38 Super resizing vs FTF ??

HKMark23

HKMark23

CGN Ultra frequent flyer
Rating - 100%
19   0   0
Location
The Far East
Began shooting 38 Super using new, un-resized, Winchester brass. All rounds chambered flawlessly and the gun recycled beautifully. Now, after my second reloading of this brass, FTF problems have developed. I've used the Lee factory crimp die for both 1st and 2nd loadings and all rounds pass through a checking block prior to use.

The only difference I can identify is that this same brass is, of course, decapped and resized prior to its second loading. My Redding Tungsten Carbide resizing die does reduce brass circumference to less than its original size. I'm wondering if this is the problem. Anyone else experienced this?
 
When I hear FTF I assume that the firing pin has hit and the cartridge has failed to fire, is this what is happening or are your rounds jamming up in the cycling process?
 
Its a custom race gun built on a STI frame. I picked it up here on CGN. I'm using 124 gr AIM and BDX bullets over 8.2 gr Vv N350 for a MV of 1380.

As I mentioned earlier, the pistol has performed flawlessly up until my Winchester brass became 1F and I resized it. That's pretty much 1000 flawless rounds fired with new unsized brass. Problems have only arisen since the brass was resized. Also, on the day I had problems, my rounds chronographed at 1430 f/s. I expect that reduced volume has caused this and plan on reducing my load to 8.0gr or so. Hopefully this will get things running sweet again.
 
HKMark23 said:
Its a custom race gun built on a STI frame. I picked it up here on CGN. I'm using 124 gr AIM and BDX bullets over 8.2 gr Vv N350 for a MV of 1380.

As I mentioned earlier, the pistol has performed flawlessly up until my Winchester brass became 1F and I resized it. That's pretty much 1000 flawless rounds fired with new unsized brass. Problems have only arisen since the brass was resized. Also, on the day I had problems, my rounds chronographed at 1430 f/s. I expect that reduced volume has caused this and plan on reducing my load to 8.0gr or so. Hopefully this will get things running sweet again.
Click to expand...

Which bullet was running well previously? Which are you running now? I'm going to guess that you ran the BDX first, then switched to the AIM's. Odds are, that's where your problems lay.

Don't sweat the sizing die issue. The only time you are going to have issues with brass is as the cases swell just ahead of the extractor groove but below where the sizing die can reach.
 
This might be off... but I will fire this question anyway. Did you buy a new magazine or used a different magazine since the first time you successfully fired your reload????
 
Pull your barrel and drop a sized case in. Then a loaded round. It's possible that the AIM bullet's nose profile is different enough that it's hitting the rifling. It is also (I believe) .0005 fatter than the BDX. .3555 vs .356

Another consideration is the OAL. If you are using a round or tapered cone seating plug, it's possible that while you may have left your die settings the same between bullet types, you actually have two different OAL's. The seating die may make contact with the bullet in a different place and seat it to a different OAL.
 
The problem developed during a match, (match #3 for this gun) and since I do have 5 new mags and none are marked it could be a problem mag that I wound up using more often in match #3 I suppose. The problem isn't consistent but now that I think of it, it may be related to occasions when I've started a stage with a round in the chamber followed up with a fresh mag in order to get an 11 round start. I'll investigate the magazine possibilities further thanx.

As far as bullets are concerned, during match #3, I used a mix of BDX (50) and the rest (150) were AIM. I had problems with both varieties where I previously had no problems with the AIM. This is why I'm stuck on the notion that the problem is brass related, as other than the 50 BDX I used, this is the only component that has changed. Otherwise, as mentioned above, I may indeed have a mag problem I simply didn't identify during the first 2 matches, unlikely but possible.

Thanx for your suggestions guys. I'm obviously going to have to do some more (non match) range time to accurately identify the problem.
 
There may be a few factor, but I had an FTF problem with my 38 SC when I bought new mags and this worked for me:

Fire a few rounds from each mag, separate the mag where you have the problem.
CHECK the opening of the mag lip using a caliper. Most likely the problem mag has a wider opening, which is possibly causing the problem. Adjust the lip opening.
 
i would check your OAL. different bullets require different OAL. what works for the Aims won't necessary work with the BDX. Mixing bullets is a sure recipe for disasters especially in some guns. My STI will feed just about anything however Cathy's SVI is very picky about what it will and won't feed.

Also who's chamber checker are you using. All chamber checkers are not the same.
 
Can you describe the FTF a little more?

Does the round make it up under the extractor completely, does it make it so that the bullet part of the cartridge gets into the chamber or does the cartridge stop short in the chamber just a little leaving the slide open just a bit?

If the last, check your resizing die to ensure it is actually touching the shell plate when all the way down. The first time you loaded the brass, it was 99% presized, but after it went off the first time, it needs a lot of resizing. Taking the barrel out and dropping the rounds into it should give you some indication what the round is doing at the end of the feeding process too. Like Canuck223 said, the AIM bullet may be engaging the rifling and you may have to have 2 OALs - one for AIM and one for BDX.

The sad news is at some point in that 38 Supers brass future, it will develop a shoulder at the very bottom which you can never get to with a standard sizing die and become useless. But not after one loading.
 
Freedom Ventures said:
Can you describe the FTF a little more?

Does the round make it up under the extractor completely, does it make it so that the bullet part of the cartridge gets into the chamber or does the cartridge stop short in the chamber just a little leaving the slide open just a bit?

If the last, check your resizing die to ensure it is actually touching the shell plate when all the way down. The first time you loaded the brass, it was 99% presized, but after it went off the first time, it needs a lot of resizing. Taking the barrel out and dropping the rounds into it should give you some indication what the round is doing at the end of the feeding process too. Like Canuck223 said, the AIM bullet may be engaging the rifling and you may have to have 2 OALs - one for AIM and one for BDX.

The sad news is at some point in that 38 Supers brass future, it will develop a shoulder at the very bottom which you can never get to with a standard sizing die and become useless. But not after one loading.
Click to expand...

I really do need to do a little diagnostic shooting. Being as this difficulty arose during a match, I'm afraid I was more interested in practicing my gun fumble and getting another bullet into the target than I was in observing the cause of the problem :redface:.

I do have an obvious bulge just forward of the cartridge head in all my resized 1F brass. I took this to be ok since the cartridges still fit the chamber gauge I bought from Evolution Gun Works in order to check em, (drop in/dump out). I actually thought my sizing die was reducing the brass diameter to less than its original spec. "Guess not :redface:".

My COL has thus far been based on the longest that would fit into the mags without binding. This seemed to serve me well until now but I'm sure I can afford to shorten em a few thou.

One thing I did notice during my gun fumbles was that cartridges often seemed to wind up in front of the chamber but reversed. Now I'm guessing that the cartridges may have partially fed initially and were flipped over by the extractor when I pulled the slide back to check things out. "NO, I didn't put em in that way :D.

My sizing die doesn't touch the shell holder at the top of the stroke but its real darn close. I'll adjust this. I'll chamber check a sample of my 1F reloads and shorten my COL a tad on spec.

Again, thanx for your help guys. Now I have a place to start. I'll make these adjustments and be off to the range the next time my wife lets me have the car.
 
HKMark23 said:
My COL has thus far been based on the longest that would fit into the mags without binding. This seemed to serve me well until now but I'm sure I can afford to shorten em a few thou.
Click to expand...

The EGW Chamber gauge is good, but won't tell you about the bullet shape engaging rifling. Only your chamber is going to do that.

If you drop a bullet into your chamber, and then use your thumb to give it a little push, it should not grab the rifling. It should then drop out freely when you hold the barrel upside down. If it doesn't fall out, it's too long and grabbing something.

FYI - AIM changed the bullet shape of thier 124s this summer, changing the ogive/ shoulder position - so keep a close eye out if you bought your supply in different batches. They're not labelled.
 
nognog said:
There may be a few factor, but I had an FTF problem with my 38 SC when I bought new mags and this worked for me:

Fire a few rounds from each mag, separate the mag where you have the problem.
CHECK the opening of the mag lip using a caliper. Most likely the problem mag has a wider opening, which is possibly causing the problem. Adjust the lip opening.
Click to expand...

This shows promise!!

Checking my mags I discovered 2 with lip gaps of .367 and .370 respectively, whereas the other 4 have gaps between .362 and .364. Brass in the 2 wide mags could be toggled (stove piped) easily with gentle upward pressure at the mouth of the brass, whereas the rest of the mags hold the brass securely in a horizontal position.

My resized brass has a consistent diameter of .372. The wide lipped mags weren't holding onto much. I've corrected this situation and all mags now hold the brass securely in a horizontal position. The nominal diameter of unresized .38 super brass is .384. I still suspect that this .012 reduction in diameter has been at least part of the problem.

I've given samples of rounds loaded with both AIM and BDX the "clunk" test. All passed. I'll try this again using thumb pressure as suggested.
 
Update: I retried the "clunk" test applying pressure to the round to force the bullet(s) into the rifling. All rounds dropped out of my chamber freely, both AIM and BDX.

I'll go to the range on the weekend to chrony a few 1F rounds using less powder and see if I can get the problem to repeat now that the mags have been adjusted. I'm hopeful this has done the trick.

Thanx again All.
 
Just finished a flawless session at the range with a mixture of AIM, BDX 9mm and BDX 38 Super bullets, all 124 gr. Did the 1 in the pipe, 10 in the mag thing and even mixed em up in the same mag. FYI, the 38 super bullets produce a longer COL by about 10 thou than the others and AIM velocities were higher than both BDX, on average, by about 12 f/s. Other than these differences, everything functioned about the same. Now, if things will just work this well during my next match.

When I originally loaded my rounds using 8.2 gr Vv N350 under the AIM, my average MV was 1380 f/s. The sized brass now produces 1430 f/s with 8.2gr and a reducing the load to 8.0 gr under the AIM brings me back to 1385 f/s ,, "gotta be the reduced case diameter".

Anyhow, 8.0 gr Vv N350 keeps me in "Major" and the gun is functioning well. Thanx again for your help guys.
 
Glad to hear things went well at the range. NOW stick to the working load data, COL etc..... Never use an untested mags (again :) ) or untested load data with your gun in a macth. :)
 
You must log in or register to reply here.
Back
Top Bottom