Barrel scope around town?

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Barrel scope around town?

Postby Bergie on Wed Aug 03, 2022 10:15 am

Last night was at the 200yrd range firing prone (slow) w/service rifle using my meticulously loaded rounds (69gr SMK, LC brass, CCI primer, 25.3gr RE15). First and second shots were 7s at 11:00. (Which is weird because a week earlier it was dialed in) Regardless, the second shot -according to the ShotMarket- said the velocity greatly varied from the sighters and first shot for record. The SD was at a whopping 1100! I dialed down the scope and was placing them in the 10s and on some I called Xs but got 9s all around the clock. The ending SD was at 131. Just weird- given the position, distance, rounds, etc, all my shots should have been in the 10 at least and the SD would be low teens or so.
I used steel pins to clean my brass and my mentor said if a pin is stuck in the case then goes down the barrel, it'll wreak havoc. I'm wondering if that happened, so want to scope the barrel. Is there anyone in town that scopes barrels or has a scope I can borrow?
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Re: Barrel scope around town?

Postby Erud on Thu Aug 04, 2022 6:55 am

Barrel damage could cause poor accuracy, but it wouldn't cause the numbers. I've heard the stories about pins down the barrel, but I've never experienced it. I wet tumbled with pins for 10 years or so while shooting at a fairly high level, and never saw anything like that actually happen in my guns or anyone else's. As often as I'd find loose pins in random places, I can't imagine that one never made it down the barrel. At any rate, I eventually went back to dry tumbling because I didn't find any benefit on target to make all of the extra wet tumbling work worthwhile.

Did you change anything since the last time you shot this rifle/ammo combo? For really major variations in velocity, inconsistent neck tension is usually the place to start looking. No idea how long you've been doing this or what level you are at, so just making general suggestions. I have run ammo over the chrono from back when I first started shooting SR in 2007, and got legit SD's of 100-150 fps. I've learned a lot since then, but at the time I didn't know what I didn't know. The HP targets are pretty huge though, so imperfect ammo is usually pretty far down the list of things causing lost points. Keep in mind that the chrono feature on a Shotmarker is good for general reference at best, and there's a lot of things happening between the muzzle and those 8 microphones to add noise to the data even at only 200 yards. An SD of 1100 would be almost impossible to actually have in real life without blowing something up, so I would not trust that number at all.

I do have a Hawkeye borescope I could loan you if you wanted to look down the barrel, or you might look into picking up one of the Teslong scopes. They are cheap (like $60 for USB version) and easy to use, they've pretty much made the Hawkeye obsolete. Here's a link:

https://teslong.com/collections/borescopes

Good luck!
Last edited by Erud on Thu Aug 04, 2022 12:40 pm, edited 1 time in total.
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Re: Barrel scope around town?

Postby hard h2o on Thu Aug 04, 2022 11:07 am

There are a lot of things that can go wrong. It is a bit of a leap to just go right to SS pin down the bore.
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Re: Barrel scope around town?

Postby crbutler on Thu Aug 04, 2022 12:51 pm

Another point on a borescope is that there is a pretty steep learning curve related to interpretation of the images.

I’ve looked at bores and thought various things, then have a gunsmith look at the same thing and tell me I was all wet.

The biggest reason I use one is to see if I got the barrel clean.
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Re: Barrel scope around town?

Postby Erud on Thu Aug 04, 2022 12:58 pm

crbutler wrote:Another point on a borescope is that there is a pretty steep learning curve related to interpretation of the images.

I’ve looked at bores and thought various things, then have a gunsmith look at the same thing and tell me I was all wet.

The biggest reason I use one is to see if I got the barrel clean.


This is a very good point. I've had mine for about 10 years, and I can't say I've ever seen any conclusive correlation between a barrel's appearance and how it shoots. I've had some really ugly barrels that shot great. One thing the bore scope did teach me is that there really isn't any reason to worry about copper fouling. I've been through 9 different .308 barrels shooting basically the same load, and some held copper and others didn't. Every one of them shot great, at least by my standards. I really don't even use the bore scope anymore.
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Re: Barrel scope around town?

Postby Erud on Thu Aug 18, 2022 10:37 pm

So, did you get this figured out?
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