Feed problems in my M&P .40 full size

[nannoman]

First off, I am fairly new to reloading.

I am still in the stages of working up my loads and have been loading bullets 10 at a time to go to the range to test. I work up test loads for the different bullets and different cases that I have.

My problem is that when I got some of my test loads using Rainier leadsafe 180gr FN bullets to the range, they wouldn't feed properly from the magazine. They start up the feed ramp but then hang up when they should turn the corner into the chamber. I can't tell for sure but it seems as if maybe the case mouth is hanging up on the top of the chamber.

My first inclination is that I need to increase the taper on my crimp. When I loaded them to begin with I did a very mild taper crimp because I had read that if you over crimp plated bullets you could strip the plating off. So, I am mainly asking if any of you have had the same problem and realized that it was simply the crimp or is it something else.

My load data for the Rainier bullets that caused the problems:

Case: Winchester and S&B
Primer: CCI500 small pistol primers.
Powder: 7 gr. HS-6
Bullet: Rainier leadsafe 180gr FN
OAL ~1.125 with variations of a couple of thousandths each way.

I also loaded some Remington 180gr FN jacketed bullets with pretty much the same specs and they fed and shot fine.

Any help/advice would be appreciated!

Bryan

 

[RealGun]

Sounds like the ogive of the plated Rainer may be more rounded than the Remington FMJ. That seems to be the only variable. I can't picture how the case mouth would affect the initial feeding motion. If the cartridge is stuck with the ramp contacting the bullet, the crimp should not be a factor. Try a 1.120 OAL. I believe the round will be able to strip off the mag a little sooner.

 

[rcmodel]

I was going to suggest seating them shorter but Realgun already beat me too it.

I think the Rainier leadsafe 180gr FN is a Truncated Cone design, and you need to seat them to almost where the angle breaks over from the full dia bearing surface.

I'm thinking maybe as short as 1.115".

While you are at it, take the barrel out of your gun to use as a cartridge guage, and seat them deep enough they will drop freely in the chamber without the bullet hitting the rifling leade.

Your case mouths should measure about .422" to .423" max if you are taper crimping them properly.

rc

 

[rbernie]

I have always had issues with Rainier TC bullets in my M&Ps, and many others have reported similar issues. The TC meplat is too wide, and they just don't want to 'turn the corner' into the M&P chamber, and get caught on the hood (almost like a 3-point jam).

You can play with seating depths to get them to work OK (so long as you keep the loads relatively light since you'll be decreasing internal case volume) but in the end I simply used up my stock of them and moved on to other bullet designs that had a smaller meplat.

 

[nannoman]

When I did my original loading I pulled the barrel from the weapon and used it as a guide. None of the loads, the Rainier or the Remington seemed to contact the rifling.

In the meantime I went out to the garage and screwed my taper/seating die down about a quarter turn or so and re-crimped all of the reloads. They seem to function through the weapon without hanging up anymore. I measured the case mouth after the extra bit of crimp and it came out to .421. It does not appear that there is any roll to the crimp yet.

With the bullets seated to ~1.125 they seem to be almost at the point where the bearing surface breaks over to the cone now. I suppose going down another 0.010 would probably put it exactly where the bearing breaks over. I think first I'll head back to the gun range and try the new crimping and see if they all function as needed. But for the future reloads I may try both, crimping a little more and seating them a little deeper.

But as RealGun suggested I was leaning more toward thinking it might be an issue with the Rainier bullet since the specs between the Remington and Rainier bullets were the same, the only difference would have been the bullet itself and therefore the most likely culprit.

Just to clarify everything I will probably remove the barrel from the gun and position the round at the point that it was hanging up and try to get a picture.

Thanks for the advice so far.

 

[LiveLife]

I also have a full-size M&P40 and I load several different 180 gr TCFP plated bullets to 1.125" OAL and they all feed fine (including Rainier, which I used quite a bit of. Now I use more of Berry's). I am with rcmodel - I think your taper crimp is not fully taking in the case neck flare.

Try this:

- Take a resized case (no bullet) and drop the case into the chamber of the barrel. It should drop in freely.

- Since you are using plated bullets, you won't need much flare of the case neck. Next, apply only the slightest flare that you can feel with your fingers but could barely see with your eyes.

- Then start adjusting the taper crimp on your die (with OAL set to around 1.125") until the loaded round drops into your chamber freely with a "clink" - these rounds should feed/chamber well from the magazine now.

 

[RealGun]

Note that when tighetning up the crimp on a plated bullet you can start to deform the bullet. If you pull one of them, you will see what I mean. Rather than fix the crimp, you might have actually changed the shape of the bullet. If the case mouth is not contacting the ramp, I don't see how crimping itself would be a solution except indirectly, affecting the bullet.

 

[LiveLife]

If the case mouth is not contacting the ramp, I don't see how crimping itself would be a solution except indirectly,

RealGun, if there is too much case neck flare to start out with and not taken in flat, the flare of the case neck will hang on the chamber and won't allow a smooth feeding. This is less of an issue with a loose Glock chamber, but M&P chamber is tighter and you really need flat taper crimp.

With the bullets seated to ~1.125 they seem to be almost at the point where the bearing surface breaks over to the cone now. I suppose going down another 0.010 would probably put it exactly where the bearing breaks over.

I had the same problem when I first got my M&P and found that longer OAL actually helped with the feeding issue.

If your taper crimp is taken in flat and your loaded rounds drop in freely into the chamber with a "clink", try increasing the OAL and feed them from the magazine.

 

[nannoman]

Here are a couple of images of the bullet sitting in the barrel at the point that it seems to want to hang up.

If I take the bullet and hold it parallel to the chamber it drops right in. It just seems like there's a problem when it is trying to feed from the magazine into the chamber.

bds, so you're saying that maybe the bullets need to be set much closer to the max OAL?

rbernie -- what's the TC meplat? But the rest of what you describe sounds almost exactly the same as the problem I'm having.

 

[LiveLife]

bds, so you're saying that maybe the bullets need to be set much closer to the max OAL?

I load all of my 180 gr TCFP to 1.125" OAL to fit the Lone Wolf barrel chamber, which is probably the tightest of all the chambers I have seen. For them to fit the LW barrel, the taper crimp must be flat. If they feed/chamber into LW barrel, the round will fit just about any other pistol chamber.

I am probably going to take some heat for this post (I apologize in advance) - this feeding and chambering issue with tight chambers has already been covered in several other threads.

When a bullet is stripped off the magazine follower, the nose of the bullet "bumps" on the ramp and often does not "ride" up the ramp. What happens next is that as soon as the base of the case clears the magazine lips, the upward pressure from the magazine follower pushes the case up the breech wall along the extractor and aligns the round straight with the chamber. Then the recoil spring continues to push the slide forward chambering the round.

With tight chambers (like Lone Wolf, M&P Pro, XDm, etc.), if the case neck flare is not taken in flat, the case "jams" against the chamber during the initial bump and the round won't "pop" up the breech face/extractor to align straight with the chamber.

 

[LiveLife]

nannoman, do you have the same feeding/chambering problem with factory 180 gr TCFP rounds? If you don't, it is your reloaded round's dimensions that's the problem.

Take measurements of the factory round and duplicate it. If factory rounds fed fine, your reloaded rounds should too.

 

[RealGun]

They start up the feed ramp but then hang up when they should turn the corner into the chamber.

The pictures make it appear that the bullet is already clear of the ramp, so yes, it sounds like the case mouth crimp would be the issue. Now we have to get permission from the naysayers to use an FCD. It works great to fine tune these things after the rounds are already loaded.

 

[nannoman]

bds: I have shot ~500 rounds of Winchester 180gr factory loads and about 10-20 rounds of Winchester 180gr JHP factory and then probably about 200 rounds of S&B 180 gr factory loads. All of those cycled through the weapon without fail.

In addition, as I noted the reloads that I did with the Remington FMJ bullets worked fine as well.

When I loaded the rounds I used an S&B factory load to take some measurements from and duplicated them as close as possible. It seems that I'm not more than a few thousandths off on the OAL and the measurement at the end of the case mouth for the crimp is exactly the same at 0.421. All of this is starting to point to the idea that it has something to do with the bullet's geometry. Maybe the cone isn't tapered at the right angle or it's truncated to short or long, I don't know. That's why I was posting here so that I could see if anyone has already figured this out.

Perhaps the M&P just doesn't like the Rainier bullets, which would frustrate me a bit since they are pretty much the cheapest out there and I just bought a 1000 of them.

 

[LiveLife]

RealGun, I agree. This is one of those rare cases where FCD will put that extra "factory crimp" to help with feeding/chambering.

I do not use the FCD and teach those new to reloading to use just the 3 dies out of the 4 die set to "hone" their reloading skills. Only after they produce rounds that will feed/chamber well do I have them use the FCD.

All of this is starting to point to the idea that it has something to do with the bullet's geometry. Maybe the cone isn't tapered at the right angle or it's truncated to short or long, I don't know ... Perhaps the M&P just doesn't like the Rainier bullets

Unless Rainier changed the nose profile of their 180 gr bullet, I am loading and shooting the same bullet in my M&P.

 

[rcmodel]

If it is in fact the case mouth catching.
Is the break from the feed ramp to the chamber a sharp edge?

It might be necessary to polish a sharp edge with a Dremel & Cratex bullet point just enough to break the edge and round it very slightly.

Anyway, I'd suggest you fully "color" a round with a black magic-marker and attempt to chamber it. Then look for where the black rubbed off.

That will tell you exactly what is catching where on what.

rc

 

[rbernie]

rbernie -- what's the TC meplat? But the rest of what you describe sounds almost exactly the same as the problem I'm having.

The meplat is the flat nose. The Rainier 180gr .401 design has a relatively broad/wide meplat (the 'cone' isn't very 'pointy'). Most other truncated cone (TC) designs will either use a smaller meplat/pointier design that will feed better in most semiautos. For example:

Rainier 180gr .401 shape ==>

..

Winchester 180gr .401 shape ==>

..

MagTech 180gr .401 shape ==>

..

Missouri cast 180gr .401 shape ==>

You can try and compensate for the Rainier's design by seating the bullet a wee bit more deeply in the case (pulling the ogive/meplat transition in), but there are limits to how much you can pull back before the bullet's shoulder is below the case mount. You'll probably be able to find an acceptable seating depth sufficient to burn thru your current stock of Rainiers, but I would suggest a more appropriate bullet shape for your next bullet buy.

rcmodel - I found that my M&P's would go into a three-point jam with the Rainiers and that the ramp-to-chamber edge was as round as I dared make it. The specific Rainier shape seemed to be the culprit. Coronach had a similar issue, and IIRC we both solved our feed issues by choosing an alternate bullet.

 

[nannoman]

RealGun... so it's sounding like I might need to buy a FCD, unfortunately that would offset the savings of buying the Rainier bullets.

 

[nannoman]

Here is one of the bullets that I "colored". I positioned the round in the magazine so that the vertical line on the bottom of the casing was facing straight up. This cartridge is one of the ones that I put back through my seating/crimp die to add a little more crimp to it. It chambered from the magazine fine, I just won't know if all of them chamber when firing until I can get back to the range.

Notice the scraped off section at the case mouth just off to the side of what would be the top as it was in the magazine.



This is the 'bottom' of the cartridge, this would have been in contact with the feed ramp.

To answer remodel's question about the feed ramp transition, it's not a sharp break, it has a bit of rounding to it. Would it hurt anything to take a dremel and round off the sharp edges around the opening to the chamber?

 

[nannoman]

This is the best picture I could get of the chamber mouth, I've annotated where I think it's hitting, I think I could see black marks from the rubbed off sharpie.

 

[rcmodel]

No, just don't get carried away and remove metal.

It is often necessary to polish that transition edge on 1911 barrels to get them to feed wadcutters without catching.

But in your case, you are messing with the chamber support on a high-pressure .40 S&W, not a low-pressure .45 ACP.

So, just polish it, but don't change it.

rc

 

[LiveLife]

rbernie, looks like the Rainier bullet may have more broad nose. I shoot 180 gr TCFP Rainier as my primary 40S&W load and also shoot Montana Gold FMJ/JHP/Berry's TCFP/PowerBond RNFP. I did have some feeding issue with TCFP when I first started reloading for the M&P when I got it in 2008 but resolved the feeding issue with taper crimp/OAL I mentioned.

nannoman, the marks I see looks like the case neck is definitely catching the inside of the chamber. Could it be that your chamber is wee-bit tight? You could always call S&W and talk to them as they offer life-time service warranty.

Rainier 180 gr TCFP:

Berry's 180 gr TCFP:

 

[nannoman]

bds, It doesn't seem that the chamber is all that tight. Once the bullet is in the chamber it has enough slop to shift back and forth a noticeable amount. The cartridge falls right out of the barrel when inverted and basically goes in and out quite freely, it's only when it's trying to make the transition from the magazine into the chamber that there seems to be any problems. I'm starting to feel that the geometry of the cone on the bullet might be the culprit.

I'm going to experiment with a few empty cartridges with changes to the OAL and crimp and see how they affect feeding.

Thanks so much for all the advice and discussion so far.

Bryan

 

[nannoman]

Just spoke with Shane over at Rainier Ballistics. They have been getting calls about this bullet specifically with the M&P line of pistols. They are changing their bullet geometry to see if it corrects the issue. Might be that those of us with M&P's could get them to exchange our bullets in a month or so once they get production up and running.

They actually went out to buy an M&P to do testing on and he did make the suggestion of setting them just a little deeper. The only problem is that for their pistol it was working better for them at 1.125 OAL, exactly what mine is set at. I may try to set mine in another 5 thousandths and see if that helps.

I am at the starting load of 7 grs of HS-6, if I stay with that charge and set the bullets deeper to 1.120 or maybe even as far as 1.115 is there going to be a pressure issue?

Bryan

 

[rcmodel]

Might want to back off a little.
You are already above the max load listed by Hodgdon with a 180 XTP seated 1.125".

They say 6.9 is MAX.
And you are already at 7.0, before you got them to feed right.

rc

 

[nannoman]

That's where all the manuals disagree. Rainier says to use lead bullet data or you can use FMJ data if you don't have access to lead bullet data. Shane at Rainier says that usually he grabs the Speer reloading manual when he works up test loads.

My Lyman manual says that for HS-6 starting load is 6.9 for a 180 JHP and in the same manual starting loads for both 175 gr. lead bullets are 7.0 grs.

The Speer manual says that their 180gr TMJ or HP should start at 7.3 grs for HS-6.

Which one should I believe?