Read many good things about DoubleTap Ammo for my 10mmAuto and decided to try some out. Also purchased a 22# recoil spring for my S&W1006 as advised by DoubleTap. The 180XTP load advertised a 1350fps mv, but I have chronied about 9rds on two different occasions and come short at 1275fps (still not bad, but not as advertised). The real kicker is that I have had 2 FTFire's. It appears that the primer is being pushed into the pin hole and then a small piece of brass is shaved off and becomes lodged in the pin hole when ejected. I have had this same problem with a 9mm using Olympic Ammo (about the cheapest stuff there is), but did not expect it with DoubleTap. See photo below where you can see the brass in the pin hole, and you can see the primer that got shaved, and the next cartridge that FTFire. What could be causing this (I have not had any problems with about 100rds of Hornady fact ammo and Hornady preprimed brass that I have loaded)?



Deke.

just on GP i'd look at the firing pin to make sure it is smooth, but it sure looks like bad primers to me. Having avoided shooting factory ammo for 40 or 50 years though I'm not sure if its supposed to go off or not.

Butch,

If it were the pin I would expect to see the same thing with the Hornady ammo. From what I can tell the pin looks smooth. The 9mm that this happened to with the Olympic ammo was new, so again, I doubt the pin. I believe the rough pin hole on the FTFire round was a result of the pin pushing the jagged brass into the primer.

Deke.

Just a thought is the firing pin draging the primer on ejection and actually scraping material off the primer that in turn is filling the Firing pin hole, the reason I asked this is that when I first started shooting my EAA Witness Compact in 10mm and later with a conversion slide and mag down to 40S&W I noticed a very distinct drag mark on the primer when I asked my gunsmith about it he said that was common on auto's but I personally didn't like it, so I stoned just a bit off of the Firing pin and it reduced the problem and was much less noticable on the spent cases.

That's a blown primer, to much pressure. Bad loads..... If you notice, even the primer is flattened, look at ring near edge of primer.....

No ... it's not a blown primer. The primers are heavily cratered and the face of the slide is shearing the excess off.

Typical of what you see in loads for a comp gun when fired in a pistol without a compensator.

Is sometimes approached by changing the shape of the firing pin ... flattening the very tip and then tapering the round to a cone and the firing pin spring pressure adjusted.

All in all, the pressure of this loading is above that suitable for the firearm unless it is redone by a very good smith.

Firing pin drag has an abvious elongation of the firing pin imprint along the vertical axis ... the tip of the firing pin is leaving a line in the face of the primer. This ain't that.

I would suggest that if you want cannon ammo for the 10mm, handload some 135 Noslers with Winchester Super Field powder. Gives the best expansion ratio and velocities in my 40 S&Ws built on 1911s and loaded to very nearly 10 mm length. Have no problem at all getting 1400 in a non-comped gun and over 1500 in a comp gun. (But these pistols are built like a bank vault with fully ramped Nowlin barrels and Baer slides. Do NOT try this with anything less!)

For what its worth, DoubleTap is replacing the 180XTP's with 215hardcast. I plan on carrying the Hornday Factory 180XTP ammo in town so the 215's would be for the woods. Will post the results in the next couple weeks.

Deke.

mstarling, I sometimes see firing pin drag in my CZ75 in .40 S&W. Is the solution as simple as changing the firing pin spring?

Wink,

I fixed the drag problem by reshaping the point of the firing pin to a flattened cone and getting a good firing pin spring from Wolfe.

I did have to replace one firing pin that broke because the drag was so severe. I can't remember provided the replacement part though. Sorry. I think I got it through Brownell's.

DoubleTap sent me the 180GoldDot instead. Shot 25rds yesterday without any problems, but looking at the primers I would call them max pressure. 5rds chronographed @ 1261fpsmv. I will practice a bit with 180hard cast loaded to same velocity to see if there is much difference in a timed shootoff between these and the Hornady's which are 85fps slower. I will also fire the Hornady and DoubleTap into wet newspaper to see what the differences may be. If the DT's are as managable with plenty of damage/penetration to the paper I will use them for in town carry since I believe that the GD is the best bullet for perps that there is. Looking at 200XTP's for hunting and 200hardcast for woods carry.

Deke.

BTW, I saw that Texas Ammo publishes 1250fps for their 200XTP. Has anybody tried this ammo?

Deke.

Texas Ammo went out of business. Did DoubleTap resend you the 180gr GD's for free? I was thinking of buying from them and want to know as much as possible.

DoubleTap did send the GD's for free and I returned the unused XTP's. Texas Ammo is closing down, but they still have plenty of 10mm for sale.

Deke.

I am getting excited about my 10mm again, I think that I will give DoubleTap a try.

If you have a chance, chrony those doubletaps and report back. I got 1275fpsmv w/180XTP(DT advertised 1350fps) and 1261fpsmv w/180GD (DT advertised 1300fps). I also tried TexasAmmo 200XTP that they advertised @ 1250fps and got 1189fpsmv. All were shot from my 1006 that has a 5" barrel and a 22# spring. Could be I have a slow gun, but I did get 1175fps from Hornady's 180XTP load that they advertised at 1180fps. Nonetheless, quite powerful from a service sized pistol.

Deke.