I shot Thursday afternoon, for part of the time it was raining. The rifle is a Savage 10T-SR in 6.5 Creedmoor with a moderate pressure load (42.5 gr H4350 with 123 gr Sierra Match Kings). It produces 2800 fps out of my rifle. New unfired-previously Lapua brass.
With the rifle horizontal, I don't think any water got in the barrel, and I was careful to keep my ammo covered. I single load, not from a magazine.
I did, however, have wet hands.
For the 5 or 6 consecutive rounds fired during the rain shower, I noticed harder than usual bolt lift and some head swipe (polished area on case head). The identical rounds that were fired during dry conditions didn't show any of these indications. No ejector marks on any of the cases, wet or dry.
I measured the distance from the case head to the shoulder datum, it averages 0.002" longer on the cases that showed heavy bolt lift (fired in the rain).
There might have been a drop or two of water on the bullet itself, but I was being careful to avoid that if possible.
What I'm thinking is that by handling the rounds with wet hands, some water transferred to the cases and acted as a lubricant between the case wall and the chamber.
If the case couldn't grip the chamber walls when the round was fired, it slid back against the bolt head as far as possible and allowed the shoulder to expand further forward. None of the cases showed signs of over-pressure on the primers or ejector marks.
After the rain stopped, I ran a couple dry patches through the barrel and dried the chamber. The next shots under dry conditions were normal.
I usually make sure the chamber is clean and dry before shooting.
Your thoughts?
With the rifle horizontal, I don't think any water got in the barrel, and I was careful to keep my ammo covered. I single load, not from a magazine.
I did, however, have wet hands.
For the 5 or 6 consecutive rounds fired during the rain shower, I noticed harder than usual bolt lift and some head swipe (polished area on case head). The identical rounds that were fired during dry conditions didn't show any of these indications. No ejector marks on any of the cases, wet or dry.
I measured the distance from the case head to the shoulder datum, it averages 0.002" longer on the cases that showed heavy bolt lift (fired in the rain).
There might have been a drop or two of water on the bullet itself, but I was being careful to avoid that if possible.
What I'm thinking is that by handling the rounds with wet hands, some water transferred to the cases and acted as a lubricant between the case wall and the chamber.
If the case couldn't grip the chamber walls when the round was fired, it slid back against the bolt head as far as possible and allowed the shoulder to expand further forward. None of the cases showed signs of over-pressure on the primers or ejector marks.
After the rain stopped, I ran a couple dry patches through the barrel and dried the chamber. The next shots under dry conditions were normal.
I usually make sure the chamber is clean and dry before shooting.
Your thoughts?
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