Gunsmithing New Impact 737R 6 Creed Magazine Issues

[Roadrace33]

I have a new Impact 737R, in a Manners PRS stock with the mini chassis. This is the first bolt gun I've built, other than 22's, and I've never had a single mag feeding issue. I have a few Accuracy Internationals, two SA and a LA. I have never had feeding issues no matter what barrel i threw on them.

Being this is my first "custom" short action, i did some research and it looks like either AW and AICS mags will work with the new Impact 737's. I have tried 1 - 5 round Accurate Mag, 2 Metal MDT 10 round mags without binder plate, and one with the binder. I have been messing with feed lips for the last few days periodically, but cant seem to get the thing to feed consistently. The rounds initially would just nose into the feed ramp. So i slowly opened up the front feed lip to give the round an upwards angle, and this is where it gets weird. If i put 10 rounds in the mag, it "typically" will feed rounds 10,9,8,7,6,5 fine, then 4 and 3 will usually nose into the feed ramp, or the case mouth just barely catches the feed ramp enough to jam and mess up the lip. Then, rounds 2 and 1 will feed fine.

I just received the MPA lip tool to adjust the lips a little bit more precisely than damn pliers, so i will mess with it tonight again and see.

I have the primer about 3/4 or more showing on the back of the mag. Seems like if i go more than that, the rounds will puke out. I figured once i was able to get rounds to feed, all of them would feed since I had the front lips opened slightly, but it seems like that isn't the case. I get about 50-60% success rate. I will add pics of what a loaded mag looks like when i get home. Any insight is appreciated. I have also ordered an AI AICS mag as well as an AW mag to try. No clue if it'll make a bit of difference, but figured it was worth a try.

 

[oldrifleman]

I had that same Issue (737r/6creed/accurate mag/manners TCS/ mini Chassis). I took the easy path and swapped in an MDT SA mag and it cured the issue.

 

[Roadrace33]

I had that same Issue (737r/6creed/accurate mag/manners TCS/ mini Chassis). I took the easy path and swapped in an MDT SA mag and it cured the issue.

The Accurate mag that is a 5 rounder i struggle to get it to feed more than 2 rounds.
The MDT SA Metal mags i have a bit more success, but still is hit or miss at around 50-60% at most. Frustrating to say the least. When you swapped from Accurate mags to MDT, did you have to mess with the feed lips at all?

 

[oldrifleman]

The Accurate mag that is a 5 rounder i struggle to get it to feed more than 2 rounds.
The MDT SA Metal mags i have a bit more success, but still is hit or miss at around 50-60% at most. Frustrating to say the least. When you swapped from Accurate mags to MDT, did you have to mess with the feed lips at all?

N, it was literally just click in and feed. Sorry you are having issues!

 

[Vivacious Stallion]

I have found that opening up the front of the feed lips helps a little bit to position the bullet presenting upwards slightly. That being said my 737r has run well with AW and AICS mags essentially flawlessly with creedmoor cases. The AW mags will require tweaking to work almost guaranteed.

 

[Cynical]

You shouldn’t be having these issues with AI style mags, and you shouldn’t need to adjust feed lips on AI mags. AW mags do need adjustment sometimes (maybe usually is a better word).

Does your stock have the manners bottom metal with the mini chassis? Or what bottom metal are you using?

 

[Roadrace33]

You shouldn’t be having these issues with AI style mags, and you shouldn’t need to adjust feed lips on AI mags. AW mags do need adjustment sometimes (maybe usually is a better word).

Does your stock have the manners bottom metal with the mini chassis? Or what bottom metal are you using?

I am using the Manners Mini Chassis yes. It works great, other than the mag issue im having... I have tried 4 different mags. 1 Accurate 5 round mag, 2 MDT Metal 308 mags, and one MDT Poly/Metal Mag. Last night i played with feed lips on the Poly/Metal MDT mag, since i got the MPA tool to adjust it, rather than pliers. I got it feeding pretty good. If i load up 10 rounds, all but the last round will feed fine.

Here is a few pics of how i have the mag adjusted. I could probably lower the front on the round down a little bit, but not very much. Any more than a few thousandths of width on the front lips and the round will ram the case mouth into the feed ramp.

The AI AICS mags will be here today, i will see how they feed. I would prefer to use AW mags, but really don't care as long as i can get them to work. Coyote hunting at night, and one jammed round will ruin a stand pretty quickly. I've been using my AXSA in 6 creed up until now for it, but it gets heavy to lug around to those stands where i walk a half mile to go into the right spot.

 

[Vivacious Stallion]

Is that where you tuned the lips at to get them to work? That seems pretty extreme.

 

[DeathBeforeDismount]

You need an adjustable mag latch. Order the MDT bottom metal and then you can set it to whatever mag you want.

 

[CK1.0]

That looks kind of crazy, like all the rounds might pop out at any moment lol.

Just use the MPA tool and some calipers to establish sort of a baseline, usually something like .410-.420” at the front of the feed lips, about the same at the rear, and then adjust it from there… and maybe smooth out the inside of the feed lips with some 600-1200 grit sandpaper, to make sure there aren’t any burrs preventing the rounds from slipping out smoothly.

 

[oldrifleman]

You need an adjustable mag latch. Order the MDT bottom metal and then you can set it to whatever mag you want.

Are the MDT M5 and the Hawkins M5 DBMs interchangeable in a Foundation?

 

[DeathBeforeDismount]

They should be. I ran the Hawkins and OTM bottom metal in my foundations and manners. One of the reasons I switched chassis is so I could have adjustable mag latch.

 

[Roadrace33]

Here’s a video. The AI mags were actually worse. Messed with feed lips, no luck, hardly at all.

Why is the feed ramp not notched like the many other rifles I’ve got? That would solve this issues pretty easily. If the rounds aren’t angled that way, like they are in the picture above, there is absolutely no way possible that they’ll feed. It either slaps the nose of the bullet into the flat feed ramp, or the case mouth catches, everytime.

 

[FCrifles]

Josh Egyed is in Amboy, IL if you're not far from there. https://www.facebook.com/JEPrecisionShooting/

Good smith that could take a look at it

 

[Roadrace33]

Spoke with Impact today. Greg was really helpful. Getting them more pics tonight, but it sounds like the feed ramp is suppose to have an angle machined into it. Mine is basically just a flat wall. They are going to confirm and if that’s the case they’re going to get me a replacement.