RE: bullet seating depth?
 

One doesn't buy 6.5-284 Benchrest guns from Gart Brothers - a gunsmith somewhere built this gun. I would get in touch with that person and find out if he set the throat to work with a certain bullet - or, as Jeff suggests, if he used a tight spec throating reamer. You may indeed have to put a little more throat in the rifle - but once you do this, there is no going back - without setting the whole barrel back and starting over with the chambering process. I would explore what you have and what it will/won't do first.

RE: bullet seating depth?
 

If I were you, I'd find out what the exact chamber dimensions were and at what length you should be able to seat the lapua bullets.

If in the end the throat needs to be longer it can be cut.

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OK, many thanks, I'll do that.

Rob

RE: bullet seating depth?
 

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Well it's a heck of a lot further seated that one bullet diameter. It's more that two. The deeper you seat the bullet the more possible you can create some very high initial pressures.

I only want to use 139 scenars. They are long slim boat tails with a very high BC.

Thanks Rob

RE: bullet seating depth?
 

Very true. My gunsmith built it as a bench rest rifle. He hasn't set it to work with any bullet and he has not got a OAL measurer in that caliber at the moment. He told me if was reamed very short because of that but to try it out and see if it shot OK. He thought it might be a good situation because as the lands wore he could ream new throat to make up for it and lenghten the barrel life. (Unfortunately I daren't shoot it at all since I don't know what the pressure effects of deeply seated bullets is on pressure. My gunsmith is not around to ask at this time so that's why I asked here. I wondered if anyone had ever seated a bullet so deeply into the case and if they got problems. I read one article on pistols and it bluntly said that over deeply seating bullets can blow the pistol up.

I could wait a couple of weeks and ask him.

Thanks

Rob

RE: bullet seating depth?
 

Robert

This is not the place to answer your question further. You had a gun made for BR shooting. That also means that the neck diameter may be tight, requiring you to turn the necks of your brass before firing. To fat and you run into pressure problems.

Get hold of your gunsmith and have a good talk before you go any further.

The 6.5x284 is a well known round shot by many folks. Its very common. As is your choice of a 140 grain(+/-) range of projectile. For it to be seated that deep in the case you need to fnd out more info. Don't just tell someone else to lengthen the throat. Find out why and whats happening. Its something we can't diagnose here without seeing the gun. I know. Because I was in your same shoes. There was an answer and it was not throating further. It was learning what I had and how to use it.

Please talk to your smith!!

Jeff

RE: bullet seating depth?
 

Rob

You and I posted at the same time....

I see that your smith is gone at the moment. Just sit tight. It sounds like I might also be shopping for a smith that is knowledgeable. More so than this fellow. His line sounds like BS to me. The 6.5x284 is used with your weight bullet more often than not for LR shooting. It should be throated as such. Coming back later to deepen-- hogwash. That barrel might not last 1000-1500 rounds anyway more than likely for top edge accuracy.

Yep, forgot about deep seating. I don't recall seating depths but here is an example in 223. I used to shoot 75 amax seated long for single loading in the AR. Was appx 2.450 give or take. Then i loaded up some at mag length with was way down in the case and looked ugly they were so deep. It was 2.240 oal. I did back off my charge about .75 grains basically but everything else was fine.

Take into consideration my 223 case capacity is about 25 grains, compare to yours, reduce load accordingly and for a safety measure and shoot if you have to. I still say you really need to find out the throat diameter vs your bullet or you still may be in trouble firing any rounds. Not to mention the neck diameter of the loaded rounds again either. Both are serious issues. Regardless of how bad you need to fire the gun. Its your gun, your money and your life. be careful.

And if you smith can't answer the questions go find one that knows something.

Jeff

RE: bullet seating depth?
 

Sure, you might not reach peek velocity. I got a friend who built his 300RUM with no freebore. So loaded to 3.6" COL with a 200gr matchking his was .005" from the lands. One, it shot extremely accurate, but he had to throw out the loading data on it. And couldn't reach 3000fps without pressure signs.

Hey, its gun, you not sure if you was asking for advise. But I gave my 2 cents.

RE: bullet seating depth?
 

Thanks everyone for your useful comments.

I need to speak to my gunsmith about seating the bullets and I will do that before firing it.

Kind Regards

Rob