Mikecr
Well-Known Member
Annealing is not your last action, nor your problem action.
Increase in velocity with stored ammo question?
- Thread starter Rflamm250
- Start date
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Make no mistake I have no problem. I was just curious as to what would cause stores ammo to increase velocity. 800 yard group from yesterday
You didn't mention the powder you are using. While fusing of the bullet to the neck can cause a spike in pressure with bare metal to metal contact, another cause can be "bridging", caused by the powder sticking/clumping in the loaded case. Retumbo is famous for this and I make it a point to bring freshly loaded ammo in my shooting excursions and hunting trips. These are loaded 2-4 weeks in advance if use. What happens is, upon ignition, the fused mass of powder being pushed into the neck/chamber causes an increase in pressure. A good way to check for this is to pull the bullet on one of the loaded rounds that is showing the pressure increase. If all the powder flows easily out of the case, this is probably not the issue. If it needs to be picked, or tapped out, this may be the cause.
Bob Wright
Well-Known Member
I go thru this with 22-250 loads that I've had loaded a few years back.
Something changes, but I haven't figured it out.
Since it occurs with fresh loads and same brass, powder lot, primer lot, maybe just revise your dope data for the velocity and just shoot them. I would just sample check what you have to make sure the higher velocity is maintaining that speed.
If it changes, you might discover one variable (lots, loading process change) that caused it if you continue loading fresh rounds.
Sounds like you are well versed in handloading.
Something changes, but I haven't figured it out.
Since it occurs with fresh loads and same brass, powder lot, primer lot, maybe just revise your dope data for the velocity and just shoot them. I would just sample check what you have to make sure the higher velocity is maintaining that speed.
If it changes, you might discover one variable (lots, loading process change) that caused it if you continue loading fresh rounds.
Sounds like you are well versed in handloading.
Yes. The only variable I can figure is time. I am just going to wait until I need to anneal all 200 pcs again and load a few immediately and see if it goes back to the old velocity. You mentioned 22250. I have a load in a 22 250 with xbr 8208 and 75 bergers I have been using for years , close to 2k rounds. I load them 200 at a time but I never anneal them. I haven't noticed any speed increases with those. Makes me believe it has something to do with fresh annealed brass, but IDK.
Bob Wright
Well-Known Member
Even though your bearing surface is loaded above the neck/shoulder junction, a donut may be forming. It adds strength and the brass may not be responding to the mandrel (shrinking back more) in this area. At least check this area and eliminate that possibility.
My 280AI with Nosler brass was sending them "over" the target until I got that fixed. I won't forget that mess, ever.
My 280AI with Nosler brass was sending them "over" the target until I got that fixed. I won't forget that mess, ever.
Rflshootr
Well-Known Member
I believe the brass still changes over time after annealing. Have you ever noticed the anneal mark gets darker over time from just sitting?
Yes I have noticed somtimes the annealing get more prominent and I've also witnessed it fade with time
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Not certain if it applies to brass cases, but I know certain types of steels and aluminum alloys "age harden".
