gouged brass on M1 Sales upper

[cubflyer75]

I'm having a problem with the feed ramps gouging the shoulder of my brass when feeding from the magazine. This is more pronounced with a 200gr cast bullet. Has anyone else had this problem? Should I just radius the edge of the feed ramps slightly? thanks, Mike

[Pitt300]

What mags are you using?
I had some scratching from some surplus GI METAL mags.
You can file the top front lip on the metal mags to use w/your "heavy" 300W loads.
I put red tape around the mags that I've modified for use w/208/220/240g loads due to location of ogive in the mag.
However, since I switched to MagPuls-NO issues.

[Flewis]

I'm using PMags with my M1S upper and having the same trouble.

I can post some pics of the brass tonight.

[Flewis]

Also, I didn't have the problem using GI mags and once-fired brass. Well, I should say I didn't notice it but I think I would have. I'll check.

However, when I switched to new Winchester brass and PMags I noticed the gouges.

[Pitt300]

Got me?
I radiused my GI mags & it stopped.
Wonder if your softer cast bullets are not "feeding" up the ramp as smoothly?
Do you have same gouging problem when you do loads w/220-240g SMKs?

[Flewis]

Got me?
I radiused my GI mags & it stopped.
Wonder if your softer cast bullets are not "feeding" up the ramp as smoothly?
Do you have same gouging problem when you do loads w/220-240g SMKs?

My has had only 220 SMKs run through it.

[cubflyer75]

I'm using PMags. My cast bullet is http://www.midwayusa.com/eproductpage.exe/showproduct?saleitemid=318153

It's pointed, but the nose is fatter. I can seat it out far enough to touch the lands and still fit in the mag, however, this is when the feed ramp takes a HUGE chunk off the shoulder of the case. Seated further in, shoulder is fine.

With M80 ball, 150gr pulled tracer, 240 SMK's, and these cast bullets, seating various lengths, I get a nick in the neck right at the mouth of the brass.

Can I just radius all sharp edges on the feed ramps without adversely affecting feeding? Just so they're no longer sharp? Forming this brass takes too long to have it damaged like this. :frown:

I try to post some pictures tomorrow some time... thanks, Mike

[Flewis]

Ok, the brass that I used with my GI mags was untouched. Here is a pic from some of the brass that was used with the PMags. This was new Winchester brass and the brass used with the GI mags was once fired Remington, but I don't know why that would make any difference.

Also, the PMag rounds were 2.170 COAL while the GI mag brass was 2.160. That might very well be the difference.

Is having a gunsmith smooth out the feed ramp edges advisable? Can they be widened out to .30 caliber size?

http://rx7.voodoobox.net/images/300gouge.jpg

[Pitt300]

Call:
Paul @
Model 1 Sales
903-546-2087
If he's out maybe John or Bryan could help.
I'll email Paul this thread.
I'm also interested in the outcome.
P

[Flewis]

I'm going to do some testing (hopefully in the next day or two) and see whether it is the COAL or the magazines and then I'll give Paul at M1S a call.

[kdiver58]

That is some pronounced gouging :eek: .. I've never had that and I'm using the Pmags and 220 SMK's. Good luck ..

[Flewis]

That is some pronounced gouging :eek: .. I've never had that and I'm using the Pmags and 220 SMK's. Good luck ..

Kdiver, what COAL are you using?

[pug]

By the distance apart I would think only the feed ramps could be doing that kind of gouging. Does it do it to rounds fed from both sides of magazine or just one side in particular? Blunt round nose bullets benefit from the M4 ramps more than the long tapered ones.

[Flewis]

Went through the brass last night and noted a few things about the gouged brass (new Winchester brass, 220 SMKs set at 2.170 oal, using PMags):

More than half were gouged, some more seriously than others, so it is happening on both sides of the magazine and ramps. I had a few, maybe 10 out of 50, that were unharmed.

The gouges match up with the top of the feed ramps.

I made up some dummy rounds and kept dropping the bolt on them, I never was able to replicate any of the gouges so something different must be happening when the bolt cycles during firing.

I'm going to shoot some this afternoon, so I should know more then.

[Flewis]

Well, it has something to do with the PMags. I have two 20 rounders... one causes more pronounced gouging than the other. The original 20 round GI mag I've been using (unmodified other than a Magpul follower) causes no problems.

Wasn't there a thread somewhere about people modding the PMags? Cutting out some area?

[pug]

One post was about cutting the ribs back so the rounds aren't forced towards the center of the mag. I have better luck with thermolds and the 20 round straight body c products mags.

[kdiver58]

I'm using a Case OAL of 1.360

My cartridge OAL is 2.170 to 2.180 using 220gr SMK bullets

It's funny how no 2 people have the same result with a M1S upper. I use Pmags with no trouble and 30 Round DPMS mags with only a few problems. Some people get a 3-4 MOA gun and others get a 1-1.5 MOA gun. It's all over the place.