Better And Better

If you don't draw yours, I won't draw mine.

Monday, January 29, 2007

Rifles

Things warp when they change temperature.
Things like, say, rifle barrels, which warp at different rates than wooden stocks.

When it's cold out (like, say-- 38 degrees), the difference between the inside of a rifle barrel and the outside (except where the barrel is shrouded in wood) is more pronounced.

This interferes with accuracy.

This REALLY interferes with accuracy when the barrel in question is extremely lightweight, and the temperature rises quickly.

From, say, a significant centerfire cartridge like the .30-'06.

Now-- let's say that you pick up the rifle for the first time in years, and go to qualify with it, and discover that it's 2.5" left and an inch lower than you wanted at 100 yards? Why, you'd take the extra cartridges that you brought, and sight it in, wouldn't you?

First two shots-- cover with a dime. Next shots-- cover with a quarter. At 6 shots-- cover with a silver dollar. At 10 shots-- cover with, oh... a dollar bill. Gawd.

While waiting for the too-hot-to-touch barrel to cool, the rangemaster said to me: "I gotta close up in 15 minutes."

So I qualified with 20 rounds in 15 minutes. It wasn't pretty. 10 rounds at 100 yards, and 10 rounds from 50. Even with a superb rest or a rock-solid prone, my rounds at this point weren't going too terribly closely to where I wanted them to. Sure, the Ruger M77 super lightweight contour barreled rifle topped with an older Redfield scope may not be the choice of snipers everywhere, but this one is actually capable of some pretty decent cold-barrel groups. Unfortunately, that requires a degree of slow fire that I just didn't have the luxury to enjoy today.

The targets were various tombstones of 2 to 4 inches in height. Should have been a snap. I think I missed black on 4 or 5. I've got it in the car, enshrouded in shame. I'm not sure I can bring myself to turn it in.

Oh, the shame!

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7 Comments:

At Monday, January 29, 2007 9:24:00 PM, Anonymous MauserMedic said...

Which target were you trying to qualify on? It sounds like the 25 meter M-16 target. Never shot them myself, but saw them frequently during annual qual.

 
At Tuesday, January 30, 2007 12:56:00 AM, Blogger Matt G said...

Yup. That's the one.

It's worse than I thought-- there's a 6th one out.

I'm not going to shame myself by turning this in.

On the positive side, I found that my assigned department CAR-15, with Eotech, YHM backup sights, tac sling and Surefire fore end was easy to squeeze decent performance out of. Off-hand chest shots at 100 yards felt smooth and easy. During sight-in, I found that the fine aperture on the BUS allowed me to put 4 shots into a widening single hole at 25 yards. Not impressive? No, not really... But reassuring.

This was my first time with Eotechs, and I was impressed at how easy sight-in was with it. It provides no real benefit at 25 yards, but at 50+ offhand, it makes shooting a snap.

The rig is in a very decent Blackwater zippered case, and I recommend them. The Blackwater case is clean and tough, and provides good protection.

 
At Tuesday, January 30, 2007 7:37:00 AM, Anonymous Anonymous said...

Try removing enough wood around the barrel to free float it. You might have a pressure point that is shoving you off center.A glass bedding of the action would help as well.

Thad

 
At Tuesday, January 30, 2007 10:37:00 PM, Blogger Matt G said...

Well duh, Thad! :)

What, you think I should have actually (smirk) prepared for the qualification? Gah!

This rifle really can turn in 1.25 to 1.5 MOA goups, but they have to be cold barrel. That makes a 20 round qualification take about an hour.

At any rate, I'll probably get out the 40 grit paper and a dowel later.

 
At Wednesday, January 31, 2007 5:18:00 PM, Anonymous Al T. said...

FWIW, I agree that free floating will probably help. Then again, running a nice sporter that fast is a lot to expect. If time is a factor, I'd think about means of cooling the barrel between strings. Maybe take a funnel and some water to pour through. That could be an interesting experiment.

 
At Thursday, February 01, 2007 12:29:00 AM, Blogger Matt G said...

Yeah, I know how to free float-- it's a pain to do it right, though.

Really, the easiest way to cool a barrel would probably be just using a can of compressed air, and let the gas expansion drop the temp.

 
At Thursday, February 01, 2007 8:39:00 PM, Anonymous Al T. said...

I thought of the air bit. I'm not sure (as in - I haven't tried it yet) that it's faster than water. I see a range day with my M70 and air/water on hand.. :)

 

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