL THE WAY into the chamber. I had this happen one time,,it ended up being that SOMETHINE was keeping the specialised case from fully chambering. I took the tool apart and reinstalled the bolt and chambered up the round and it was obvious that something was resisting. I cycled the bolt a few times till it would fully chamber, took the bolt out and tried it again and POOF....was actually perfect.

Tod

Yes I am 100% sure. I have even done it the old fashion way with a cleaning rod and a sharpie. I got the exact same measurement.

 

[HeathGT]

It may well shoot fine seated way off the lands, but I think most would not want their new rifle built with only .100" into the neck when just touching the lands. I know that I wouldn't.

No sir, I am not happy with it at all, if I seat the bullet like I like, with the boat tail just above where donuts form, I will have .116” jump. That is a mile in my opinion for a rifle that is having custom loads developed for it. JMO.

 

[HeathGT]

What is your target telling you??
I know H.S. Precision has looong free bores on their .308 rifles and are DEADLY accurate with a LOT of jump to the lands.
You looking at a problem that isn't there??

I haven’t shot it enough to really tell, I’m worried that if i shoot a lot before I talk to Christensen they’ll say I did something to it. I’ve got 22 rounds out of it now. I made up some generic rounds for fire forming and barrel break in.

 

[Milo 2.0]

I'm not implying your fault, but if having a custom gun built, you need to know the freebore of the reamer upfront and understand what it means in terms of your bullet choice. I'd bet you 5 bucks if you bought a box of hornady eld bullets, the whole picture will change.
There's more 6 creedmoor chambers out with ungodly freebores thanks to smiths buying a hornady match reamer, then guys try to run hybrids or a 110 sierra<way bad.

 

[HeathGT]

J

I'm not implying your fault, but if having a custom gun built, you need to know the freebore of the reamer upfront and understand what it means in terms of your bullet choice. I'd bet you 5 bucks if you bought a box of hornady eld bullets, the whole picture will change.
There's more 6 creedmoor chambers out with ungodly freebores thanks to smiths buying a hornady match reamer, then guys try to run hybrids or a 110 sierra<way bad.

its not a custom rifle. It’s made by Christensen arms, just a high end factory rifle. I’ve had 3 custom rifles built and I always specify what specs I want. Thats why this is not making sense. I don’t see how a saami reamer should have that much freebore. I can’t find a standard drawing on the internet. I want to find out what the measurement is supposed to be from boltface to the lands and grooves.

 

[Milo 2.0]

J

its not a custom rifle. It’s made by Christensen arms, just a high end factory rifle. I’ve had 3 custom rifles built and I always specify what specs I want. Thats why this is not making sense. I don’t see how a saami reamer should have that much freebore. I can’t find a standard drawing on the internet. I want to find out what the measurement is supposed to be from boltface to the lands and grooves.

Will they not supply you with the reamer diagram?

 

[284winner]

What is your target telling you??
I know H.S. Precision has looong free bores on their .308 rifles and are DEADLY accurate with a LOT of jump to the lands.
You looking at a problem that isn't there??

I agree. Take your rifle out for a test drive. All this concern may be for not. I've had similar concerns regarding TOO MUCH freebore but after shooting it, my concerns were history. Relax and head out with what you want to load for this rifle and see what it does. Good luck.