Jump to content
Brian Enos's Forums... Maku mozo!

Failure To Chamber


Supermoto

Recommended Posts

I am getting failure to chamber with my open gun, which has about 2K rounds thru it.

It has a recoilmaster and an Aftec. All the rounds drop in the chamber fine. The jam happens with all mags at no particular time.

I have tried compressing the aftec springs, ran great for one range trip

I am going to try adding more crimp as mine is around .382-.383 and I can set back the bullet if I press down on the round.

I am running .38 super

PMC brass

8.4gr 4756 or 8.2 3n37

zero 125 jhp or Montana 124gr JHP

any other suggestion?

I have attached a picture of the jam

post-4994-1170902933.jpg

Edited by Supermoto
Link to comment
Share on other sites

It does sound like you need more crimp. The ability to set the bullet further into the case can lead to pressure spikes. A good rule of thumb for setting crimp is take the side wall thickness multiply by 2 and add it to the bullet diameter and set it to about .001 or .002 less than the number you come up with.

Most super cases seem to run about a .012 case wall and with a .355 bullet it would put you about where Larry suggests.

If after doing so the problem still happens. You can file down the aftec springs but do so in very small amounts. Aftec springs can be a little funny. The first set I had I had to trim them because they were way to tight but later on when I decided to replace them the replacement pair fit perfect.

Link to comment
Share on other sites

Polish the part of the Aftec that the case rim slides into, JUST polish it because that is all it needs. Drop down to one full length spring in the Aftec. Figure out why your sizing die isn't doing the job, if you can push the bullet back in the case crimp isn't going to fix it. The case MUST hold the bullet tightly enough before crimping to prevent setback or you aren't going to prevent setback, it is just that simple. Setback blows guns up, figure out that problem first and do it ASAP.

Link to comment
Share on other sites

I am getting failure to chamber with my open gun, which has about 2K rounds thru it.

It has a recoilmaster and an Aftec. All the rounds drop in the chamber fine. The jam happens with all mags at no particular time. I have tried compressing the aftec springs, ran great for one range trip I am going to try adding more crimp as mine is around .382-.383 and I can set back the bullet if I press down on the round. I am running .38 super

PMC brass 8.4gr 4756 or 8.2 3n37 zero 125 jhp or Montana 124gr JHP

any other suggestion? I have attached a picture of the jam

The picture you sent looks very much like what I got when I tried to chamber one of my loads that somehow missed the crimping station. Your ability to press the bullet into the case is a nother indication of the same problem. The first place I'd look is at the crimp. Take the barrel out of the gun and see how the round fits in the chamber. If that's not the problem, check the extractor. It may be a bit too tight.

Lee

Link to comment
Share on other sites

As they say, polish the surface on the AFTEC that the case rim rides up.

Also with the aftec you can dial in the tension by using one new spring & one old spring, or one full spring & one clipped spring...

The crimp wouldn't affect your chambering IF you drop check your ammo & it all falls out of the chamber. Until this problem goes away I would use the actual barrel, not a gauge.

Link to comment
Share on other sites

Also with the aftec you can dial in the tension by using one new spring & one old spring, or one full spring & one clipped spring...

Or remove one spring entirely ...

You can also check the extractor length to see if it is too short. Measure the internal dimension from the hook to the slot where the slide stop pin rides and post the resulting measurement.

Link to comment
Share on other sites

The crimp wouldn't affect your chambering IF you drop check your ammo & it all falls out of the chamber. Until this problem goes away I would use the actual barrel, not a gauge.

The crimp will affect chambering. Drop checking into the barrel isn't the same. When feeding, the round is coming in on an angle, with some side loading of pressure. Insufficient crimp has a sharp edge rubbing against the chamber wall, and scraping any crud as it is forced in.

Link to comment
Share on other sites

Before you go jerking around w/ the AFTEC, take a close look in there - is the case rim even touching the extractor, at that point? Looks like its in that point of the feed cycle where it might not yet be in contact w/ the lower part of the hook.

If you can set the bullet back, you're expending some part of your recoil spring energy into shortening the round instead of feeding the round, and you may not have enough recoil spring left to push the round under the hook, regardless of how tight the extractor tension is set to. You need to correct this condition first. For reference - I shoot .38 Supercomp brass, .356 bullets, resize in a Dillon .38 Super die, and crimp to .378 at the mouth. No bullet setback at all. ;)

2nd thing to try, if the crimp doesn't correct it - as others have said, yank out the RM and try a straight rate spring.

3rd think to look at would be the extractor, but if and only if the rim of the case is making contact with the extractor when the slide comes to a stop, as in your picture.

Again, I can't tell from that pic if the rim is touching the extractor or not, but you should be able to see if you angle the gun around correctly. It has the appearance being in the zone where it might be touching, or it might be just before that, as the cartridge tries to "round the corner" up into the chamber....

Did Dan Bedell build that gun (looks like one of his???)??? If so, what has he said about it???

Link to comment
Share on other sites

It is one of Dan's he said crimp also. He tested the gun before he sent it. it ran perfect with my mags, so the only change is my ammo

I shot today about 175rounds, some PMC some Winchester brass,

The PMC went thru a FCD since it was already loaded

The Winchester was loaded with more crimp.

Had one failure, PMC with montana JHP the round did not fully chamber. it was also set back.

I think the round may have hit the feedramp, compresses, bounced up then the spring did not have enough force to chamber it. every once in a while it feels like the slide is closing slower but the round chamber

another problem is. I can't get crimp down to .378-.379 with out shaving copper if I seat and crimp at the same station. and a heavy crimp with the FCD doesn't get me to .378 with out deforming the bullet

I resize to .379, bell to .382 and then a crimp gets me to .380-381. I can get the bullet to set back if I push really hard with my palm, even with a heavy crimp. I am using a lot of force, so is this normal or should the bullet not move at all?

At home I try to recreate the jam, by letting the slide move slowly forward to pick up the round. when it doesn't chamber, it looks like it is getting to the extractor, a light tap to the case from underneath gets the round to chamber, but it still does it even if I remove a spring on the Aftec. If I let the slide go at normal speed, it chambers, so something must be slowing down the slide when shooting

all the round chamber gauge fine.

Should I try FMJ instead?

I have ordered a U-Die to see if it makes a difference.

I will try again tomorrow

Link to comment
Share on other sites

Get an EGW U-die that will under size the case slightly. Bullet seating and taper crimping should be done at separate stations. Seat the Zero's or M/G to 1.230 and taper crimp to .381 and you should be good to go. The undersized case will hold the bullet from any set back. Load an empty case and pull the bullet ,it should'nt have any mark from the taper crimp. Setting up the aftec is another issue. If the gun came from Dan you should not have to mess with it. If you feel it needs attention give him a call and he will probably walk you through it

Link to comment
Share on other sites

Get an EGW U-die that will under size the case slightly. Bullet seating and taper crimping should be done at separate stations. Seat the Zero's or M/G to 1.230 and taper crimp to .381 and you should be good to go. The undersized case will hold the bullet from any set back. Load an empty case and pull the bullet ,it should'nt have any mark from the taper crimp. Setting up the aftec is another issue. If the gun came from Dan you should not have to mess with it. If you feel it needs attention give him a call and he will probably walk you through it

Have a U-die on the way. I found an issue with my belling/powder die, it was full of crap. now I not getting any set back and can crimp to .379-. 378

Dan has been very helpful, I have talked and emailed alot, To bad I can't get him to make my reloads :D

Link to comment
Share on other sites

Lee pro 1000 :(

Mike,

Maybe you now see why Dillon presses rule in this game. You cannot properly crimp while seating. Tony Barone is right on that. I knew Tony before he moved to Arizona, years ago :) Dan has an excellent reputation. As he told you, the gun functioned before he sent it. He knows how to load ammo, and probably uses a Dillon :lol: Minor adjustments on crimp will make a big difference. As I posted earlier, dropping a round straight into a gage is NOT the same as the feeding cycle in a pistol.

I know you load .45ACP, but, your Smith has a stock barrel, and the chamber is probably looser. The .45ACP is a VERY forgiving round.

Tweak the ammo, not the gun.

Note: On another forum, SuperMoto stated that he didn't need no Dillon press, his Lee was just as good, and much less costly.

Edited by Dan Sierpina
Link to comment
Share on other sites

Note: On another forum, SuperMoto stated that he didn't need no Dillon press, his Lee was just as good, and much less costly.

Told you so! :P

:P will I have to eat my words? Never!!! even if I'm secretly loading on a Dillon.

LEE is good LEE is great Follow the LEEder :wacko:

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...