Email from Kevin at Underwood

[REDLINE]

I ask Kevin about his hottest loads and the support required by the barrel for the G20 and G29. He said...the simple fact was that the factory Glock barrel had more than enough support around the case on their ammo.

That being said what are the reasons for Ka Booms.  ...any manafacture that exceeds pressure limits is asking for it.

Some great food for thought has been brought up in this thread.  I guess at this point I don't know what else could be said.  We have some facts and theories, good baselines and questionable reasoning/practices. 

In what I'm seeing it doesn't appear Kevin Underwood is too concerned about his ammo to change a thing.  There's a concensus by some that nothing needs to change.  I would submit some facts suggest otherwise.  At any rate time will tell if further issues arise with Underwood 10mm ammo.  In the mean time those interested in shooting factory ammo will have to decide from crossroads which path to take, shoot Underwood 10mm ammo or not. 

I for one hope Kevin is working behind the scenes to see to it that discrepancies with his 10mm ammo disappear.  What leaves me uncomfortable with his 10mm ammo is he doesn't seem to acknowledge there is or has been any issue at all.  Maybe I missed something.  In the mean time (which has a chance of never ending) I know for myself that if I do shoot any of his ammo in my Glocks, it won't be with the stock barrels.  Of course all others will make that decision for themselves.

That's my 2 cents of a take away from this conversation.

[Intercooler]

Or don't shoot it and save it all for me 


Shadow,

            Got some of Kevin's 180 and 300 XTP .44's this week. Been a long time since I could grab any so will send those down with his newer scaled back 180's to see what's in there.

[The_Shadow]

Sounds great...

[REDLINE]

I had a some Hornady 200XTP's above the 1250fps mark with the stock G-29 barrel with no smiles using LongShot and 800X.

That's impressive.  Forgot to ask;  Did you use new Starline brass cases in those workups?

[undeRGRound]

Desiring an update, I have a G20 with the 6.6" LWD threaded barrel, and about 240 rounds of Underwood Ammo  "D

[4949shooter]

Both my Glocks have run fine with the hottest loads from Underwood, Buffalo Bore, and even some Doubletap hard cast (I know...no lead).

I do believe the earlier Glock barrels were less supported. I also believe that Glock got wise to this and began offering their barrels with more support. When I compare the barrels from Lone Wolf with my two stock Glock 20 barrels, they really look similar.

Glock knows we shoot Underwood out of their guns these days.

[Captain O]

If you're shooting the Delta Elite, you are best served by installing a supported barrel, (duh) a flat-bottomed firing pin retainer, (focusing energies on the mainspring) and, if possible, a slightly heavier mainspring (by 1 lb.). All the aforementioned modifications will retard the rapid recoil without battering the slide. After accomplishing these, you can shoot all the hotter ammunition your heart desires. (So I have been told).

[Geeman]

My Gen4 G20 has consumed many varieties of pre-loaded ammo.  Of the things I've tried, there were two that produced some smiled cases.

1. Doubletap 135g Nosler loading.  Lost some primers when run through the Witness too. 

2. Underwood 150g Nolser loading.  Plenty warm.

I can't say smiled cases are necessarily dangerous, but my comfort level is exceeded with these loads, especially the Doubletap.  Absolutely don't re-use the smiled cases!

I've run UW in  135g Nosler, 165g Gold Dots, 180g Gold dots, 220g Hardcast (feeding issues in the G20), and others that escape my memory.  No bad signs from any of those.

Greg

[Captain O]

Of all the loads I have read about and shot, It seems that the 165-180 grain loads are the "cat's pajamas" when it comes down to personal defense. Penetration depth,  expansion (sometimes questionable). With the ligher bullet weights the high-velocity loads expand violently, but may not be effective. (It's doubtful, yet possible). Controllablility is an issue, because shot placment seems the prime imperative.

[undeRGRound]

Ran a box of 20 Buffalo Bore HC Lead through a Gen3 G20C and noticed no lead build-up...
Recoil was not bad, considering the lightweight frame, but you guys have spoiled my
expectations talking about S&W 1006 and Witness Hunter recoil with full-house 10mm 

I was putting all rounds within a 6" pattern at ~10yds 

[warren5421]

I have 3 guns in 10mm.  EAA and S&W handle the 200 gr fine but get case separation in my 6" Perfect 10 STI.  One separation was so bad the gun went back to STI.  The G20 handled the 200 gr Underwood ok with stock barrel I just couldn't hit the side of a barn shooting from the inside.  Not the only Glock I couldn't shoot.  Been shooting a 1911 for 62 years.

[Mike_Fontenot]

I have 3 guns in 10mm.  EAA and S&W handle the 200 gr fine but get case separation in my 6" Perfect 10 STI. 

What do you think caused that?  Is the unsupported area at the bottom rear of the barrel noticeably larger on the STI?

[The_Shadow]

Have you measured or slugged the barrel?  Not saying this is your issue...There are some barrels that may fall in the 0.3990" size and that could raise pressures over that of looser bores.   

[sqlbullet]

Also might have a shorter leade that is causing pressures to spike.

[Mike_Fontenot]

Also might have a shorter leade that is causing pressures to spike.

Can you refresh my memory on what a "leade" is?  Maybe the distance between the front of the bullet and the beginning of the riflings?