Longshot & HST chrono report

[Dieselman]

I loaded up a few test rounds of pulled 180 gr Federal HST's loaded in front of Longshot and fired them across the Chrono yesterday.  Test gun was a Kimber TLE II fired from 10 feet.

180gr HST JHP, 9.0 grains Longshot , WLP, Armscor brass, 1.255" C.O.L.

Avg: 1299 fps No signs of pressure



180gr HST JHP, 9.2 grains Longshot , WLP, Armscor brass, 1.255" C.O.L.

Avg: 1342 fps No signs of pressure



180gr HST JHP, 9.4 grains Longshot , WLP, Armscor brass, 1.255" C.O.L.

Avg: 1356 fps  Some firing pin swipe noted on primers.



Overall I was pretty happy with the 9.0 load and consider the  9.2 load to be about max for my gun.  I may try some 9.1 loads to see where they come in at later.

[The_Shadow]

Nice report DieselMan! 

[Taterhead]

Great report. It is interesting to see the results in the field coming in from different platforms. I can't seem to get a 180 over 1200 fps with Longshot. Gun is a gen 3 G20. I've loaded up to 9.5 grains with a couple of different bullets and top velocities average about 1190.

[Dieselman]

Interestingly enough, I have been giving a lot of thought to the velocities that I achieve when using these pulled HST bullets.  I routinely am getting much higher chronograph numbers when using these compared to people who use otherwise similar loads with other bullets such as XTP's HAP's or Noslers. 

One thing I have noted is that the 180 gr HST OAL is .642"  Compare that with a Nosler 180 gr at .620" or the XTP at .625" So the HST is a little long for a 180 gr. bullet.  I tend to seat them to a depth that gives me a Cartridge Overall Length of 1.255"  This would be similar to seating that XTP Bullet to 1.238" for example. This alone may be the only reason for these discrepancies in velocity numbers and signs of pressure that I see.  The same HST with the same COL and components with a 8.4 gr charge of 800X gives me 1250 fps on average. Also much faster than what most people report for a 8.4 gr 800X charge.   I have tried seating them a little longer, out to 1.262 I think.  (I can't find my notes for this, so I am trying to go off of memory)  But I did not see a drastic reduction in velocity. 

When I load XTP bullets, I find my chronograph numbers are much closer to what other people are finding in their own testing.  For example a 10.9 gr charge of Blue Dot with WLP primer and C.O.L. of 1.255" pushing a Hornady 180 gr. XTP averages about 1300 fps.

[Taterhead]

That's a good take. Sitting deeper in the case, less internal volume, greater pressures. Thise must be some LONG bullets. It would be educational to see side-by-side velocities with the different COLs.

[The_Shadow]

Yep, the internal volume being smaller does increase pressures.  I have the CHRONY brand chronograph and I don't think it is very generous with the readings I see others getting...

[Dieselman]

I am using a Chrony F1 to get my data

[Dieselman]

........... It would be educational to see side-by-side velocities with the different COLs.

I probably won't take the time to do this experiment with different COL's. Or at least not anytime too soon. I did initially have a few loaded longer when I very first started working with them due to the lack of available load data for this pulled bullet.  Then once I became comfortable with the 1.255" COL, I standardized all further testing at that length to remove that variable from the equation.

The reason I say I probably won't go back and run this comparison is due to the difficulty of obtaining the chrony. I don't own one, I borrow a family members instead. So I usually wait until I have a bunch of different stuff worked up to test and then set a date with him to use his chronograph. 

[45BBH]

Just asking, how do you set the Chrony up?  I do know the 180gr HST is a bit long for a 180gr and at 1.255" pressures would be higher, but in all the Longshot testing I've done, even with 10.0gr I've yet to break 1,300 fps avg.  from a 4.6" Glock 20.  To get that (1299 fps you listed) with 1.0gr less powder and only .4" more barrel seems strange even if the longer bullet creates more pressure.

[Dieselman]

I set up the chronograph on a camera tripod. Adjust to the proper height. Install Sun shields. Shoot from a distance of ten feet .   


Edit to add- 
I don't believe my chronograph readings to be inaccurate based on velocity numbers observed while shooting factory ammo as a control across it during the same sessions. For example, Remington UMC 180 gr was coming in around 1130 fps. Underwood 180 gr gold dot at 1330 fps.  I shot some 230gr 45acp ball across it too from my other 5" 1911 and recorded 840 fps.

Now I'm not saying it isn't possible that my chrono could be off, but I really don't think that it is. I have to wonder if the bullet composition doesn't also play some sort of role in it. Maybe the softness of the lead core or the properties of the jacket.  It's really difficult to know because of the lack of available data for this bullet, due to it not being released as a reloading component from Federal. Of course no manuals have anything for the bullet. There isn't a whole lot of user data that I can find on the net from others that have bought these pulled bullets and reloaded them.  It does serve as a reminder though why it is important to start low and work up carefully when developing a load with unusual components.

[The_Shadow]

I am a cheap OSB...I repurposed a "FREE" ironing board from the curb.  It folds down flat, height adjustable, fairly stable, but weighted sandbags can be used in high wind conditions, even mounted a fold down target on the back end so the aim point can be at the right height for the shots.  It fits on the rear seat of my truck, light enough to carry in one hand.

[Dieselman]

I like the ironing board! That's quite an ingenious use for one!

[cwall64]

Just asking, how do you set the Chrony up?  I do know the 180gr HST is a bit long for a 180gr and at 1.255" pressures would be higher, but in all the Longshot testing I've done, even with 10.0gr I've yet to break 1,300 fps avg.  from a 4.6" Glock 20.  To get that (1299 fps you listed) with 1.0gr less powder and only .4" more barrel seems strange even if the longer bullet creates more pressure.

I was noddling over this too, using Federal 150M, Hornady 180gr HAP, Hodgdon Longshot 9.4 grains my average velocity out of a Glock G20 Gen4 w/ 22# RSA was 1,238 fps (highest was 1,251).  I am assuming ~100 fps over my numbers were due to barrel length and a little less COL (mine was 1.260").  I was going to try the shorter COL next time I get out with the chronograph.  then again, my powder measurements could have been a little off (first rounds I have loaded in a long while and i definitely made sure not to go over when checking on the beam).  Different scales, different chronographs, etc.  I'll have to test with the S&W 1006, so the barrels are comparable.  I must say last time I reloaded was before forums, so this is great to be able to compare data points!!!

I also like the 9.0 and 9.2 loads best for my needs and their standard deviations were the best.

[Pinsnscrews]

I wonder if the HSTs are running a softer copper jacket than the XTP/HAPs...This could be allowing them to carve into the grooving better, sealing the bore better and allowing the pressure to rise more. The harder XTP/HAP jackets may not be sealing as well, and allowing pressure bleed around the bore through the rifling.

[Dieselman]

Perhaps.  Of course one of the other variables that we haven't discussed is the difference in rifling techniques.  Both posters here stated they can't achieve velocities like mine with Glocks.  So perhaps Glock's polygonal rifling vs my Kimber's traditional rifling has something to do with the discrepancies seen here.  I'm not sure, it's just a thought.