C.O.A.L. for .270 Browning Bar MK II Safari


PDA






atonguis
January 4, 2012, 07:39 PM
I have a bunch of Sierra bullets (Game King I think) #1835 140 gr. HPBT, Sierra's manual lists that bullets coal at 3.265 and although that will easily fit the magazine when I chamber a dummy round I dang near have to beat the receiver open because it jams the bullet into the lands and marks/scuffs it up. I colored the bullet black and when I eject the round there are 4 clean square marks where the color was rubbed off. I have re-colored and incremented the bullet seating down to 3.208 and there is 2 clean marks on the bullet now not 4.

Is this common for this bullet design ? and or rifle? Should I keep seating down further until the marks dis-appear?

I can provide pics if needed, I have some Nosler 140 gr. Ballistic Tips and I can seat those much farther out with no marks but Nosler does not provide col in their manuals just charge weights vs fps.

I full length sized the New (Winchester) Brass with RCBS small base dies.

I have never loaded for this rifle before.

If you enjoyed reading about "C.O.A.L. for .270 Browning Bar MK II Safari" here in TheHighRoad.org archive, you'll LOVE our community. Come join TheHighRoad.org today for the full version!
ROCKFISH
January 4, 2012, 08:09 PM
The COAL listings are more like suggestions. You need to determine the best fit for your rifle-cartridge-bullet configuration. I would back off a few thousandths from the lands.

rcmodel
January 4, 2012, 08:18 PM
Should I keep seating down further until the marks dis-appear?Yes!!!

Fo Sure!!

rc

NeuseRvrRat
January 4, 2012, 08:21 PM
hornady makes a COAL gauge for semi-autos that makes the process of getting just off the lands much easier.

rcmodel
January 4, 2012, 08:28 PM
Forget "just off the lands".

For a hunting semi-auto, you want 110% positive function, and no possible chance of a long load hanging you up with a stuck round you can't get out 100 miles from home.

The most accrate factory ammo loaded in the world is Varmint and Match ammo.

And they could give a rats axx where your lands are, as long as they are SAAMI spec or longer.

rc

kelbro
January 4, 2012, 08:41 PM
If you are shortening the length from the recommended COAL, you had better not be at the max charge. You didn't mention your load but any time you reduce the case volume, your max powder charge should also be reduced to compensate.

atonguis
January 5, 2012, 06:46 PM
The COAL listings are more like suggestions. You need to determine the best fit for your rifle-cartridge-bullet configuration. I would back off a few thousandths from the lands.


Just wondering how the Nosler manual can list charge weight with fps without a coal ?

atonguis
January 5, 2012, 06:48 PM
Forget "just off the lands".

For a hunting semi-auto, you want 110% positive function, and no possible chance of a long load hanging you up with a stuck round you can't get out 100 miles from home.

The most accrate factory ammo loaded in the world is Varmint and Match ammo.

And they could give a rats axx where your lands are, as long as they are SAAMI spec or longer.

rc


If I load to SAAMI spec for this particular bullet it jams in the lands, I am wondering if these bullets are off?

atonguis
January 5, 2012, 06:53 PM
If you are shortening the length from the recommended COAL, you had better not be at the max charge. You didn't mention your load but any time you reduce the case volume, your max powder charge should also be reduced to compensate.

Well, that is what I am alluding too. I am not sure where to start with these bullets as they are so far off from what the sierra manual lists for that powder and charge.

I have RL22 and H4831SC to use for this .270 but that particular bullet has to be seated at least .060 thousandths shorter than what they list in their manual for it not to touch the lands, kinda scares me to even use the lowest charge they list. Maybe I should just put those bullets away and use the ones that do come close to what the different manuals list as COAL. Its just that I have several hundred of them and hated for them to go to waste.

kelbro
January 5, 2012, 07:42 PM
The bullet length is usually in the specs.

Did you just buy the rifle?

Have you tried to chamber a factory round?

If it is just short throated, I would start at the start load and work up. .060 isn't that extreme.

Coltdriver
January 5, 2012, 07:51 PM
The number one thing I have learned in my very few short years of reloading rifles is that you must learn your chamber dimensions.

I totally ignore what any reloading manual says. Every bullet you use will have a different potential col. And as you have found following a manual and getting a length that fits your magazine can absolutely be too long.

You are on the right track with learning by inserting a blackened bullet. Keep going and be prepared to do this for every different bullet you reload.

Or get a Stoney Point/Hornady length gauge. Best reloading investment I ever made. Makes simple, easy fast and accurate work of recording bullet types and the col you can use.

243winxb
January 5, 2012, 09:44 PM
SAAMI COL for 270 win. is 3.065" to 3.340" http://www.saami.org/PubResources/CC_Drawings/Rifle/270%20Winchester.pdf

atonguis
January 6, 2012, 09:36 AM
The bullet length is usually in the specs.

Did you just buy the rifle?

Have you tried to chamber a factory round?

If it is just short throated, I would start at the start load and work up. .060 isn't that extreme.

It was given to me, ( only used for one season and not a scratch on it) and I did chamber a rem 130 grn soft point and it went in perfectly but the bullet ogive is different from those sierra HPBT and the coal on that factory round is 3.230

atonguis
January 6, 2012, 09:37 AM
SAAMI COL for 270 win. is 3.065" to 3.340" http://www.saami.org/PubResources/CC_Drawings/Rifle/270%20Winchester.pdf

Thank You for this info.

If you enjoyed reading about "C.O.A.L. for .270 Browning Bar MK II Safari" here in TheHighRoad.org archive, you'll LOVE our community. Come join TheHighRoad.org today for the full version!