Over length question - rifle

taybri · March 8, 2009, 12:50 AM

I've loaded many thousands of straight wall pistol, but I'm new to rifle. I'm trying to develop and accurate load for my Winchester model 70 in .270. I borrowed a tool (bullet comparator?) for measuring the size of the chamber in hopes of finding an ideal cartridge length, but I learned the magazine is the limiting factor (chamber is deeper that the max oal 3.34in.)

I'm loading 130 gr Sierra Game King spitzer boat tail bullets over a staritng load of 50.5 grains of IMR 4831.

Here's the question: Should I load them at 3.34 or some shorter length. They seem to stand way out of the case at this length. Should I crimp?

Thanks,
Brian

rwilson452 · March 8, 2009, 01:07 AM

If the magazine size is the limiting factor and you don't want to load the rifle as a single shot then you would set the length as long as you can get them in the magazine. If you still have the tool check it again as you don't want the bullet against the lands but close. Usually the best accuracy is found when the bullet is .015-.030 off the lands. so when you check it be sure you not pushing the bullet into the lands but just barely touching.

Personally I work a new load starting a SAMMI spec length and work with the powder load first to get the best accuracy that way and then start working OAL.

Quote:

Over length question - rifle
I've loaded many thousands of straight wall pistol, but I'm new to rifle. I'm trying to develop and accurate load for my Winchester model 70 in .270. I borrowed a tool (bullet comparator?) for measuring the size of the chamber in hopes of finding an ideal cartridge length, but I learned the magazine is the limiting factor (chamber is deeper that the max oal 3.34in.)

I'm loading 130 gr Sierra Game King spitzer boat tail bullets over a staritng load of 50.5 grains of IMR 4831.

Here's the question: Should I load them at 3.34 or some shorter length. They seem to stand way out of the case at this length. Should I crimp?

Thanks,
Brian

jamaica · March 8, 2009, 01:08 AM

I load for the 270. My hornady manual calls for a length of 3.210 with the 130 grain bullet. This works fine for me. Don't crimp.

In many cases, the magazine is the limiting factor on length. They have to work in the gun.

I would never have them so long that they hit the lands. I feel it is better if they have around 0.020 movement before hitting the lands.

I think you picked a good powder. That has been a good one for me.

March 8, 2009, 12:50 AM	#1
taybri Member Join Date: July 7, 2006 Location: Utah Posts: 18	Over length question - rifle I've loaded many thousands of straight wall pistol, but I'm new to rifle. I'm trying to develop and accurate load for my Winchester model 70 in .270. I borrowed a tool (bullet comparator?) for measuring the size of the chamber in hopes of finding an ideal cartridge length, but I learned the magazine is the limiting factor (chamber is deeper that the max oal 3.34in.) I'm loading 130 gr Sierra Game King spitzer boat tail bullets over a staritng load of 50.5 grains of IMR 4831. Here's the question: Should I load them at 3.34 or some shorter length. They seem to stand way out of the case at this length. Should I crimp? Thanks, Brian

March 8, 2009, 01:08 AM	#3
jamaica Senior Member Join Date: March 24, 2006 Location: Northern Utah Posts: 705	I load for the 270. My hornady manual calls for a length of 3.210 with the 130 grain bullet. This works fine for me. Don't crimp. In many cases, the magazine is the limiting factor on length. They have to work in the gun. I would never have them so long that they hit the lands. I feel it is better if they have around 0.020 movement before hitting the lands. I think you picked a good powder. That has been a good one for me.