9mm catching on chamber at entry

[peterk1234]

So, I fired off my first 150 rounds of reloaded 9mm. Love it! I had three or four out of the bunch that got hung up when chambering. It actually took some effort to cycle the slide by hand to get it to eject. When I looked at the bullet, the bullet near the mouth of the brass and the brass had a bit of a scrape. Is this most likely a "not enough tapered crimp issue". meaning the mouth is hang up on the chamber a bit? I could re-chamber and shoot it.

Thanks

Pete

 

[Shaq]

Could be insufficient taper crimp or a case that is out of spec or bulged. You can easily test that by removing the barrel & dropping a loaded round into the chamber. It should fall all the way in with gravity alone. I fully resize the case - the shellholder should almost touch the bottom of the sizing die.

 

[hps1]

You did not state bullet used, but if a SWC, this may help.

I had a similar problem with 45 ACP in a Kimber 1911 when I first started loading that caliber, using a commercial, swaged SWC lead bullet. I was seating the bullet so that the shoulder of the .45 cal. portion of the bullet was flush with case mouth. Found that seating bullet with about .060" of the .45 cal. bullet diameter protruding from case solved the problem. Figured the lead bullet allowed slight deformation, tipping the cartridge just enough to allow it to hit feed ramp at proper angle & keep case neck from hanging up. Have had no issues since making this adjustment.



Regards,
hps

 

[Sunray]

"...Is this most likely a..." A very decided 'maybe'. Also most likely and easiest fixed. You should be able to see a wee, tiny, shiney part on the case mouth. And a wee, tiny, taper on a side view. Check the OAL on the offending cartridges too. A tick too long can do that too.
Usually caused by not operating the ram handle exactly the same every time.
Shaq is describing what's called the 'plunk' test. Nothing is a better gauge than the chamber.

 

[Rule3]

It would help to know the bullet. Type, weight profile etc. Lead, plated FMJ, HP??

Also COL

Impossible to say without info,

 

[peterk1234]

Thank you guys. I did the plunk test when I was setting the dies up. I am going to go back and plunk all of them. I also added a quarter turn to the tapered crimp stage. Honestly, I don't think the fourth die was doing much of anything. At least no I can feel it when I pull on the lever.

 

[LiveLife]

When I looked at the bullet, the bullet near the mouth of the brass and the brass had a bit of a scrape.

The round on top of the magazine is pushed down by the slide rib so extracting case base won't hit the round in the magazine and slide rib sliding on top of the round will often leave a scrape mark.

I had three or four out of the bunch that got hung up when chambering. It actually took some effort to cycle the slide by hand to get it to eject. Is this most likely a "not enough tapered crimp issue". meaning the mouth is hang up on the chamber a bit? I could re-chamber and shoot it.

Make sure you are full-length resizing the brass, returning flare back to flat and using working OAL that reliably feed from the magazine and not hit the start of rifling:

- Adjust the resizing die so you don't see daylight between bottom of die and top of shell holder/plate.
- Add .022" to the diameter of the bullet for taper crimp amount (so .377" taper crimp for .355" sized bullet and .378" taper crimp for .356" sized bullet).
- Working OAL should drop in the chamber freely with a "plonk" and spin without hitting the rifling and feed reliably from the magazine.

Honestly, I don't think the fourth die was doing much of anything.

If you are using Lee 4 die set with FCD, the carbide sizer ring of FCD will only post-size the round that is out of round/spec.

 

[peterk1234]

The round on top of the magazine is pushed down by the slide rib so extracting case base won't hit the round in the magazine and slide rib sliding on top of the round will often leave a scrape mark.

Make sure you are full-length resizing the brass, returning flare back to flat and using working OAL that reliably feed from the magazine and not hit the start of rifling:

- Adjust the resizing die so you don't see daylight between bottom of die and top of shell holder/plate.
- Add .022" to the diameter of the bullet for taper crimp amount (so .377" taper crimp for .355" sized bullet and .378" taper crimp for .356" sized bullet).
- Working OAL should drop in the chamber freely with a "plonk" and spin without hitting the rifling and feed reliably from the magazine.

If you are using Lee 4 die set with FCD, the carbide sizer ring of FCD will only post-size the round that is out of round/spec.

bds, I lost you on some of your comments. I don't understand about adding .022 to the diameter. I am interested to understand what your explaining.

My OAL is 1.125, although I do have some cases mixed that are giving me an OAL of 1.141, which is still shorter than the factory round I typically use. I tested some of the bullets and they do drop right into the chamber.

Thank you for helping. Pete

P.S. I am using Lee 4 dies set

 

[LiveLife]

You don't have to guess to determine the taper crimp amount. Case wall thickness average .011" (depending on headstamp, .010" to .012") so I add double the average case wall thickness to the bullet diameter (.022") to get the taper crimp amount that will return the case mouth flare flat on the bullet.

Depending on the bullets you use and whether you are reloading on a progressive press with shell plate tilt/deflection from resizing brass, you may experience .005" to .010"+ variance on OAL. As long as longer rounds fully chamber without hitting the rifling, you will be fine.

 

[peterk1234]

You don't have to guess to determine the taper crimp amount. Case wall thickness average .011" (depending on headstamp, .010" to .012") so I add double the average case wall thickness to the bullet diameter (.022") to get the taper crimp amount that will return the case mouth flare flat on the bullet.

Depending on the bullets you use and whether you are reloading on a progressive press with shell plate tilt/deflection from resizing brass, you may experience .005" to .010"+ variance on OAL. As long as longer rounds fully chamber without hitting the rifling, you will be fine.

Ah......... got it. Thank you. I will check that. I measured the width at the mouth earlier and was consistantly getting .380, but I never thought to do a comparison to the bullet. When I adjusted the FCD a bit, I reduced the size by .005.

Man, I love this stuff.

Thanks again. Pete

 

[earplug]

I have had lock rings and other adjustments get loose while loading a batch of ammo. This left a bit of oversized unsized case, a longer OAL and I cleaned a seating die and didn't recheck the OAL again.
All this can be cured with a drop of blue loctite,

 

[rfwobbly]

Results of .374/.375" may actually buckle the case and give you the same symptoms for an entirely different reason. Taper Crimp can be an exceedingly hard die to set for someone not accustomed to fine adjustments on machinery. That's OK, just remember that with .380" being the max and ~.374" being the min, you are working in a zone equivalent to the diameter of 2 human hairs.

Personally, I like to see dimensions closer to .377/.378". This setting works for any 9mm bullet and means the TC die can be locked down in position for up to a year with no other adjustments.

The object is to build ammo that will slide into the chamber and then back out using only the weight of the cartridge.

 

[Jim Watson]

TC die can be locked down in position for up to a year with no other adjustments

What do you have to adjust after the year is up?

 

[Walkalong]

I had never measured the "crimp" on a 9MM round until folks here kept asking about it. I would adjust the die as I have posted before (Adjust it so the shortest cases get the bell removed completely, which means the longest ones will get a hair of inward "crimp", .001 or maybe .002.), and use magnification to check it. No 1/4 turn, or 1/2 turn, no measuring, just slowly adjusting until I had it right.

 

[Walkalong]

What do you have to adjust after the year is up?

When they toss up an easy one, ya just have to hit it out of the park.

 

[RecoilRob]

For sure check the crimp to make certain it's enough but not too much. Another thing that can affect feeding is the OAL being too short which can allow the round to catch on the chamber a bit as it's going in...which can deform it enough to make it stick. When using FMJ's it's easy to match factory ammo but other bullet types can be a little more challenging to get them set to the proper feed length. If you compare the silhouette of your loaded round with a factory FMJ...note where the bullet will first contact the feed ramp and be sure to keep the new bullet within the confines of the FMJ profile. TC or SWC's often need a much different OAL to feed properly even if they plunk OK.

 

[peterk1234]

For sure check the crimp to make certain it's enough but not too much. Another thing that can affect feeding is the OAL being too short which can allow the round to catch on the chamber a bit as it's going in...which can deform it enough to make it stick. When using FMJ's it's easy to match factory ammo but other bullet types can be a little more challenging to get them set to the proper feed length. If you compare the silhouette of your loaded round with a factory FMJ...note where the bullet will first contact the feed ramp and be sure to keep the new bullet within the confines of the FMJ profile. TC or SWC's often need a much different OAL to feed properly even if they plunk OK.

That is an interesting point. I noticed that some of the problem bullets are a bit crooked, I assume from hitting something when trying to feed. I certainly have the ability to increase the length a bit.

 

[rfwobbly]

What do you have to adjust after the year is up?

Jim, you may not have to adjust a thing, but you always need to account for wear. Actually, I check the first round of every run to make sure everything is in spec.

However, the point of the statement is that while the die can be difficult to "dial in", once you find that happy place (however that might be determined) it's worth the extra effort because the setting doesn't change for a long time.