StraightSh00ter Posted January 4, 2016 Share Posted January 4, 2016 (edited) I've been loading 9mm 124gr RN plated bullets, and have some RNFP to try. For the same weight bullet, would I load it with the same charge and same OAL? My guess is the bullet ends up being a little shorter, so the same OAL and charge would result in slightly lower velocity and pressure. This is based on the assumption that whatever volume of material was moved from the tip is added to the tail to keep the same weight, and ends up trading length for diameter (that's a poor explanation but I tried to keep it short and simple). So maybe keep the same OAL and add 0.1gr? Edited January 4, 2016 by StraightSh00ter Link to comment Share on other sites More sharing options...
Sarge Posted January 4, 2016 Share Posted January 4, 2016 Don't over think it! lol What does the rest of the profile look like? If you make one to the same oal will it drop freely in and out of the chamber? Thats the first concern. Typically FP's have a longer shoulder that will contact the rifling if you try to stretch them out like RN's Link to comment Share on other sites More sharing options...
StraightSh00ter Posted January 4, 2016 Author Share Posted January 4, 2016 These are RNFP, the profile looks identical but with the tip cutoff. I will verify that they feed but my gun's got a pretty deep chamber. Link to comment Share on other sites More sharing options...
Sarge Posted January 4, 2016 Share Posted January 4, 2016 These are RNFP, the profile looks identical but with the tip cutoff. I will verify that they feed but my gun's got a pretty deep chamber. If they are truly identical measure each of them. Do some math and figure out the oal to keep the bases the same depth in the case and keep powder charge the same. Link to comment Share on other sites More sharing options...
Sarge Posted January 4, 2016 Share Posted January 4, 2016 Are these Xtremes? Link to comment Share on other sites More sharing options...
Sarge Posted January 4, 2016 Share Posted January 4, 2016 also, if they are truly the same EXACT profile you shouldn't have to change anything if your seater die is using the ogive and not the point to push on. Link to comment Share on other sites More sharing options...
StraightSh00ter Posted January 4, 2016 Author Share Posted January 4, 2016 (edited) Yeah, Xtremes. I screwed up though - the RNFP are 135. I was just trying to figure out how to accommodate the different profile in OAL. Originally I was looking at getting 124 RNFP, but then realized they are FP which is a different profile so I deleted them from my order, and tried to change my post. The 135 RNFP are longer than the 124RN, but I don't know how much longer they would be than a 135RN. I can find load data for 135RN - I can load to the published OAL (after confirming it will feed in my gun), and just use a chrono to adjust the charge? I don't think the difference in length is gonna cause a squib or anything, maybe it will just shoot a little soft... Maybe I should just go to bed and try again tomorrow, LOL Edited January 4, 2016 by StraightSh00ter Link to comment Share on other sites More sharing options...
StraightSh00ter Posted January 4, 2016 Author Share Posted January 4, 2016 also, if they are truly the same EXACT profile you shouldn't have to change anything if your seater die is using the ogive and not the point to push on. Thanks! That's the piece I was missing. I should be able to get it figured out from here. Link to comment Share on other sites More sharing options...
Sarge Posted January 4, 2016 Share Posted January 4, 2016 (edited) I would load a handful at an oal that works but charge with 147 load powder charges. Guaranteed safe but probably pretty weak. Then increase gradually from there. Edited January 4, 2016 by Sarge Link to comment Share on other sites More sharing options...
Southpaw Posted January 4, 2016 Share Posted January 4, 2016 I've been loading the Xtreme 135gr RNFP to the same OAL as their RN 124gr and 147gr. All Xtremes can be loaded very long compared to many other bullet profiles. Link to comment Share on other sites More sharing options...
IDescribe Posted January 4, 2016 Share Posted January 4, 2016 That is true. XTReme's also tend to seat shallow. Also, your assumption in the original post is typically correct. BUT you just need to do a push/plunk test and determine the max OAL for that bullet in your chamber and work up a load from there. If you don't have a chrono, then what you're doing right now is saying, "I want to load LOAD B to be similar in velocity to LOAD A, but I have no idea what velocity Load A is and now way to measure the velocity of LOAD B." You're looking for load data for the XT 135gr RNFP, correct? Can I ask with what powders? I may have some useful data for you. Link to comment Share on other sites More sharing options...
Hi-Power Jack Posted January 4, 2016 Share Posted January 4, 2016 you need to do a plunk test and determine the max OAL for that bullet in your chamber and work up a load from there. Yup. +1. Link to comment Share on other sites More sharing options...
Sarge Posted January 4, 2016 Share Posted January 4, 2016 I've been loading the Xtreme 135gr RNFP to the same OAL as their RN 124gr and 147gr. All Xtremes can be loaded very long compared to many other bullet profiles. almost but not quite. The HP's are very round on the ends compared to their RN bullets and have to be a good bit shorter for me. But other than that yes.Seating shallow is true though. I couldn't use their 115 HP's for Open because at 1.165 there was like a millimeter of bullet in the case! Link to comment Share on other sites More sharing options...
Southpaw Posted January 4, 2016 Share Posted January 4, 2016 I've been loading the Xtreme 135gr RNFP to the same OAL as their RN 124gr and 147gr. All Xtremes can be loaded very long compared to many other bullet profiles.almost but not quite. The HP's are very round on the ends compared to their RN bullets and have to be a good bit shorter for me. But other than that yes.Seating shallow is true though. I couldn't use their 115 HP's for Open because at 1.165 there was like a millimeter of bullet in the case! Oh forgot about HPs. I've only loaded their RN and RNFP so far. I do have some of their 147gr HPs that I got for free from Black Friday but haven't loaded any yet. Link to comment Share on other sites More sharing options...
StraightSh00ter Posted January 4, 2016 Author Share Posted January 4, 2016 Yeah, just to clarify I'm asking about RNFP vs RN. They are the ones that appear to have similar profile. Hard to say about HP but I believe the HP have a different trailing edge shape/radius. Link to comment Share on other sites More sharing options...
StraightSh00ter Posted January 4, 2016 Author Share Posted January 4, 2016 That is true. XTReme's also tend to seat shallow. Also, your assumption in the original post is typically correct. BUT you just need to do a push/plunk test and determine the max OAL for that bullet in your chamber and work up a load from there. If you don't have a chrono, then what you're doing right now is saying, "I want to load LOAD B to be similar in velocity to LOAD A, but I have no idea what velocity Load A is and now way to measure the velocity of LOAD B." You're looking for load data for the XT 135gr RNFP, correct? Can I ask with what powders? I may have some useful data for you. Thanks IDescribe, I've been loading the 124s with 3.8gr of Titegroup at 1.158" OAL. I have access to a chrono when needed, and my current load clocked in at ~1045 fps (a touch light at 129 PF), For the 135s I was hoping to eventually use either WSF or CFE Pistol as I have both. Titegroup could be an option but I feel like it doesn't burn as well with charges less than 3.8gr - I tried some shorter loads with lighter charge and found it to be dirty and less consistent. Link to comment Share on other sites More sharing options...
Recommended Posts
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 accountSign in
Already have an account? Sign in here.
Sign In Now