So I have a 6.5 SAUM with a proof barrel I've recently started load development on that I had SAC build on a badger 2013 action. I am using hornady 4s brass with H1000 and the 140 hybrid with a .015 jump. I ran all rounds over lab radar looking for velocity and max load. Here was how it went.
85-90 degrees during this testing and only had a few rounds of 60.0 grains through barrel at this point for zeroing optics
2 shots each this is average velocity so ES & SD are small sample size. Goal was to collect some initial data to work on fine tuning a load range
60.0--3005
60.3--3013
60.6--3013
61.0--3039
61.3--3085
61.6--3076 SD 5.8 ES 8
61.9--3075
62.2--3094
62.5--3130
62.8--3141
After this trip I loaded up some 3 round sets to check for individual groups and POI shift with 61.3-61.6-61.9 and a few extra 61.6 to shoot at distcance to check drop. Again good accuracy and the 61.6 was better than .5 MOA so I decided to work closer to that charge weight. After this range trip I have 33 rounds down the barrel and feel good about where it is speed and accuracy this early.
*Never saw any heavy bolt lift or pressure signs on case clear up to the 62.8, actually thought about going back with some into the 63 range to see what max was and look for higher node. But knowing these speed up some after 100 or so rounds I didn't feel the need to push it and since I was going a full grain below highest tested I didn't think it was neccessary. I liked what I saw with the 61.6 load so I loaded up 10 each 61.5 and 61.6 to test larger strings and see which would group better or any difference at all.
I decided to clean the barrel before going out for testing and knew it would take a couple "fouling" shots before I started to get consistent data again. Using a bore guide and a coated rod (cant remember brand) like all my rifles. I started with some bore foam letting is sit for a few minutes then ran a nylon brush one pass- dry patch- then used alternating wet/dry with bore cleaner until clean. Only took 3 wet/dry then a couple more dry just for good measure. I ran a patch with light oil then a dry patch to finish it up. This routine has always worked well for me even though it may not be to somes standards on cleaning. (maybe I need to revise my methods???)
Back to the range this is where I need help.
Yesterday it was 83 degrees and calm so I decided to go test these loads out since conditions were very similar to first couple range trips.
Started at 100 with lab radar to confirm zero and get a couple rounds through it then planned to move to 500 yards for some group testing. First round noticed heavy bolt lift, thought maybe it was new badger action feel. With rounds 2 & 3 I almost quit as bolt was very heavy and I started to see ejector marks and some definite pressure signs. Round 4 was better so I sent number 5 and it was better yet with less noticable pressure sings. Just to make note the ammo was inside my pack in a box and I think was actually cooler temperature compared to last range trip with no pressure. My velocity was also off on these. So lower velocity and higher pressure... By round 7 no heavy bolt lift no pressure whatsoever but still 50 fps slower than previous trips.
61.5 was in the 3021-3032 range and once I got to the last 5 it was 3020-3021 awsome ES/SD but off 50 fps from initial testing. 500 yard accuracy was very good on this load.
61.6 was 3025-3032 with last 3-4 at 3040-3043.
Again still using lab radar which has been very consistent for me.
Has anyone ever had a similar experience? Is pressure spike or velocity loss normal on a new just cleaned barrel? I have never had it happen but also never loaded 6.5 saum or proof barrel either. My 243 with bartlien and 300 win mag with bartlien never had this issue. Ideas?
Dies/OAL were not changed or touched
Powder came from same 8# jug
brass was same bag prep was the same
primers same box
Using chargemaster calibrated just like always.
85-90 degrees during this testing and only had a few rounds of 60.0 grains through barrel at this point for zeroing optics
2 shots each this is average velocity so ES & SD are small sample size. Goal was to collect some initial data to work on fine tuning a load range
60.0--3005
60.3--3013
60.6--3013
61.0--3039
61.3--3085
61.6--3076 SD 5.8 ES 8
61.9--3075
62.2--3094
62.5--3130
62.8--3141
After this trip I loaded up some 3 round sets to check for individual groups and POI shift with 61.3-61.6-61.9 and a few extra 61.6 to shoot at distcance to check drop. Again good accuracy and the 61.6 was better than .5 MOA so I decided to work closer to that charge weight. After this range trip I have 33 rounds down the barrel and feel good about where it is speed and accuracy this early.
*Never saw any heavy bolt lift or pressure signs on case clear up to the 62.8, actually thought about going back with some into the 63 range to see what max was and look for higher node. But knowing these speed up some after 100 or so rounds I didn't feel the need to push it and since I was going a full grain below highest tested I didn't think it was neccessary. I liked what I saw with the 61.6 load so I loaded up 10 each 61.5 and 61.6 to test larger strings and see which would group better or any difference at all.
I decided to clean the barrel before going out for testing and knew it would take a couple "fouling" shots before I started to get consistent data again. Using a bore guide and a coated rod (cant remember brand) like all my rifles. I started with some bore foam letting is sit for a few minutes then ran a nylon brush one pass- dry patch- then used alternating wet/dry with bore cleaner until clean. Only took 3 wet/dry then a couple more dry just for good measure. I ran a patch with light oil then a dry patch to finish it up. This routine has always worked well for me even though it may not be to somes standards on cleaning. (maybe I need to revise my methods???)
Back to the range this is where I need help.
Yesterday it was 83 degrees and calm so I decided to go test these loads out since conditions were very similar to first couple range trips.
Started at 100 with lab radar to confirm zero and get a couple rounds through it then planned to move to 500 yards for some group testing. First round noticed heavy bolt lift, thought maybe it was new badger action feel. With rounds 2 & 3 I almost quit as bolt was very heavy and I started to see ejector marks and some definite pressure signs. Round 4 was better so I sent number 5 and it was better yet with less noticable pressure sings. Just to make note the ammo was inside my pack in a box and I think was actually cooler temperature compared to last range trip with no pressure. My velocity was also off on these. So lower velocity and higher pressure... By round 7 no heavy bolt lift no pressure whatsoever but still 50 fps slower than previous trips.
61.5 was in the 3021-3032 range and once I got to the last 5 it was 3020-3021 awsome ES/SD but off 50 fps from initial testing. 500 yard accuracy was very good on this load.
61.6 was 3025-3032 with last 3-4 at 3040-3043.
Again still using lab radar which has been very consistent for me.
Has anyone ever had a similar experience? Is pressure spike or velocity loss normal on a new just cleaned barrel? I have never had it happen but also never loaded 6.5 saum or proof barrel either. My 243 with bartlien and 300 win mag with bartlien never had this issue. Ideas?
Dies/OAL were not changed or touched
Powder came from same 8# jug
brass was same bag prep was the same
primers same box
Using chargemaster calibrated just like always.
