IronicTwitch Posted March 24, 2014 Share Posted March 24, 2014 I picked up some 225 FMJ FP from Xtreme. I used the same profile in my 9mm and they feed from the magazine very well. Observation on the OAL for the 45, the load data in the book starts at 1.200 but I found this projectile loads shorter at 1.80 to fit in the barrel of my Sig 1911. I'm tested some at 1.20 OAL but they didn't feed reliably (about 50% FTF). I've shortened to 1.80 using 4.2 grains of WST. Anyone had a similar experience? Link to comment Share on other sites More sharing options...
Hi-Power Jack Posted March 24, 2014 Share Posted March 24, 2014 I'm tested at 1.20 OAL but they didn't feed reliably. I've shortened to 1.80 Shortened to 1.18"? Link to comment Share on other sites More sharing options...
IronicTwitch Posted March 24, 2014 Author Share Posted March 24, 2014 Yes, shortened to 1.18, sorry for the typo on the most important number! Link to comment Share on other sites More sharing options...
Hi-Power Jack Posted March 24, 2014 Share Posted March 24, 2014 Very important the load works in your gun - if 1.20 is too long, and 1.18 works, that's your number. You might get higher velocity/pressure from shortening the OAL - so be sure to check your velocity with a Chrono .. And, look for primer signs of overpressure. But, if the velocity and accuracy are good - you're set to go. Link to comment Share on other sites More sharing options...
IronicTwitch Posted March 24, 2014 Author Share Posted March 24, 2014 Thanks, Jack. I saw OAL's for people loading RN that were above 1.20 to 1.25, so it must be the profile of the FP that accounts for the difference. I don't have any RNs or I'd measure to confirm the delta. Link to comment Share on other sites More sharing options...
Blankenhole Posted March 25, 2014 Share Posted March 25, 2014 I think it is generally normal for this. My OAL for my SWC or FMJ FP are different than my RN so they do not hang in my 1911. Jack is right though, if its a good safe round, who cares? Link to comment Share on other sites More sharing options...
ChuckB Posted March 25, 2014 Share Posted March 25, 2014 Out of curiosity, what where the feeding issues with the 1.2? Link to comment Share on other sites More sharing options...
IronicTwitch Posted March 26, 2014 Author Share Posted March 26, 2014 (edited) They didn't pass the "plunk test" in the barrel (done with the gun disassembled), the profile was pushing onto the grooves and had to be forcible pulled out instead of easily dropping free when I turned the barrel chamber down. Also had some feeding issues with the steeper ramp, but this is a brand new gun and one mag fed better than the first so I didn't put too much extra attention into the mags (although I've seen plenty of topics along those lines). I was more concerned with having to force the slide forward to fully seat the round. Edited March 26, 2014 by IronicTwitch Link to comment Share on other sites More sharing options...
IronicTwitch Posted March 31, 2014 Author Share Posted March 31, 2014 Just a note after a range trip: using WST 4.2grains at 1.20 OAL was a decent light load, same charge of 4.2grains with 1.18 OAL was noticably stronger (no signs of overpressure but my palm is sore after 70 rounds yesterday) and the cases dropped about 10 feet away instead of 2-4 feet away. I think I'll scale back the charge and go middle of the road with 1.19 OAL and test it again. One of my LGS's allows a rental of a chrono - so that's next on my list once I settle on a good bunny fart charge! Still having some issues getting the first round to feed, but no issues with rounds 2-7. Maybe more of the "break-in" period for a new gun than the ammo... Link to comment Share on other sites More sharing options...
cguy1177 Posted March 31, 2014 Share Posted March 31, 2014 also bear in mind that typically FP's are shorter bullets than RN so what's important for chamber pressure is really 'seating depth' of how much case volume is available. For a shorter bullet (FP) with a shorter OAL this can be the same as a longer OAL with a longer bullet. Hope that makes sense and gives some peace of mind. Link to comment Share on other sites More sharing options...
IronicTwitch Posted March 31, 2014 Author Share Posted March 31, 2014 Yessir, it does. I found a similar topic on projectile lengths in the 9mm forum and found the the RN is about .02" longer than the FP, so it makes good sense with the load data I have in the book starting at 1.200" for RN. Just need to tweak the charge to meet my liking now. Next time I buy projectiles for .45's I'll be going with the RN just to see if that helps the first round to feed up the steeper ramp on the officer-sized barrel. I noticed the full-size Sig 1911 my friend has has barely any ramp at all, so it may not be as important in that config. Link to comment Share on other sites More sharing options...
Steve RA Posted March 31, 2014 Share Posted March 31, 2014 Remember that the profile of the two, RN and FP, is probably the same except for the tip of the bullet being missing on the FP. So, the seating depth - in the case - will be about the same. The reason it seems that you have to seat the FP deeper is that when the tip of the bullet is missing the portion that actually touches the lede or end of rifling will then be at the same point as it is with the round nose. Link to comment Share on other sites More sharing options...
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