I received my new CDNN M40-A1 on Tuesday and I field stripped it to clean and lube. I found some strange scratches on the feed ramp - the surface was highly polished but it looked like the barrel had been lying next to some small sharp object that "jiggled" a bunch of fine scratches into the polished surface in one small area (maybe 0.2 x 0.2 inches). They were a little hard to see but you sure could feel them with a fingernail! I sanded and buffed out the damage with my Dremel tool and some metal polish.
Today I took the pistol to the range with three numbered 12 round mags. I had not stripped and cleaned the mags! Mistake! I did number them so I could keep track of which was which, in case I found a bad one.
The first 200 rounds of WWB went without a hitch. What a hoot - the gun kicks less and punches nice tight groups compared to my G23. The trigger pull was variable tho, and that was pissing me off, and it caused a bunch of flyers.
I switched to DoubleTap 155gr JHP and number 1 mag caused three FTF within the first 8 shots. The nose of the bullet would hang up on the front lip of the mag - it was like the follower wasn't pressing up hard enough. After those three FTFs everything went smoothly for 100 rounds.
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DoubleTap 200 gr JFP - one FTF from number 2 mag (jammed into the left side of the chamber and feed ramp) out of 30 rounds. This ammo kicks noticeably harder - it is a great "woods load" for furry critter defense (small ones). I noticed that maybe 15% of the firing pin marks on the primers had blown back out nearly or completely flush - I guess this is a really hot load (1050 fps, 490 ft lbs) - one reviewer calls it a 10 mm in a .40 case...
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Corbon 150(?) gr JHP - 20 rounds, no problems. I was just using up some old stock that was about 10 years old. My box was labeled 1150 fps - the newer stuff is a little faster..
Hornady 155gr JHP TAP - 20 rounds, no problems, except the sexy black cases left a bunch of un-sexy black crud on the feed ramp that was _really_ hard to get off..... That is a shame since the ammo is so cool looking, until you fire it. I don't think you could reload the cases without scratching the heck out of that exotic surface coating.
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When I got home I stripped the gun, including removing the trigger group (way cool design, except it's kinda tricky getting back in place), and cleaned it well. I took out the firing pin and found a light burr and scratch from the spring retainer that I polished out. I used Mil-Comm synthetic grease and oil on the action - that seems to have helped the trigger pull. If it's still variable I may have to dig deeper. I took the mags apart and got a fair bit of brown gunk out - I guess that was cosmoline. After lubing lightly, the followers move lots better. I'm hoping that FTF will not be a problem now.
Sooo.... does it sound like those 3 FTFs were caused by the brown glop in the mags, or is there some other cause? I did look at the springs and they appear to be the correct length.
BTW: I plan to carry the DoubleTap 155 gr JHPs but want to put some more rounds through the gun without feed problems before I will be 100% happy... I really like their ammo - it is loaded stout, high quality (except for the crummy boxes) and relatively affordable ($0.50 per pop cheaper than the high end ammo).
Thanks.
John Davies
Spokane WA
Today I took the pistol to the range with three numbered 12 round mags. I had not stripped and cleaned the mags! Mistake! I did number them so I could keep track of which was which, in case I found a bad one.
The first 200 rounds of WWB went without a hitch. What a hoot - the gun kicks less and punches nice tight groups compared to my G23. The trigger pull was variable tho, and that was pissing me off, and it caused a bunch of flyers.
I switched to DoubleTap 155gr JHP and number 1 mag caused three FTF within the first 8 shots. The nose of the bullet would hang up on the front lip of the mag - it was like the follower wasn't pressing up hard enough. After those three FTFs everything went smoothly for 100 rounds.
DoubleTap 200 gr JFP - one FTF from number 2 mag (jammed into the left side of the chamber and feed ramp) out of 30 rounds. This ammo kicks noticeably harder - it is a great "woods load" for furry critter defense (small ones). I noticed that maybe 15% of the firing pin marks on the primers had blown back out nearly or completely flush - I guess this is a really hot load (1050 fps, 490 ft lbs) - one reviewer calls it a 10 mm in a .40 case...
Corbon 150(?) gr JHP - 20 rounds, no problems. I was just using up some old stock that was about 10 years old. My box was labeled 1150 fps - the newer stuff is a little faster..
Hornady 155gr JHP TAP - 20 rounds, no problems, except the sexy black cases left a bunch of un-sexy black crud on the feed ramp that was _really_ hard to get off..... That is a shame since the ammo is so cool looking, until you fire it. I don't think you could reload the cases without scratching the heck out of that exotic surface coating.
When I got home I stripped the gun, including removing the trigger group (way cool design, except it's kinda tricky getting back in place), and cleaned it well. I took out the firing pin and found a light burr and scratch from the spring retainer that I polished out. I used Mil-Comm synthetic grease and oil on the action - that seems to have helped the trigger pull. If it's still variable I may have to dig deeper. I took the mags apart and got a fair bit of brown gunk out - I guess that was cosmoline. After lubing lightly, the followers move lots better. I'm hoping that FTF will not be a problem now.
Sooo.... does it sound like those 3 FTFs were caused by the brown glop in the mags, or is there some other cause? I did look at the springs and they appear to be the correct length.
BTW: I plan to carry the DoubleTap 155 gr JHPs but want to put some more rounds through the gun without feed problems before I will be 100% happy... I really like their ammo - it is loaded stout, high quality (except for the crummy boxes) and relatively affordable ($0.50 per pop cheaper than the high end ammo).
Thanks.
John Davies
Spokane WA
