New 30br difficulty(update with another?)

[mudduck]

So I just had a new 30br chamber and brass turned for it but have some difficulty getting some to chamber. Please look at attached pics. Some chambers fine and some is pretty snug when closing the bolt. Might be hard to see in pics but looks as if the neck turner hit lower on one side compared to the other.

 

[Rat Rifle]

What brand of Brass ? 6mmBR Brass ?

 

[mudduck]

What brand of Brass ? 6mmBR Brass ?

Lapua. 6br

 

[br1111]

Lapua. 6br

i have found if you full size it the first time on new brass with a full length sizer (not a bushing die) with the proper bump it will chamber fine. after that you can use a bushing die.A bushing die does not size all the way to the shoulder neck junction and that causes the chambering problem. If you still have chambering problems after fireforming and die all the way to the ram, you need a thinner shell holder. my gunsmith machined me a shellholder and a set my bump with that.I hope this helps.

 

[RGRobinett]

Along with br1111's post (#4), check the actual [chamber] OAL, and verify that the OAL of the brass is compatible/shorter!! RG

 

[gunsandgunsmithing]

This is normal but yes, it may help to run it through a die first. Verify that you have a minimum of .002 clearance over a loaded round at the neck. Then do what's necessary to get them to chamber. A tad bit of resistance is not a problem or even bad. Keep the lugs lubed and fire them. They straighten out nicely once fired with a moderate load.

 

[Jayplace]

I had a similar issue when I started with my new brass.
I don't know for certain, but I think when I was preparing my brass the neck was being slightly tweaked when I expanded the neck. Some would chamber fine and others were tight after neck turning.
The use of a neck bushing in the die worked for me.


I ran the expander through them again and then through the sizing die a second time and everything was fine.

 

[Greg@wfcustom]

I normally set my shoulder in the 30 BR FL bushing die without a bushing first so I get a crush fit for the first FF, then expand the neck, (moves thick shoulder brass "doughnut" to outside), then FL size again,
then neck turn "blending" the shoulder, then FF. Usually come out pretty straight, trim, chamfer, deburr, good to go.
Works for me YMMV.
G

 

[AlNyhus]

The 'wave' into the shoulder comes from the neck not being perfectly straight with the case body before it was neck turned. A little of that is ok.

Did you full length size the case and size the neck before loading them? If you look at the picture posted, you can see the drag mark on the bullet on one side caused by it being cocked into the throat. If you look at the cut blend into the shoulder, you can see how that correlates to the drag mark on the bullet. What's the runout on the neck with a seated bullet? And how much neck clearance?

Echoing R.G.'s comment...make double damn sure of the exact chamber length by using a chamber length gauge.

Let us know what you find out. -Al

 

[mudduck]

The 'wave' into the shoulder comes from the neck not being perfectly straight with the case body before it was neck turned. A little of that is ok.

Did you full length size the case and size the neck before loading them? If you look at the picture posted, you can see the drag mark on the bullet on one side caused by it being cocked into the throat. If you look at the cut blend into the shoulder, you can see how that correlates to the drag mark on the bullet. What's the runout on the neck with a seated bullet? And how much neck clearance?

Echoing R.G.'s comment...make double damn sure of the exact chamber length by using a chamber length gauge.

Let us know what you find out. -Al

The loaded round was not sized before. The pics with colored neck was sized with f/l Wilson bushing die. I pulled a few that I loaded and sized them and was a little better but still a little snug. I did not trim the loaded round or the others but did check the ones I pulled using borescope from muzzle and they where almost touching so went ahead and trimmed the remaining to1.518 until I get them fired as that what was recommended to me.

 

[JEFFPPC]

Along with br1111's post (#4), check the actual [chamber] OAL, and verify that the OAL of the brass is compatible/shorter!! RG

AN easy way to visually check is.......drill out a primer hole to accept a bore scope. Insert the case and with the bore scope inspect where the case neck ends. Will also tell you where to trim to.

 

[Jayplace]

I use the borescope through the muzzle to verify where my case ends and where my freeborn ends also.

If my understanding is correct, the recommended trim length is 1.500 for a typical 30 BR. If I recall correctly, the distance from the end of the case to the beginning of the rifling is typically about .010, or 1.500 +.010 to beginning of the rifling.

To me 1.518 seems a little long.
Perhaps someone who knows could correct me if I'm incorrect. I'm far from being an expert.

 

[Larry Koch]

You need to trim your brass. It’s to long.

 

[AlNyhus]

I use the borescope through the muzzle to verify where my case ends and where my freeborn ends also.

If my understanding is correct, the recommended trim length is 1.500 for a typical 30 BR. If I recall correctly, the distance from the end of the case to the beginning of the rifling is typically about .010, or 1.500 +.010 to beginning of the rifling.

There is no one set case length dimension. Even if the reamer maker's print calls for a chamber length of 1.520 (for example), the actual chamber length can be different due to the tolerances that reamer makers work to.

For example, I have 30BR chambers done with two different reamers that by the prints show them both to be 1.520. When checked with a chamber length gauge plug, one is 1.527 and the other is 1.535.

The 'smith that chambered it can supply a stub that's partially chambered and milled so you can visually see and check the length. You can also make or buy a Sinclair chamber length plug. The neck end on it has to be reduced to fit your chamber neck dimension...it's easy to do since the plug is pretty soft.

SINCLAIR INTERNATIONAL 30 Caliber Chamber Length Gage SKU: 749000804 | Brownells

Check out the SINCLAIR INTERNATIONAL 30 Caliber Chamber Length Gage SKU: 749000804 available Online at Brownells Today and many more Case Length Gauges products are available in our Reloading Department.

www.brownells.com

Jackie Schmidt has posted pics of the ones he does on here, too.

Chamber length is something you have to know for certain.

Hope this helps. -Al

 

[Larry Koch]

There is no one set case length dimension. Even if the reamer maker's print calls for a chamber length of 1.520 (for example), the actual chamber length can be different due to the tolerances that reamer makers work to.

For example, I have 30BR chambers done with two different reamers that by the prints show them both to be 1.520. When checked with a chamber length gauge plug, one is 1.527 and the other is 1.535.

The 'smith that chambered it can supply a stub that's partially chambered and is milled lengthwise so you can visually see and check the length. You can also make or buy a chamber length plug.

Chamber length is something you have to know for certain.

Hope this helps. -Al

a smith can but it will not be cheap.

 

[Dimner]

a smith can but it will not be cheap.

My smith only charged me 40 bucks for my stubby. For a guy who is learning, like my situation, it's worth double the price.

 

[Greg@wfcustom]

My smith only charged me 40 bucks for my stubby. For a guy who is learning, like my situation, it's worth double the price.

I usually add it in to the price of the first barrel I do for someone when using that reamer. After that they are on their own (provided they use the same barrels).
Has multiple uses and is good to have.
G

 

[jackieschmidt]

I made these for my three Competition chambers.. 6 PPC, 6BRA, and 30 BR.

 

[Webster]

So I just had a new 30br chamber and brass turned for it but have some difficulty getting some to chamber. Please look at attached pics. Some chambers fine and some is pretty snug when closing the bolt. Might be hard to see in pics but looks as if the neck turner hit lower on one side compared to the other.

Nothing to do with your problem but it looks like you turned much farther into the shoulder than they recommend. I always wondered where The theory originated that you should turn lightly into the shoulder. I see no purpose for going into the shoulder at all? Opinions welcome.

 

[Bill Norris]

Nothing to do with your problem but it looks like you turned much farther into the shoulder than they recommend. I always wondered where The theory originated that you should turn lightly into the shoulder. I see no purpose for going into the shoulder at all? Opinions welcome.

It is O K to kiss the shoulders but I stay away from cutting into it.