.010 from the lands. Too close for hunting?

30 December 2005, 04:00

Matt Norman

I think the .030 number is just a good "rule of thumb" standard. If you are certain you are .010, aren't living on the edge pressure-wise, and it fits the magazine and feeds fine, then you have nothing to worry about.

That said, I once cut it a bit too fine and stuck a bullet in the throat while afield. Happened when I was extracting an unfired round in a 6x47 that had a tightly cut chamber. Had to hike back to my pick-up (no big deal) to retrieve a cleaning rod. Lesson learned.

Make sure you have .010 on each round!

Frank

"I don't know what there is about buffalo that frightens me so.....He looks like he hates you personally. He looks like you owe him money."
- Robert Ruark, Horn of the Hunter, 1953

NRA Life, SAF Life, CRPA Life, DRSS lite

Mike

Legistine actu quod scripsi?

Never under estimate the internet community's ability to reply to your post with their personal rant about their tangentially related, single occurrence issue.

What I have learned on AR, since 2001:
1. The proper answer to: Where is the best place in town to get a steak dinner? is…You should go to Mel's Diner and get the fried chicken.
2. Big game animals can tell the difference between .015 of an inch in diameter, 15 grains of bullet weight, and 150 fps.
3. There is a difference in the performance of two identical projectiles launched at the same velocity if they came from different cartridges.
4. While a double rifle is the perfect DGR, every 375HH bolt gun needs to be modified to carry at least 5 down.
5. While a floor plate and detachable box magazine both use a mechanical latch, only the floor plate latch is reliable. Disregard the fact that every modern military rifle uses a detachable box magazine.
6. The Remington 700 is unreliable regardless of the fact it is the basis of the USMC M40 sniper rifle for 40+ years with no changes to the receiver or extractor and is the choice of more military and law enforcement sniper units than any other rifle.
7. PF actions are not suitable for a DGR and it is irrelevant that the M1, M14, M16, & AK47 which were designed for hunting men that can shoot back are all PF actions.
8. 95 deg F in Africa is different than 95 deg F in TX or CA and that is why you must worry about ammunition temperature in Africa (even though most safaris take place in winter) but not in TX or in CA.
9. The size of a ding in a gun's finish doesn't matter, what matters is whether it’s a safe ding or not.
10. 1 in a row is a trend, 2 in a row is statistically significant, and 3 in a row is an irrefutable fact.
11. Never buy a WSM or RCM cartridge for a safari rifle or your go to rifle in the USA because if they lose your ammo you can't find replacement ammo but don't worry 280 Rem, 338-06, 35 Whelen, and all Weatherby cartridges abound in Africa and back country stores.
12. A well hit animal can run 75 yds. in the open and suddenly drop with no initial blood trail, but the one I shot from 200 yds. away that ran 10 yds. and disappeared into a thicket and was not found was lost because the bullet penciled thru. I am 100% certain of this even though I have no physical evidence.
13. A 300 Win Mag is a 500 yard elk cartridge but a 308 Win is not a 300 yard elk cartridge even though the same bullet is travelling at the same velocity at those respective distances.

01 January 2006, 20:26

Jaywalker

It depends a lot on the bullet. If you stay with a premium bullet, you'll be fine. If you buy Speer, for instance, you might run into trouble.

A couple of years ago, with too much time on my hands, I measured the Ogive Length (OL) of a box (100) of Speer 140g .264 bullets. They were not very uniform. The OL varied from 0.429" to 0.442," a spread of 0.013". For comparison, Hornady Interlocks varied 0.006", and Nosler Partitions varied 0.001", IIRC.

This Speer variance is greater than the 0.010" you described. If you measured a short OL for one bullet and set your bullet seater for it, some of the longer OLs would be closer to the lands. Some might even be touching. (My seaters, at least, do not push on the Ogive, and therefore have to be reset for each bullet, even though I plan the same 0.030" jump to lands for each bullet.)

As much as I enjoy 0.4" groups with my hunting rifles, I tend to ease the tolerances off a bit for hunting. A bit more headspace ensures the catridge will chamber, even in the face of biomass (twigs, dirt) in the action, and a bit more jump to lands ensures no nasty pressure events while you're far from your truck.

Jaywalker

02 January 2006, 03:02

Bear in Fairbanks

Andy:
If you're feeding them from the magazine and they chamber, they should be just fine. I normally load my hunting cartridges to 0.010" off the lands. If I'm loading a box to take on a hunting trip I run every cartridge thru the chamber afterwards to make sure there are no problems however if I'm going to the range, I don't. I'd probably be considered anal about seating depth but I use competition seating dies and ALWAYS measure length to the ogive and NOT the OAL. As was mentioned above,you'd be surprised at the variation in bullet length of some of the manufacturers.
Bear in Fairbanks