Keyholing with a Glock 20

[operator81]

Aside from a bad barrel, what would cause a bullet to keyhole? I was firing Bitterroot Valley Ammunition Co (BVAC) 180 grain FMJ. Their claimed velocity is 1200 fps. This was the first time using BVACs 10mm ammo and most of the rounds fired keyholed.

I haven't fired my G20SF much, but I don't think this is due to a bad barrel. I've fired 50 rounds of American Eagle 180 grain FMJ, which was rated at 1060 FPS, and 20 rounds of Double Tap 200 grain with a Hornady XTP Hollow point rated at 1250 FPS.

The American Eagle was fired on a small IPSC steal target from 25 yards in to 15 yards. The Double Tap was fired from 15 yards and in. Both loadings grouped very nicely, all rounds hit POA.

Then today, while shooting a drill, I fired 2 shots from 25 yards. Only one round hit the target (full sized BG target), nicking the bottom edge about two feet below my POA. I moved in to 15 yards and fired 2 more rounds COM. One round hit high right and the other was high left, each about 1 foot from where i was aiming. I noticed the holes in the paper appeared to be rectangular, suggesting the rounds were keyholing. I moved to 7 yards and about half the rounds fired would keyhole. At 10 yards about 75% keyholed.

Each round fed, fired and extracted just fine. Recoil felt appropriate for the claimed velocity.

I'm ordering more ammo tonight from various different makers to see if this is an issue with just BVAC. Again, after checking my barrel, the rifling looks consistent. I've used BVAC exclusively lately in .40, 9mm, .45 and .223 and in those loadings the ammo, while dirty, is quite accurate (they're 15 min from home and I can buy at wholesale).

I haven't been able to contact them about which bullet they use for this particular loading but I'm wondering if some of the cheaper plating used on lower end ammo reduces the overall size of the bullet or causes it to otherwise not contact the rifling enough to fully stablize the bullet. BVAC closes shop on fridays so I won't be able to reach them until Monday. Again, I'm not dissing their ammo, its been great so far. I'm just wondering if maybe I should start using something a little higher quality for the 10mm.

Here's a pic of a round fired from 15 yards. Its a tad blurry due to the iPhone but you can make out the outline of the round.

http://i427.photobucket.com/albums/pp357/operator81/photo.jpg

[1_click_off]

Can you pull a bullet and mic it?

[operator81]

That was the first thing I thought of but I lack the gear. I saved 5 rounds from the box. I'll give BVAC a call Monday and see what bullet they use for that load. I can't help but wonder if the cheaper plated bullet (I believe this is what they use) just doesn't get enough contact with the rifling to stabilize when the velocity is turned up. Their 180 grain .40 load works great in my Glock 22 and I believe they are using the same projectile for both rounds.

[1_click_off]

You can get a so-so dial caliper from Autozone and check the area just out of the case mouth if you don't have a bullet puller. I know I would have to mic it, theres no way I could wait until Monday. Good luck, hope it is just ammo and not the barrel.

[skyugo]

set a loaded cartridge bullet down into the muzzle. Just an idea here, but if it fits in deeper than rounds you know not to keyhole, you should have some idea of the diameter. probably not the most accurate test, but it's easy and free.

[operator81]

Update:

I went to the BVAC outlet to get some HP 10mm they had in stock (loaded with a 180 grain hydroshok bullet). I asked the sales lady if she'd heard any complaints about key-holing with the 180 grain FMJ round I'd purchased previously. She didn't have any technical info, but was able to tell me that BVAC has gotten complaints across the board about that particular load key-holing in a variety of different weapon platforms. She said BVAC had been using (what she could recall) a plated bullet and that they are replacing it with a standard jacketed bullet in future loadings. She suggested I email their Tech for further information, which I will do Monday with they open.

So I can rule out a barrel issue on my end, it sounds like its just an issue with the cheaper plated FMJ. I'll update the post again when I hear back from the Tech about what specifically about the bullet was causing key-holing.

[Hat Creek]

To borrow a phrase..."garbage in, garbage out." I've not seen the most stellar results from ammunition made in this small MT town. Had the same thing happen with plated bullet reloads from Ultramax (low bid at the time) which resulted in their taking back many, umpteen thousand rounds and replacing it was name brand commercial ammunition.

Ammunition selection is always an exercise in cost versus performance. That is, how bad do you need it to perform to high levels of reliability.

[operator81]

I hear you there. However, this is the first and only issue I've had with this company's ammo. The cost I can get here is marginally more than what I could load it myself. Since I'm not doing bullseye or competition the additional training time afforded by the lower cost suits my needs. I plan on reloading within the next year to make use of the little bit of savings as well as tailor the loads to my specs. In the meantime, BVAC is meeting my needs quite well.

[Supermoto]

If the plated bullet is over crimped, it will crack the plating causing it to tear away while fired. 1200fps is about the max that most plated manufacturers recommend

There are also a few barrels that do not like plated bullets, like schuemann barrel. top notch barrel but they really like jacket rounds better

[operator81]

If the plated bullet is over crimped, it will crack the plating causing it to tear away while fired. 1200fps is about the max that most plated manufacturers recommend

There are also a few barrels that do not like plated bullets, like schuemann barrel. top notch barrel but they really like jacket rounds better

Good to know. BVAC's 10mm loading with the Hydrashok bullet sells for $1 more per 50 rounds than the key-hole rounds, I'll just use those for now.