1/32" ?

[thedude]

I have a Colt Series 70 Government Reissue in stainless. It has about 600-700 rounds through it. I get a failure to go into battery or FTF every 50-75 rounds or so. I use the factory Colt magazines that came with the pistol. I bought two Checkmate 7 rounders based on the recommendations I read on this forum, but have not had a chance to try them yet. They are completely identical to the Colt mags except for the markings. (Doesn't Checkmate make Colt mags? )
At any rate, I thought the mags were probably causing the problem until I started reading up on other possibilities. My new theory points to the 1/32 in gap between the frame feed ramp and the barrel feed ramp. The gap looks a little too small on my gun. Its hard to tell because when the slide is locked back (thats when the gap is supposed to be 1/32in right?) the barrel can move slightly back and fourth on its link. When the barrel is all the way back and laying flat on the frame bridge the gap looks to be less the 1/32". Here are some pictures. Sorry about the bad quality, they were taken with a camera phone. I couldn't really get a good shot because of the camera so I'm posting several pictures.

http://i263.photobucket.com/albums/ii139/thedude2211/5-1.jpg?t=1202004291

http://i263.photobucket.com/albums/ii139/thedude2211/2.jpg?t=1202003413

http://i263.photobucket.com/albums/ii139/thedude2211/3-1.jpg?t=1202004334

http://i263.photobucket.com/albums/ii139/thedude2211/1-1.jpg?t=1202004358

http://i263.photobucket.com/albums/ii139/thedude2211/4.jpg?t=1202003549


I also found this site in my research.

http://how-i-did-it.org/1911-project/fed_up.html

There's a pic about halfway down that shows how big the gap should be. The one on my gun is defiantly not that big. What do you guys think?

-Matt

[pa_guns]

Hi

I may be wrong here.

To me it looks like the ramp on the frame is cut a bit deep. That or the barrel is off by a bit. Either way it's not an easy fix.

I'd say it's a let Colt handle it sort of thing.

Like I said, could be wrong.

Bob

[Lazarus]

The photos are out of focus, and I can't make out too much from them. I can tell you that after purchasing several current production series 70's, Colt can get carried away with cutting their frame ramps too far forward. It would be nice to just "send it to Colt" and get the real problem fixed. But, the real problem is probably exactly that the frame ramp is over-cut. Colt won't replace the frame. They may install a new barrel, as they did to mine, that compensates for the poor feed ramp.

In any case, please get that camera in focus and show a side shot of the barrel in the frame. Also, show a magazine feeding a round into the ramp. Where does the bullet hit first?

Lazarus

[Iron bottom]

I have the same problem with a Series 70 reissue. I'm thinking of sending it off to someone and having it built up and machined correctly. But then there's that slide to frame fit. Loose on one side making the slide sit to one side of the frame. Sigh.

[sevenL4]

What ammo? Is it a new pistol? Did someone polish the ramp? If it is new and unmolested, I would try some ammo and magazine changes before mailing it back to Colt.

[1911Tuner]

Either way it's not an easy fix.

feh...30-45 minutes. If dude can bring it...me fix. ;)

[thedude]

I've had the pistol for about a year and a half. Bought it new. My range ammo is Blazer Brass, the cheap Walmart stuff. I put about 50 Remington HPs through it at one point and I don't think it had any issues.

I tried to take more pictures this morning but they're not coming out very well. This cell phone camera only 1.3 mega pixels and it doesn't seem to want to focus on extreme close ups. I tried to take pictures of a magazine feeding a round. They came out blurry too. I did notice something however. With a fully loaded magazine the first round dips slightly and contacts the frame feed ramp then rides up as the slide comes forward. When I put only one round in the mag it contacts higher, right on the gap between the frame ramp and barrel ramp.

A full mag looks just like this

http://how-i-did-it.org/magazines/img/metalform_rnd_dip_side.jpg

A mag with only one round looks more like this

http://how-i-did-it.org/magazines/img/wilson_side.jpg


these pics are from this mag test article

http://how-i-did-it.org/magazines/feeding-time.html

[1911Tuner]

Your magazine is at least part of the problem...but not much of it.

Use a chisel-point Sharpie marker to color the barrel ramp and hand-cycle a few rounds through the gun. Take note of how much ink has been removed by the bullet nose...and where it's removed.

The barrel ramp is a clearance...not a bullet guide or feedway. If the bullet nose impacts it at any point below the top corner as it glides over...it can cause problems.

Your frame ramp appears to be okay, other than the possibility that the barrel bed could use a few thousandths taken out of it.

The barrel ramp looks to be a bit too steep, which tends to exacerbate the effect of bullet contact with the ramp.

Standin' by...

[pa_guns]

feh...30-45 minutes. If dude can bring it...me fix. ;)

Hi

Trivial for Tuner isn't quite the same as let's grab the Dremmel at the kitchen table for the rest of us.

Bob

[thedude]

Ok Tuner, I tried the Sharpie thing and hand cycled 7 hardball rounds. No ink was removed from the barrel feed ramp. Thats good I guess, but now where do I look? Weak mag spring?

[Lazarus]

Those photos are from Candiru's article and not representative of the Colt in question.

....So, if the bullet tips are not striking the barrel ramp, things are looking up. Just for reference purposes, my questionable frame ramp upper edge measured .779" from the slide stop center line. And that was after lowering the bed a little. The gun feeds without jamming, but there is a telltale chunking noise that the others don't have.

Lazarus

[pa_guns]

Those photos are from Candiru's article and not representative of the Colt in question.


Hi

I was kind of wondering when Colt started marking their slides "Springfield". Confusion is a pretty common thing around here ...

Bob

[thedude]

Sorry about the confusion guys. Since my camera is proving inadequate I was trying to use some other examples that had similar round placement in the feed cycle. Maybe its time to buy a real digital camera.

Lazarus, I took a ruler to my frame to get a crude measurement from the center of the top of the frame feed ramp to the center line of the slide stop pin. The measurement is roughly 11/16" or 0.6875". This is with the ruler laying across the top of the frame and me looking straight down on it. Not the most scientific way I know, but thats a big difference compared to yours. Do you know what an "in spec" measurement is for this distance?

[Lazarus]

The ruler method just won't give you the information you need. Calipers are needed for this one...you insert the s.s. pin and measure from the front side of the pin to the tip of the frame ramp. Then subtract .100" to get the center line measurement. But, leaving that aside for the moment, you may find that using mags with the GI fully tapered feed lips will make this run just fine. Note that you will be shooting ball ammo when going to the GI style magazines.

Lazarus

[1911Tuner]

but now where do I look? Weak mag spring?

Start with that, and then try to induce your failure with hand cycling. If you can...remove the extractor and see if it makes a difference. If it does...the extractor is very likely whence the bug nests.

[thedude]

Went to the range this afternoon and put 100 rounds of Blazer Brass through the Colt with no failures. I used a single Checkmate 7 round mag the entire time. This is the first time I've ever used one of the Checkmates. I guess this is good news; maybe the factory Colt mags have weak springs? Though 100 rounds without failure is not very conclusive.

Tuner, after I cleaned the gun I put it back together minus the extractor and hand cycled 7 rounds through it. They seemed to go in a little smoother then usual although they didn't eject (I'm guessing they're not supposed to). I'll compare the feel of the feeding difference with and without the extractor some more and report back.

[Lazarus]

I have recently experienced next-to-last round feed jams with the Colt hybrid magazines that came with the gun. It was obvious that the mag spring wasn't as strong as it should be, so I replaced them with Wolff 11 pounders. That solves the problem plenty quickly. (Full credit goes to the Tuner for this advice.)

Lazarus

[niemi24s]

...you insert the s.s. pin and measure from the front side of the pin to the tip of the frame ramp. Then subtract .100" to get the center line measurement.

Hi Lazarus: I finally see (*) how you were making this measurement. In the PM sent yesterday, the dimensions given were the horizontal ones. The direct distance from the SS pin hole CL to the bed/ramp junction is 0.787 inch for a mid-spec 1911.

Regards

(*) "I see", said the blind carpenter - as he picked up his hammer and saw.

[thedude]

I guess I'll pick up some Wolff 11 pounders. Thanks for the help guys. I'll holler if I have any more issues.

[niemi24s]

Forgot about this drawing, originally in Post #40 of the "Dimensional Conflict" thread:

http://i129.photobucket.com/albums/p232/niemi24s/P076230001d.jpg

It has some additional "direct distance" dimensions that may be useful in determining what, if anything, is wrong with the frame.

[1911Tuner]

zebrazebrazebrazebra(The magazine cured it)zebrazebrazebrazebra

[thedude]

zebrazebrazebrazebra(The magazine cured it)zebrazebrazebrazebra

I'm guessing that happens a lot around here? :D

I'm going to order the Wolff 3 pack 11lb mag springs plus a Wolff recoil spring. I'm guessing 16lb is the one to get?

[1911Tuner]

I'm going to order the Wolff 3 pack 11lb mag springs plus a Wolff recoil spring.


The 11-pound mag springs are compatible with standard 7-round followers only. Note also that...if your magazines are of the parellel-lipped "wadcutter" design, they may not offer optimum feed performance. They might...but they might not.

[thedude]

My mags are the Colt hybrid 7 rounders made by Checkmate. Should be good.

[1911Tuner]

My mags are the Colt hybrid 7 rounders made by Checkmate. Should be good.

That's right. You said that your problem was improved or eliminated whith those magazines...didn't you? (May have been another thread. I get'em crossed up sometimes.)

Check-Mate's springs have proven to be very good so far...at least in the 7-round versions. Seemingly as strong as Wolff's. Whether or not they'll hold that strength over the long haul remains to be seen...but so far, so good. Wolff's springs are a tough act to follow. For years and years, springs was their only business. They've got a clean handle on it.

[pa_guns]

Hi

Change the mag or attack the frame with a Dremel.

Life is full of so many decisions. ....

Bob