Chrono Data: Silvertip, XTP and Underwood

[enidpd804]

Test Gun:  Stock Glock 20
Weather:  78 degrees

Underwood 180 Grain Gold Dot:

1st            2nd          3rd          4th           5th           Avg
1259   1216   1275   1278   1313   1268.2

Winchester Silvertip 175 grain

1189   1184   1179   1170   1190   1182.4

Hornady 155 grain XTP

1293   1303   1273   1295   1273   1287.4


I had three stoppages with Underwood in my Glock.  I was using two different magazines than the one I'd had trouble with before.  I shot the rest of the boxes of Hornady and Silvertip along with 50 American Eagle with no drama.  The Underwood stoppages were all jammed into the left side of the chamber. 

[The_Shadow]

Warren, do you tap your magazine on the palm of you hand or againt your leg to seat the rounds fully to the rear of the magazine?

I have found that while loading magazines (double stack glock and other) if the rounds rattle the magazine is not stacked correctly.  The last time I loaded the mags for my G-30 this happened, unloaded and reloaded, no more loose or rattling rounds.  Not saying this is your issue but someting to look for.

Thanks for the report!

[4949shooter]

Thanks for the info, enidpd.

A short while ago I fired some Hornady 155 grainers and I thought they felt fairly stout for a mid range load. Your tests show they are faster than advertised.

Has anyone chrono'd the Underwood Delta Elite specific load?

[Intercooler]

Not the specific ones but Kevin based it off the reloads he did for me and probably some others at the time in the 1200-1240 FPS range. My reloads test out there when I shoot them.

[4949shooter]

Thanks, Intercooler.

[enidpd804]

Warren, do you tap your magazine on the palm of you hand or againt your leg to seat the rounds fully to the rear of the magazine?

Yes, sir.  It's one of my Type A habits.  Load three to five, seat, repeat.  This time, everything but Underwood functioned perfectly.  After consulting with my armorer, I have a new recoil spring/guide en route-just because it can't hurt.  I'm considering buying some more ST, running 100 rounds through all of my mags and calling it my outdoor load. 

[REDLINE]

Interesting how the Underwood 180gr GD load came in at virtually equal velocity as their own 200XTP load, even though both are meant for different specific velocities.

[Intercooler]

180gr 1300 FPS. If your pistol setup is right expect 1310-1340 FPS
200gr 1250 FPS. If your pistol setup is right expect 1260-1300 FPS

Looks about right to me. If I'm reading that right it's a Glock and a stock setup at that.


The sheet has:

180gr GD's at 1325 David's stock Glock. In my Witness 1340.
175gr ST's at 1276 out of my Witness. I replaced what David got out of a stock Glock because it was much lower.
155gr Hornay XTP's 1265 out of David's stock Glock.


I have no idea on why my Winchester numbers were so high. Others have reported lower too so maybe I need to retest or let me dig up what I can find. Given Buffalo Bore says you can get a 50 FPS difference with a spring it's plausable. In my Witness it's been proven an 11lb. spring changes nothing.

[Intercooler]

Here you go skip to 10:06 for the summary.

The spring is a 24lb = good. From what I recall on the Glock barrels the stocker will give an increase of maybe 10-15 FPS over the aftermarket barrels. 1336 FPS on the GD's and 1214 Silvertips so depending which barrel looks right. My Witness will give about 30 FPS more than a Glock (1276-30= 1246). All makes numerical sense.

[REDLINE]

enidpd804 uses bone stock G20
He chronographs Underwood 180gr Gold Dot rated @ 1300fps
Results =  1216, 1259, 1275, 1278, and 1313
Average =  1268fps

MrRedbull616 uses G20 with 4.6" Lone Wolf barrel and 24# Wolff Spring
He chronographs Underwood 200gr XTP rated @ 1250fps
Results =  1239, 1240, 1255, 1255, 1259, 1259, 1279, 1291, and 1299
Average =  1264fps


In my book that is the same.  Where you're getting it that Buffalo Bore claims a higher spring weight equals more velocity I don't know, nor do I believe there is truth to it, or at least anywhere near to the tune of the 50fps you claim they claim.  What I do know Buffalo Bore says regarding more spring weight is a lower extreme spread.

[Intercooler]

Exactly. I hate to just spell it out but enidpd804's Glock isn't up to the ammo he is shooting. That's as direct as you can be I guess.

Given Buffalo Bore and even SwampFox way back in the day wrote it out in text what happened with the Glocks and too weak for the load springs. It wouldn't be a good test gun for repeatability except up to par and kept that way. A revolver like a 610 would give you probably about the best shot to shot because their is no spring or slide. Maybe someone with a 610 can do a long string and see.

[REDLINE]

Maybe, maybe not.  According to Underwood, enidpd804's Glock is perfectly suitable.  If you choose to believe otherwise, that's fine.  At this time we simply differ in opinion based on how we each weigh what we've seen and heard.  That's cool.

I'm only aware that Buffalo Bore has suggested going to a heavier spring to bring extreme spread down, nothing else.

I don't know much about Swampfox ammo.  It didn't exist very long and from what I can tell the owner didn't manufacturer ammo for sale till maybe a year before he passed on, so what he ever knew or thought he knew I don't know.  Most of what I know about the owner of Swampfox is from the writeup The_Shadow did on another forum that he gave us a link to here and posted for us all of us to reference.  Including the 10.0gr Longshot 200XTP load that was hitting 1325fps from a G20 with an aftermarket barrel.

I do my best not to make assumptions regardless who said what till it's either shown by more than one source and agrees with any other data that might be at least semi related or I see it myself with my own equipment for me.  That's not to say I disregard what others say or have said, just that I generally default to erring on the side of caution.

[Intercooler]

   You can shoot any of it in a stock Glock. Just don't expect the optimum results from it. You have to normalize data if you have one that is or isn't optimum. Just like different platforms. I wondered why my 1006 at a 5" barrel gives the same numbers as my Match 4.75" barrel. They shouldn't and it's in the barrels but is now factored if I do testing.

[REDLINE]

So many variables, so little time and MONEY!

[Intercooler]

Yea. Just buy yourself a box of springs, different ammos and your own Chrony and pick your own based off personal results.