SLM Posted May 9, 2009 Share Posted May 9, 2009 I picked up a Doug Jones built Open blaster with a SVI slide with IBF on it a few months ago and I've been racking my brain trying to figure out why I'm getting primer flow with it. With the exact same loads neither of my other guns has any flow. I'm even getting flow on this gun with 155 PF ammo. It leaves a ring around the firing pin indent with a little material smeared off. Imagine what a Glock primer looks like except round. I've tried both a Limcat extended and SVI firing pin in the gun. So finally I get really serious and start looking at the breech face and lo and behold... The firing pin hole has a chamfer on the breech face. I'm pretty sure this is where the flow is coming from. Do they all have this chamfer, is it something Doug added for some reason or is it a bad breach face? One other thing this gun does that my others don't is that when the hammer is down it's back from the firing pin stop. I can push it forward (naturally) but the firing pin spring pushes it back. Yes, the spring is a short SVI spring. Some time ago I read on here that a longer main spring cap or hammer strut could "fix" that but I can't find the thread now. Would that help stop the primer flow? A new IBF? Link to comment Share on other sites More sharing options...
yoshidaex Posted May 10, 2009 Share Posted May 10, 2009 (edited) Call Brandon at SVI about a replacement breech face. I have a IBF but it has no chamfer whatsoever and I get zero primer flow with 172 pf ammo out of my 9mm breech face. As for your hammer down issue, its possible the hammer strut was shortened a bit to allow the removal of your magwell/mainspring housing/etc,etc without having to take the slide off. Try comparing the hammer strut in your SVI to another 1911/2011 and see if there is a difference in length. I don't think its a huge issue if it ignites primers reliably. Edited May 10, 2009 by yoshidaex Link to comment Share on other sites More sharing options...
SLM Posted May 10, 2009 Author Share Posted May 10, 2009 (edited) Common guys. I know I'm not the only one here with an IBF slide, LOL! Can ya'll post weather or not yours has a chamfer around the firing pin hole? Please?? EDIT: Thanks Yoshidaex. And yea, this is a 9 gun. Edited May 10, 2009 by SLM Link to comment Share on other sites More sharing options...
yoshidaex Posted May 10, 2009 Share Posted May 10, 2009 (edited) if the gun is running good, replace the breech face with the exact same one. the numbers are stamped somewhere. also when you get a replacement breech face, get an extra breech face screw just in case Edited May 10, 2009 by yoshidaex Link to comment Share on other sites More sharing options...
Service Desk Posted May 10, 2009 Share Posted May 10, 2009 I just checked a new SVI slide and two IBF's....... no chamfer, so I guess your smithy has done the chamfering. Have you tried a slightly heavier rated mainspring ? I normally use a 17lb in my PPC guns and a 19 or 20 in my IPSC guns. I also use small rifle primers and nothin' titanium from the mainspring cap up. PS - the IBF will require fitting to the slide, if you are not mechanically inclined take the gun to a gunsmith. Link to comment Share on other sites More sharing options...
larry cazes Posted May 10, 2009 Share Posted May 10, 2009 No chamfer on mine. Zero flow with a long pin. Link to comment Share on other sites More sharing options...
SLM Posted May 10, 2009 Author Share Posted May 10, 2009 Thanks guys. It looks like I'm going to have to get a new one fit. Now to find that number. Link to comment Share on other sites More sharing options...
z40acp Posted May 10, 2009 Share Posted May 10, 2009 Hey Ryan, don't forget that they come in different depth sizes. You will need to see what number is on your current one or measure the length from the back of the hood to the first lug. Link to comment Share on other sites More sharing options...
SLM Posted May 10, 2009 Author Share Posted May 10, 2009 I saw on SV's web site there's 5 different 9mm ones listed. I'm going to leave it alone until after A5 and I'll get it changed out then. The gun runs perfectly and I'm not willing to chance changing it with a couple Major matches coming up fast because I won't have the time to test it out right but it annoys me the way it is. It was also suggested to me to remove the main spring cap retaining pin to keep the hammer down on the firing pin a bit longer to keep the pin more flush with the breech face so I may try that also. Link to comment Share on other sites More sharing options...
RIIID Posted May 10, 2009 Share Posted May 10, 2009 What does the end of your firing pin look like? Your firing pin maybe piercing the primer. A dimpled breech face is an old way to prevent the primer from flowing into the firing pin hole. Rich Link to comment Share on other sites More sharing options...
SLM Posted May 11, 2009 Author Share Posted May 11, 2009 What does the end of your firing pin look like? Your firing pin maybe piercing the primer. A dimpled breech face is an old way to prevent the primer from flowing into the firing pin hole.Rich Hi Rich. Nope, they aren't pierced. Both pins I've had in the gun have rounded ends. One was a Limcat extended and there's currently a SVI stainless in it. Both have the same amount of flow back into the dimple. Interesting theory. I've never heard about that before. Link to comment Share on other sites More sharing options...
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