Clean barrel and slight pressure signs For first couple shots On A clean barrel. Thoughts.

[Vol1975]

A question and I would like some general thoughts. I've not seen this before.

First- after a light clean of the barrel I noticed that I had pressure signs on brass for the first couple of shots. After a couple fouling shots 5 or so then signs basically went away. My pressure signs were ejector marks but no flattened primers or no bolt lift issues.
load is for a 300 prc ADG brass with 215 Berger's pushing it around 2925 FPS. N570 82 gr. 24 inch barrel 10t
barrel clean was basically hopps clean with patched and Then dry patch out. Nothing aggressive but I'd call it clean.

during load work up I had no ejector mark so I chalk it up to barrel needing to be fouled. I went .5 gr higher on initial powder Charges but never seen Ejector marks. I stopped there because I like speed and accuracy.
also funny thing is every once in a while I'll see A ejector mark On the brass. Maybe 1 in 10.
firings on gun is 112.

maybe I'm just on the edge of pressure.
any thoughts beside not cleaning the thing.

 

[Andrew Massi]

Residue in chamber from cleaning will cause that

 

[Vol1975]

Residue in chamber from cleaning will cause that

maybe. But I dry cleaned it out pretty dang good. Chamber and tube. I'm usually pretty OCD on that about leaving anything that could build pressure like a residue. but, Maybe I missed something though.

must of workEd it self free. My last three shoots chrographed 2928,2926,2927.

 

[johnnyk]

I have a similar situation with a Shilen Stainless Select Match in 6mmBR. How I discovered this, or got my Ah-ha moment, was I had developed an accurate load for a competition. I decided a couple of days before the shoot to clean the barrel real good and I'd be set. Well I did, but I just couldn't stand it, I had to shoot it again to make sure everything was still good.
The first two shots were about 4" high and almost touching, the next 3 progressively walked down the paper to my original or intended POI. I knew immediately what it was and I have since repeated it to verify it.

This barrel has shown me a totally clean barrel all the time is not necessary. I mean, sure it is after you're done with it (i.e., end of deer season) and put it up for any length of time.
I took the advise of a few who were saying to shoot it until you noticed the accuracy starting to go. Let the rifle tell you when it needs to be cleaned. When this 6BR goes from .2's and .3's out to .5", I start looking at my brass and then my barrel.

 

[Dmagna]

I always load up a few rounds after cleaning with a grain less or so of powder. Then shoot the full powder loads.

 

[Vol1975]

I always load up a few rounds after cleaning with a grain less or so of powder. Then shoot the full powder loads.

thank you. I was thinking I was going to start doing that. W

 

[Dmagna]

thank you. I was thinking I was going to start doing that. W

I like doing it with magnums, sending a large bullet down the barrel with 80-90 grains of powder kinda worries me sometimes. So I started doing it.