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londonhunter
02-13-2010, 12:28 AM
Hi to all

I have been here seeking for advice for some time. After 02 years I finally received by first BR rifle.

I MUST stress I am NOT a benchrest shooter but have always admired the skilled and knowledge on this forum. I need some help.

Here we go.

The rifle is a tubegun I intend to use it for F Class or McQueens at Bisley in England.

It's a multishot 30BR. reamer is from PAcific Tools 30 Rabinett specification with a 330 neck.

Bluerprinted remington action with a lilja 1 in 15 twist.

My gunsmith did all the initial preps and made me 16 cases.

he started off with 6mm Norma cases which I have a surplus. After a week he discovered that there is 5 grain less capacity as compared to 6mm lapua cases

On his second attempt he used a RCBS mandrel and necked the lub cases to 30 caliber in one pass.

Then firefored the cases with cheap sierra 125 grain projectiles.

I understand he used load data from 6mmBR.com

i.e. H4198 and 34.5 grain of powder seating 0.005 short of the lands to reduce pressure for first firering.

When I recieved the rifle last week used these very SAME cases and started to reload.

Problem 1

I am struggling to get 34.5 grain of powder into the case.

These cases have NOT been trimmed and have been fired only twice previously - standard lapua 6BR brass.

I then changed to a long drop tube and even a tried folding a peice of A4 paper (21.9 inches as compared to american letter format) so I am dropping from about 18 inches in height with extreme caution.

The best I can get is the powder settleling is half way up the neck.

I tried 02 different tubs of powder with 02 different batch numbers and got the same result.

I have not measured the water capacity.

May be this is the next step but the over fill is SIGNIGICANT not a little bit.

I even checked the calibration of my RCBS chargemaster and crossed checked using a mechanical scale to check my charge weight

Problem 2

I used the best setteld powder case and proceed to seat a projectile

This is how how I calculate the neck bushing.

Cases have very uniform neck thicnkness of 0.009 inches all round

Porjectile is 0.3075 in diameter.

0.0090 wall thickness
0.0090 wall thickness
0.3075 projectile
0.3255 TOTAL

I started with 0.325 bush then proceeded to 0.324 hoping this will give me enough grip

I use wilson dies and seaters.

When I withdraw the top of the seater die the vacum sucked the bullet out with the top with withdrawing and there is so much resistance on compression the top rebounced back up!

Obviously this is completely wrong. Can somebody advice my next step

I live in London england and my gunsmith is in scotland.

I really feel like an idiot making some fundemental mistakes

I have gone over my step many many times but cannot see where I am going wrong.

There must be a lot of bench rest shooter out there using 30BR.
Can you advice ?

A shooter friend without 30BR experience suggested a high neck tension. What do you guys think? 323 322 ? What is enough

I can post pictures if it helps

alinwa
02-13-2010, 01:37 AM
OK, I'll have a lash at it. :)

1st, take some powder out. Drop your charge wt until you can fit the bullet into the case without compressing the charge.

Don't force stuff.

Don't worry too much about neck tension, you just need enough to keep the bullet from falling out.

Just get the parts to stay together and shoot it! :)

Note that the decrease in case capacity will result in an INCREASE in pressure. The cases will compensate somewhat. You'll probably be able to get an acceptable velocity and accuracy from your combination. At least get'cher feet wet. This should give you some'at to do whilst you wait for your neck bushings and maybe some proper brass. You may even try another powder with time, but for now........you've got rifle, powder and ball...... I say HAVE AT IT!!!

good luck

al

Jim Wooten
02-13-2010, 03:42 PM
Use more neck tension. Seat about .010 into the lands. Use the Lapua brass. Don't worry about the powder coming up the neck a bit, or about compressing the powder (sorry Al :)).

Jim

Charles E
02-13-2010, 03:53 PM
What bullet are you using? The "Robinett reamer" has zero freebore, and is designed to work with BIBs 112 or 118 (10 ogive for the latter) bullets. Powder halfway up the neck is just fine with these bullets.

If you are using a longer bullet (suggested by the 15-twist barrel), you might need to have a throater run in to give you a better fit of the bullet in the case.

The Wilson seater needs a hole drilled in it about the neck/body junction. Then clean up the burrs with the chamber reamer. "Vacuum" issue gone.

Edit: That should be "body/shoulder junction." Obviously, the neck and body don't "join" in a bottleneck case.

jackie schmidt
02-13-2010, 10:57 PM
The way I see it, you have turned your necks too thin. While most of us do use a little more neck clearance with our 30BR's than we do a 6PPC, .005 seems a little excessive.

I give mine .002 with a 112 BIB.

.........jackie

ConRich
02-14-2010, 01:31 PM
What bullet are you using ? You mentioned that the projectile was 0.3075", that is at least 0.001" smaller that the typical bullets used for that set-up.

Add to that what Jackie said about the necks being too thin and you end up with way too much clearance.

You might want to try some bullets that are around 0.3087" at the pressure ring to reduce the clearance.

Also, a bullet with a shorter jacket or one with a 10 ogive rather that a 7 ogive would help with the compression problem that you described.

Hope this helps,

Dick

alinwa
02-15-2010, 02:04 AM
Use more neck tension. Seat about .010 into the lands. Use the Lapua brass. Don't worry about the powder coming up the neck a bit, or about compressing the powder (sorry Al :)).

Jim

I got the impression that he didn't have the proper bushings ;)

I'm just trying to tell him to "shoot whatcha' brung" until he can sort out the details.

al

londonhunter
02-15-2010, 03:56 AM
Thank you for all your input

I think the next step I will try is to use more neck tension and reduce the load

I followed the advice on 6mmBR.com adn went straight to H4198 with 34.5 grain of powder. I will now start on 33.0 working myself up at 0.3 grain interval

All stockist in UK are out of 323 bushings so I will have to wait a week for new stock to arrive.

I think in the whole of UK there cannot be more than 03 04 04 people shooting a 30BR so there is a void in experience to advise me here

I will come back wth more results soon

I will also speak to the gun smith about reaming the wilson seating dies wth the same reamer. (BTW I own the reamer set)