Can my measurements be correct?

[mrawesome22]

Quote from 918v "I take a new case, FL size it, and use a dremel to cut a slit through the neck and into the shoulder. I then insert a bullet, chamber and close the bolt. I carefully eject, and measure the oal. I keep these together as a reference and to track throat erosion." I did this friday evening and it worked great. After I did this I decided I was going to start out .015" away from the rifling. Only problem is the C.O.L. on a .22-250 is listed at 2.350". At .015" off the lands my C.O.L. is 2.425". That's .075" longer than listed specs . Can this be? Did I do something wrong? I know .075" is just slightly longer than 1/16" but this seems like a lot. Another thing is with this measurement I don't think I'll be able to shoot 40gr. bullets. The 50gr. Nosler Ballistic tips are only seated about 1/8" into the neck so I doubt 40 grainers would even be seated at all What yall think?

 

[deadin]

Sounds like you already have some throat erosion. (or your barrel/chamber is set up with freebore.)
Is it 22/250's that are notorious for eating barrels?

Dean

 

[mrawesome22]

Well it is a stock 700VLS factory barrel and only has about 80 rounds through it. Would Remington give it that much freebore for safeties sake or something?

 

[Shoney]

First, are you sure the bullet did not stick in the lands and pull out of the case just a hair???? Try a dummy case in that length and slowly close the bolt as a test. If the bold closes with no resistance, no difficulty in closing, the length is at least not touching the lands. Now remove that bullet from the chamber and make sure the OAL didn't change, in case it is touching and is being set back.

Also, you don't mention the bullet you are using. The ogive of bullets vary. Ogive is the curve of a bullet. When you are measuring for the max OAL (the split case method for one) it is where the ojive touches the lands. For instance, the ojive of a round nose bullet will give a relatively shorter OAL than a spire point. So when you use different bullets, either in weight, or in design, or brand, you will nead to remeasure the OAL for that bullet.

 

[Nortonics]

I believe your measurements are accurate, and I believe you'll be just fine with how you're thinking.

OAL in the rifle field is really telling you the max OAL that you can use in order to assure proper magazine fed ammo (as in a hunting scenario). This allows the ammo to feed up correctly within the magazine to the chamber, without the bullet tips getting snagged. Obviously when you handload ammo so close to the lands you'll be inserting one cartridge directly into the chamber one at a time, firing, ejecting the case, then inserting another single cartridge and doing it all over again - totally normal and generally safe, as long as you understand the pressure differences in doing so, and not loading your ammo so hot as to exceed the pressure capability of your rifle.

I too handload my Savage .243 just off the lands, and sometimes right on the lands, and yes the OAL of those cartridges are much longer than what you see published in the books. Generally speaking, all the accuracy minded and benchrest shooters do this just about 100% of the time. For some great detail on these factors check out the forums at benchrest.com and/or 6mmbr.com for lots of good additional information on this practice...

 

[firechicken]

I shoot Nosler 130 gr Ballistic Tips in my 700 BDL 270. I load them to an overall length of 3.420". If I remember correctly, that's about .030" off the lands. Listed maximum OAL for the 270 Win. is 3.340". And they still fit in my magazine. Ballistic Tips are very long/slender bullets. In most rifles you can't get them close to the lands while still fitting in the magazine.

 

[mrawesome22]

Shoney, yes I'm sure it didn't stick in the lands. I seated a live round at 2.425" just to make sure it would chamber and it chambered perfectly. Yes I know ogive will change with EVERY different bullet brand and weight. The bullet is a 50gr Nosler Ballistic Tip, .224" diameter. Glad to here someone else does this too Nortonics. I figured this was normal but just wanted to be sure. But if I want to shoot 40gr bullets am I going to just have to seat way off the lands and hope for accuracy? Seems to me that the closer the ogive was to the lands, the more accurate it should be. Am I correct in that assumption?

 

[Shoney]

Seems to me that the closer the ogive was to the lands, the more accurate it should be. Am I correct in that assumption?

Not necessarily, there are to many variables. For example, the twist of the rifling may not be compatible with a 40 gr no matter the OAL. You just have to try.

I have tried Barns X 50 gr in my 222 at all concievable OAL and loads (primer powder varients), and they just will not group. Yet Hornady 50, 52, 53 , and 55 gr bullets group at 0.19 to 0.38 at 100 yrds, each with little change in group with OAL slight changes.