Question for Reloaders

triman5 · August 2, 2009, 12:53 PM

I bought some Magtech .308 150g FMJ and they make the bolt difficult to open and close. I do not have equipment to measure the base to shoulder length which seems like the most logical place for the problem. I did check the OAL though, and they are all .004 to .007 over the max SAAMI spec which I believe is 2.800. Can anyone give me any insight as to what might be causing the problem? I have run many other brands through the rifle with no issues. Any insight would be appreciated.

brickeyee · August 2, 2009, 01:02 PM

Color the shoulders of a round with a marker, then chamber and eject it a couple times.

Look for places on he case the marker has been scratched through.

SL1 · August 2, 2009, 01:12 PM

It is POSSIBLE that the bullets are touching the rifling instead of the case shoulder being too long. IF that is the situation, it will increase pressure, so you should be cautious here.

It is unusual to find factory ammo over SAAMI max length specification, so I don't know what to expect. And, a substantially different bullet nose shape can make the bullet hit the rifling even though the cartridge overall length is below spec. So, since this may be European ammo (and not subject to SAAMI spec) there may be several factors to consider. (Magtech is listed in Germany as well as Minnesots, and is owned by CBC in Brazil. CBC also bought S&B in the Czech Republic, so I have no idea what standards are being followed with that ammo.) Also, are you sure they are Magtech factory ammo and not somebody's reloads using Magtech cases?

One thing you can check is the bullets after you try to chamber them and pull them back out of the gun. Are there any scratch marks on the bullets near where they start tapering from full diameter down towards the pointed nose. If there are scratches at that point, that is a clear sign that the bullets are being jammed into the rifling and pressure would be unusually high if you fired them.

SL1

triman5 · August 2, 2009, 05:18 PM

Thanks for the pointers. I'll definitely check it out.

brickeyee · August 3, 2009, 08:42 AM

You can color the bullet with a marker also.

It will make any contact with the lands very easy to see.

August 2, 2009, 12:53 PM	#1
triman5 Member Join Date: June 7, 2009 Location: Out West Posts: 18	Question for Reloaders I bought some Magtech .308 150g FMJ and they make the bolt difficult to open and close. I do not have equipment to measure the base to shoulder length which seems like the most logical place for the problem. I did check the OAL though, and they are all .004 to .007 over the max SAAMI spec which I believe is 2.800. Can anyone give me any insight as to what might be causing the problem? I have run many other brands through the rifle with no issues. Any insight would be appreciated.

August 2, 2009, 01:12 PM	#3
SL1 Senior Member Join Date: November 8, 2007 Posts: 2,001	It is POSSIBLE that the bullets are touching the rifling instead of the case shoulder being too long. IF that is the situation, it will increase pressure, so you should be cautious here. It is unusual to find factory ammo over SAAMI max length specification, so I don't know what to expect. And, a substantially different bullet nose shape can make the bullet hit the rifling even though the cartridge overall length is below spec. So, since this may be European ammo (and not subject to SAAMI spec) there may be several factors to consider. (Magtech is listed in Germany as well as Minnesots, and is owned by CBC in Brazil. CBC also bought S&B in the Czech Republic, so I have no idea what standards are being followed with that ammo.) Also, are you sure they are Magtech factory ammo and not somebody's reloads using Magtech cases? One thing you can check is the bullets after you try to chamber them and pull them back out of the gun. Are there any scratch marks on the bullets near where they start tapering from full diameter down towards the pointed nose. If there are scratches at that point, that is a clear sign that the bullets are being jammed into the rifling and pressure would be unusually high if you fired them. SL1 Last edited by SL1; August 2, 2009 at 01:30 PM.

August 2, 2009, 01:02 PM	#2
brickeyee Senior Member Join Date: December 29, 2004 Posts: 3,351	Color the shoulders of a round with a marker, then chamber and eject it a couple times. Look for places on he case the marker has been scratched through.

August 2, 2009, 05:18 PM	#4
triman5 Member Join Date: June 7, 2009 Location: Out West Posts: 18	Thanks for the pointers. I'll definitely check it out.

August 3, 2009, 08:42 AM	#5
brickeyee Senior Member Join Date: December 29, 2004 Posts: 3,351	You can color the bullet with a marker also. It will make any contact with the lands very easy to see.