Pressure after cleaning new barrel???

[Gilly]

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.

 

[Milo 2.5]

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.

I Think, you cleaned your barrel and lost some speed temporarily, keep shooting it and monitor.
As for your pressure on the first 5 or so, I bet your chamber did not get cleaned all the way, or when done cleaning, you stood rifle upright and residue leaked back in the chamber, the first few shots absorbed it to a point, allowing subsequent ones to tone down.
Moisture in the chamber is not your friend.

 

[Steel head]

A bit of oil in the chamber from the last stage of your cleaning could do it.

 

[Gilly]

I never considered a light oil film could do that but makes sense. There was some oil on spent case coming out the first couple pieces of brass so probably explains pressure issue. As for velocity loss is it a matter of cleaning too much copper out slowing it down? Should I avoid using a brush or bore cleaner (butchs bore shine) ?

Have not had this much data on a load in past as lab radar makes it too easy to chrono every shot so it's possible I've lost velocity before and didn't know it. I've got 20 more ready to go and see how it progresses.

 

[Milo 2.5]

I never considered a light oil film could do that but makes sense. There was some oil on spent case coming out the first couple pieces of brass so probably explains pressure issue. As for velocity loss is it a matter of cleaning too much copper out slowing it down? Should I avoid using a brush or bore cleaner (butchs bore shine) ?

Have not had this much data on a load in past as lab radar makes it too easy to chrono every shot so it's possible I've lost velocity before and didn't know it. I've got 20 more ready to go and see how it progresses.

For the first 20 shots you took, no the barrel should not have been fouled much at all, but the first few shots should yield the most copper as rifling is at it's sharpest. I'd bet it is LR placement, tomorrow shit may be back to normal, barrels do not slow down per se.

 

[orkan]

http://www.primalrights.com/library/articles/understanding-pressure

 

[Gilly]

For the first 20 shots you took, no the barrel should not have been fouled much at all, but the first few shots should yield the most copper as rifling is at it's sharpest. I'd bet it is LR placement, tomorrow shit may be back to normal, barrels do not slow down per se.

I have to say I have not had any issue with lab radar consistency from one range trip to the next. Thats why I made the jump seemed like all other chorographs minus maybe the magneto had some issue with repeatability. Lab radar in the last 8 months across many rifles and loads has not been off, my spreadsheets will back this up. I could be wrong about this I have little data to prove it 100% accurate, but my 980 dope with the 3025 was spot on so I am going to believe that LR was correct about speed this trip. It was also correct on dope to 520 the previous trip with the 3075 speed plugged in. Only way to know is collect more data on this next trip out and see if it gradually speeds up or is immediately back to 3020 or 3070 or some other speed and stays there based on LR placement. Altough our shooting bench setup eliminates too much setup differences. I will keep you all posted. I appreciate the info thus far and need to tighten up my cleaning regimine to eliminate the oil in chamber issue from coming back.

Orkan that was some good stuff in the link you sent. I haven't read it all but what I did read was very imformative.

 

[Citius7]

U took the barrel from an ice rink that slid the bullet thru the barrel smoothly to a desert with grainy sand all over it. What do u think will happen to the bullet? Goes slower and takes more pressure to get it up to speed. Never clean ur barrel like that in my opinion it wastes ammo cause u gotta lay the ice rink again.

 

[Gilly]

U took the barrel from an ice rink that slid the bullet thru the barrel smoothly to a desert with grainy sand all over it. What do u think will happen to the bullet? Goes slower and takes more pressure to get it up to speed. Never clean ur barrel like that in my opinion it wastes ammo cause u gotta lay the ice rink again.

So what type of cleaning do you perform ? You've told me I'm doing it wrong so help me out with some advice.

 

[spife7980]

What he's trying to say is only clean it when your accuracy starts to fall apart. Some times you draw the short straw (barrel) and it only shoots well for the first 15 clean. I usually go a few hundred rounds before cleaning. I've gone 1k. I think of it as a cast iron skillet, once it's seasoned it's great but once every long while you have to scrape it a bit.

 

[PowPowHawg]

Had almost the exact same experience when developing loads for a custom 260 Krieger. Havn't had it happen since I've cleaned the chamber whenever I've cleaned the bore from that point forward... I use to be a clean bore freak, cleaning as much as I was shooting. But with guidance and imput form many within this forum I've changed my ways and thank god for that. I shoot much more now and a lot better to boot! Like many of the wise have stated they are built to be shot not cleaned for the most part.

 

[demonjigger]

good post. I too have quit cleaning my barrels after shooting and only clean when accuracy falls off or if water or dirt may have gotten in the barrel.