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

need some HELP FTF in .38 SC top end


Mat Price

Recommended Posts

ok guys I have an issue I can't seem to resolve. I have intermittent FTF issue with a .38 super top end. I also run a 9 major top end on this same frame it runs 100 % all the time every time full of mud or sand using the same mags I just pop out the super grams springs and followers and put in my grams springs and followers and psacers for the 9. this top I just got fit and was used on another frame dont have any info on how it run on the other frame. it run great for about 500 rounds then started having FTF on. It seems to get worse as the chamber gets dirtier and is almost guaranteed if the mags get fine dust in them after a dusty mag change for example.

the FTF looks like this.

jam1.jpg

jam4.jpg

jam2jpeg.jpg

.38 super load

9.9 grains of hs-6

115 FMJ rn p delta

1.235 oal Wolf SRP

this is what I have already done to try and remedy the problem

1 started with a 9 lb spring went all the way to a 13 did not help

2 used to different extractors the original and an aftec. I tried compressing the springs running just one spring I polsihed the the hook the tension seems to be ok.

3 today I noticed my followers where sort of bent and favoring the right side of the mag and not coming up fully loosing some spring tension the last round in my big stick would literly just fall out. so I tuned the followers a little removed some material off the right side and got them better. this seemed to help some.

4. my sized case mouth is .378 my crimped case is .378 I increased my to .375 and none of the 20 of them ftf but it was only 20 rounds.

5.I have not tuned the feed lips on these mags as i never had to do anything to them with my 9 major gun but stick them in and they run 100% and I not even sure how to measure them I will include pics of that as well.

6.I use a lee size die in station 1 a EGW undersize die in station 2 a expander/ powder drop station 3 rcbs seat die and lee factory crimp die load on a dillon 650

here is the photos of the feed lips on my two main mags being measured not sure if i am doing this right.

maglip.jpg

maglip2.jpg

this is the measurements I got

170 = .371 in the front and.359 rear

140= .363 front and .357 rear

I am at loss again this seems to happen intermittently but is gurenteed to happen after a mag change and the mag has gotten some dust in it even after brushing it out or when the gun is dirty. any ideas guys?

Edited by Mat Price
Link to comment
Share on other sites

Mags seem to be a bit 'out of spec' .. I recommend the Dawson Mag tune-up kit ... got one last year ... no more 'intermittent' issues for me ...recommended measures are .355 on the back and .360 in the front.

Can be another plethora of things ... but mags are always a good start. New springs and followers never hurt either.

Link to comment
Share on other sites

well I fiddled with my big stick some not sure how to correctly close up the gap in the front. I could on the last round in my big stick reproduce the problem every single time hand cycling rounds through. three round first chamber ok eject ok 2 chamber ok eject ok last ftf. so I just grabbed a pair of channel lock and gave the front of the feed lips a squeeze and kept measuring till I got around .359. I can't reproduce the problem any longer hand cycling the gun. I also used all kind of junk ammo to match ammo ammo and if fed every time. So maybe this is my issue.

Link to comment
Share on other sites

Looking at the picture of the jam, it appears that the rim doesn't want to slide up/under the extractor. Are you SURE that the extractor tension isn't too tight? Does it do it on the last few rounds out of the mag, or also when the mag is full? If it only seems to do it when you are towards the end of the mag, it would point to not enough spring pressure.

Link to comment
Share on other sites

Mags issues must be worked out first. Then on to other things. If it runs good for 500 and then doesn't want to feed your chamber may be cut a little tight. Is the problem feeding or extracting?

Link to comment
Share on other sites

I think RH45 is onto something.

Is the Aftec for a 38 Super or 9mm? The semi-rimmed super won't go under an extractor for a 9 as easily.

Unless you're using SuperComp, then forget it.

And, maybe it's the lighting, but how old is that brass? Looks pretty beat...maybe some new brass might help.

Link to comment
Share on other sites

I have an Aftec tuned by Cameron on my 38 Super Comp with zero issues to date after many thousands of rounds.

My advice is do one thing at a time, mags, springs, followers, mag catch, extractor, chamber.

Not the fastest way but the best way ...

Link to comment
Share on other sites

Yep mags today. I have 40-45k rounds through my aftec on the 9 major top then 300 on the same extractor in super top end till I bought a new aftec both tuned and fit by me! I kind of pride myself in fitting Aftec extractors. I fit one for an aperio in 40 that has about 20 k flawless through and did 9 for other people that has never come back.

I have never tuned mags before so this is new to me. I have always just through guts in tubes and they run 100%.

But the on thing I think is the key to all of this is my crimp. Even though I was finishing with .378 I don't think the where right I think the case mouth may be scrapping on the way end. So I increased crimp to .375 on these 200 today so at the range now let's see what happens.

Link to comment
Share on other sites

Matt I know this may be a dumb question but do you have a shock buffer installed. I was having a similar problem with my Cameron's super comp, removed the shock buffer and haven't had the problem since.

Link to comment
Share on other sites

Naw no shock buffer. But right now I am taking a break to let bbl cool. I have went through each mag and I am 75% with a7 lb spring 90 % with an 8lb spring 100% with a 10lb spring all in old ammo before the gun would not at all with an 8 and no jams that require more than a gentle push forward of the chamber. After my bbl cools a bit I am going to crimp ammo and 9 lb spring for 200 rounds

Link to comment
Share on other sites

Oh hey guys here is a tip lol. Don't forget to put the mount screw cover back on your cmore after you remove it. It hold the diode in place haha. But with seriousness I hear people say all the time they can't keep zero. That's one thing to check

Link to comment
Share on other sites

Well after 200 rounds I have learned these things.

1. The mags are good because i have the problem with all 4 mags

2. I need to go back to 90degree mount or tune my ejector. 3. I have isolated the problem to only occurring when the bbl is very hot and dirty. So maybe it is just a simple issue oh hs-6 is just plain to dirty to run in this chamber with out some chamber work.

This frame and new slide is going to Jeff abernathey Monday since I cracked my 9 major slide I am going to send this top end along with it and let him put some better trained eyes on it than I have.

Link to comment
Share on other sites

Hello: If the ejector is too long it causes problems. If the barrel does not have a nice radius it will cause feeding problems. If the extractor is set too tight it causes problems. If the breach face on the left side is not smooth--you guessed it. I set the feed lips to 0.363" front to back for 38SC. Thanks, Eric

Link to comment
Share on other sites

I wish I would have come across this thread sooner. I could have told you it is definitely NOT a mag issue, especially with your measurements. Breech Face and extractor are the two places to look, and you may have fixed it with the face.

Link to comment
Share on other sites

Lol one day 100% next Nadda. It's not tunable it am convinced now it either had the wrong link for this frame or the lower lugs are not cut correctly for this frame even though the local gs said it was good. Jeff will figure it out.

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...