Underwood 200 XTP Brass Blow OUT!

[doverpack12]

Chronographed more of the Underwood 200 XTP today.  First I changed my chrono battery and adjusted so I was shooting a little more level through it.  Seemed to fix the problem.  Anyway they averaged the exact same 1263 fps shot from about 20 feet from chrono.  Previously I got 1264 fps.  No split brass this time and no smiles.  Velocities were not near as extreme had on 1288 on the first shot and then everything else was 1250-1265.  This was from the next box since my partial of the other one is gone.  Seems maybe the powder measure got away on a few rounds which ended up in the last box or something to cause some low 1300 fps readings which I believe were correct.

[Intercooler]

Sounds good!

[REDLINE]

Ditto for Sounds Good!

[DM1906]

....Or it could be climate/weather related.  Some powders are more sensitive to it than others.  800X being one of them, in my experience.

[d762nato]

I sure hope those 200 grain xtp's are good to go because I got 300 rounds of those loads around the first of may. I haven't gotten out to shoot any of them yet though. It sounds like they are from the same run as the Op's. I just wish they had lot numbers on the box like most manufacturers of ammo.

[doverpack12]

All days I shot were roughly the same weather conditions.  Partly cloudy and around 60 degrees F.

[DM1906]

All days I shot were roughly the same weather conditions.  Partly cloudy and around 60 degrees F.

There's more to it than just that.  A box of bullets in direct sunlight, even for a short period, can increase the cartridge temp considerably, and a hot pistol will develop different pressures than when cold.  Barometric pressure and humidity have a great affect, as well.  When the rounds are on the ragged edge to begin with, every environmental factor is greatly exaggerated.

[sqlbullet]

All days I shot were roughly the same weather conditions.  Partly cloudy and around 60 degrees F.

There's more to it than just that.  A box of bullets in direct sunlight, even for a short period, can increase the cartridge temp considerably, and a hot pistol will develop different pressures than when cold.  Barometric pressure and humidity have a great affect, as well.  When the rounds are on the ragged edge to begin with, every environmental factor is greatly exaggerated.

+1

[REDLINE]

When the rounds are on the ragged edge to begin with, every environmental factor is greatly exaggerated.

Excellent point.  On top of that, any variation is exponentially exaggerated when rounds are on the ragged edge to begin with.  All of a sudden chamber dimensions become more relevant between different platforms.  A little difference in powder charge bocomes the difference between a light pressure sign and a major pressure sign.  The odd occurance of bullet setback becomes a much greater issue.  On and on.

[sqlbullet]

Not to mention that there are deviances in loading.  I know that at Lake City and other big mfg's rounds are weighed before and after charging with powder, and then random samples are still QC'd.  If more than a certain number are outside qc the whole lot is scrapped.

I appreciate what Underwood does for 10mm, but in reality I doubt he can afford to pull down an entire run if there is a large QC issue, and I doubt each round is weighed before and after charging.

It creates windows that when loading in mass ensure that will eventually let an overcharge slip through.

Most of us here get that and accept the risk.  Not sure everyone that buys does understand that.

[d762nato]

I ran 100 rds of these nickel plated Underwood 200 gr. xtp's through my DW-Cbob and NH-Falcon today with no issues. The cases all looked great. I just don't get what all the hype is over recoil and the 10mm's, it was nice. I guess after shooting 3 and 4" barreled 44 mags with full power ammo though the 10's no big deal. 

[Intercooler]

Good report. Thanks!

[Mike_Fontenot]

I pick up a Double Tap Nickel case every 2-3 months at the range. Oddly, none have ever contained a primer 

DoubleTaps (alternating 150gr and 180gr in all mags) are my carry rounds, and are also mostly what I shoot lately at the range.  I've never seen a missing primer in those casings.  I haven't ever shot any DT 135gr, though.  I HAVE seen missing primers (multiple times) in Underwood (either 155gr and/or 180gr ... I don't know which, because I alternate them in all mags, and the casings look the same).

[Intercooler]

Next time I find a few I will throw up a picture with the measurements.