STRANGE BARREL QUESTION

[rdsii640]

I have a rather weird question about the barrel of one of my bolt guns. This is an honest .5 to .6 inch rifle starting out. If I load up 100 rounds for a Saturday afternoon at the range, my rifle starts off shooting super tight. By the end of the day its shooting about 1.25 inch groups. Once I clean it, we are right back to .5 to .6 inch groups. What I don't understand is why it looses precision so quickly. My goal is to get through a range day with the nut behind the trigger being the only problem. I'm considering trying Tubbs Final finish but I'm not sure that is the right tool for the job. I know ahead of time that final finish won't work miracles. Any advise is greatly appreciated.

 

[Mike Casselton]

Is it a Savage?

 

[rdsii640]

Is it a Savage?

No its a Howa with a Mcgowan barrel.

 

[stanley_white]

What cartridge?

What ammunition?

-Stan

 

[Hawk in WY]

Is the barrel heating up?

Are you getting tired or dehydrated?

Don't clean the barrel before your next range session and see how it does.

 

[rdsii640]

What cartridge?

What ammunition?

Its a 223.
I'm shooting a 77 grain tmk handload

 

[stanley_white]

Its a 223.
I'm shooting a 77 grain tmk handload

Does the rifle do the same thing with factory ammunition?

-Stan

 

[rdsii640]

Is the barrel heating up?

Are you getting tired or dehydrated?

Don't clean the barrel before your next range session and see how it does.

I drink water through out the day. The barrel is 26 inches and .875 at the muzzle. I don't think its heat but I'm not an expert either.
Also, its a 223 so I don't think shooter fatigue is a problem but I could be wrong there too. This is a public range and they go cold every 15 minutes so I'm getting breaks through out the day.

 

[Ex E6]

Its a 223.
I'm shooting a 77 grain tmk handload

What powder and charge ,is all the powder being burned ?. How much crap is left in the bore when You clean it ? In particular how much copper is left behind ?

 

[rdsii640]

Does the rifle do the same thing with factory ammunition?

-Stan

I've never shot factory ammo with this rifle. It might worth an experiment though.

 

[rdsii640]

What powder and charge ,is all the powder being burned ?. How much crap is left in the bore when You clean it ?

I either run 23.8 grains of 8208 or 24.7 grains of LVR depending on whats in stock when I need powder.

 

[Ex E6]

You can try a bore mop with JB bore paste and run it through your barrel as if it were a Jag cleaning it . #15-20 times ,wash it and patch it out real good ,shoot an see what happens .

 

[rdsii640]

What powder and charge ,is all the powder being burned ?. How much crap is left in the bore when You clean it ? In particular how much copper is left behind ?

The patches come out super black when I start to clean. I usually soak the barrel first before I scrub.

 

[Ex E6]

I don't use either of those powders ,so can't say for sure as to their ability of cleanliness .

I use mainly VV powders these days but also use IMR 4064 , BlC-2 as Varget didn't work well out of My weapon . I'm also using a AR platform and VV 540 has given ME my best groups .300- .625 at 165 yd. . Closest target shed on My Rifle range . 165- 1144 Yd.

 

[Ex E6]

The patches come out super black when I start to clean. I usually soak the barrel first before I scrub.

NOT Blue as in copper fouling ?. Black suggest possibly excessive powder either NOT burning or burning down the bore ?. LOOK closely and see if any unspent powder residue is present . Are You getting any Soot around necks of cartridges ?.

Normally most precision Rifles prefer fouling ,so as to settle in a conditioned bore . There are always exceptions too the rule .

 

[cas6969]

By the end of the day its shooting about 1.25 inch groups. Once I clean it, we are right back to .5 to .6 inch groups.

I have one that goes from 3/4 MOA to 7MOA somewhere between 15 and 20 rounds.

(LOTS-O-PITTING in the barrel)

 

[rdsii640]

NOT Blue as in copper fouling ?. Black suggest possibly excessive powder either NOT burning or burning down the bore ?. LOOK closely and see if any unspent powder residue is present . Are You getting any Soot around necks of cartridges ?.

Normally most precision Rifles prefer fouling ,so as to settle in a conditioned bore . There are always exceptions too the rule .

The next time I clean I will make sure to look to see if the patches are black or blue.

 

[Baron23]

Black suggest possibly excessive powder either NOT burning or burning down the bore ?. LOOK closely and see if any unspent powder residue is present . Are You getting any Soot around necks of cartridges ?.

I’ve always rather thought black was carbon and brown was powder fouling.

But I’m willing to be wrong about this.

 

[jbell]

Did you buy the barrel new? Who chambered it? How many rounds on the barrel & has it done this from day 1? Do you clean after every range session / 100 rounds / have you taken it past the 100 round point before cleaning it? If you haven’t I would definitely see what happens after 150 - 200…

 

[Chickentoast]

Suggest swab it at the range as soon as it falls off.

 

[Changed]

In my opinion, nearly all issues of this nature are caused by the shooter. That is the first place I always look.

If you are shooting 100 rounds at a sitting, and trying to get super small groups, I would say you are probably experiencing shooter fatigue.

If that is not the case, you may not allow sufficient time for the barrel to cool. As barrels warm, they can/will open up. Especially if in long strings of fire.

 

[Ex E6]

I’ve always rather thought black was carbon and brown was powder fouling.

But I’m willing to be wrong about this.

Spent smokeless powder is carbon residue ( Black ) ,excessive can be a sign of incomplete burning or improper powder per charge ,even a primer or ignition problem . There's a happy medium . Certain powders are " Dirtier" than others ,as more burn inhibitors ,graphite and even copper reducing agents can leave residue . They DON'T eliminate carbon or enhance powder burning .
Brown and or particles mixed with black residue would certainly indicate incomplete burning ,aka powder fouling .

It's a catch 22 without actually seeing a close up of bore or patches , As so many factors contribute .

I'll also add specific charges do better in longer barrels ,as in certain instances power burn is too slow for shorter barreled weapons .

 

[Baron23]

Spent smokeless powder is carbon residue ( Black ) ,excessive can be a sign of incomplete burning or improper powder per charge ,even a primer or ignition problem . There's a happy medium . Certain powders are " Dirtier" than others ,as more burn inhibitors ,graphite and even copper reducing agents can leave residue . They DON'T eliminate carbon or enhance powder burning .
Brown and or particles mixed with black residue would certainly indicate incomplete burning ,aka powder fouling .

It's a catch 22 without actually seeing a close up of bore or patches , As so many factors contribute .

I'll also add specific charges do better in longer barrels ,as in certain instances power burn is too slow for shorter barreled weapons .

I got this idea first off of a bottle of Patch Out (though I've settled on Bore Tech products) and I got it backwards. From their site:

​

"Powder fouling (both smokeless powder and black powder) will be grayish black on the patch. Copper fouling will be deep navy blue. Carbon will be tannish to brown in color"​

​

Now, whether this ^^ is accurate or not I can't say.

 

[supercorndogs]

I had some trouble with sevral McGowan barrels in a row. They could not make me a barrel with either end threaded correctly over three tries. Did they make your barrel or just the blank? Do you have a picture of the tenon threads? Is stuff moving around when it gets hot because the tenon threads are so sloppy?

 

[jbell]

I had some trouble with sevral McGowan barrels in a row. They could not make me a barrel with either end threaded correctly over three tries. Did they make your barrel or just the blank? Do you have a picture of the tenon threads? Is stuff moving around when it gets hot because the tenon threads are so sloppy?

That is exactly why I asked who chambered it. I had a good friend go through a few as well and I helped him diagnose the inconsistency on all of them. Not my 1st choice for a barrel…

 

[Ex E6]

I got this idea first off of a bottle of Patch Out (though I've settled on Bore Tech products) and I got it backwards. From their site:

​

"Powder fouling (both smokeless powder and black powder) will be grayish black on the patch. Copper fouling will be deep navy blue. Carbon will be tannish to brown in color"​

​

Now, whether this ^^ is accurate or not I can't say.

Well carbon is BLACK ,as in a pencil lead , valve on an combustible engine or top of pistons . I can assure you it's black unless it's put under tremendous pressure ,then it becomes transparent or nearly so as in a diamond but all diamonds aren't clear or transparent .
I have a Yellow diamond as well as a blue diamond .

 

[rdsii640]

I had some trouble with sevral McGowan barrels in a row. They could not make me a barrel with either end threaded correctly over three tries. Did they make your barrel or just the blank? Do you have a picture of the tenon threads? Is stuff moving around when it gets hot because the tenon threads are so sloppy?

They made the complete barrel. I didn't take any pics of the threads.

 

[jbell]

I would ask McGowan to evaluate the barrel and if they don’t then like you said I would shoot Tubbs Final Finish through it. Can’t hurt at this point…

FinalFinish® & FinalFinish® TMS Bullet Kits

By using David Tubb's FinalFinish & FinalFinish TMS Bullet Kits, you will experience better accuracy, reduced fouling and easier barrel clean up.

www.davidtubb.com

 

[supercorndogs]

I woukd take it apart and post some pics here for people to look at. McGowan assured me they measured all threads multiple times before they left their shop and there was no way my threads were undersized or bad. They told me I coukd send it in if I wanted but that there nothing wrong with it.