30BR help needed

T

tricrown

Guest
I’m trying out the 30BR again. The new barrel is a Bartlien gain twist 18-17.5” chambered with the Robinett reamer. I have a couple thousand 10 ogive 118 BIBs half .3085 half .3086. We shoot 200 yards, 300, & either 400 or 500 depending on the club, no flags, off the bench. Hence the desire for the 10 ogive and the extra 10% BC it offers.

My old 30BR records showed 33.5g H4198 was max with 117g Fowlers. I have no trouble getting this barrel to shoot 36g H4198 with the 118g .3086” BIBs. No trouble except there’s next to no room for the bullet. When seated to the lands the bullet is only around .140” into the case. So I plan on accuracy testing with a slightly compacted 35.5g as the upper limit.

Problem is the erratic poor neck and bullet runouts I’m getting. I’ve been shooting the clouds from my cellar while working out the kinks. The die is a Redding small base body 6BR that has been converted to use bushings that’ll give from near nothing to a full .002” runout from my CoAx press that holds 22BR and 6BR runouts to near zero with their Harrell’s die. I’m using a bushing that gives .004 tension and that sizes .150” or more down the neck. I’ve tried all kinds of tricks and sizing depths to no avail. The shoulder bump is set at what looks to be just under .001”. The seater is a non-custom Wilson that’s adding at least another .001”.

My questions are I know most people like to seat the 30BR into the lands with lots of neck tension. Does anyone successfully use a very low neck tension and let the lands do the seating work for the 30BR? I can go to a Wilson bushing die and seat the bullets in just .050” and let the lands do the rest. I’ve never had luck with this with any calibers before. Always felt I was getting erratic seating depths and was afraid I was bumping the bullets in too far while loading or handling. Will powder compression with lands seating cause trouble? Is the 30BR less sensitive to runout? Should I forget the 10 ogives and be trying 7 ogives to get a deeper seat? The fact that I’m having trouble with both the sizer and seater leads me to believe I’m doing somethings wrong. Any idea what they could be?

Thank you,
Bill
 
To add to Ray's excellent advice:

An unmodified Wilson 30BR seater will have a neck i.d of .335-.338. When using .003-.004 of neck tension (as many 30BR's like), this clearance between the case neck o.d. and the i.d. of the seater can be the cause of excessive runout.

Add some work hardened necks into the equation and the runout numbers can get big in a hurry.

Try stress relieving a fired case that showed bad runout before firing. Then, go through the sizing/seating process and see if the runout gets better. It might not get to .001 unless the seater gets modified by chambering it with the chamber reamer...but if it drops from .004 or .005 to .002 (for example) you know you're on the right track.

To see if the extra clearance in the seater is part of the issue, wrap a thin strip of thin adhesive tape around the case neck (with no overlap), seat a bullet and check the runout. The tape will effectively reduce the clearance and give an indication of what amount of runout may be induced by the seater.

Dirt clod troubleshooting at it's best......;)
 
Not Everybody

With the 112 7-ogive BIB, I use a rather light neck tension, probaly only about .0015 max.

I seat the bullets about .010 in from just touching.

The Rifle shoots very well.

I have been shooting the same cases since I put this thing together, probably 20 firings at least on each.

I personally think you are using way too much neck tension, and that is from where most of the runnout eminates.

I assume you are using a "zero" freebore reamer. Even with that, the 10 ogive BIB doesn't go into the neck very much. In fact, a 7 ogive 12 on a shorter jacket actually goes deeper into the necks.

I am curious. If you are not allowed to use flags, why are you wasting your time with a 30BR. It would seem like a 6BR with a 1-8 twist and true long range bullets would be a better choice.

Extreme Accuracy chamberrings like the 6PPC and 30BR only have an advantage when a shooter is able to take advantage of the inhereted acuracy potential by using flags. Take away flags, and a combo that has less potential accuracy but a much higher BC would seem better.

Shooting at 200-300 yards without flags. You might just as well close your eyes and squeeze hard:D...........jackie
 
Most 30 BRs will shoot well with a lot of tension, alot of jam and a stout charge of H4198...but flags are a must. I agree with Jackie. If ya can't use flags, get something that bucks the wind better. A 6mm 105vld has about half the drift at 200 that a 30BR has(or my 30 Major), both at about 3000fps. Also, I've had barrels that just don't like 10 ogive bullets. Figure out what the gun likes with flags...anything else is a waste of ammo IMO. You just can't argue much with BC advantage and NO flags. I'd take a good thirty and good wind reading over anything if the "anything" can't use flags, at those distances.---Mike Ezell
 
There are several good points here . . .

As Jackie points out, even with ZERO free-bore, when seated for ogive/land contact, the base of the the ten ogive bullets (1.00" long jacket) will be less than half way into the case neck - the base of the typical 110-112 Gr. bullets (seven to eight ogive and 0.925" long jacket) will barely make the halfway mark.

As a [thirty caliber] generality - MORE neck tension is better; MORE 'jam' (actually-'jam-seat') is better . . . for thirty caliber chamberings, Al's neck-tension/seating depth numbers are pretty close to my own long-time "got to", or, starting point set-up. Oh, I have, as a rule, found compressed powder to be a good thing. :D

For fussy barrels, skip right over the incremental iterations of 'jam' and go straight to a [GRAND CANYON like] 0.040-0.050" JUMP!:eek: You may be pleasantly surprised by the leap of faith!;) Good shootin'! RG
 
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I am definitely not of the same caliber (punny, I know) as that of the posters above, but I did have a repeatable runout issue with my neck bushings. The
.324 in titanium nitride left me with .002 runout in a Redding 30br die. My dad needed bushings and so I let him borrow it knowing that the runout existed. Bought a steel
.324 bushing for myself, and the runout is now .001 or less with the same die.
I am not trying to say that the titanium is the culprit, but if you have a way of borrowing a bushing from another shooter that has a proven setup it may be worth trying.
There was another thread recently about seater stem runout that might be worth checking out as well.
Hope this helps,
Mike
 
thanks for the suggestions

No flags are part of the rules of the Groundhog Shoot game. Although some clubs do have ribbons or a couple flags at each backstop. Wind readings are taken from trees or whatever is present. Guess it started that way to more closely duplicate hunting conditions. Some of the shoots don’t even allow sighters. All the shoots I know of have 5 timed shots for score at 3 distances, from a bench using 10 point to 6 point scoring rings with a groundhog outline for a 5 point shot. As far as I know they are the best regularly attended kind of shoots in the region. With one club averaging over 100 for their monthly shoots and 2 dozen regular shooters showing up for the 26 weekly Tuesday shoots at another. We draw in many present and former IBS shooters. It gets pretty serious.

There's a great variety in the calibers used. The 30BR makes it much easier to see hits in high mirage and is of little disadvantage on any no wind day. It holds the score record at a couple of the clubs and was used by the 2 top Tuesday high agg shooters. We’ve had a lot of calm summer days the last 2 seasons. It also seems to be the easiest to keep in tune. Here’s some of the clubs that are close to me with St. Thomas and Shippensburg being my home clubs.

http://www.mifflincosportsmens.com/groundhog.htm
http://www.mayberrygpa.com/ground_hog.html
http://www.shippensburgfishandgame.com/Groundhog_Shoots.html
http://southforkrifleclub.homestead.com/groundhog.html
http://stthomassportsmen.com/default.html

Thanks, I will be getting a 30cal Wilson seater blank reamed out with the same reamer. I’d bet that’s where the added bullet runout is coming from. And will try and playing with bigger bushings and a Wilson neck die to see if the .004+ tension is what’s causing the neck runout. Annealing will have to wait as a last resort since I’ve never done it and getting 5 different guns, 3 with multiple barrels and calibers, ready to shoot in 4 different classes will be taking a lot of time.
 
All fixed thank you

All fixed. Dropped neck tension to .003 and used a Wilson neck die and that fixed that. Had a Wilson 30 blank made into a 30BR seater using the same 330 reamer as the chamber and that fixed that. Under .001 bullet runout now. Thank you.

On a side note I near mistakenly blamed my gunsmith for doing my chamber off center. While checking the runouts I found that rounds that had near zero runout and were seated into the lands were coming out of the chamber unfired with .002-.003 runout. I was about to call McCauslin Rifles and ask if there was anything other then an off center chamber that could cause the lands to move the bullet like that. But the land marks on the bullets looked so even. Then it dawned on me to remove the strong ejector from the Lawton 7500SS dual port and sure enough the ejector was pushing on the bullet on the way out enough to move it in the shallow seated case. Without the ejector the unfired rounds come out of the action with the same runout as they go in.
 
It's kind of funny that this was the first thread that caught my eye when I signed on. I finally got to shoot my new 30BR for the first time today, using leftover powder--which is absolutely the wrong kind according to what everyone has told me. I had a bunch of it sitting around and just wanted to stuff a case full and shoot it to do the final forming of the brass. My neck tension was wrong from what I've been told, too. I had loaded the rounds way back in January when I thought Shilen had shipped this barrel, but it was the 22BR I had ordered later than the 30 BR--go figure.

Anyway, I think I am now a 30BR fan. Even with all that wrong and also I guess I had not cleaned up the doughnut from necking up the cases as well as I thought I had, this cartridge shot better than any I have ever shot on the very first try. After setting the scope zero, the group was just one ragged hole at 100 yards. If it shoots this well with all that wrong, imagine what it will do when I fix it up the way it should be......... or should I?
 
you might have a really good barrel there, they are almost impossible to make shoot bad, if it is enjoy it they ain't all that way :) steve
 
amamnn said:
Anyway, I think I am now a 30BR fan. Even with all that wrong and also I guess I had not cleaned up the doughnut from necking up the cases as well as I thought I had, this cartridge shot better than any I have ever shot on the very first try.
Click to expand...

Thats the way a really good cartridge is , it's sometimes hard to get tuned to it's optimum because it shoots so darned good even when everything is not perfect.

Dick
 
I think I may have worded my last post poorly. The 30BR I shot the other day did better on the first outing than any other cartridge I have ever shot--for the first, case forming, outing. I have had better groups after load development with other cartridges, so I am hoping for great things in the future from the 30BR.
 
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