Slide not fully going into battery

[tranders]

Loaded 185 lswc Missouri bullets over 4.5 grains of Titegroup. Firing these out of my Sig Nitemare the first round fires fine but the next round the slide will not fully go into battery. A mag drop, clear the round, install mag rack slide round fires and slide not fully into battery again.
These were loaded to 1.16 oak. Powder charge seems good.
Any ideas?
Thanks!

 

[notaglockfanboy]

Plunk test, always do a plunk test with your barrel. This will eliminate range surprises.

 

[tranders]

I forgot to mention these rounds were plunk tested and were fine.

 

[MEHavey]

You are below minimum load and short-stroking the slide.
Pick the charge up and/or install the next lower spring.

 

[tightgroup tiger]

Yea, I have an idea. Check the neck tension on your loads.

I have to wonder if the bullets are slipping in the cases.

Put some of them against something unmovable and push as hard as you can. You shouldn't be able to move any of them. I can't move any of mine.

I hurt my hand before that can happen.

1.6 is pretty far out, others mentioned a plunk test. It's really good advise but if your neck tension is not up to par to hold the bullet you loaded it won't matter.

But it sounds like your loading 40S&W, you will usually experience setback before you experience set-forward.



To me it sounds like your OAL is too long to account for the + and - of your OAL and your first round happened to be one of the short ones.

 

[243winxb]

185 lswc Missouri bullets

My guess on cartridge is 45 acp.

 

[tranders]

Yes. 45acp and loaded to 1.16 oal

 

[steve4102]

Loaded 185 lswc Missouri bullets over 4.5 grains of Titegroup.

Lyman cast bullet handbook has you well Below Minimum.

Where did you get your cast bullet data from?

 

[tranders]

According to the Lee loading manual 4.2 is minimum and 5.2 is max using Titegroup with 185 lead bullet 45acp.

 

[tranders]

The more I keep comparing the plunk test with factory ammo I'm thinking I need to crimp more. Factory ammo sits below barrel hood and my reloads are even with hood

 

[243winxb]

Feeding of cartridge to chamber

Does this happen with all magazines? Feeding can slow the side at times. How the case head slides up the bolt face under the extractor can also slow things down. Load a few rounds/eject and see if there is a very light crease in the middle front of the brass. The taper crimp is still the most likely place to look. Brass of different trim length will crimp differently.

 

[GLOOB]

Try locking the slide back, loading in a mag, and releasing the slide. If this causes the same jam, then you have something to test at home in front of your press. If the round feeds fine, then I would increase the charge by a 2-3 tenths and try again.

If the round jams, first thing I would do is to make a dummy round with NO PRIMER (because you don't want to accidentally lose track of it), and start with a longer OAL, the longest that will fit in the mag/chamber. If it feeds, then work the OAL down by a hundredth or so at a time, while repeating the test, to find out the shortest OAL that will feed, and then you can load somewhere in the middle.

 

[MEHavey]

OP has already stated the pistol feeds fine with a full rack on the slide.
Ergo it follows the likely problem is that the cited load is not fully functioning the slide.

Lyman has the Min load as 4.8gr/TiteGrp, OP is running 4.5gr
QuickLoad and Lyman both agree that probable pressure is <65% rated
Ergo it follows again that the slide is not fully functioning against the spring.

RECOMMENDATION: Kick the charge up to at least 4.8/5.0gr TiteGrp

 

[j357]

+1 on light load being the issue.

1.16 OAL should be right on the money for 185 LSWC.

 

[tranders]

Thanks all for the advice. Going to increase crimp a bit and go from there.

 

[243winxb]

Using an auto pistol barrel to find a MAX O.A.L with your bullet

Walkalong has a great thread, with many photos . http://www.thehighroad.org/showthread.php?t=506678

 

[Laphroaig]

I'm not sayin' that this is your problem, but I had the same issue the other day with 200 gr. SWC's. One or 2 rounds per mag wouldn't chamber fully. My loads were all good plunkers. When I got home I took my pistol apart and found that the chamber was dirty and restricted the cartridge.

I cleaned it and they plunk again. I estimate that I had shot 60 to 80 rounds since the last cleaning.

Laphroaig

 

[MEHavey]

Going to increase crimp a bit and go from there....

The OP says,

- The rounds pass the plunk test
- Then the OP does not have a crimp problem.

IF on the other and...
- The slide when released from full rear/locked position chambers the round.
- BUT the slide won't fully chamber the round when fired by a below minimum load...

THEN...
The OP has a load problem.

RECOMMENDATION (again)...
- Get the load up to where the slide functions as designed.

 

[Sunray]

1.16" OAL is too long. 1.135" is max for a 185.
4.5 grains of Titegroup is below minimum for a jacketed bullet. No 185 grain cast data on Hodgdon's site. Lee's data comes from Hodgdon anyway. Suspect it's the OAL and not the crimp(use just enough to hold the bullet in place. Heavy crimping isn't necessary.) or load.

 

[joneb]

Does the extractor easily engage the shell base, or does it take some effort to engage? Insert a empty shell in barrel and slowly release the slide, if you need to push hard to get the extractor to engage this could be part of the problem.

 

[MEHavey]

1.16" OAL is too long.

- OP has stated it passes the plunk test.
- OP has stated it functions just fine w/ a full-stroke slide release.
- Lyman lists the 185 RCBS #45-185_SWC (Cast) Min load as TiteGrp/4.8gr & OAL as 1.18"
- I'm running these 185gr ProofMarks at 1.16"

I don't think it's OAL.
I again recommend getting charge up to [more] fully function the slide.

 

[joneb]

Another possible cause, I found that seating and crimping in one step can result in lead and or lube on the case mouth when a longer than normal case is loaded. this gunk can build up in the chamber.
As already mentioned working up the load or using a weaker recoil spring may solve the problem.

 

[tranders]

I did have some gunk build up in the chamber after only trying to fire 10 rounds.

I cleaned the barrel and crimped a bit more. Will see if that works for the next range session. If not,I will pull bullets, increase powder charge, and shorten up oal.
My one concern is my up to date Lee manual shows 4.2 grains{Titegroup} as a beginning load and 1.14 as a min oal {185 lswc}.

Thanks for all the help!

 

[steve4102]

As already pointed out, if your loads pass the "plunk" test odds are it is not your crimp. To much crimp can case many problems.

As already pointed out your load is weak, below Minimum according to Hodgdon. Bring the charge up to acceptable levels, first.

 

[Curator]

If the cast bullets you are using are too soft for the chamber pressure, there is the possibility of lead shavings building up at the end of the chamber, preventing the next round form fully going into battery. I have had this problem with .45ACP cast bullets below 12BHN with fast burning powder like TightGroup. Using bullets with hardness of 15+BHN and it goes away.