A couple of questions after cleaning Benchrest guns

T

thekubiaks

New member
I had an interesting result after deep cleaning my (2) 6.5x284 benchrest guns, both have Krieger barrels. Looking at the barrels with a borescope I could see some baked in carbon that was being very stubborn and didn't want to come out. The guns were shooting .20 to ,25 MOA so I was happy. I scrubbed them with C4 and IOSSO and finally got them spotless.

The question is, after cleaning, my velocities dropped about 20fps and the nodes changed. Is this a result of the clean barrels not having as much restriction? I'm stumped. The accuracy opened up to about .40 MOA, I think I will have to rerun my ladder tests.

Any ideas??

Thanks
 
thekubiaks said:
I had an interesting result after deep cleaning my (2) 6.5x284 benchrest guns, both have Krieger barrels. Looking at the barrels with a borescope I could see some baked in carbon that was being very stubborn and didn't want to come out. The guns were shooting .20 to ,25 MOA so I was happy. I scrubbed them with C4 and IOSSO and finally got them spotless.

The question is, after cleaning, my velocities dropped about 20fps and the nodes changed. Is this a result of the clean barrels not having as much restriction? I'm stumped. The accuracy opened up to about .40 MOA, I think I will have to rerun my ladder tests.

Any ideas??

Thanks
Click to expand...

It is pretty common for a thoroughly cleaned barrel to not behave as desired.
Dirty it up a little bit.
It is what 'fouling shots' are designed to do.
 
Last edited:
brickeyee said:
It is pretty common for a thoroughly cleaned barrel to not behave as desired.
Dirty it up a little bit.
It is what 'fouling shots are designed to do.
Click to expand...

Thanks for the reply. I follow F-Class guys like Erik Cortina and he says he cleans his gun between every event which is usually 20 - 40 rounds. So perhaps he has found the node in a spotless barrel. The PRB guys on the other hand don't clean their guns for many hundreds of rounds. I am just looking for consistency and need to keep the gun very clean or not clean it as thoroughly if it is shooting .20"
 
thekubiaks said:
Thanks for the reply. I follow F-Class guys like Erik Cortina and he says he
cleans his gun between every event which is usually 20 - 40 rounds. So perhaps he has found the node
in a spotless barrel. The PRB guys on the other hand don't clean their guns for many hundreds of rounds.
I am just looking for consistency and need to keep the gun very clean or not clean it as thoroughly if it is shooting .20"
Click to expand...



I think a lot of it depends on how dirty is 'dirty' and probably how smooth the bore actually is.
Even a few shots may be laying down a layer of copper from bullet jackets to further smooth the walls of the bore.

After 20 to 30 shots I can start to see spreading at longer ranges with my varmint rifle.
.22-250AI and 6mmREMAI barrels; Panda action, R-B, L-P, no ejector.
Even a brief cleaning puts things back into the same group.
A few passes with a wet patch (50-50 Kroil & shooters Choice).

I have barrels for use with Moly coated bullets.
The last thing you want to do in those barrels is scrub out ALL the Moly.

I do make sure to put a complete oil film on the bores during storage to limit galvanic corrosion.

I did have to adjust loads when using Moly.
The slightly greater speed moved many loads off their nodes.
A few grains less powder and everything settled in.
I use a Chronograph (home built) to adjust the loads back to optimum velocity.

Try different things in as tightly controlled a way as you can.
Holes in target in a small group are what really matters.
 
You must log in or register to reply here.
Back
Top