Trying to find information on X-Caliber barrels.

[ratbuster]

I did chronograph some of the loads, but my chronograph was acting up with bad sunlight angle. was saying my 20 Tactical was pushing 34gr bullets at over 4100 fps, but my barrel is only 20" long so that can't be right. Especially since the charge before that was running around 3700 fps with one grain less powder. I have a new chronograph now, but haven't re-shot those loads through it yet.

However, I do not believe in the speeds of reloading manuals. In fact, I can't remember the last time I really even paid much attention to the listed speeds? I honestly only look at powder type, charge weights, and case fill volumes. Then will reference the burn rates of powders listed in the manual to develop loads using powders not in any manuals or websites for a particular chambering. My barrels do whatever speeds they do.

Some of my chamberings in barrels produce much faster speeds than any manual lists or what my calculations are. Some are a little disappointing and not what I expected. Is what it is.

Have you ever chronographed a box of factory ammo? I have never found one that lives up to the speeds claimed on the box.

If you are having issues getting the speed you want, you need to try a fair amount of other powders before looking to blame the barrel.

I use a chrono 2-3 times a week. I used to own a LabRadar but got rid of it because it was inadequate for fast, small projectiles but I did compare it to my Magneto Speed enough to know it is very accurate.

My son in law's 204 Ruger was chronoed with 4 different factory loads: 32 and 40 gn Hornady Vmax as well as Fiochi. The velocities for all 4 cartridges were down; I went back and looked at the records and they were actually down nearly 300 fps lower than published claims. 24" Xcaliber barrels, AR platform.

The other was an AR 20 Practical. I could not get within 200 fps of my 26" Criterion barrels. I have shot 40gn Vmax's at 3900 fps (I usually run it at 3850) with that but I had major pressure signs at 3750 with the 24" AR barrel. I had to run it at 3650 fps and finally sold the rifle as I can get better than that with my 20VT. The rifles shot accurately but the velocity was not there.

 

[GrocMax]

Between myself and my PD partner we've got 5 up and running with several more on the way and have not had an issue with low velocity.

 

[stacy]

Did they tell you a wait time?

6 WEEKS

 

[msinc]

I have one on a 223. It shoots great and does not foul. In fact there was really little to no break in time required. I have a borescope and I will say this: you will have to look at a Shilen select match, Pac-Nor super match, or Hart or Lilja to see as good a bore as mine. There are no flaws or tooling marks at all, zero...the bore is about as perfect looking as a bore can ever get. I am seeing a little more throat erosion than I believe I should for no more rounds than have been down the pipe. I don't load them hot and the 223 is not known as a barrel burner. I am happy with it and would buy another one.

 

[Dgd6mm]

I have one on a 223. It shoots great and does not foul. In fact there was really little to no break in time required. I have a borescope and I will say this: you will have to look at a Shilen select match, Pac-Nor super match, or Hart or Lilja to see as good a bore as mine. There are no flaws or tooling marks at all, zero...the bore is about as perfect looking as a bore can ever get. I am seeing a little more throat erosion than I believe I should for no more rounds than have been down the pipe. I don't load them hot and the 223 is not known as a barrel burner. I am happy with it and would buy another one.

What do you base this on, have you measured throat erosion on similar .223 barrel/s being shot with the same powder,etc?


Don Dunlap

 

[msinc]

What do you base this on, have you measured throat erosion on similar .223 barrel/s being shot with the same powder,etc?


Don Dunlap

Yes sir, that is exactly what I based this on...same powder, same powder charge {my pet load}, same primers, same bullet, same barrel lengths, same actions {bolt}. I see zero {as in none} throat erosion in a Wilson, Pac-Nor or factory Remington barrels. They are all 416 stainless, with well over 400 rounds each, but I am seeing the beginnings of a scorched throat in the Excaliber with right around 100.
I can plainly see a burned surface with the blasted blackened appearance, the beginnings of what appears as fine "martensite" like cracks on the surface yet this barrel was not shot rapidly and it was not allowed to get what I consider overheated. I could easily keep my bare hand anywhere on the barrel at any time. This is a 416 stainless barrel. I have an old Pac-Nor chrome-moly barrel that was taken out of service that had close to 900 rounds and it didn't appear as bad as this one.
I made the comment that 416 is 416 on another thread and someone suggested that it may be the hardness heat treat that is the difference. I will say that the barrel is a tack driver and the scorched appearance has not affected the accuracy.

 

[Dgd6mm]

That is good information but I was asking more on the line of measurements, before and after.

 

[msinc]

I didn't bother to measure it with a gauge because accuracy has not fallen off any. I was just surprised to see the throat burned while checking to make certain the barrel was clean. I changed the load to a 64 grain bullet and N-140 powder. Haven't had a chance to run enough shots thru it to see if it continues. If and when accuracy drops off i will shoulder it back and rechamber. I will take some measurements at that time though just so I can watch it. The kick in the tail is that this kind of stuff don't happen to a barrel that wont shoot, it's always the ones that work great and you want to keep!!!!

 

[captain23steve]

Thank you all for the information. Sounds like I will be getting a good barrel.