Extraction problems - power factor ? - powder burn rate ?

[hkvp9]

I've had some extraction problems with my STI DVC open gun for a while. I played around with the stock extractor and also installed a Aftec extractor and followed all the instructions but still have some intermittent extraction issues. So I am wonder if ammot power factor or powder burn rate can have any effect on this. Any ideas ?

 

I'm shooting a DVC open gun chambered in 38SC using Starline brass, Montana Gold 124g JHP and  7.5g   Winchester Autocomp powder for a power factor of approx. 176.

 

Would this high of a power factor cause extraction problems ?

 

Is the burn rate of WAC too fast ? Should I try a slower burn rate powder like maybe VV3n38 ?

 

Thanks in advance for your help

[ltdmstr]

Likelihood of power factor or load being the problem is close to zero.  Have you checked the extractor tension?  Was either extractor fit properly?  More than likely the stock extractor wasn't done right.  And the AFTEC isn't a drop in part.  There are many threads on the forum that explain how to do it.

[hkvp9]

5 minutes ago, ltdmstr said:

Likelihood of power factor or load being the problem is close to zero.  Have you checked the extractor tension?  Was either extractor fit properly?  More than likely the stock extractor wasn't done right.  And the AFTEC isn't a drop in part.  There are many threads on the forum that explain how to do it.

Yeah I have read most of the threads and some of the videos including the one on the STI site. Played around with the stock and the Aftec ones quite a bit also. 

[sauza45]

I don’t think the load could be the problem unless the brass is not right. But I think with 38 SC

you would be better off with a different powder.

[gerritm]

I had a DVC in 38 super and had extraction issues from day one. Tried an Aftec and it got better by playing with the springs and tension, but never solved completely. Went to a Brazos tuned extractor and set the tension pretty tight and it was much better. Never solved it completely.

 

What is it actually doing? Reason I ask is when I had the original full size C-More & factory mount a lot of the times it was extracting OK but hitting the bottom of the mount and stove piping. Could tell by all the marks on the bottom of the mount. Eventually got a crack in the comp & STI took very good care of me on the warrantee work and I had them replace the 38 super slide with a 9mm major. I then replaced the mount with a smaller Everglades mount & an RTS2 dot. Solved it then. They put a stock STI extractor back in it with the new slide and returned the Brazos.

 

I used HS6, 124 PD JHPs, with around 7.7grs.

 

gerritm

[vetts1911]

I have a DVC in 40 that runs flawless. My friend bought DVC 40 and had the same issues you are having. He found the ejector wasn’t fitted and was moving causing the issue. Another shooter learned this same lesson with his brand Trojan 9mm with a broken ejector fresh from the factory. Did the same thing, bought a new extractor, tension tool, and then sent it to STI. STI repaired it (no charge) and told him the ejector was broken. 

[hkvp9]

6 hours ago, gerritm said:

I had a DVC in 38 super and had extraction issues from day one. Tried an Aftec and it got better by playing with the springs and tension, but never solved completely. Went to a Brazos tuned extractor and set the tension pretty tight and it was much better. Never solved it completely.

 

What is it actually doing? Reason I ask is when I had the original full size C-More & factory mount a lot of the times it was extracting OK but hitting the bottom of the mount and stove piping. Could tell by all the marks on the bottom of the mount. Eventually got a crack in the comp & STI took very good care of me on the warrantee work and I had them replace the 38 super slide with a 9mm major. I then replaced the mount with a smaller Everglades mount & an RTS2 dot. Solved it then. They put a stock STI extractor back in it with the new slide and returned the Brazos.

 

I used HS6, 124 PD JHPs, with around 7.7grs.

 

gerritm

I have the same problem with casings hitting the bottom of the full C-More mount although I haven't had any stovepipe problems.

[gerritm]

What exactly is it doing when this happens?

 

I have a shooting buddy who shoots a Tanfo Extreme open gun and changed his major load of HS6 up a couple of grains to get a little more gas to operate the popple holes & comp. The minute he did that he started to have extraction/ejection issues. Went back to his old load and it stopped. So depending on what yours is doing, it can be the load. Mine was always the extractor. 

 

The idea of the ejector being bad also happened to me on my DVC open. Had a factory one bend. Bad tempering of the metal and I replaced it myself. The way the ejector is beveled can also change the way it ejects, but not know what exactly is happening to you is hard to figure.

 

Loved the DVC open gun, and eventually got rid of it due to a hand injury and not able to shoot open, went to PCC. But now started back and have a CK Arms Hardcore it it runs great.

 

gerritm

[TRPOperator]

 

4 hours ago, hkvp9 said:

I have the same problem with casings hitting the bottom of the full C-More mount although I haven't had any stovepipe problems.

Based on this statement it could be the tuning of the ejector and not so much the extractor. If the angle of the ejector is off it can throw brass upward first then out causing it to hit the mount. 

 

What exactly are the issues? Brass falling back in the chamber? Stove pipes? But I haven't seen in the post exactly what it was doing. Gas and pressure could attribute, but so can several other things.