Hard bolt lift on 30BR

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oldpup223

Guest
I just finished chambering my first barrel and took it out and shot it for the first time with 33gr 4198 and have very hard bolt lift.
The reamer is 30BR .330 neck Randy Robennet reamer from PTG and the chamber looks great. Action is Panda. Die is my old die from Harrell and brass is old brass that I refurbished by sizing, expanding, turning and triming. Brass fits great and has .0093 neck thickness, chamber came out tight .2295 .2298 and loaded round is .2280 to .2285 so I have only .001 or a little better clearance (may be a little tight). Go gauge fits nice and No Gauge will not go. Brass and loaded round chamber good and bolt closes very easy as headspace is .002 short after being bumped back.
brass was trimmed to .520 and has room in chamber, fired brass after using a little steel wool over it rechambers easy.
velocity was 2825 so no pressure problems. But after firing bolt comes 80% up easy then the rest is very hard and clicks but case comes out easy after that.
So what do you think is causing the problem? old die? old cases? too tight tolerances. or ?????
I have been a toolmaker for 45 years and a gunsmith about 5 minutes.
Thanks for any information or sugestions in advance or critics welcome
Denton Smith
 
A good starting point would be to try some new brass. If it works good, you have your answer. If not, then we can start looking at other things. Just make up about 3 pieces to start, so you don't waste a bunch of expensive brass and effort.
 
Probably the cases. Although I am beginning to wonder if you can ever wear them out. That half way up and then tight is primary extraction, that usually indicates cases have just had it.

I have cases that I have long since lost count of as to how many firings they have, and they have been in multiple barrels at 3000fps+

That 1.520. Isn't that the actual length of the chamber that the standard Robinet Reamer makes? Plus your math on your neck thickness shows you shout have a tad over .0025 total loaded round clearance if your bullets have that gas ring in the .3087-3088 range.

Also, I would not doubt your skills as you say you are a tool maker, but it is very rare for one of Dave's reamers to cut undersize, the print dimension is .330. There is a +.0004 on decimal diameters, no "-".......jackie
 
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I just rechecked my brass and it is 1.5195 then checked total depth of neck dia and with a Stony point gauge I get 1.5285 to 1.5290 so brass should be ok then seated four bullets and measured od and got .3282 on every one of them. Could very well be the brass as I have more firings than I would like to admit. I will use some new brass this weekend and see if that helps. I also rechecked my velocities and it was 2885 to 2915 with the 33gr and I went up to 34gr and it was 2995 to 3015 and accuracy was very promising. I checked the neck with an (intramic) and it surprised me too but that is what I got, I may go back rip the barrel off and check it again. I use some Sony Digital Gauges that I have to check brass od, headspace, and oal.
Thanks jacki I appreciate the reply.
Denton
 
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Don't take the barrel off just yet....If your primers aren't flattened to the edge of the primer pocket and there is no bright marks on the head of the brass...then the pressure is not the problem...make sure you inspect you bolt lugs and cocking notch for gauling or signs of dry wear...dissassemble and clean the bolt thoroughly the lubricate properly...and inspect the trigger/hanger...it sounds like some thing outside the barrel is awry...and lastly clean your chamber out with a clean patch and some lighter fluid...I have found the newer bore cleaners leave a sticky residue in the chamber if not wiped thoroughly...

Good Luck...and enjoy that 30BR

Eddie in Texas
 
Denton, you might want to try this: Take a case that's been fired in your chamber, but not sized. Do a quick anneal of the case, size it, load it,
shoot it and see if it acts any different.
 
This ocurs quite often when brass fired in one chamber is then used in a new chamber. Not the fault of either chamber, but
rather the die. It is a must that brass be reduced in dia at the base, just ahead of the ext. groove. Where it was fine in the original
chamber, the die sometimes does not reduce this for the newer chamber adequately, which just could be a bit tighter. Yup, it goes in
but doesn't come out well after firing. Measure the brass before sizing and then after, at the expansion line. You can polish the chamber
out slightly or find a more useable die, or just new cases alone may solve it.
 
I just came back from the range and I think that Mr Kingsbury has hit the problem right on the head. Got up this morning after sleeping on it and went to work, I grabbed two cases from a new box of brass and expanded, trimmed, turned, and sized them. Then took two cases that had been fired twice in the old chamber, sized them. Then took two cases from the batch of many times fired brass and annealed them good and sized those. I loaded all six cases with the same load 34gr 4198 and same bullet. Headed to the range and fired all six so here is the results. The two many times fired and annealed was still very sticky with maybe even harder bolt lift. The two twice fired cases ejected easily with what I think was a very small resistance at the very top and maybe very small click. The two pieces of new brass ejected very easily with one finger and absolutely no click or resistance. So I came right home and called Harrell's and ordered a new die and am sending the two new cases as a pattern. I also did rig up a gauge to measure each case at the pressure ring and found that my old cases were approximately .0005 to .0008 larger than the new cases (that was the best I could measure with calipers so tenths with those are just a guess. Anyway it looks like the old die made for the old chamber just wont work for this one.
I think that will solve my dilemma and I wish to thank all of you that took your valuable time and effort to assist me in this as it was my first time with problem.
Denton
 
Glad you got things narrowed down. New brass. in a new chamber, with a die that fits....is always a good way to go. -Al
 
Harrell's makes several dies for the 30BR. Do yourself a favor and buy the B-3 die. It will size the base the most. Goodbye clicking.
 
David this is the first time hearing of such a thing as B-3 dies and finding that Harrell's even makes such a thing as I have three dies from them and they have never mentioned a choice but it sounds good.
How many others use such a die and what is the pros and cons of such a critter.
Al what is the "fat butt" cartridge as I already have a fat butt for myself thank you.
Denton
 
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oldpup223 said:
David this is the first time hearing of such a thing as B-3 dies and finding that Harrell's even makes such a thing as I have three dies from them and they have never mentioned a choice but it sounds good.
How many others use such a die and what is the pros and cons of such a critter.
Al what is the "fat butt" cartridge as I already have a fat butt for myself thank you.
Denton
Click to expand...

A fat butt chamber is a description I've coined to describe the spec's that I use for all my chambers. I spent ten years going through this crap with PPC's/BR's and several "308 case" sized chambers (HBR) and heard all sorts of "fixes" but it wasn't until I started really measuring the relationships involved that I realized....... FOR ME the easy way out is just to buy reamers that cut a chamber .005 or more larger than the virgin brass. Right now I have my reamers made .007 to .009 over the cases I intend to use, depending on size of case. 6PPC is .007 over, 338 Lapua is .009 over.

"fat butt"

It just solves everything AND allows for a quick visual inspection for case eccentricity if this matters to you.

Of course most people are still convinced that close tolerance offers some sort of advantage and that a reamer marked "Tony Boyer" has a magically balanced agglomeration of specified angles and such :)

The only tolerance you need "close" is headspace..... I'm anal about headspace. IMO if you headspace isn't so tight that you have to heel the bolt closed when you fireform then all the other angles/dimensions are meaningless.


al
 
Thanks for the explanation Al I think I just learned a little more now about 98% more knowledge and I may get a little smarter.
 
oldpup223 said:
David this is the first time hearing of such a thing as B-3 dies and finding that Harrell's even makes such a thing as I have three dies from them and they have never mentioned a choice but it sounds good.
How many others use such a die and what is the pros and cons of such a critter.
Al what is the "fat butt" cartridge as I already have a fat butt for myself thank you.
Denton
Click to expand...

For some reason, Harrel seem reluctant to sell the B-3 but as far as I am concrned, they can stop making those smaller than the B-3. I am going to try Alinwa's theory this summer. He may have the ultimate answer. With a good Small Base Die and annealing, Brass should never have to be replaced unless the primer pockets wear out.

OH, and be careful to not let the shoulders of your cases touch the bushing lest you break the necks on your aged cases. Took me only 9 years to find this small item out. Thank You Kent H.
 
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Pete Wass said:
Oh, and be careful to not let the shoulders of your cases touch the bushing lest you break the necks on your aged cases. Took me only 9 years to find this small item out. Thank You Kent H.
Click to expand...

Yep. A little DyKem on the case necks when setting up the dies can keep you out of trouble. For those that like to size as much of the length of the neck as possible (I do), a little extra chamfer on the 'down' side of the neck bushing, if needed, can help.
 
For some reason, Harrel seem reluctant to sell the B-3 but as far as I am concerned, they can stop making those smaller than the B-3.
OK now I think I am a little confused! I had assumed that the B-3 or B-2 1/2 would size the base a little smaller than the regular dies but your statement above appears to indicate they may be a little larger than regular. Could you please straighten my old brain out just a little.
Harrell's makes several dies for the 30BR.
Do yourself a favor and buy the B-3 die. It will size the base the most. Goodbye clicking.
According to Mr Apple as above it sizes most?
The other dies I have only neck sizes to approx. .080 to .100 from the shoulder with the bushing down as far as I can get it. so no worry about touching the shoulder.
Thanks
Denton
 
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